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edd7ab7684
- Consolidate all kmap_atomic() internals into a generic implementation which builds the base for the kmap_local() API and make the kmap_atomic() interface wrappers which handle the disabling/enabling of preemption and pagefaults. - Switch the storage from per-CPU to per task and provide scheduler support for clearing mapping when scheduling out and restoring them when scheduling back in. - Merge the migrate_disable/enable() code, which is also part of the scheduler pull request. This was required to make the kmap_local() interface available which does not disable preemption when a mapping is established. It has to disable migration instead to guarantee that the virtual address of the mapped slot is the same accross preemption. - Provide better debug facilities: guard pages and enforced utilization of the mapping mechanics on 64bit systems when the architecture allows it. - Provide the new kmap_local() API which can now be used to cleanup the kmap_atomic() usage sites all over the place. Most of the usage sites do not require the implicit disabling of preemption and pagefaults so the penalty on 64bit and 32bit non-highmem systems is removed and quite some of the code can be simplified. A wholesale conversion is not possible because some usage depends on the implicit side effects and some need to be cleaned up because they work around these side effects. The migrate disable side effect is only effective on highmem systems and when enforced debugging is enabled. On 64bit and 32bit non-highmem systems the overhead is completely avoided. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAl/XyQwTHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYoUolD/9+R+BX96fGir+I8rG9dc3cbLw5meSi 0I/Nq3PToZMs2Iqv50DsoaPYHHz/M6fcAO9LRIgsE9jRbnY93GnsBM0wU9Y8yQaT 4wUzOG5WHaLDfqIkx/CN9coUl458oEiwOEbn79A2FmPXFzr7IpkufnV3ybGDwzwP p73bjMJMPPFrsa9ig87YiYfV/5IAZHi82PN8Cq1v4yNzgXRP3Tg6QoAuCO84ZnWF RYlrfKjcJ2xPdn+RuYyXolPtxr1hJQ0bOUpe4xu/UfeZjxZ7i1wtwLN9kWZe8CKH +x4Lz8HZZ5QMTQ9sCHOLtKzu2MceMcpISzoQH4/aFQCNMgLn1zLbS790XkYiQCuR ne9Cua+IqgYfGMG8cq8+bkU9HCNKaXqIBgPEKE/iHYVmqzCOqhW5Cogu4KFekf6V Wi7pyyUdX2en8BAWpk5NHc8de9cGcc+HXMq2NIcgXjVWvPaqRP6DeITERTZLJOmz XPxq5oPLGl7wdm7z+ICIaNApy8zuxpzb6sPLNcn7l5OeorViORlUu08AN8587wAj FiVjp6ZYomg+gyMkiNkDqFOGDH5TMENpOFoB0hNNEyJwwS0xh6CgWuwZcv+N8aPO HuS/P+tNANbD8ggT4UparXYce7YCtgOf3IG4GA3JJYvYmJ6pU+AZOWRoDScWq4o+ +jlfoJhMbtx5Gg== =n71I -----END PGP SIGNATURE----- Merge tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull kmap updates from Thomas Gleixner: "The new preemtible kmap_local() implementation: - Consolidate all kmap_atomic() internals into a generic implementation which builds the base for the kmap_local() API and make the kmap_atomic() interface wrappers which handle the disabling/enabling of preemption and pagefaults. - Switch the storage from per-CPU to per task and provide scheduler support for clearing mapping when scheduling out and restoring them when scheduling back in. - Merge the migrate_disable/enable() code, which is also part of the scheduler pull request. This was required to make the kmap_local() interface available which does not disable preemption when a mapping is established. It has to disable migration instead to guarantee that the virtual address of the mapped slot is the same across preemption. - Provide better debug facilities: guard pages and enforced utilization of the mapping mechanics on 64bit systems when the architecture allows it. - Provide the new kmap_local() API which can now be used to cleanup the kmap_atomic() usage sites all over the place. Most of the usage sites do not require the implicit disabling of preemption and pagefaults so the penalty on 64bit and 32bit non-highmem systems is removed and quite some of the code can be simplified. A wholesale conversion is not possible because some usage depends on the implicit side effects and some need to be cleaned up because they work around these side effects. The migrate disable side effect is only effective on highmem systems and when enforced debugging is enabled. On 64bit and 32bit non-highmem systems the overhead is completely avoided" * tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) ARM: highmem: Fix cache_is_vivt() reference x86/crashdump/32: Simplify copy_oldmem_page() io-mapping: Provide iomap_local variant mm/highmem: Provide kmap_local* sched: highmem: Store local kmaps in task struct x86: Support kmap_local() forced debugging mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL microblaze/mm/highmem: Add dropped #ifdef back xtensa/mm/highmem: Make generic kmap_atomic() work correctly mm/highmem: Take kmap_high_get() properly into account highmem: High implementation details and document API Documentation/io-mapping: Remove outdated blurb io-mapping: Cleanup atomic iomap mm/highmem: Remove the old kmap_atomic cruft highmem: Get rid of kmap_types.h xtensa/mm/highmem: Switch to generic kmap atomic sparc/mm/highmem: Switch to generic kmap atomic powerpc/mm/highmem: Switch to generic kmap atomic nds32/mm/highmem: Switch to generic kmap atomic ...
220 lines
5.2 KiB
C
220 lines
5.2 KiB
C
/*
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* arch/xtensa/mm/init.c
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*
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* Derived from MIPS, PPC.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001 - 2005 Tensilica Inc.
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* Copyright (C) 2014 - 2016 Cadence Design Systems Inc.
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*
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* Chris Zankel <chris@zankel.net>
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* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
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* Marc Gauthier
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* Kevin Chea
