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linux-next/arch/x86/mm/init_32.c

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/*
* linux/arch/i386/mm/init.c
*
* Copyright (C) 1995 Linus Torvalds
*
* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
*/
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/pfn.h>
#include <linux/poison.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/memory_hotplug.h>
#include <linux/initrd.h>
#include <linux/cpumask.h>
#include <asm/asm.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/dma.h>
#include <asm/fixmap.h>
#include <asm/e820.h>
#include <asm/apic.h>
#include <asm/bugs.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
#include <asm/paravirt.h>
#include <asm/setup.h>
unsigned int __VMALLOC_RESERVE = 128 << 20;
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
unsigned long highstart_pfn, highend_pfn;
static noinline int do_test_wp_bit(void);
/*
* Creates a middle page table and puts a pointer to it in the
* given global directory entry. This only returns the gd entry
* in non-PAE compilation mode, since the middle layer is folded.
*/
static pmd_t * __init one_md_table_init(pgd_t *pgd)
{
pud_t *pud;
pmd_t *pmd_table;
#ifdef CONFIG_X86_PAE
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
paravirt_alloc_pd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
pud = pud_offset(pgd, 0);
BUG_ON(pmd_table != pmd_offset(pud, 0));
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
}
#endif
pud = pud_offset(pgd, 0);
pmd_table = pmd_offset(pud, 0);
return pmd_table;
}
/*
* Create a page table and place a pointer to it in a middle page
* directory entry:
*/
static pte_t * __init one_page_table_init(pmd_t *pmd)
{
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
x86: fix CONFIG_PAGEALLOC related boot hangs/OOMs if CONFIG_PAGEALLOC is enabled then X86_FEATURE_PSE is disabled and all the kernel physical RAM pagetables are set up as 4K pages. This is needed so that CONFIG_PAGEALLOC can do finegrained mapping and unmapping of pages. as a side-effect though, the total size of memory allocated as kernel pagetables increases significantly. All these pagetables are allocated via alloc_bootmem_low_pages(), straight out of the lowmem DMA pool. If the system has enough RAM and a large kernel image then almost all of the 16 MB lowmem DMA pool is allocated to the image and to pagetables - leaving no space for __GFP_DMA allocations. this results in drivers failing and the bootup hanging: swapper invoked oom-killer: gfp_mask=0x80d1, order=0, oomkilladj=0 [<4015059f>] out_of_memory+0x17f/0x1c0 [<40151f3c>] __alloc_pages+0x37c/0x3a0 [<40168cd7>] slob_new_page+0x37/0x50 [<40168dff>] slob_alloc+0x10f/0x190 [<40169010>] __kmalloc_node+0x80/0x90 [<405a17e3>] scsi_host_alloc+0x33/0x2c0 [<405a1a82>] scsi_register+0x12/0x60 [<40d5889e>] aha1542_detect+0x9e/0x940 [<405c5ba5>] ultrastor_detect+0x265/0x5f0 [<401352f5>] getnstimeofday+0x35/0xf0 [<40d58751>] init_this_scsi_driver+0x41/0xf0 [<40d0b856>] kernel_init+0x136/0x310 [<40d58710>] init_this_scsi_driver+0x0/0xf0 [<40d0b720>] kernel_init+0x0/0x310 [<40105547>] kernel_thread_helper+0x7/0x10 ======================= the fix is to first allocate from above the DMA pool, and if that fails (for example due to it being a machine with less than 16 MB of RAM), allocate from the DMA pool as a fallback. With this fix applied i was able to boot a PAGEALLOC=y kernel that would hang before. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-18 00:04:34 +08:00
pte_t *page_table = NULL;
#ifdef CONFIG_DEBUG_PAGEALLOC
page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
#endif
if (!page_table) {
