diff options
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/init.c | 6 | ||||
| -rw-r--r-- | arch/x86/mm/iomap_32.c | 12 | ||||
| -rw-r--r-- | arch/x86/mm/ioremap.c | 71 | ||||
| -rw-r--r-- | arch/x86/mm/pageattr-test.c | 1 | ||||
| -rw-r--r-- | arch/x86/mm/pageattr.c | 84 | ||||
| -rw-r--r-- | arch/x86/mm/pat.c | 337 | ||||
| -rw-r--r-- | arch/x86/mm/pat_internal.h | 2 | ||||
| -rw-r--r-- | arch/x86/mm/pat_rbtree.c | 6 | ||||
| -rw-r--r-- | arch/x86/mm/pgtable.c | 60 |
9 files changed, 393 insertions, 186 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 1d55318..8533b46 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -40,7 +40,7 @@ */ uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = { [_PAGE_CACHE_MODE_WB ] = 0 | 0 , - [_PAGE_CACHE_MODE_WC ] = _PAGE_PWT | 0 , + [_PAGE_CACHE_MODE_WC ] = 0 | _PAGE_PCD, [_PAGE_CACHE_MODE_UC_MINUS] = 0 | _PAGE_PCD, [_PAGE_CACHE_MODE_UC ] = _PAGE_PWT | _PAGE_PCD, [_PAGE_CACHE_MODE_WT ] = 0 | _PAGE_PCD, @@ -50,11 +50,11 @@ EXPORT_SYMBOL(__cachemode2pte_tbl); uint8_t __pte2cachemode_tbl[8] = { [__pte2cm_idx( 0 | 0 | 0 )] = _PAGE_CACHE_MODE_WB, - [__pte2cm_idx(_PAGE_PWT | 0 | 0 )] = _PAGE_CACHE_MODE_WC, + [__pte2cm_idx(_PAGE_PWT | 0 | 0 )] = _PAGE_CACHE_MODE_UC_MINUS, [__pte2cm_idx( 0 | _PAGE_PCD | 0 )] = _PAGE_CACHE_MODE_UC_MINUS, [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | 0 )] = _PAGE_CACHE_MODE_UC, [__pte2cm_idx( 0 | 0 | _PAGE_PAT)] = _PAGE_CACHE_MODE_WB, - [__pte2cm_idx(_PAGE_PWT | 0 | _PAGE_PAT)] = _PAGE_CACHE_MODE_WC, + [__pte2cm_idx(_PAGE_PWT | 0 | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS, [__pte2cm_idx(0 | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS, [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC, }; diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index 2b7ece0..9c0ff04 100644 --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -78,13 +78,13 @@ void __iomem * iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) { /* - * For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS. - * PAGE_KERNEL_WC maps to PWT, which translates to uncached if the - * MTRR is UC or WC. UC_MINUS gets the real intention, of the - * user, which is "WC if the MTRR is WC, UC if you can't do that." + * For non-PAT systems, translate non-WB request to UC- just in + * case the caller set the PWT bit to prot directly without using + * pgprot_writecombine(). UC- translates to uncached if the MTRR + * is UC or WC. UC- gets the real intention, of the user, which is + * "WC if the MTRR is WC, UC if you can't do that." */ - if (!pat_enabled && pgprot_val(prot) == - (__PAGE_KERNEL | cachemode2protval(_PAGE_CACHE_MODE_WC))) + if (!pat_enabled() && pgprot2cachemode(prot) != _PAGE_CACHE_MODE_WB) prot = __pgprot(__PAGE_KERNEL | cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS)); diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 27ff212..cc5ccc4 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -42,6 +42,9 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size, case _PAGE_CACHE_MODE_WC: err = _set_memory_wc(vaddr, nrpages); break; + case _PAGE_CACHE_MODE_WT: + err = _set_memory_wt(vaddr, nrpages); + break; case _PAGE_CACHE_MODE_WB: err = _set_memory_wb(vaddr, nrpages); break; @@ -172,6 +175,10 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, prot = __pgprot(pgprot_val(prot) | cachemode2protval(_PAGE_CACHE_MODE_WC)); break; + case _PAGE_CACHE_MODE_WT: + prot = __pgprot(pgprot_val(prot) | + cachemode2protval(_PAGE_CACHE_MODE_WT)); + break; case _PAGE_CACHE_MODE_WB: break; } @@ -234,10 +241,11 @@ void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size) { /* * Ideally, this should be: - * pat_enabled ? _PAGE_CACHE_MODE_UC : _PAGE_CACHE_MODE_UC_MINUS; + * pat_enabled() ? _PAGE_CACHE_MODE_UC : _PAGE_CACHE_MODE_UC_MINUS; * * Till we fix all X drivers to use ioremap_wc(), we will use - * UC MINUS. + * UC MINUS. Drivers that are certain they need or can already + * be converted over to strong UC can use ioremap_uc(). */ enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS; @@ -247,6 +255,39 @@ void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size) EXPORT_SYMBOL(ioremap_nocache); /** + * ioremap_uc - map bus memory into CPU space as strongly uncachable + * @phys_addr: bus address of the memory + * @size: size of the resource to map + * + * ioremap_uc performs a platform specific sequence of operations to + * make bus memory CPU accessible via the readb/readw/readl/writeb/ + * writew/writel functions and the other mmio helpers. The returned + * address is not guaranteed to be usable directly as a virtual + * address. + * + * This version of ioremap ensures that the memory is marked with a strong + * preference as completely uncachable on the CPU when possible. For non-PAT + * systems this ends up setting page-attribute flags PCD=1, PWT=1. For PAT + * systems this will set the PAT entry for the pages as strong UC. This call + * will honor existing caching rules from things like the PCI bus. Note that + * there are other caches and buffers on many busses. In particular driver + * authors should read up on PCI writes. + * + * It's useful if some control registers are in such an area and + * write combining or read caching is not desirable: + * + * Must be freed with iounmap. + */ +void __iomem *ioremap_uc(resource_size_t phys_addr, unsigned long size) +{ + enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC; + + return __ioremap_caller(phys_addr, size, pcm, + __builtin_return_address(0)); +} +EXPORT_SYMBOL_GPL(ioremap_uc); + +/** * ioremap_wc - map memory into CPU space write combined * @phys_addr: bus address of the memory * @size: size of the resource to map @@ -258,14 +299,28 @@ EXPORT_SYMBOL(ioremap_nocache); */ void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size) { - if (pat_enabled) - return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC, + return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC, __builtin_return_address(0)); - else - return ioremap_nocache(phys_addr, size); } EXPORT_SYMBOL(ioremap_wc); +/** + * ioremap_wt - map memory into CPU space write through + * @phys_addr: bus address of the memory + * @size: size of the resource to map + * + * This version of ioremap ensures that the memory is marked write through. + * Write through stores data into memory while keeping the cache up-to-date. + * + * Must be freed with iounmap. + */ +void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size) +{ + return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(ioremap_wt); + void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size) { return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB, @@ -331,7 +386,7 @@ void iounmap(volatile void __iomem *addr) } EXPORT_SYMBOL(iounmap); -int arch_ioremap_pud_supported(void) +int __init arch_ioremap_pud_supported(void) { #ifdef CONFIG_X86_64 return cpu_has_gbpages; @@ -340,7 +395,7 @@ int arch_ioremap_pud_supported(void) #endif } -int arch_ioremap_pmd_supported(void) +int __init arch_ioremap_pmd_supported(void) { return cpu_has_pse; } diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c index 6629f39..8ff686a 100644 --- a/arch/x86/mm/pageattr-test.c +++ b/arch/x86/mm/pageattr-test.c @@ -9,6 +9,7 @@ #include <linux/random.h> #include <linux/kernel.h> #include <linux/mm.h> +#include <linux/vmalloc.h> #include <asm/cacheflush.h> #include <asm/pgtable.h> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 89af288..727158c 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -14,6 +14,7 @@ #include <linux/percpu.h> #include <linux/gfp.h> #include <linux/pci.h> +#include <linux/vmalloc.h> #include <asm/e820.h> #include <asm/processor.h> @@ -129,16 +130,15 @@ within(unsigned long addr, unsigned long start, unsigned long end) */ void clflush_cache_range(void *vaddr, unsigned int size) { - void *vend = vaddr + size - 1; + unsigned long clflush_mask = boot_cpu_data.x86_clflush_size - 1; + void *vend = vaddr + size; + void *p; mb(); - for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size) - clflushopt(vaddr); - /* - * Flush any possible final partial cacheline: - */ - clflushopt(vend); + for (p = (void *)((unsigned long)vaddr & ~clflush_mask); + p < vend; p += boot_cpu_data.x86_clflush_size) + clflushopt(p); mb(); } @@ -418,13 +418,11 @@ phys_addr_t slow_virt_to_phys(void *__virt_addr) phys_addr_t phys_addr; unsigned long offset; enum pg_level level; - unsigned long psize; unsigned long pmask; pte_t *pte; pte = lookup_address(virt_addr, &level); BUG_ON(!pte); - psize = page_level_size(level); pmask = page_level_mask(level); offset = virt_addr & ~pmask; phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; @@ -1468,6 +1466,9 @@ int _set_memory_uc(unsigned long addr, int numpages) { /* * for now UC MINUS. see comments in ioremap_nocache() + * If you really need strong UC use ioremap_uc(), but note + * that you cannot override IO areas with set_memory_*() as + * these helpers cannot work with IO memory. */ return change_page_attr_set(&addr, numpages, cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS), @@ -1502,12 +1503,10 @@ EXPORT_SYMBOL(set_memory_uc); static int _set_memory_array(unsigned long *addr, int addrinarray, enum page_cache_mode new_type) { + enum page_cache_mode set_type; int i, j; int ret; - /* - * for now UC MINUS. see comments in ioremap_nocache() - */ for (i = 0; i < addrinarray; i++) { ret = reserve_memtype(__pa(addr[i]), __pa(addr[i]) + PAGE_SIZE, new_type, NULL); @@ -1515,9 +1514,12 @@ static int _set_memory_array(unsigned long *addr, int addrinarray, goto out_free; } + /* If WC, set to UC- first and then WC */ + set_type = (new_type == _PAGE_CACHE_MODE_WC) ? + _PAGE_CACHE_MODE_UC_MINUS : new_type; + ret = change_page_attr_set(addr, addrinarray, - cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS), - 1); + cachemode2pgprot(set_type), 1); if (!ret && new_type == _PAGE_CACHE_MODE_WC) ret = change_page_attr_set_clr(addr, addrinarray, @@ -1549,6 +1551,12 @@ int set_memory_array_wc(unsigned long *addr, int addrinarray) } EXPORT_SYMBOL(set_memory_array_wc); +int set_memory_array_wt(unsigned long *addr, int addrinarray) +{ + return _set_memory_array(addr, addrinarray, _PAGE_CACHE_MODE_WT); +} +EXPORT_SYMBOL_GPL(set_memory_array_wt); + int _set_memory_wc(unsigned long addr, int numpages) { int ret; @@ -1571,27 +1579,42 @@ int set_memory_wc(unsigned long addr, int numpages) { int ret; - if (!pat_enabled) - return set_memory_uc(addr, numpages); - ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, _PAGE_CACHE_MODE_WC, NULL); if (ret) - goto out_err; + return ret; ret = _set_memory_wc(addr, numpages); if (ret) - goto out_free; - - return 0; + free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); -out_free: - free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); -out_err: return ret; } EXPORT_SYMBOL(set_memory_wc); +int _set_memory_wt(unsigned long addr, int numpages) +{ + return change_page_attr_set(&addr, numpages, + cachemode2pgprot(_PAGE_CACHE_MODE_WT), 0); +} + +int set_memory_wt(unsigned long addr, int numpages) +{ + int ret; + + ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, + _PAGE_CACHE_MODE_WT, NULL); + if (ret) + return ret; + + ret = _set_memory_wt(addr, numpages); + if (ret) + free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); + + return ret; +} +EXPORT_SYMBOL_GPL(set_memory_wt); + int _set_memory_wb(unsigned long addr, int numpages) { /* WB cache mode is hard wired to all cache attribute bits being 0 */ @@ -1682,6 +1705,7 @@ static int _set_pages_array(struct page **pages, int addrinarray, { unsigned long start; unsigned long end; + enum page_cache_mode set_type; int i; int free_idx; int ret; @@ -1695,8 +1719,12 @@ static int _set_pages_array(struct page **pages, int addrinarray, goto err_out; } + /* If WC, set to UC- first and then WC */ + set_type = (new_type == _PAGE_CACHE_MODE_WC) ? + _PAGE_CACHE_MODE_UC_MINUS : new_type; + ret = cpa_set_pages_array(pages, addrinarray, - cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS)); + cachemode2pgprot(set_type)); if (!ret && new_type == _PAGE_CACHE_MODE_WC) ret = change_page_attr_set_clr(NULL, addrinarray, cachemode2pgprot( @@ -1730,6 +1758,12 @@ int set_pages_array_wc(struct page **pages, int addrinarray) } EXPORT_SYMBOL(set_pages_array_wc); +int set_pages_array_wt(struct page **pages, int addrinarray) +{ + return _set_pages_array(pages, addrinarray, _PAGE_CACHE_MODE_WT); +} +EXPORT_SYMBOL_GPL(set_pages_array_wt); + int