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linux-next/arch/parisc/kernel/cache.c
John David Anglin 50861f5a02 parisc: Fix cache routines to ignore vma's with an invalid pfn
The parisc architecture does not have a pte special bit. As a result,
special mappings are handled with the VM_PFNMAP and VM_MIXEDMAP flags.
VM_MIXEDMAP mappings may or may not have a "struct page" backing. When
pfn_valid() is false, there is no "struct page" backing. Otherwise, they
are treated as normal pages.

The FireGL driver uses the VM_MIXEDMAP without a backing "struct page".
This treatment caused a panic due to a TLB data miss in
update_mmu_cache. This appeared to be in the code generated for
page_address(). We were in fact using a very circular bit of code to
determine the physical address of the PFN in various cache routines.
This wasn't valid when there was no "struct page" backing.  The needed
address can in fact be determined simply from the PFN itself without
using the "struct page".

The attached patch updates update_mmu_cache(), flush_cache_mm(),
flush_cache_range() and flush_cache_page() to check pfn_valid() and to
directly compute the PFN physical and virtual addresses.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # 3.10
Signed-off-by: Helge Deller <deller@gmx.de>
2013-07-31 23:41:47 +02:00

669 lines
18 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1999-2006 Helge Deller <deller@gmx.de> (07-13-1999)
* Copyright (C) 1999 SuSE GmbH Nuernberg
* Copyright (C) 2000 Philipp Rumpf (prumpf@tux.org)
*
* Cache and TLB management
*
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <asm/pdc.h>
#include <asm/cache.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/sections.h>
#include <asm/shmparam.h>
int split_tlb __read_mostly;
int dcache_stride __read_mostly;
int icache_stride __read_mostly;
EXPORT_SYMBOL(dcache_stride);
void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
EXPORT_SYMBOL(flush_dcache_page_asm);
void flush_icache_page_asm(unsigned long phys_addr, unsigned long vaddr);
/* On some machines (e.g. ones with the Merced bus), there can be
* only a single PxTLB broadcast at a time; this must be guaranteed
* by software. We put a spinlock around all TLB flushes to
* ensure this.
*/
DEFINE_SPINLOCK(pa_tlb_lock);
struct pdc_cache_info cache_info __read_mostly;
#ifndef CONFIG_PA20
static struct pdc_btlb_info btlb_info __read_mostly;
#endif
#ifdef CONFIG_SMP
void
flush_data_cache(void)
{
on_each_cpu(flush_data_cache_local, NULL, 1);
}
void
flush_instruction_cache(void)
{
on_each_cpu(flush_instruction_cache_local, NULL, 1);
}
#endif
void
flush_cache_all_local(void)
{
flush_instruction_cache_local(NULL);
flush_data_cache_local(NULL);
}
EXPORT_SYMBOL(flush_cache_all_local);
/* Virtual address of pfn. */
#define pfn_va(pfn) __va(PFN_PHYS(pfn))
void
update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
{
unsigned long pfn = pte_pfn(*ptep);
struct page *page;
/* We don't have pte special. As a result, we can be called with
an invalid pfn and we don't need to flush the kernel dcache page.