x86: fix CONFIG_PAGEALLOC related boot hangs/OOMs if CONFIG_PAGEALLOC is enabled then X86_FEATURE_PSE is disabled and all the kernel physical RAM pagetables are set up as 4K pages. This is needed so that CONFIG_PAGEALLOC can do finegrained mapping and unmapping of pages. as a side-effect though, the total size of memory allocated as kernel pagetables increases significantly. All these pagetables are allocated via alloc_bootmem_low_pages(), straight out of the lowmem DMA pool. If the system has enough RAM and a large kernel image then almost all of the 16 MB lowmem DMA pool is allocated to the image and to pagetables - leaving no space for __GFP_DMA allocations. this results in drivers failing and the bootup hanging: swapper invoked oom-killer: gfp_mask=0x80d1, order=0, oomkilladj=0 [<4015059f>] out_of_memory+0x17f/0x1c0 [<40151f3c>] __alloc_pages+0x37c/0x3a0 [<40168cd7>] slob_new_page+0x37/0x50 [<40168dff>] slob_alloc+0x10f/0x190 [<40169010>] __kmalloc_node+0x80/0x90 [<405a17e3>] scsi_host_alloc+0x33/0x2c0 [<405a1a82>] scsi_register+0x12/0x60 [<40d5889e>] aha1542_detect+0x9e/0x940 [<405c5ba5>] ultrastor_detect+0x265/0x5f0 [<401352f5>] getnstimeofday+0x35/0xf0 [<40d58751>] init_this_scsi_driver+0x41/0xf0 [<40d0b856>] kernel_init+0x136/0x310 [<40d58710>] init_this_scsi_driver+0x0/0xf0 [<40d0b720>] kernel_init+0x0/0x310 [<40105547>] kernel_thread_helper+0x7/0x10 ======================= the fix is to first allocate from above the DMA pool, and if that fails (for example due to it being a machine with less than 16 MB of RAM), allocate from the DMA pool as a fallback. With this fix applied i was able to boot a PAGEALLOC=y kernel that would hang before. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-18 00:04:34 +08:00
page_table =
(pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
}
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
paravirt_alloc_pt(&init_mm, __pa(page_table) >> PAGE_SHIFT);
set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
BUG_ON(page_table != pte_offset_kernel(pmd, 0));
}
x86: fix CONFIG_PAGEALLOC related boot hangs/OOMs if CONFIG_PAGEALLOC is enabled then X86_FEATURE_PSE is disabled and all the kernel physical RAM pagetables are set up as 4K pages. This is needed so that CONFIG_PAGEALLOC can do finegrained mapping and unmapping of pages. as a side-effect though, the total size of memory allocated as kernel pagetables increases significantly. All these pagetables are allocated via alloc_bootmem_low_pages(), straight out of the lowmem DMA pool. If the system has enough RAM and a large kernel image then almost all of the 16 MB lowmem DMA pool is allocated to the image and to pagetables - leaving no space for __GFP_DMA allocations. this results in drivers failing and the bootup hanging: swapper invoked oom-killer: gfp_mask=0x80d1, order=0, oomkilladj=0 [<4015059f>] out_of_memory+0x17f/0x1c0 [<40151f3c>] __alloc_pages+0x37c/0x3a0 [<40168cd7>] slob_new_page+0x37/0x50 [<40168dff>] slob_alloc+0x10f/0x190 [<40169010>] __kmalloc_node+0x80/0x90 [<405a17e3>] scsi_host_alloc+0x33/0x2c0 [<405a1a82>] scsi_register+0x12/0x60 [<40d5889e>] aha1542_detect+0x9e/0x940 [<405c5ba5>] ultrastor_detect+0x265/0x5f0 [<401352f5>] getnstimeofday+0x35/0xf0 [<40d58751>] init_this_scsi_driver+0x41/0xf0 [<40d0b856>] kernel_init+0x136/0x310 [<40d58710>] init_this_scsi_driver+0x0/0xf0 [<40d0b720>] kernel_init+0x0/0x310 [<40105547>] kernel_thread_helper+0x7/0x10 ======================= the fix is to first allocate from above the DMA pool, and if that fails (for example due to it being a machine with less than 16 MB of RAM), allocate from the DMA pool as a fallback. With this fix applied i was able to boot a PAGEALLOC=y kernel that would hang before. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-18 00:04:34 +08:00
return pte_offset_kernel(pmd, 0);
}
/*
* This function initializes a certain range of kernel virtual memory
* with new bootmem page tables, everywhere page tables are missing in
* the given range.
*
* NOTE: The pagetables are allocated contiguous on the physical space
* so we can cache the place of the first one and move around without
* checking the pgd every time.
