diff options
Diffstat (limited to 'arch/x86/mm/pat.c')
-rw-r--r-- | arch/x86/mm/pat.c | 83 |
1 files changed, 48 insertions, 35 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 06b7a1c90fb..7c21572bbdd 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -26,11 +26,11 @@ #include <asm/io.h> #ifdef CONFIG_X86_PAT -int __read_mostly pat_wc_enabled = 1; +int __read_mostly pat_enabled = 1; void __cpuinit pat_disable(char *reason) { - pat_wc_enabled = 0; + pat_enabled = 0; printk(KERN_INFO "%s\n", reason); } @@ -42,6 +42,19 @@ static int __init nopat(char *str) early_param("nopat", nopat); #endif + +static int debug_enable; +static int __init pat_debug_setup(char *str) +{ + debug_enable = 1; + return 0; +} +__setup("debugpat", pat_debug_setup); + +#define dprintk(fmt, arg...) \ + do { if (debug_enable) printk(KERN_INFO fmt, ##arg); } while (0) + + static u64 __read_mostly boot_pat_state; enum { @@ -53,24 +66,25 @@ enum { PAT_UC_MINUS = 7, /* UC, but can be overriden by MTRR */ }; -#define PAT(x,y) ((u64)PAT_ ## y << ((x)*8)) +#define PAT(x, y) ((u64)PAT_ ## y << ((x)*8)) void pat_init(void) { u64 pat; - if (!pat_wc_enabled) + if (!pat_enabled) return; /* Paranoia check. */ - if (!cpu_has_pat) { - printk(KERN_ERR "PAT enabled, but CPU feature cleared\n"); + if (!cpu_has_pat && boot_pat_state) { /* - * Panic if this happens on the secondary CPU, and we + * If this happens we are on a secondary CPU, but * switched to PAT on the boot CPU. We have no way to * undo PAT. - */ - BUG_ON(boot_pat_state); + */ + printk(KERN_ERR "PAT enabled, " + "but not supported by secondary CPU\n"); + BUG(); } /* Set PWT to Write-Combining. All other bits stay the same */ @@ -86,8 +100,8 @@ void pat_init(void) * 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); + 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) @@ -103,11 +117,11 @@ void pat_init(void) static char *cattr_name(unsigned long flags) { switch (flags & _PAGE_CACHE_MASK) { - case _PAGE_CACHE_UC: return "uncached"; - case _PAGE_CACHE_UC_MINUS: return "uncached-minus"; - case _PAGE_CACHE_WB: return "write-back"; - case _PAGE_CACHE_WC: return "write-combining"; - default: return "broken"; + case _PAGE_CACHE_UC: return "uncached"; + case _PAGE_CACHE_UC_MINUS: return "uncached-minus"; + case _PAGE_CACHE_WB: return "write-back"; + case _PAGE_CACHE_WC: return "write-combining"; + default: return "broken"; } } @@ -211,8 +225,8 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, unsigned long actual_type; int err = 0; - /* Only track when pat_wc_enabled */ - if (!pat_wc_enabled) { + /* Only track when pat_enabled */ + if (!pat_enabled) { /* This is identical to page table setting without PAT */ if (ret_type) { if (req_type == -1) { @@ -278,7 +292,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, struct memtype *saved_ptr; if (parse->start >= end) { - pr_debug("New Entry\n"); + dprintk("New Entry\n"); list_add(&new_entry->nd, parse->nd.prev); new_entry = NULL; break; @@ -328,7 +342,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, break; } - pr_debug("Overlap at 0x%Lx-0x%Lx\n", + dprintk("Overlap at 0x%Lx-0x%Lx\n", saved_ptr->start, saved_ptr->end); /* No conflict. Go ahead and add this new entry */ list_add(&new_entry->nd, saved_ptr->nd.prev); @@ -380,7 +394,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, break; } - pr_debug(KERN_INFO "Overlap at 0x%Lx-0x%Lx\n", + dprintk("Overlap at 0x%Lx-0x%Lx\n", saved_ptr->start, saved_ptr->end); /* No conflict. Go ahead and add this new entry */ list_add(&new_entry->nd, &saved_ptr->nd); @@ -402,16 +416,16 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, if (new_entry) { /* No conflict. Not yet added to the list. Add to the tail */ list_add_tail(&new_entry->nd, &memtype_list); - pr_debug("New Entry\n"); + dprintk("New Entry\n"); } if (ret_type) { - pr_debug( + dprintk( "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n", start, end, cattr_name(actual_type), cattr_name(req_type), cattr_name(*ret_type)); } else { - pr_debug( + dprintk( "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n", start, end, cattr_name(actual_type), cattr_name(req_type)); @@ -426,8 +440,8 @@ int free_memtype(u64 start, u64 end) struct memtype *ml; int err = -EINVAL; - /* Only track when pat_wc_enabled */ - if (!pat_wc_enabled) { + /* Only track when pat_enabled */ + if (!pat_enabled) { return 0; } @@ -452,7 +466,7 @@ int free_memtype(u64 start, u64 end) current->comm, current->pid, start, end); } - pr_debug("free_memtype request 0x%Lx-0x%Lx\n", start, end); + dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end); return err; } @@ -521,12 +535,12 @@ 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_wc_enabled && - ! ( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) || - test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) || - test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) || - test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability)) && - (pfn << PAGE_SHIFT) >= __pa(high_memory)) { + if (!pat_enabled && + !(boot_cpu_has(X86_FEATURE_MTRR) || + boot_cpu_has(X86_FEATURE_K6_MTRR) || + boot_cpu_has(X86_FEATURE_CYRIX_ARR) || + boot_cpu_has(X86_FEATURE_CENTAUR_MCR)) && + (pfn << PAGE_SHIFT) >= __pa(high_memory)) { flags = _PAGE_CACHE_UC; } #endif @@ -548,7 +562,7 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, return 0; if (pfn <= max_pfn_mapped && - ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) { + ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) { free_memtype(offset, offset + size); printk(KERN_INFO "%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n", @@ -586,4 +600,3 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) free_memtype(addr, addr + size); } - |