This occurs with FireGL card in C8000. */
if (!pfn_valid(pfn))
return;
page = pfn_to_page(pfn);
if (page_mapping(page) && test_bit(PG_dcache_dirty, &page->flags)) {
flush_kernel_dcache_page_addr(pfn_va(pfn));
clear_bit(PG_dcache_dirty, &page->flags);
} else if (parisc_requires_coherency())
flush_kernel_dcache_page_addr(pfn_va(pfn));
}
void
show_cache_info(struct seq_file *m)
{
char buf[32];
seq_printf(m, "I-cache\t\t: %ld KB\n",
cache_info.ic_size/1024 );
if (cache_info.dc_loop != 1)
snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s)\n",
cache_info.dc_size/1024,
(cache_info.dc_conf.cc_wt ? "WT":"WB"),
(cache_info.dc_conf.cc_sh ? ", shared I/D":""),
((cache_info.dc_loop == 1) ? "direct mapped" : buf));
seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
cache_info.it_size,
cache_info.dt_size,
cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
);
#ifndef CONFIG_PA20
/* BTLB - Block TLB */
if (btlb_info.max_size==0) {
seq_printf(m, "BTLB\t\t: not supported\n" );
} else {
seq_printf(m,
"BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
"BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
"BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
btlb_info.max_size, (int)4096,
btlb_info.max_size>>8,
btlb_info.fixed_range_info.num_i,
btlb_info.fixed_range_info.num_d,
btlb_info.fixed_range_info.num_comb,
btlb_info.variable_range_info.num_i,
btlb_info.variable_range_info.num_d,
btlb_info.variable_range_info.num_comb
);
}
#endif
}
void __init
parisc_cache_init(void)
{
if (pdc_cache_info(&cache_info) < 0)
panic("parisc_cache_init: pdc_cache_info failed");
#if 0
printk("ic_size %lx dc_size %lx it_size %lx\n",
cache_info.ic_size,
cache_info.dc_size,
cache_info.it_size);
printk("DC base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
cache_info.dc_base,
cache_info.dc_stride,
cache_info.dc_count,
cache_info.dc_loop);
printk("dc_conf = 0x%lx alias %d blk %d line %d shift %d\n",
*(unsigned long *) (&cache_info.dc_conf),
cache_info.dc_conf.cc_alias,
cache_info.dc_conf.cc_block,
cache_info.dc_conf.cc_line,
cache_info.dc_conf.cc_shift);
printk(" wt %d sh %d cst %d hv %d\n",
cache_info.dc_conf.cc_wt,
cache_info.dc_conf.cc_sh,
cache_info.dc_conf.cc_cst,
cache_info.dc_conf.cc_hv);
printk("IC base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
cache_info.ic_base,
cache_info.ic_stride,
cache_info.ic_count,
cache_info.ic_loop);
printk("ic_conf = 0x%lx alias %d blk %d line %d shift %d\n",
*(unsigned long *) (&cache_info.ic_conf),
cache_info.ic_conf.cc_alias,
cache_info.ic_conf.cc_block,
cache_info.ic_conf.cc_line,
cache_info.ic_conf.cc_shift);
printk(" wt %d sh %d cst %d hv %d\n",
cache_info.ic_conf.cc_wt,
cache_info.ic_conf.cc_sh,
cache_info.ic_conf.cc_cst,
cache_info.ic_conf.cc_hv);
printk("D-TLB conf: sh %d page %d cst %d aid %d pad1 %d\n",
cache_info.dt_conf.tc_sh,
cache_info.dt_conf.tc_page,
cache_info.dt_conf.tc_cst,
cache_info.dt_conf.tc_aid,
cache_info.dt_conf.tc_pad1);
printk("I-TLB conf: sh %d page %d cst %d aid %d pad1 %d\n",
cache_info.it_conf.tc_sh,
cache_info.it_conf.tc_page,
cache_info.it_conf.tc_cst,
cache_info.it_conf.tc_aid,
cache_info.it_conf.tc_pad1);
#endif
split_tlb = 0;
if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
if (cache_info.dt_conf.tc_sh == 2)
printk(KERN_WARNING "Unexpected TLB configuration. "
"Will flush I/D separately (could be optimized).\n");
split_tlb = 1;
}
/* "New and Improved" version from Jim Hull
* (1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
* The following CAFL_STRIDE is an optimized version, see
* http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
* http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
*/