*/
static void __init
page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
{
int pgd_idx, pmd_idx;
unsigned long vaddr;
pgd_t *pgd;
pmd_t *pmd;
vaddr = start;
pgd_idx = pgd_index(vaddr);
pmd_idx = pmd_index(vaddr);
pgd = pgd_base + pgd_idx;
for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
pmd = one_md_table_init(pgd);
pmd = pmd + pmd_index(vaddr);
for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
pmd++, pmd_idx++) {
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
one_page_table_init(pmd);
vaddr += PMD_SIZE;
}
pmd_idx = 0;
}
}
static inline int is_kernel_text(unsigned long addr)
{
if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end)
return 1;
return 0;
}
/*
* This maps the physical memory to kernel virtual address space, a total
* of max_low_pfn pages, by creating page tables starting from address
* PAGE_OFFSET:
*/
static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
{
int pgd_idx, pmd_idx, pte_ofs;
unsigned long pfn;
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
pgd_idx = pgd_index(PAGE_OFFSET);
pgd = pgd_base + pgd_idx;
pfn = 0;
for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
pmd = one_md_table_init(pgd);
if (pfn >= max_low_pfn)
continue;
for (pmd_idx = 0;
pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn;
pmd++, pmd_idx++) {
unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
/*
* Map with big pages if possible, otherwise
* create normal page tables:
*/
if (cpu_has_pse) {
unsigned int addr2;
pgprot_t prot = PAGE_KERNEL_LARGE;
addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
PAGE_OFFSET + PAGE_SIZE-1;
if (is_kernel_text(addr) ||
is_kernel_text(addr2))
prot = PAGE_KERNEL_LARGE_EXEC;
set_pmd(pmd, pfn_pmd(pfn, prot));
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
pfn += PTRS_PER_PTE;
continue;
}
pte = one_page_table_init(pmd);
for (pte_ofs = 0;
pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn;
pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
pgprot_t prot = PAGE_KERNEL;
if (is_kernel_text(addr))
prot = PAGE_KERNEL_EXEC;
set_pte(pte, pfn_pte(pfn, prot));
}
}
}
}
static inline int page_kills_ppro(unsigned long pagenr)
{
if (pagenr >= 0x70000 && pagenr <= 0x7003F)
return 1;
return 0;
}
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
pgprot_t kmap_prot;
static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
{
return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
vaddr), vaddr), vaddr);
}
static void __init kmap_init(void)
{
unsigned long kmap_vstart;
/*
* Cache the first kmap pte:
*/
kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
kmap_prot = PAGE_KERNEL;
}
static void __init permanent_kmaps_init(pgd_t *pgd_base)
{
unsigned long vaddr;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
vaddr = PKMAP_BASE;
page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
pgd = swapper_pg_dir + pgd_index(vaddr);
pud = pud_offset(pgd, vaddr);
pmd = pmd_offset(pud, vaddr);
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
}
static void __meminit free_new_highpage(struct page *page)
{
init_page_count(page);
__free_page(page);
totalhigh_pages++;
}
void __init add_one_highpage_init(struct page *page, int pfn, int bad_ppro)
{
if (page_is_ram(pfn) && !(bad_ppro && page_kills_ppro(pfn))) {
ClearPageReserved(page);
free_new_highpage(page);
} else
SetPageReserved(page);
}
static int __meminit
add_one_highpage_hotplug(struct page *page, unsigned long pfn)
{
free_new_highpage(page);
totalram_pages++;
#ifdef CONFIG_FLATMEM
max_mapnr = max(pfn, max_mapnr);
#endif
num_physpages++;
return 0;
}
/*
* Not currently handling the NUMA case.
* Assuming single node and all memory that
* has been added dynamically that would be
* onlined here is in HIGHMEM.
*/
void __meminit online_page(struct page *page)
{
ClearPageReserved(page);
add_one_highpage_hotplug(page, page_to_pfn(page));
}
#ifndef CONFIG_NUMA
static void __init set_highmem_pages_init(int bad_ppro)
{
int pfn;
for (pfn = highstart_pfn; pfn < highend_pfn; pfn++) {
/*
* Holes under sparsemem might not have no mem_map[]:
*/
if (pfn_valid(pfn))
add_one_highpage_init(pfn_to_page(pfn), pfn, bad_ppro);
}
totalram_pages += totalhigh_pages;
}
#endif /* !CONFIG_NUMA */
#else
# define kmap_init() do { } while (0)
# define permanent_kmaps_init(pgd_base) do { } while (0)
# define set_highmem_pages_init(bad_ppro) do { } while (0)
#endif /* CONFIG_HIGHMEM */
pteval_t __PAGE_KERNEL = _PAGE_KERNEL;
EXPORT_SYMBOL(__PAGE_KERNEL);
pteval_t __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC;
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
void __init native_pagetable_setup_start(pgd_t *base)
{
unsigned long pfn, va;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
/*
* Remove any mappings which extend past the end of physical
* memory from the boot time page table:
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
*/
for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
pgd = base + pgd_index(va);
if (!pgd_present(*pgd))
break;
pud = pud_offset(pgd, va);
pmd = pmd_offset(pud, va);
if (!pmd_present(*pmd))
break;
pte = pte_offset_kernel(pmd, va);
if (!pte_present(*pte))
break;
pte_clear(NULL, va, pte);
}
paravirt_alloc_pd(&init_mm, __pa(base) >> PAGE_SHIFT);
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
}
void __init native_pagetable_setup_done(pgd_t *base)
{
}
/*
* Build a proper pagetable for the kernel mappings. Up until this
* point, we've been running on some set of pagetables constructed by
* the boot process.