set_pages_wb(struct page *page, int numpages) { unsigned long addr = (unsigned long)page_address(page); diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 35af677..188e3e0 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -33,13 +33,17 @@ #include "pat_internal.h" #include "mm_internal.h" -#ifdef CONFIG_X86_PAT -int __read_mostly pat_enabled = 1; +#undef pr_fmt +#define pr_fmt(fmt) "" fmt + +static bool boot_cpu_done; + +static int __read_mostly __pat_enabled = IS_ENABLED(CONFIG_X86_PAT); static inline void pat_disable(const char *reason) { - pat_enabled = 0; - printk(KERN_INFO "%s\n", reason); + __pat_enabled = 0; + pr_info("x86/PAT: %s\n", reason); } static int __init nopat(char *str) @@ -48,13 +52,12 @@ static int __init nopat(char *str) return 0; } early_param("nopat", nopat); -#else -static inline void pat_disable(const char *reason) + +bool pat_enabled(void) { - (void)reason; + return !!__pat_enabled; } -#endif - +EXPORT_SYMBOL_GPL(pat_enabled); int pat_debug_enable; @@ -65,22 +68,24 @@ static int __init pat_debug_setup(char *str) } __setup("debugpat", pat_debug_setup); -static u64 __read_mostly boot_pat_state; - #ifdef CONFIG_X86_PAT /* - * X86 PAT uses page flags WC and Uncached together to keep track of - * memory type of pages that have backing page struct. X86 PAT supports 3 - * different memory types, _PAGE_CACHE_MODE_WB, _PAGE_CACHE_MODE_WC and - * _PAGE_CACHE_MODE_UC_MINUS and fourth state where page's memory type has not - * been changed from its default (value of -1 used to denote this). - * Note we do not support _PAGE_CACHE_MODE_UC here. + * X86 PAT uses page flags arch_1 and uncached together to keep track of + * memory type of pages that have backing page struct. + * + * X86 PAT supports 4 different memory types: + * - _PAGE_CACHE_MODE_WB + * - _PAGE_CACHE_MODE_WC + * - _PAGE_CACHE_MODE_UC_MINUS + * - _PAGE_CACHE_MODE_WT + * + * _PAGE_CACHE_MODE_WB is the default type. */ -#define _PGMT_DEFAULT 0 +#define _PGMT_WB 0 #define _PGMT_WC (1UL << PG_arch_1) #define _PGMT_UC_MINUS (1UL << PG_uncached) -#define _PGMT_WB (1UL << PG_uncached | 1UL << PG_arch_1) +#define _PGMT_WT (1UL << PG_uncached | 1UL << PG_arch_1) #define _PGMT_MASK (1UL << PG_uncached | 1UL << PG_arch_1) #define _PGMT_CLEAR_MASK (~_PGMT_MASK) @@ -88,14 +93,14 @@ static inline enum page_cache_mode get_page_memtype(struct page *pg) { unsigned long pg_flags = pg->flags & _PGMT_MASK; - if (pg_flags == _PGMT_DEFAULT) - return -1; + if (pg_flags == _PGMT_WB) + return _PAGE_CACHE_MODE_WB; else if (pg_flags == _PGMT_WC) return _PAGE_CACHE_MODE_WC; else if (pg_flags == _PGMT_UC_MINUS) return _PAGE_CACHE_MODE_UC_MINUS; else - return _PAGE_CACHE_MODE_WB; + return _PAGE_CACHE_MODE_WT; } static inline void set_page_memtype(struct page *pg, @@ -112,11 +117,12 @@ static inline void set_page_memtype(struct page *pg, case _PAGE_CACHE_MODE_UC_MINUS: memtype_flags = _PGMT_UC_MINUS; break; - case _PAGE_CACHE_MODE_WB: - memtype_flags = _PGMT_WB; + case _PAGE_CACHE_MODE_WT: + memtype_flags = _PGMT_WT; break; + case _PAGE_CACHE_MODE_WB: default: - memtype_flags = _PGMT_DEFAULT; + memtype_flags = _PGMT_WB; break; } @@ -174,78 +180,154 @@ static enum page_cache_mode pat_get_cache_mode(unsigned pat_val, char *msg) * configuration. * Using lower indices is preferred, so we start with highest index. */ -void pat_init_cache_modes(void) +void pat_init_cache_modes(u64 pat) { - int i; enum page_cache_mode cache; char pat_msg[33]; - u64 pat; + int i; - rdmsrl(MSR_IA32_CR_PAT, pat); pat_msg[32] = 0; for (i = 7; i >= 0; i--) { cache = pat_get_cache_mode((pat >> (i * 8)) & 7, pat_msg + 4 * i); update_cache_mode_entry(i, cache); } - pr_info("PAT configuration [0-7]: %s\n", pat_msg); + pr_info("x86/PAT: Configuration [0-7]: %s\n", pat_msg); } #define PAT(x, y) ((u64)PAT_ ## y << ((x)*8)) -void pat_init(void) +static void pat_bsp_init(u64 pat) { - u64 pat; - bool boot_cpu = !boot_pat_state; + u64 tmp_pat; - if (!pat_enabled) + if (!cpu_has_pat) { + pat_disable("PAT not supported by CPU."); return; + } - if (!cpu_has_pat) { - if (!boot_pat_state) { - pat_disable("PAT not supported