#define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
icache_stride = CAFL_STRIDE(cache_info.ic_conf);
#undef CAFL_STRIDE
#ifndef CONFIG_PA20
if (pdc_btlb_info(&btlb_info) < 0) {
memset(&btlb_info, 0, sizeof btlb_info);
}
#endif
if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
PDC_MODEL_NVA_UNSUPPORTED) {
printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
#if 0
panic("SMP kernel required to avoid non-equivalent aliasing");
#endif
}
}
void disable_sr_hashing(void)
{
int srhash_type, retval;
unsigned long space_bits;
switch (boot_cpu_data.cpu_type) {
case pcx: /* We shouldn't get this far. setup.c should prevent it. */
BUG();
return;
case pcxs:
case pcxt:
case pcxt_:
srhash_type = SRHASH_PCXST;
break;
case pcxl:
srhash_type = SRHASH_PCXL;
break;
case pcxl2: /* pcxl2 doesn't support space register hashing */
return;
default: /* Currently all PA2.0 machines use the same ins. sequence */
srhash_type = SRHASH_PA20;
break;
}
disable_sr_hashing_asm(srhash_type);
retval = pdc_spaceid_bits(&space_bits);
/* If this procedure isn't implemented, don't panic. */
if (retval < 0 && retval != PDC_BAD_OPTION)
panic("pdc_spaceid_bits call failed.\n");
if (space_bits != 0)
panic("SpaceID hashing is still on!\n");
}
static inline void
__flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
unsigned long physaddr)
{
preempt_disable();
flush_dcache_page_asm(physaddr, vmaddr);
if (vma->vm_flags & VM_EXEC)
flush_icache_page_asm(physaddr, vmaddr);
preempt_enable();
}
void flush_dcache_page(struct page *page)
{
struct address_space *mapping = page_mapping(page);
struct vm_area_struct *mpnt;
unsigned long offset;
unsigned long addr, old_addr = 0;
pgoff_t pgoff;
if (mapping && !mapping_mapped(mapping)) {
set_bit(PG_dcache_dirty, &page->flags);
return;
}
flush_kernel_dcache_page(page);
if (!mapping)
return;
pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
/* We have carefully arranged in arch_get_unmapped_area() that
* *any* mappings of a file are always congruently mapped (whether
* declared as MAP_PRIVATE or MAP_SHARED), so we only need
* to flush one address here for them all to become coherent */
flush_dcache_mmap_lock(mapping);
vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
addr = mpnt->vm_start + offset;
/* The TLB is the engine of coherence on parisc: The
* CPU is entitled to speculate any page with a TLB
* mapping, so here we kill the mapping then flush the
* page along a special flush only alias mapping.
* This guarantees that the page is no-longer in the
* cache for any process and nor may it be
* speculatively read in (until the user or kernel
* specifically accesses it, of course) */
flush_tlb_page(mpnt, addr);
if (old_addr == 0 || (old_addr & (SHMLBA - 1)) != (addr & (SHMLBA - 1))) {
__flush_cache_page(mpnt, addr, page_to_phys(page));
if (old_addr)
printk(KERN_ERR "INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %s\n", old_addr, addr, mpnt->vm_file ? (char *)mpnt->vm_file->f_path.dentry->d_name.name : "(null)");
old_addr = addr;
}
}
flush_dcache_mmap_unlock(mapping);
}
EXPORT_SYMBOL(flush_dcache_page);
/* Defined in arch/parisc/kernel/pacache.S */
EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
EXPORT_SYMBOL(flush_kernel_dcache_page_asm);
EXPORT_SYMBOL(flush_data_cache_local);
EXPORT_SYMBOL(flush_kernel_icache_range_asm);
#define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
int parisc_cache_flush_threshold __read_mostly = FLUSH_THRESHOLD;
void __init parisc_setup_cache_timing(void)
{
unsigned long rangetime, alltime;
unsigned long size;
alltime = mfctl(16);
flush_data_cache();
alltime = mfctl(16) - alltime;
size = (unsigned long)(_end - _text);
rangetime = mfctl(16);