*
* If we're booting on native hardware, this will be a pagetable
* constructed in arch/x86/kernel/head_32.S. The root of the
* pagetable will be swapper_pg_dir.
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
*
* If we're booting paravirtualized under a hypervisor, then there are
* more options: we may already be running PAE, and the pagetable may
* or may not be based in swapper_pg_dir. In any case,
* paravirt_pagetable_setup_start() will set up swapper_pg_dir
* appropriately for the rest of the initialization to work.
*
* In general, pagetable_init() assumes that the pagetable may already
* be partially populated, and so it avoids stomping on any existing
* mappings.
*/
static void __init pagetable_init(void)
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
{
pgd_t *pgd_base = swapper_pg_dir;
unsigned long vaddr, end;
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
paravirt_pagetable_setup_start(pgd_base);
/* Enable PSE if available */
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
if (cpu_has_pse)
set_in_cr4(X86_CR4_PSE);
/* Enable PGE if available */
if (cpu_has_pge) {
set_in_cr4(X86_CR4_PGE);
__PAGE_KERNEL |= _PAGE_GLOBAL;
__PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;
}
kernel_physical_mapping_init(pgd_base);
remap_numa_kva();
/*
* Fixed mappings, only the page table structure has to be
* created - mappings will be set by set_fixmap():
*/
early_ioremap_clear();
vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
page_table_range_init(vaddr, end, pgd_base);
early_ioremap_reset();
permanent_kmaps_init(pgd_base);
[PATCH] i386: PARAVIRT: Hooks to set up initial pagetable This patch introduces paravirt_ops hooks to control how the kernel's initial pagetable is set up. In the case of a native boot, the very early bootstrap code creates a simple non-PAE pagetable to map the kernel and physical memory. When the VM subsystem is initialized, it creates a proper pagetable which respects the PAE mode, large pages, etc. When booting under a hypervisor, there are many possibilities for what paging environment the hypervisor establishes for the guest kernel, so the constructon of the kernel's pagetable depends on the hypervisor. In the case of Xen, the hypervisor boots the kernel with a fully constructed pagetable, which is already using PAE if necessary. Also, Xen requires particular care when constructing pagetables to make sure all pagetables are always mapped read-only. In order to make this easier, kernel's initial pagetable construction has been changed to only allocate and initialize a pagetable page if there's no page already present in the pagetable. This allows the Xen paravirt backend to make a copy of the hypervisor-provided pagetable, allowing the kernel to establish any more mappings it needs while keeping the existing ones. A slightly subtle point which is worth highlighting here is that Xen requires all kernel mappings to share the same pte_t pages between all pagetables, so that updating a kernel page's mapping in one pagetable is reflected in all other pagetables. This makes it possible to allocate a page and attach it to a pagetable without having to explicitly enumerate that page's mapping in all pagetables. And: +From: "Eric W. Biederman" <ebiederm@xmission.com> If we don't set the leaf page table entries it is quite possible that will inherit and incorrect page table entry from the initial boot page table setup in head.S. So we need to redo the effort here, so we pick up PSE, PGE and the like. Hypervisors like Xen require that their page tables be read-only, which is slightly incompatible with our low identity mappings, however I discussed this with Jeremy he has modified the Xen early set_pte function to avoid problems in this area. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: William Irwin <bill.irwin@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2007-05-03 01:27:13 +08:00
paravirt_pagetable_setup_done(pgd_base);
}
#ifdef CONFIG_ACPI_SLEEP
/*
* ACPI suspend needs this for resume, because things like the intel-agp
* driver might have split up a kernel 4MB mapping.
