diff options
Diffstat (limited to 'arch/x86/mm/init.c')
| -rw-r--r-- | arch/x86/mm/init.c | 100 |
1 files changed, 83 insertions, 17 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 22af912d66d2..138bad2fb6bc 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -6,7 +6,7 @@ #include <linux/bootmem.h> /* for max_low_pfn */ #include <asm/cacheflush.h> -#include <asm/e820.h> +#include <asm/e820/api.h> #include <asm/init.h> #include <asm/page.h> #include <asm/page_types.h> @@ -373,14 +373,14 @@ static int __meminit split_mem_range(struct map_range *mr, int nr_range, return nr_range; } -struct range pfn_mapped[E820_X_MAX]; +struct range pfn_mapped[E820_MAX_ENTRIES]; int nr_pfn_mapped; static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn) { - nr_pfn_mapped = add_range_with_merge(pfn_mapped, E820_X_MAX, + nr_pfn_mapped = add_range_with_merge(pfn_mapped, E820_MAX_ENTRIES, nr_pfn_mapped, start_pfn, end_pfn); - nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_X_MAX); + nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_MAX_ENTRIES); max_pfn_mapped = max(max_pfn_mapped, end_pfn); @@ -430,7 +430,7 @@ unsigned long __ref init_memory_mapping(unsigned long start, /* * We need to iterate through the E820 memory map and create direct mappings - * for only E820_RAM and E820_KERN_RESERVED regions. We cannot simply + * for only E820_TYPE_RAM and E820_KERN_RESERVED regions. We cannot simply * create direct mappings for all pfns from [0 to max_low_pfn) and * [4GB to max_pfn) because of possible memory holes in high addresses * that cannot be marked as UC by fixed/variable range MTRRs. @@ -643,21 +643,40 @@ void __init init_mem_mapping(void) * devmem_is_allowed() checks to see if /dev/mem access to a certain address * is valid. The argument is a physical page number. * - * - * On x86, access has to be given to the first megabyte of ram because that area - * contains BIOS code and data regions used by X and dosemu and similar apps. - * Access has to be given to non-kernel-ram areas as well, these contain the PCI - * mmio resources as well as potential bios/acpi data regions. + * On x86, access has to be given to the first megabyte of RAM because that + * area traditionally contains BIOS code and data regions used by X, dosemu, + * and similar apps. Since they map the entire memory range, the whole range + * must be allowed (for mapping), but any areas that would otherwise be + * disallowed are flagged as being "zero filled" instead of rejected. + * Access has to be given to non-kernel-ram areas as well, these contain the + * PCI mmio resources as well as potential bios/acpi data regions. */ int devmem_is_allowed(unsigned long pagenr) { - if (pagenr < 256) - return 1; - if (iomem_is_exclusive(pagenr << PAGE_SHIFT)) + if (page_is_ram(pagenr)) { + /* + * For disallowed memory regions in the low 1MB range, + * request that the page be shown as all zeros. + */ + if (pagenr < 256) + return 2; + return 0; - if (!page_is_ram(pagenr)) - return 1; - return 0; + } + + /* + * This must follow RAM test, since System RAM is considered a + * restricted resource under CONFIG_STRICT_IOMEM. + */ + if (iomem_is_exclusive(pagenr << PAGE_SHIFT)) { + /* Low 1MB bypasses iomem restrictions. */ + if (pagenr < 256) + return 1; + + return 0; + } + + return 1; } void free_init_pages(char *what, unsigned long begin, unsigned long end) @@ -701,7 +720,7 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end) void __ref free_initmem(void) { - e820_reallocate_tables(); + e820__reallocate_tables(); free_init_pages("unused kernel", (unsigned long)(&__init_begin), @@ -724,6 +743,53 @@ void __init free_initrd_mem(unsigned long start, unsigned long end) } #endif +/* + * Calculate the precise size of the DMA zone (first 16 MB of RAM), + * and pass it to the MM layer - to help it set zone watermarks more + * accurately. + * + * Done on 64-bit systems only for the time being, although 32-bit systems + * might benefit from this as well. + */ +void __init memblock_find_dma_reserve(void) +{ +#ifdef CONFIG_X86_64 + u64 nr_pages = 0, nr_free_pages = 0; + unsigned long start_pfn, end_pfn; + phys_addr_t start_addr, end_addr; + int i; + u64 u; + + /* + * Iterate over all memory ranges (free and reserved ones alike), + * to calculate the total number of pages in the first 16 MB of RAM: + */ + nr_pages = 0; + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) { + start_pfn = min(start_pfn, MAX_DMA_PFN); + end_pfn = min(end_pfn, MAX_DMA_PFN); + + nr_pages += end_pfn - start_pfn; + } + + /* + * Iterate over free memory ranges to calculate the number of free + * pages in the DMA zone, while not counting potential partial + * pages at the beginning or the end of the range: + */ + nr_free_pages = 0; + for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start_addr, &end_addr, NULL) { + start_pfn = min_t(unsigned long, PFN_UP(start_addr), MAX_DMA_PFN); + end_pfn = min_t(unsigned long, PFN_DOWN(end_addr), MAX_DMA_PFN); + + if (start_pfn < end_pfn) + nr_free_pages += end_pfn - start_pfn; + } + + set_dma_reserve(nr_pages - nr_free_pages); +#endif +} + void __init zone_sizes_init(void) { unsigned long max_zone_pfns[MAX_NR_ZONES]; |