flush_kernel_dcache_range((unsigned long)_text, size);
rangetime = mfctl(16) - rangetime;
printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
alltime, size, rangetime);
/* Racy, but if we see an intermediate value, it's ok too... */
parisc_cache_flush_threshold = size * alltime / rangetime;
parisc_cache_flush_threshold = (parisc_cache_flush_threshold + L1_CACHE_BYTES - 1) &~ (L1_CACHE_BYTES - 1);
if (!parisc_cache_flush_threshold)
parisc_cache_flush_threshold = FLUSH_THRESHOLD;
if (parisc_cache_flush_threshold > cache_info.dc_size)
parisc_cache_flush_threshold = cache_info.dc_size;
printk(KERN_INFO "Setting cache flush threshold to %x (%d CPUs online)\n", parisc_cache_flush_threshold, num_online_cpus());
}
extern void purge_kernel_dcache_page_asm(unsigned long);
extern void clear_user_page_asm(void *, unsigned long);
extern void copy_user_page_asm(void *, void *, unsigned long);
void flush_kernel_dcache_page_addr(void *addr)
{
unsigned long flags;
flush_kernel_dcache_page_asm(addr);
purge_tlb_start(flags);
pdtlb_kernel(addr);
purge_tlb_end(flags);
}
EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
void clear_user_page(void *vto, unsigned long vaddr, struct page *page)
{
clear_page_asm(vto);
if (!parisc_requires_coherency())
flush_kernel_dcache_page_asm(vto);
}
EXPORT_SYMBOL(clear_user_page);
void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
struct page *pg)
{
/* Copy using kernel mapping. No coherency is needed
(all in kmap/kunmap) on machines that don't support
non-equivalent aliasing. However, the `from' page
needs to be flushed before it can be accessed through
the kernel mapping. */
preempt_disable();
flush_dcache_page_asm(__pa(vfrom), vaddr);
preempt_enable();
copy_page_asm(vto, vfrom);
if (!parisc_requires_coherency())
flush_kernel_dcache_page_asm(vto);
}
EXPORT_SYMBOL(copy_user_page);
#ifdef CONFIG_PA8X00
void kunmap_parisc(void *addr)
{
if (parisc_requires_coherency())
flush_kernel_dcache_page_addr(addr);
}
EXPORT_SYMBOL(kunmap_parisc);
#endif
void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
{
unsigned long flags;
/* Note: purge_tlb_entries can be called at startup with
no context. */
purge_tlb_start(flags);
mtsp(mm->context, 1);
pdtlb(addr);
pitlb(addr);
purge_tlb_end(flags);
}
EXPORT_SYMBOL(purge_tlb_entries);
void __flush_tlb_range(unsigned long sid, unsigned long start,
unsigned long end)
{
unsigned long npages;
npages = ((end - (start & PAGE_MASK)) + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (npages >= 512) /* 2MB of space: arbitrary, should be tuned */
flush_tlb_all();
else {
unsigned long flags;
purge_tlb_start(flags);
mtsp(sid, 1);
if (split_tlb) {
while (npages--) {
pdtlb(start);
pitlb(start);
start += PAGE_SIZE;
}
} else {
while (npages--) {
pdtlb(start);
start += PAGE_SIZE;
}
}
purge_tlb_end(flags);
}
}
static void cacheflush_h_tmp_function(void *dummy)
{
flush_cache_all_local();
}
void flush_cache_all(void)
{
on_each_cpu(cacheflush_h_tmp_function, NULL, 1);
}
static inline unsigned long mm_total_size(struct mm_struct *mm)
{
struct vm_area_struct *vma;
unsigned long usize = 0;
for (vma = mm->mmap; vma; vma = vma->vm_next)
usize += vma->vm_end - vma->vm_start;
return usize;
}
static inline pte_t *get_ptep(pgd_t *pgd, unsigned long addr)
{
pte_t *ptep = NULL;
if (!pgd_none(*pgd)) {
pud_t *pud = pud_offset(pgd, addr);
if (!pud_none(*pud)) {
pmd_t *pmd = pmd_offset(pud, addr);
if (!pmd_none(*pmd))
ptep = pte_offset_map(pmd, addr);
}
}
return ptep;
}
void flush_cache_mm(struct mm_struct *mm)
{
struct vm_area_struct *vma;
pgd_t *pgd;
/* Flushing the whole cache on each cpu takes forever on
rp3440, etc. So, avoid it if the mm isn't too big. */