*/
char swsusp_pg_dir[PAGE_SIZE]
__attribute__ ((aligned(PAGE_SIZE)));
static inline void save_pg_dir(void)
{
memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE);
}
#else /* !CONFIG_ACPI_SLEEP */
static inline void save_pg_dir(void)
{
}
#endif /* !CONFIG_ACPI_SLEEP */
void zap_low_mappings(void)
{
int i;
save_pg_dir();
/*
* Zap initial low-memory mappings.
*
* Note that "pgd_clear()" doesn't do it for
* us, because pgd_clear() is a no-op on i386.
*/
for (i = 0; i < USER_PTRS_PER_PGD; i++) {
#ifdef CONFIG_X86_PAE
set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
#else
set_pgd(swapper_pg_dir+i, __pgd(0));
#endif
}
flush_tlb_all();
}
int nx_enabled;
pteval_t __supported_pte_mask __read_mostly = ~_PAGE_NX;
EXPORT_SYMBOL_GPL(__supported_pte_mask);
#ifdef CONFIG_X86_PAE
static int disable_nx __initdata;
/*
* noexec = on|off
*
* Control non executable mappings.
*
* on Enable
* off Disable
*/
static int __init noexec_setup(char *str)
{
if (!str || !strcmp(str, "on")) {
if (cpu_has_nx) {
__supported_pte_mask |= _PAGE_NX;
disable_nx = 0;
}
} else {
if (!strcmp(str, "off")) {
disable_nx = 1;
__supported_pte_mask &= ~_PAGE_NX;
} else {
return -EINVAL;
}
}
return 0;
}
early_param("noexec", noexec_setup);
static void __init set_nx(void)
{
unsigned int v[4], l, h;
if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
if ((v[3] & (1 << 20)) && !disable_nx) {
rdmsr(MSR_EFER, l, h);
l |= EFER_NX;
wrmsr(MSR_EFER, l, h);
nx_enabled = 1;
__supported_pte_mask |= _PAGE_NX;
}
}
}
#endif
/*
* paging_init() sets up the page tables - note that the first 8MB are
* already mapped by head.S.
*
* This routines also unmaps the page at virtual kernel address 0, so
* that we can trap those pesky NULL-reference errors in the kernel.
*/
void __init paging_init(void)
{
#ifdef CONFIG_X86_PAE
set_nx();
if (nx_enabled)
printk(KERN_INFO "NX (Execute Disable) protection: active\n");
#endif
pagetable_init();
load_cr3(swapper_pg_dir);
__flush_tlb_all();
kmap_init();
}
/*
* Test if the WP bit works in supervisor mode. It isn't supported on 386's
* and also on some strange 486's (NexGen etc.). All 586+'s are OK. This
* used to involve black magic jumps to work around some nasty CPU bugs,
* but fortunately the switch to using exceptions got rid of all that.
*/
static void __init test_wp_bit(void)
{
printk(KERN_INFO
"Checking if this processor honours the WP bit even in supervisor mode...");
/* Any page-aligned address will do, the test is non-destructive */
__set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
boot_cpu_data.wp_works_ok = do_test_wp_bit();
clear_fixmap(FIX_WP_TEST);
if (!boot_cpu_data.wp_works_ok) {
printk(KERN_CONT "No.\n");
#ifdef CONFIG_X86_WP_WORKS_OK
panic(
"This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
#endif
} else {
printk(KERN_CONT "Ok.\n");
}
}
static struct kcore_list kcore_mem, kcore_vmalloc;
void __init mem_init(void)
{
int codesize, reservedpages, datasize, initsize;
int tmp, bad_ppro;
#ifdef CONFIG_FLATMEM
BUG_ON(!mem_map);
#endif
bad_ppro = ppro_with_ram_bug();
#ifdef CONFIG_HIGHMEM
/* check that fixmap and pkmap do not overlap */
if (PKMAP_BASE + LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
printk(KERN_ERR
"fixmap and kmap areas overlap - this will crash\n");
printk(KERN_ERR "pkstart: %lxh pkend: %lxh fixstart %lxh\n",
PKMAP_BASE, PKMAP_BASE + LAST_PKMAP*PAGE_SIZE,
FIXADDR_START);
BUG();
}
#endif
/* this will put all low memory onto the freelists */
totalram_pages += free_all_bootmem();
reservedpages = 0;
for (tmp = 0; tmp < max_low_pfn; tmp++)
/*
* Only count reserved RAM pages:
*/
if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
reservedpages++;
set_highmem_pages_init(bad_ppro);
codesize = (unsigned long) &_etext - (unsigned long) &_text;
datasize = (unsigned long) &_edata - (unsigned long) &_etext;
initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
VMALLOC_END-VMALLOC_START);
printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
"%dk reserved, %dk data, %dk init, %ldk highmem)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
