diff options
Diffstat (limited to 'arch/x86/mm/pat.c')
| -rw-r--r-- | arch/x86/mm/pat.c | 132 |
1 files changed, 106 insertions, 26 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 2a50e0fa64a5..738fd0f24958 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -7,24 +7,24 @@ * Loosely based on earlier PAT patchset from Eric Biederman and Andi Kleen. */ -#include <linux/mm.h> +#include <linux/seq_file.h> +#include <linux/bootmem.h> +#include <linux/debugfs.h> #include <linux/kernel.h> #include <linux/gfp.h> +#include <linux/mm.h> #include <linux/fs.h> -#include <linux/bootmem.h> -#include <linux/debugfs.h> -#include <linux/seq_file.h> -#include <asm/msr.h> -#include <asm/tlbflush.h> +#include <asm/cacheflush.h> #include <asm/processor.h> -#include <asm/page.h> +#include <asm/tlbflush.h> #include <asm/pgtable.h> -#include <asm/pat.h> -#include <asm/e820.h> -#include <asm/cacheflush.h> #include <asm/fcntl.h> +#include <asm/e820.h> #include <asm/mtrr.h> +#include <asm/page.h> +#include <asm/msr.h> +#include <asm/pat.h> #include <asm/io.h> #ifdef CONFIG_X86_PAT @@ -46,6 +46,7 @@ early_param("nopat", nopat); static int debug_enable; + static int __init pat_debug_setup(char *str) { debug_enable = 1; @@ -145,14 +146,14 @@ static char *cattr_name(unsigned long flags) */ struct memtype { - u64 start; - u64 end; - unsigned long type; - struct list_head nd; + u64 start; + u64 end; + unsigned long type; + struct list_head nd; }; static LIST_HEAD(memtype_list); -static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */ +static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */ /* * Does intersection of PAT memory type and MTRR memory type and returns @@ -180,8 +181,8 @@ static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type) return req_type; } -static int chk_conflict(struct memtype *new, struct memtype *entry, - unsigned long *type) +static int +chk_conflict(struct memtype *new, struct memtype *entry, unsigned long *type) { if (new->type != entry->type) { if (type) { @@ -211,6 +212,66 @@ static struct memtype *cached_entry; static u64 cached_start; /* + * For RAM pages, mark the pages as non WB memory type using + * PageNonWB (PG_arch_1). We allow only one set_memory_uc() or + * set_memory_wc() on a RAM page at a time before marking it as WB again. + * This is ok, because only one driver will be owning the page and + * doing set_memory_*() calls. + * + * For now, we use PageNonWB to track that the RAM page is being mapped + * as non WB. In future, we will have to use one more flag + * (or some other mechanism in page_struct) to distinguish between + * UC and WC mapping. + */ +static int reserve_ram_pages_type(u64 start, u64 end, unsigned long req_type, + unsigned long *new_type) +{ + struct page *page; + u64 pfn, end_pfn; + + for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { + page = pfn_to_page(pfn); + if (page_mapped(page) || PageNonWB(page)) + goto out; + + SetPageNonWB(page); + } + return 0; + +out: + end_pfn = pfn; + for (pfn = (start >> PAGE_SHIFT); pfn < end_pfn; ++pfn) { + page = pfn_to_page(pfn); + ClearPageNonWB(page); + } + + return -EINVAL; +} + +static int free_ram_pages_type(u64 start, u64 end) +{ + struct page *page; + u64 pfn, end_pfn; + + for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { + page = pfn_to_page(pfn); + if (page_mapped(page) || !PageNonWB(page)) + goto out; + + ClearPageNonWB(page); + } + return 0; + +out: + end_pfn = pfn; + for (pfn = (start >> PAGE_SHIFT); pfn < end_pfn; ++pfn) { + page = pfn_to_page(pfn); + SetPageNonWB(page); + } + return -EINVAL; +} + +/* * req_type typically has one of the: * - _PAGE_CACHE_WB * - _PAGE_CACHE_WC @@ -226,14 +287,15 @@ static u64 cached_start; * it will return a negative return value. */ int reserve_memtype(u64 start, u64 end, unsigned long req_type, - unsigned long *new_type) + unsigned long *new_type) { struct memtype *new, *entry; unsigned long actual_type; struct list_head *where; + int is_range_ram; int err = 0; - BUG_ON(start >= end); /* end is exclusive */ + BUG_ON(start >= end); /* end is exclusive */ if (!pat_enabled) { /* This is identical to page table setting without PAT */ @@ -266,17 +328,24 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, actual_type = _PAGE_CACHE_WB; else actual_type = _PAGE_CACHE_UC_MINUS; - } else + } else { actual_type = pat_x_mtrr_type(start, end, req_type & _PAGE_CACHE_MASK); + } + + is_range_ram = pagerange_is_ram(start, end); + if (is_range_ram == 1) + return reserve_ram_pages_type(start, end, req_type, new_type); + else if (is_range_ram < 0) + return -EINVAL; new = kmalloc(sizeof(struct memtype), GFP_KERNEL); if (!new) return -ENOMEM; - new->start = start; - new->end = end; - new->type = actual_type; + new->start = start; + new->end = end; + new->type = actual_type; if (new_type) *new_type = actual_type; @@ -335,6 +404,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, start, end, cattr_name(new->type), cattr_name(req_type)); kfree(new); spin_unlock(&memtype_lock); + return err; } @@ -358,6 +428,7 @@ int free_memtype(u64 start, u64 end) { struct memtype *entry; int err = -EINVAL; + int is_range_ram; if (!pat_enabled) return 0; @@ -366,6 +437,12 @@ int free_memtype(u64 start, u64 end) if (is_ISA_range(start, end - 1)) return 0; + is_range_ram = pagerange_is_ram(start, end); + if (is_range_ram == 1) + return free_ram_pages_type(start, end); + else if (is_range_ram < 0) + return -EINVAL; + spin_lock(&memtype_lock); list_for_each_entry(entry, &memtype_list, nd) { if (entry->start == start && entry->end == end) { @@ -386,6 +463,7 @@ int free_memtype(u64 start, u64 end) } dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end); + return err; } @@ -492,9 +570,9 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) { + unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK); u64 addr = (u64)pfn << PAGE_SHIFT; unsigned long flags; - unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK); reserve_memtype(addr, addr + size, want_flags, &flags); if (flags != want_flags) { @@ -514,7 +592,7 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) free_memtype(addr, addr + size); } -#if defined(CONFIG_DEBUG_FS) +#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT) /* get Nth element of the linked list */ static struct memtype *memtype_get_idx(loff_t pos) @@ -537,6 +615,7 @@ static struct memtype *memtype_get_idx(loff_t pos) } spin_unlock(&memtype_lock); kfree(print_entry); + return NULL; } @@ -567,6 +646,7 @@ static int memtype_seq_show(struct seq_file *seq, void *v) seq_printf(seq, "%s @ 0x%Lx-0x%Lx\n", cattr_name(print_entry->type), print_entry->start, print_entry->end); kfree(print_entry); + return 0; } @@ -598,4 +678,4 @@ static int __init pat_memtype_list_init(void) late_initcall(pat_memtype_list_init); -#endif /* CONFIG_DEBUG_FS */ +#endif /* CONFIG_DEBUG_FS && CONFIG_X86_PAT */ |