if (mm_total_size(mm) >= parisc_cache_flush_threshold) {
flush_cache_all();
return;
}
if (mm->context == mfsp(3)) {
for (vma = mm->mmap; vma; vma = vma->vm_next) {
flush_user_dcache_range_asm(vma->vm_start, vma->vm_end);
if ((vma->vm_flags & VM_EXEC) == 0)
continue;
flush_user_icache_range_asm(vma->vm_start, vma->vm_end);
}
return;
}
pgd = mm->pgd;
for (vma = mm->mmap; vma; vma = vma->vm_next) {
unsigned long addr;
for (addr = vma->vm_start; addr < vma->vm_end;
addr += PAGE_SIZE) {
unsigned long pfn;
pte_t *ptep = get_ptep(pgd, addr);
if (!ptep)
continue;
pfn = pte_pfn(*ptep);
if (!pfn_valid(pfn))
continue;
__flush_cache_page(vma, addr, PFN_PHYS(pfn));
}
}
}
void
flush_user_dcache_range(unsigned long start, unsigned long end)
{
if ((end - start) < parisc_cache_flush_threshold)
flush_user_dcache_range_asm(start,end);
else
flush_data_cache();
}
void
flush_user_icache_range(unsigned long start, unsigned long end)
{
if ((end - start) < parisc_cache_flush_threshold)
flush_user_icache_range_asm(start,end);
else
flush_instruction_cache();
}
void flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
unsigned long addr;
pgd_t *pgd;
BUG_ON(!vma->vm_mm->context);
if ((end - start) >= parisc_cache_flush_threshold) {
flush_cache_all();
return;
}
if (vma->vm_mm->context == mfsp(3)) {
flush_user_dcache_range_asm(start, end);
if (vma->vm_flags & VM_EXEC)
flush_user_icache_range_asm(start, end);
return;
}
pgd = vma->vm_mm->pgd;
for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) {
unsigned long pfn;
pte_t *ptep = get_ptep(pgd, addr);
if (!ptep)
continue;
pfn = pte_pfn(*ptep);
if (pfn_valid(pfn))
__flush_cache_page(vma, addr, PFN_PHYS(pfn));
}
}
void
flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
{
BUG_ON(!vma->vm_mm->context);
if (pfn_valid(pfn)) {
flush_tlb_page(vma, vmaddr);
__flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));
}
}
#ifdef CONFIG_PARISC_TMPALIAS
void clear_user_highpage(struct page *page, unsigned long vaddr)
{
void *vto;
unsigned long flags;
/* Clear using TMPALIAS region. The page doesn't need to
be flushed but the kernel mapping needs to be purged. */
vto = kmap_atomic(page);
/* The PA-RISC 2.0 Architecture book states on page F-6:
"Before a write-capable translation is enabled, *all*
non-equivalently-aliased translations must be removed
from the page table and purged from the TLB. (Note
that the caches are not required to be flushed at this
time.) Before any non-equivalent aliased translation
is re-enabled, the virtual address range for the writeable
page (the entire page) must be flushed from the cache,
and the write-capable translation removed from the page
table and purged from the TLB." */
purge_kernel_dcache_page_asm((unsigned long)vto);
purge_tlb_start(flags);
pdtlb_kernel(vto);
purge_tlb_end(flags);
preempt_disable();
clear_user_page_asm(vto, vaddr);
preempt_enable();
pagefault_enable(); /* kunmap_atomic(addr, KM_USER0); */
}
void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma)
{
void *vfrom, *vto;
unsigned long flags;
/* Copy using TMPALIAS region. This has the advantage
that the `from' page doesn't need to be flushed. However,
the `to' page must be flushed in copy_user_page_asm since
it can be used to bring in executable code. */
vfrom = kmap_atomic(from);
vto = kmap_atomic(to);
purge_kernel_dcache_page_asm((unsigned long)vto);
purge_tlb_start(flags);
pdtlb_kernel(vto);
pdtlb_kernel(vfrom);
purge_tlb_end(flags);
preempt_disable();
copy_user_page_asm(vto, vfrom, vaddr);
flush_dcache_page_asm(__pa(vto), vaddr);
preempt_enable();
pagefault_enable(); /* kunmap_atomic(addr, KM_USER1); */
pagefault_enable(); /* kunmap_atomic(addr, KM_USER0); */
}
#endif /* CONFIG_PARISC_TMPALIAS */