num_physpages << (PAGE_SHIFT-10),
codesize >> 10,
reservedpages << (PAGE_SHIFT-10),
datasize >> 10,
initsize >> 10,
(unsigned long) (totalhigh_pages << (PAGE_SHIFT-10))
);
#if 1 /* double-sanity-check paranoia */
printk(KERN_INFO "virtual kernel memory layout:\n"
" fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
#ifdef CONFIG_HIGHMEM
" pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
#endif
" vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
" lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
" .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
" .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
" .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
FIXADDR_START, FIXADDR_TOP,
(FIXADDR_TOP - FIXADDR_START) >> 10,
#ifdef CONFIG_HIGHMEM
PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
(LAST_PKMAP*PAGE_SIZE) >> 10,
#endif
VMALLOC_START, VMALLOC_END,
(VMALLOC_END - VMALLOC_START) >> 20,
(unsigned long)__va(0), (unsigned long)high_memory,
((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
(unsigned long)&__init_begin, (unsigned long)&__init_end,
((unsigned long)&__init_end -
(unsigned long)&__init_begin) >> 10,
(unsigned long)&_etext, (unsigned long)&_edata,
((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
(unsigned long)&_text, (unsigned long)&_etext,
((unsigned long)&_etext - (unsigned long)&_text) >> 10);
#ifdef CONFIG_HIGHMEM
BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
BUG_ON(VMALLOC_END > PKMAP_BASE);
#endif
BUG_ON(VMALLOC_START > VMALLOC_END);
BUG_ON((unsigned long)high_memory > VMALLOC_START);
#endif /* double-sanity-check paranoia */
if (boot_cpu_data.wp_works_ok < 0)
test_wp_bit();
/*
* Subtle. SMP is doing it's boot stuff late (because it has to
* fork idle threads) - but it also needs low mappings for the
* protected-mode entry to work. We zap these entries only after
* the WP-bit has been tested.
*/
#ifndef CONFIG_SMP
zap_low_mappings();
#endif
}
#ifdef CONFIG_MEMORY_HOTPLUG
int arch_add_memory(int nid, u64 start, u64 size)
{
struct pglist_data *pgdata = NODE_DATA(nid);
[PATCH] reduce MAX_NR_ZONES: remove two strange uses of MAX_NR_ZONES I keep seeing zones on various platforms that are never used and wonder why we compile support for them into the kernel. Counters show up for HIGHMEM and DMA32 that are alway zero. This patch allows the removal of ZONE_DMA32 for non x86_64 architectures and it will get rid of ZONE_HIGHMEM for arches not using highmem (like 64 bit architectures). If an arch does not define CONFIG_HIGHMEM then ZONE_HIGHMEM will not be defined. Similarly if an arch does not define CONFIG_ZONE_DMA32 then ZONE_DMA32 will not be defined. No current architecture uses all the 4 zones (DMA,DMA32,NORMAL,HIGH) that we have now. The patchset will reduce the number of zones for all platforms. On many platforms that do not have DMA32 or HIGHMEM this will reduce the number of zones by 50%. F.e. ia64 only uses DMA and NORMAL. Large amounts of memory can be saved for larger systemss that may have a few hundred NUMA nodes. With ZONE_DMA32 and ZONE_HIGHMEM support optional MAX_NR_ZONES will be 2 for many non i386 platforms and even for i386 without CONFIG_HIGHMEM set. Tested on ia64, x86_64 and on i386 with and without highmem. The patchset consists of 11 patches that are following this message. One could go even further than this patchset and also make ZONE_DMA optional because some platforms do not need a separate DMA zone and can do DMA to all of memory. This could reduce MAX_NR_ZONES to 1. Such a patchset will hopefully follow soon. This patch: Fix strange uses of MAX_NR_ZONES Sometimes we use MAX_NR_ZONES - x to refer to a zone. Make that explicit. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 14:31:09 +08:00
struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
return __add_pages(zone, start_pfn, nr_pages);
}
#endif
/*
* This function cannot be __init, since exceptions don't work in that
* section. Put this after the callers, so that it cannot be inlined.