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/memblock.h>
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#include <linux/gfp.h>
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#include <linux/highmem.h>
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#include <linux/swap.h>
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#include <linux/mman.h>
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#include <linux/nodemask.h>
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#include <linux/mm.h>
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#include <linux/of_fdt.h>
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#include <linux/dma-map-ops.h>
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#include <asm/bootparam.h>
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#include <asm/page.h>
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#include <asm/sections.h>
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#include <asm/sysmem.h>
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/*
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* Initialize the bootmem system and give it all low memory we have available.
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*/
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void __init bootmem_init(void)
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{
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/* Reserve all memory below PHYS_OFFSET, as memory
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* accounting doesn't work for pages below that address.
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*
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* If PHYS_OFFSET is zero reserve page at address 0:
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* successfull allocations should never return NULL.
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*/
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memblock_reserve(0, PHYS_OFFSET ? PHYS_OFFSET : 1);
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early_init_fdt_scan_reserved_mem();
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if (!memblock_phys_mem_size())
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panic("No memory found!\n");
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min_low_pfn = PFN_UP(memblock_start_of_DRAM());
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min_low_pfn = max(min_low_pfn, PFN_UP(PHYS_OFFSET));
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max_pfn = PFN_DOWN(memblock_end_of_DRAM());
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max_low_pfn = min(max_pfn, MAX_LOW_PFN);
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early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT,
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(phys_addr_t)max_low_pfn << PAGE_SHIFT);
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memblock_set_current_limit(PFN_PHYS(max_low_pfn));
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dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
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memblock_dump_all();
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}
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void __init zones_init(void)
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{
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/* All pages are DMA-able, so we put them all in the DMA zone. */
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unsigned long max_zone_pfn[MAX_NR_ZONES] = {
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[ZONE_NORMAL] = max_low_pfn,
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#ifdef CONFIG_HIGHMEM
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[ZONE_HIGHMEM] = max_pfn,
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#endif
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};
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free_area_init(max_zone_pfn);
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}
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static void __init free_highpages(void)
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{
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#ifdef CONFIG_HIGHMEM
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unsigned long max_low = max_low_pfn;
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phys_addr_t range_start, range_end;
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u64 i;
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/* set highmem page free */
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for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
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&range_start, &range_end, NULL) {
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unsigned long start = PFN_UP(range_start);
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unsigned long end = PFN_DOWN(range_end);
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/* Ignore complete lowmem entries */
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if (end <= max_low)
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continue;
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/* Truncate partial highmem entries */
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if (start < max_low)
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start = max_low;
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for (; start < end; start++)
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free_highmem_page(pfn_to_page(start));
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}
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#endif
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}
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/*
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* Initialize memory pages.