by CPU."); - return; - } else { - /* - * If this happens we are on a secondary CPU, but - * switched to PAT on the boot CPU. We have no way to - * undo PAT. - */ - printk(KERN_ERR "PAT enabled, " - "but not supported by secondary CPU\n"); - BUG(); - } + if (!pat_enabled()) + goto done; + + rdmsrl(MSR_IA32_CR_PAT, tmp_pat); + if (!tmp_pat) { + pat_disable("PAT MSR is 0, disabled."); + return; } - /* Set PWT to Write-Combining. All other bits stay the same */ - /* - * PTE encoding used in Linux: - * PAT - * |PCD - * ||PWT - * ||| - * 000 WB _PAGE_CACHE_WB - * 001 WC _PAGE_CACHE_WC - * 010 UC- _PAGE_CACHE_UC_MINUS - * 011 UC _PAGE_CACHE_UC - * PAT bit unused - */ - pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | - PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); - - /* Boot CPU check */ - if (!boot_pat_state) { - rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); - if (!boot_pat_state) { - pat_disable("PAT read returns always zero, disabled."); - return; - } + wrmsrl(MSR_IA32_CR_PAT, pat); + +done: + pat_init_cache_modes(pat); +} + +static void pat_ap_init(u64 pat) +{ + if (!pat_enabled()) + return; + + if (!cpu_has_pat) { + /* + * If this happens we are on a secondary CPU, but switched to + * PAT on the boot CPU. We have no way to undo PAT. + */ + panic("x86/PAT: PAT enabled, but not supported by secondary CPU\n"); } wrmsrl(MSR_IA32_CR_PAT, pat); +} + +void pat_init(void) +{ + u64 pat; + struct cpuinfo_x86 *c = &boot_cpu_data; + + if (!pat_enabled()) { + /* + * No PAT. Emulate the PAT table that corresponds to the two + * cache bits, PWT (Write Through) and PCD (Cache Disable). This + * setup is the same as the BIOS default setup when the system + * has PAT but the "nopat" boot option has been specified. This + * emulated PAT table is used when MSR_IA32_CR_PAT returns 0. + * + * PTE encoding: + * + * PCD + * |PWT PAT + * || slot + * 00 0 WB : _PAGE_CACHE_MODE_WB + * 01 1 WT : _PAGE_CACHE_MODE_WT + * 10 2 UC-: _PAGE_CACHE_MODE_UC_MINUS + * 11 3 UC : _PAGE_CACHE_MODE_UC + * + * NOTE: When WC or WP is used, it is redirected to UC- per + * the default setup in __cachemode2pte_tbl[]. + */ + pat = PAT(0, WB) | PAT(1, WT) | PAT(2, UC_MINUS) | PAT(3, UC) | + PAT(4, WB) | PAT(5, WT) | PAT(6, UC_MINUS) | PAT(7, UC); - if (boot_cpu) - pat_init_cache_modes(); + } else if ((c->x86_vendor == X86_VENDOR_INTEL) && + (((c->x86 == 0x6) && (c->x86_model <= 0xd)) || + ((c->x86 == 0xf) && (c->x86_model <= 0x6)))) { + /* + * PAT support with the lower four entries. Intel Pentium 2, + * 3, M, and 4 are affected by PAT errata, which makes the + * upper four entries unusable. To be on the safe side, we don't + * use those. + * + * PTE encoding: + * PAT + * |PCD + * ||PWT PAT + * ||| slot + * 000 0 WB : _PAGE_CACHE_MODE_WB + * 001 1 WC : _PAGE_CACHE_MODE_WC + * 010 2 UC-: _PAGE_CACHE_MODE_UC_MINUS + * 011 3 UC : _PAGE_CACHE_MODE_UC + * PAT bit unused + * + * NOTE: When WT or WP is used, it is redirected to UC- per + * the default setup in __cachemode2pte_tbl[]. + */ + pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | + PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); + } else { + /* + * Full PAT support. We put WT in slot 7 to improve + * robustness in the presence of errata that might cause + * the high PAT bit to be ignored. This way, a buggy slot 7 + * access will hit slot 3, and slot 3 is UC, so at worst + * we lose performance without causing a correctness issue. + * Pentium 4 erratum N46 is an example for such an erratum, + * although we try not to use PAT at all on affected CPUs. + * + * PTE encoding: + * PAT + * |PCD + * ||PWT PAT + * ||| slot + * 000 0 WB : _PAGE_CACHE_MODE_WB + * 001 1 WC : _PAGE_CACHE_MODE_WC + * 010 2 UC-: _PAGE_CACHE_MODE_UC_MINUS + * 011 3 UC : _PAGE_CACHE_MODE_UC + * 100 4 WB : Reserved + * 101 5 WC : Reserved + * 110 6 UC-: Reserved + * 111 7 WT : _PAGE_CACHE_MODE_WT + * + * The reserved slots are unused, but mapped to their + * corresponding types in the presence of PAT errata. + */ + pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | + PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, WT); + } + + if (!boot_cpu_done) { + pat_bsp_init(pat); + boot_cpu_done = true; + } else { + pat_ap_init(pat); + } } #undef PAT @@ -267,9 +349,9 @@ static unsigned long pat_x_mtrr_type(u64 start, u64 end, * request is for WB. */ if (req_type == _PAGE_CACHE_MODE_WB) { - u8 mtrr_type; + u8 mtrr_type, uniform; - mtrr_type = mtrr_type_lookup(start, end); + mtrr_type = mtrr_type_lookup(start, end, &uniform); if (mtrr_type != MTRR_TYPE_WRBACK) return _PAGE_CACHE_MODE_UC_MINUS; @@ -324,9 +406,14 @@ static int pat_pagerange_is_ram(resource_size_t start, resource_size_t end) /* * For RAM pages, we use page flags to mark the pages with appropriate type. - * Here we do two pass: - * - Find the memtype of all the pages in the range, look for any conflicts - * - In case of no conflicts, set the new memtype for pages in the range + * The page flags are limited to four types, WB (default), WC, WT and UC-. + * WP request fails with -EINVAL, and UC gets redirected to UC-. Setting + * a new memory type is only allowed for a page mapped with the default WB + * type. + * + * Here we do two passes: + * - Find the memtype of all the pages in the range, look for any conflicts. + * - In case of no conflicts, set the new memtype for pages in the range. */ static int reserve_ram_pages_type(u64 start, u64 end, enum page_cache_mode req_type, @@ -335,6 +422,12 @@ static int reserve_ram_pages_type(u64 start, u64 end, struct page *page; u64 pfn; + if (req_type == _PAGE_CACHE_MODE_WP) { + if (new_type) + *new_type = _PAGE_CACHE_MODE_UC_MINUS; + return -EINVAL; + } + if (req_type == _PAGE_CACHE_MODE_UC) { /* We do not support strong UC */ WARN_ON_ONCE(1); @@ -346,8 +439,8 @@ static int reserve_ram_pages_type(u64 start, u64 end, page = pfn_to_page(pfn); type = get_page_memtype(page); - if (type != -1) { - pr_info("reserve_ram_pages_type failed [mem %#010Lx-%#010Lx], track 0x%x, req 0x%x\n", + if (type != _PAGE_CACHE_MODE_WB) { + pr_info("x86/PAT: reserve_ram_pages_type failed [mem %#010Lx-%#010Lx], track 0x%x, req 0x%x\n", start, end - 1, type, req_type); if (new_type) *new_type = type; @@ -373,7 +466,7 @@ static int free_ram_pages_type(u64 start, u64 end) for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { page = pfn_to_page(pfn); - set_page_memtype(page, -1); + set_page_memtype(page, _PAGE_CACHE_MODE_WB); } return 0; } @@ -384,6 +477,7 @@ static int free_ram_pages_type(u64 start, u64 end) * - _PAGE_CACHE_MODE_WC * - _PAGE_CACHE_MODE_UC_MINUS * - _PAGE_CACHE_MODE_UC + * - _PAGE_CACHE_MODE_WT * * If new_type is NULL, function will return an error if it cannot reserve the * region with req_type. If new_type is non-NULL, function will return @@ -400,14 +494,10 @@ int reserve_memtype(u64 start, u64 end, enum page_cache_mode req_type, BUG_ON(start >= end); /* end is exclusive */ - if (!pat_enabled) { + if (!pat_enabled()) { /* This is identical to page table setting without PAT */ - if (new_type) { - if (req_type == _PAGE_CACHE_MODE_WC) - *new_type = _PAGE_CACHE_MODE_UC_MINUS; - else - *new_type = req_type; - } + if (new_type) + *new_type = req_type; return 0; } @@ -451,9 +541,9 @@ int reserve_memtype(u64 start, u64 end, enum page_cache_mode req_type, err = rbt_memtype_check_insert(new, new_type); if (err) { - printk(KERN_INFO "reserve_memtype failed [mem %#010Lx-%#010Lx], track %s, req %s\n", - start, end - 1, - cattr_name(new->type), cattr_name(req_type)); + pr_info("x86/PAT: reserve_memtype failed [mem %#010Lx-%#010Lx], track %s, req %s\n", + start, end - 1, + cattr_name(new->type), cattr_name(req_type)); kfree(new); spin_unlock(&memtype_lock); @@ -475,7 +565,7 @@ int free_memtype(u64 start, u64 end) int is_range_ram; struct memtype *entry; - if (!pat_enabled) + if (!pat_enabled()) return 0; /* Low ISA region is always mapped WB. No need to track */ @@ -497,8 +587,8 @@ int free_memtype(u64 start, u64 end) spin_unlock(&memtype_lock); if (!entry) { - printk(KERN_INFO "%s:%d freeing invalid memtype [mem %#010Lx-%#010Lx]\n", - current->comm, current->pid, start, end - 1); + pr_info("x86/PAT: %s:%d freeing invalid memtype [mem %#010Lx-%#010Lx]\n", + current->comm, current->pid, start, end - 1); return -EINVAL; } @@ -517,7 +607,7 @@ int free_memtype(u64 start, u64 end) * Only to be called when PAT is enabled * * Returns _PAGE_CACHE_MODE_WB, _PAGE_CACHE_MODE_WC, _PAGE_CACHE_MODE_UC_MINUS - * or _PAGE_CACHE_MODE_UC + * or _PAGE_CACHE_MODE_WT. */ static enum page_cache_mode lookup_memtype(u64 paddr) { @@ -529,16 +619,9 @@ static enum page_cache_mode lookup_memtype(u64 paddr) if (pat_pagerange_is_ram(paddr, paddr + PAGE_SIZE)) { struct page *page; - page = pfn_to_page(paddr >> PAGE_SHIFT); - rettype = get_page_memtype(page); - /* - * -1 from get_page_memtype() implies RAM page is in its - * default state and not reserved, and hence of type WB - */ - if (rettype == -1) - rettype = _PAGE_CACHE_MODE_WB; - return rettype; + page = pfn_to_page(paddr >> PAGE_SHIFT); + return get_page_memtype(page); } spin_lock(&memtype_lock); @@ -623,13 +706,13 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size) u64 to = from + size; u64 cursor = from; - if (!pat_enabled) + if (!pat_enabled()) return 1; while (cursor < to) { if (!devmem_is_allowed(pfn)) { - printk(KERN_INFO "Program %s tried to access /dev/mem between [mem %#010Lx-%#010Lx], PAT prevents it\n", - current->comm, from, to - 1); + pr_info("x86/PAT: Program %s tried to access /dev/mem between [mem %#010Lx-%#010Lx], PAT prevents it\n", + current->comm, from, to - 1); return 0; } cursor += PAGE_SIZE; @@ -659,7 +742,7 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, * caching for the high addresses through the KEN pin, but * we maintain the tradition of paranoia in this code. */ - if (!pat_enabled && + if (!pat_enabled() && !(boot_cpu_has(X86_FEATURE_MTRR) || boot_cpu_has(X86_FEATURE_K6_MTRR) || boot_cpu_has(X86_FEATURE_CYRIX_ARR) || @@ -698,8 +781,7 @@ int kernel_map_sync_memtype(u64 base, unsigned long size, size; if (ioremap_change_attr((unsigned long)__va(base), id_sz, pcm) < 0) { - printk(KERN_INFO "%s:%d ioremap_change_attr failed %s " - "for [mem %#010Lx-%#010Lx]\n", + pr_info("x86/PAT: %s:%d ioremap_change_attr failed %s for [mem %#010Lx-%#010Lx]\n", current->comm, current->pid, cattr_name(pcm), base, (unsigned long long)(base + size-1)); @@ -729,12 +811,12 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, * the type requested matches the type of first page in the range. */ if (is_ram) { - if (!pat_enabled) + if (!pat_enabled()) return 0; pcm = lookup_memtype(paddr); if (want_pcm != pcm) { - printk(KERN_WARNING "%s:%d map pfn RAM range req %s for [mem %#010Lx-%#010Lx], got %s\n", + pr_warn("x86/PAT: %s:%d map pfn RAM range req %s for [mem %#010Lx-%#010Lx], got %s\n", current->comm, current->pid, cattr_name(want_pcm), (unsigned long long)paddr, @@ -755,13 +837,12 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, if (strict_prot || !is_new_memtype_allowed(paddr, size, want_pcm, pcm)) { free_memtype(paddr, paddr + size); - printk(KERN_ERR "%s:%d map pfn expected mapping type %s" - " for [mem %#010Lx-%#010Lx], got %s\n", - current->comm, current->pid, - cattr_name(want_pcm), - (unsigned long long)paddr, - (unsigned long long)(paddr + size - 1), - cattr_name(pcm)); + pr_err("x86/PAT: %s:%d map pfn expected mapping type %s for [mem %#010Lx-%#010Lx], got %s\n", + current->comm, current->pid, + cattr_name(want_pcm), + (unsigned long long)paddr, + (unsigned long long)(paddr + size - 1), + cattr_name(pcm)); return -EINVAL; } /* @@ -844,7 +925,7 @@ int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot, return ret; } - if (!pat_enabled) + if (!pat_enabled()) return 0; /* @@ -872,7 +953,7 @@ int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot, { enum page_cache_mode pcm; - if (!pat_enabled) + if (!pat_enabled()) return 0; /* Set prot based on lookup */ @@ -913,14 +994,18 @@ void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn, pgprot_t pgprot_writecombine(pgprot_t prot) { - if (pat_enabled) - return __pgprot(pgprot_val(prot) | + return __pgprot(pgprot_val(prot) | cachemode2protval(_PAGE_CACHE_MODE_WC)); - else - return pgprot_noncached(prot); } EXPORT_SYMBOL_GPL(pgprot_writecombine); +pgprot_t pgprot_writethrough(pgprot_t prot) +{ + return __pgprot(pgprot_val(prot) | + cachemode2protval(_PAGE_CACHE_MODE_WT)); +} +EXPORT_SYMBOL_GPL(pgprot_writethrough); + #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT) static struct memtype *memtype_get_idx(loff_t pos) @@ -996,7 +1081,7 @@ static const struct file_operations memtype_fops = { static int __init pat_memtype_list_init(void) { - if (pat_enabled) { + if (pat_enabled()) { debugfs_create_file("pat_memtype_list", S_IRUSR, arch_debugfs_dir, NULL, &memtype_fops); } diff --git a/arch/x86/mm/pat_internal.h b/arch/x86/mm/pat_internal.h index f641162..a739bfc 100644 --- a/arch/x86/mm/pat_internal.h +++ b/arch/x86/mm/pat_internal.h @@ -4,7 +4,7 @@ extern int pat_debug_enable; #define dprintk(fmt, arg...) \ - do { if (pat_debug_enable) printk(KERN_INFO fmt, ##arg); } while (0) + do { if (pat_debug_enable) pr_info("x86/PAT: " fmt, ##arg); } while (0) struct memtype { u64 start; diff --git a/arch/x86/mm/pat_rbtree.c b/arch/x86/mm/pat_rbtree.c index 6582adc..6393108 100644 --- a/arch/x86/mm/pat_rbtree.c +++ b/arch/x86/mm/pat_rbtree.c @@ -160,9 +160,9 @@ success: return 0; failure: - printk(KERN_INFO "%s:%d conflicting memory types " - "%Lx-%Lx %s<->%s\n", current->comm, current->pid, start, - end, cattr_name(found_type), cattr_name(match->type)); + pr_info("x86/PAT: %s:%d conflicting memory types %Lx-%Lx %s<->%s\n", + current->comm, current->pid, start, end, + cattr_name(found_type), cattr_name(match->type)); return -EBUSY; } diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 0b97d2c..fb0a9dd 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -563,16 +563,31 @@ void native_set_fixmap(enum fixed_addresses idx, phys_addr_t phys, } #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +/** + * pud_set_huge - setup kernel PUD mapping + * + * MTRRs can override PAT memory types with 4KiB granularity. Therefore, this + * function sets up a huge page only if any of the following conditions are met: + * + * - MTRRs are disabled, or + * + * - MTRRs are enabled and the range is completely covered by a single MTRR, or + * + * - MTRRs are enabled and the corresponding MTRR memory type is WB, which + * has no effect on the requested PAT memory type. + * + * Callers should try to decrease page size (1GB -> 2MB -> 4K) if the bigger + * page mapping attempt fails. + * + * Returns 1 on success and 0 on failure. + */ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) { - u8 mtrr; + u8 mtrr, uniform; - /* - * Do not use a huge page when the range is covered by non-WB type - * of MTRRs. - */ - mtrr = mtrr_type_lookup(addr, addr + PUD_SIZE); - if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF)) + mtrr = mtrr_type_lookup(addr, addr + PUD_SIZE, &uniform); + if ((mtrr != MTRR_TYPE_INVALID) && (!uniform) && + (mtrr != MTRR_TYPE_WRBACK)) return 0; prot = pgprot_4k_2_large(prot); @@ -584,17 +599,24 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) return 1; } +/** + * pmd_set_huge - setup kernel PMD mapping + * + * See text over pud_set_huge() above. + * + * Returns 1 on success and 0 on failure. + */ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) { - u8 mtrr; + u8 mtrr, uniform; - /* - * Do not use a huge page when the range is covered by non-WB type - * of MTRRs. - */ - mtrr = mtrr_type_lookup(addr, addr + PMD_SIZE); - if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF)) + mtrr = mtrr_type_lookup(addr, addr + PMD_SIZE, &uniform); + if ((mtrr != MTRR_TYPE_INVALID) && (!uniform) && + (mtrr != MTRR_TYPE_WRBACK)) { + pr_warn_once("%s: Cannot satisfy [mem %#010llx-%#010llx] with a huge-page mapping due to MTRR override.\n", + __func__, addr, addr + PMD_SIZE); return 0; + } prot = pgprot_4k_2_large(prot); @@ -605,6 +627,11 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) return 1; } +/** + * pud_clear_huge - clear kernel PUD mapping when it is set + * + * Returns 1 on success and 0 on failure (no PUD map is found). + */ int pud_clear_huge(pud_t *pud) { if (pud_large(*pud)) { @@ -615,6 +642,11 @@ int pud_clear_huge(pud_t *pud) return 0; } +/** + * pmd_clear_huge - clear kernel PMD mapping when it is set + * + * Returns 1 on success and 0 on failure (no PMD map is found). + */ int pmd_clear_huge(pmd_t *pmd) { if (pmd_large(*pmd)) { |