*/
static noinline int do_test_wp_bit(void)
{
char tmp_reg;
int flag;
__asm__ __volatile__(
" movb %0, %1 \n"
"1: movb %1, %0 \n"
" xorl %2, %2 \n"
"2: \n"
_ASM_EXTABLE(1b,2b)
:"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
"=q" (tmp_reg),
"=r" (flag)
:"2" (1)
:"memory");
return flag;
}
#ifdef CONFIG_DEBUG_RODATA
const int rodata_test_data = 0xC3;
EXPORT_SYMBOL_GPL(rodata_test_data);
void mark_rodata_ro(void)
{
unsigned long start = PFN_ALIGN(_text);
unsigned long size = PFN_ALIGN(_etext) - start;
#ifndef CONFIG_KPROBES
#ifdef CONFIG_HOTPLUG_CPU
/* It must still be possible to apply SMP alternatives. */
if (num_possible_cpus() <= 1)
#endif
{
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
printk(KERN_INFO "Write protecting the kernel text: %luk\n",
size >> 10);
#ifdef CONFIG_CPA_DEBUG
printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
start, start+size);
set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
printk(KERN_INFO "Testing CPA: write protecting again\n");
set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
#endif
}
#endif
start += size;
size = (unsigned long)__end_rodata - start;
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
size >> 10);
rodata_test();
#ifdef CONFIG_CPA_DEBUG
printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
printk(KERN_INFO "Testing CPA: write protecting again\n");
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
#endif
}
#endif
[PATCH] x86: SMP alternatives Implement SMP alternatives, i.e. switching at runtime between different code versions for UP and SMP. The code can patch both SMP->UP and UP->SMP. The UP->SMP case is useful for CPU hotplug. With CONFIG_CPU_HOTPLUG enabled the code switches to UP at boot time and when the number of CPUs goes down to 1, and switches to SMP when the number of CPUs goes up to 2. Without CONFIG_CPU_HOTPLUG or on non-SMP-capable systems the code is patched once at boot time (if needed) and the tables are released afterwards. The changes in detail: * The current alternatives bits are moved to a separate file, the SMP alternatives code is added there. * The patch adds some new elf sections to the kernel: .smp_altinstructions like .altinstructions, also contains a list of alt_instr structs. .smp_altinstr_replacement like .altinstr_replacement, but also has some space to save original instruction before replaving it. .smp_locks list of pointers to lock prefixes which can be nop'ed out on UP. The first two are used to replace more complex instruction sequences such as spinlocks and semaphores. It would be possible to deal with the lock prefixes with that as well, but by handling them as special case the table sizes become much smaller. * The sections are page-aligned and padded up to page size, so they can be free if they are not needed. * Splitted the code to release init pages to a separate function and use it to release the elf sections if they are unused. Signed-off-by: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 18:59:32 +08:00
void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
#ifdef CONFIG_DEBUG_PAGEALLOC
/*
* If debugging page accesses then do not free this memory but
* mark them not present - any buggy init-section access will
* create a kernel page fault:
*/
printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
begin, PAGE_ALIGN(end));
set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
#else
unsigned long addr;
/*
* We just marked the kernel text read only above, now that
* we are going to free part of that, we need to make that
* writeable first.