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*/
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void __init mem_init(void)
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{
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free_highpages();
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max_mapnr = max_pfn - ARCH_PFN_OFFSET;
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high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT);
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memblock_free_all();
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mem_init_print_info(NULL);
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pr_info("virtual kernel memory layout:\n"
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#ifdef CONFIG_KASAN
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" kasan : 0x%08lx - 0x%08lx (%5lu MB)\n"
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#endif
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#ifdef CONFIG_MMU
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" vmalloc : 0x%08lx - 0x%08lx (%5lu MB)\n"
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#endif
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#ifdef CONFIG_HIGHMEM
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" pkmap : 0x%08lx - 0x%08lx (%5lu kB)\n"
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" fixmap : 0x%08lx - 0x%08lx (%5lu kB)\n"
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#endif
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" lowmem : 0x%08lx - 0x%08lx (%5lu MB)\n"
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" .text : 0x%08lx - 0x%08lx (%5lu kB)\n"
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" .rodata : 0x%08lx - 0x%08lx (%5lu kB)\n"
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" .data : 0x%08lx - 0x%08lx (%5lu kB)\n"
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" .init : 0x%08lx - 0x%08lx (%5lu kB)\n"
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" .bss : 0x%08lx - 0x%08lx (%5lu kB)\n",
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#ifdef CONFIG_KASAN
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KASAN_SHADOW_START, KASAN_SHADOW_START + KASAN_SHADOW_SIZE,
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KASAN_SHADOW_SIZE >> 20,
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#endif
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#ifdef CONFIG_MMU
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VMALLOC_START, VMALLOC_END,
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(VMALLOC_END - VMALLOC_START) >> 20,
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#ifdef CONFIG_HIGHMEM
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PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
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(LAST_PKMAP*PAGE_SIZE) >> 10,
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FIXADDR_START, FIXADDR_END,
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(FIXADDR_END - FIXADDR_START) >> 10,
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#endif
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PAGE_OFFSET, PAGE_OFFSET +
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(max_low_pfn - min_low_pfn) * PAGE_SIZE,
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#else
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min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE,
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#endif
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((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20,
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(unsigned long)_text, (unsigned long)_etext,
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(unsigned long)(_etext - _text) >> 10,
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(unsigned long)__start_rodata, (unsigned long)__end_rodata,
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(unsigned long)(__end_rodata - __start_rodata) >> 10,
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(unsigned long)_sdata, (unsigned long)_edata,
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(unsigned long)(_edata - _sdata) >> 10,
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(unsigned long)__init_begin, (unsigned long)__init_end,
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(unsigned long)(__init_end - __init_begin) >> 10,
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(unsigned long)__bss_start, (unsigned long)__bss_stop,
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(unsigned long)(__bss_stop - __bss_start) >> 10);
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}
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static void __init parse_memmap_one(char *p)
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{
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char *oldp;
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unsigned long start_at, mem_size;
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if (!p)
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return;
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oldp = p;
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mem_size = memparse(p, &p);
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if (p == oldp)
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return;
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switch (*p) {
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case '@':
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start_at = memparse(p + 1, &p);
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memblock_add(start_at, mem_size);
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break;
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case '$':
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start_at = memparse(p + 1, &p);
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memblock_reserve(start_at, mem_size);
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break;
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case 0:
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memblock_reserve(mem_size, -mem_size);
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break;
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default:
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pr_warn("Unrecognized memmap syntax: %s\n", p);
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break;
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}
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}
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static int __init parse_memmap_opt(char *str)
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{
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while (str) {
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char *k = strchr(str, ',');
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if (k)
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*k++ = 0;
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parse_memmap_one(str);
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str = k;
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}
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return 0;
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}
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early_param("memmap", parse_memmap_opt);
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