*/
set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
[PATCH] x86: SMP alternatives Implement SMP alternatives, i.e. switching at runtime between different code versions for UP and SMP. The code can patch both SMP->UP and UP->SMP. The UP->SMP case is useful for CPU hotplug. With CONFIG_CPU_HOTPLUG enabled the code switches to UP at boot time and when the number of CPUs goes down to 1, and switches to SMP when the number of CPUs goes up to 2. Without CONFIG_CPU_HOTPLUG or on non-SMP-capable systems the code is patched once at boot time (if needed) and the tables are released afterwards. The changes in detail: * The current alternatives bits are moved to a separate file, the SMP alternatives code is added there. * The patch adds some new elf sections to the kernel: .smp_altinstructions like .altinstructions, also contains a list of alt_instr structs. .smp_altinstr_replacement like .altinstr_replacement, but also has some space to save original instruction before replaving it. .smp_locks list of pointers to lock prefixes which can be nop'ed out on UP. The first two are used to replace more complex instruction sequences such as spinlocks and semaphores. It would be possible to deal with the lock prefixes with that as well, but by handling them as special case the table sizes become much smaller. * The sections are page-aligned and padded up to page size, so they can be free if they are not needed. * Splitted the code to release init pages to a separate function and use it to release the elf sections if they are unused. Signed-off-by: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 18:59:32 +08:00
for (addr = begin; addr < end; addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
free_page(addr);
[PATCH] x86: SMP alternatives Implement SMP alternatives, i.e. switching at runtime between different code versions for UP and SMP. The code can patch both SMP->UP and UP->SMP. The UP->SMP case is useful for CPU hotplug. With CONFIG_CPU_HOTPLUG enabled the code switches to UP at boot time and when the number of CPUs goes down to 1, and switches to SMP when the number of CPUs goes up to 2. Without CONFIG_CPU_HOTPLUG or on non-SMP-capable systems the code is patched once at boot time (if needed) and the tables are released afterwards. The changes in detail: * The current alternatives bits are moved to a separate file, the SMP alternatives code is added there. * The patch adds some new elf sections to the kernel: .smp_altinstructions like .altinstructions, also contains a list of alt_instr structs. .smp_altinstr_replacement like .altinstr_replacement, but also has some space to save original instruction before replaving it. .smp_locks list of pointers to lock prefixes which can be nop'ed out on UP. The first two are used to replace more complex instruction sequences such as spinlocks and semaphores. It would be possible to deal with the lock prefixes with that as well, but by handling them as special case the table sizes become much smaller. * The sections are page-aligned and padded up to page size, so they can be free if they are not needed. * Splitted the code to release init pages to a separate function and use it to release the elf sections if they are unused. Signed-off-by: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 18:59:32 +08:00
totalram_pages++;
}
printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
#endif
[PATCH] x86: SMP alternatives Implement SMP alternatives, i.e. switching at runtime between different code versions for UP and SMP. The code can patch both SMP->UP and UP->SMP. The UP->SMP case is useful for CPU hotplug. With CONFIG_CPU_HOTPLUG enabled the code switches to UP at boot time and when the number of CPUs goes down to 1, and switches to SMP when the number of CPUs goes up to 2. Without CONFIG_CPU_HOTPLUG or on non-SMP-capable systems the code is patched once at boot time (if needed) and the tables are released afterwards. The changes in detail: * The current alternatives bits are moved to a separate file, the SMP alternatives code is added there. * The patch adds some new elf sections to the kernel: .smp_altinstructions like .altinstructions, also contains a list of alt_instr structs. .smp_altinstr_replacement like .altinstr_replacement, but also has some space to save original instruction before replaving it. .smp_locks list of pointers to lock prefixes which can be nop'ed out on UP. The first two are used to replace more complex instruction sequences such as spinlocks and semaphores. It would be possible to deal with the lock prefixes with that as well, but by handling them as special case the table sizes become much smaller. * The sections are page-aligned and padded up to page size, so they can be free if they are not needed. * Splitted the code to release init pages to a separate function and use it to release the elf sections if they are unused. Signed-off-by: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 18:59:32 +08:00
}
void free_initmem(void)
{
free_init_pages("unused kernel memory",
(unsigned long)(&__init_begin),
(unsigned long)(&__init_end));
[PATCH] x86: SMP alternatives Implement SMP alternatives, i.e. switching at runtime between different code versions for UP and SMP. The code can patch both SMP->UP and UP->SMP. The UP->SMP case is useful for CPU hotplug. With CONFIG_CPU_HOTPLUG enabled the code switches to UP at boot time and when the number of CPUs goes down to 1, and switches to SMP when the number of CPUs goes up to 2. Without CONFIG_CPU_HOTPLUG or on non-SMP-capable systems the code is patched once at boot time (if needed) and the tables are released afterwards. The changes in detail: * The current alternatives bits are moved to a separate file, the SMP alternatives code is added there. * The patch adds some new elf sections to the kernel: .smp_altinstructions like .altinstructions, also contains a list of alt_instr structs. .smp_altinstr_replacement like .altinstr_replacement, but also has some space to save original instruction before replaving it. .smp_locks list of pointers to lock prefixes which can be nop'ed out on UP. The first two are used to replace more complex instruction sequences such as spinlocks and semaphores. It would be possible to deal with the lock prefixes with that as well, but by handling them as special case the table sizes become much smaller. * The sections are page-aligned and padded up to page size, so they can be free if they are not needed. * Splitted the code to release init pages to a separate function and use it to release the elf sections if they are unused. Signed-off-by: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 18:59:32 +08:00
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
free_init_pages("initrd memory", start, end);
}
#endif