diff options
Diffstat (limited to 'arch/x86/mm/pat.c')
| -rw-r--r-- | arch/x86/mm/pat.c | 207 |
1 files changed, 191 insertions, 16 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 72c0f60..277446c 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -11,16 +11,19 @@ #include <linux/kernel.h> #include <linux/gfp.h> #include <linux/fs.h> +#include <linux/bootmem.h> #include <asm/msr.h> #include <asm/tlbflush.h> #include <asm/processor.h> +#include <asm/page.h> #include <asm/pgtable.h> #include <asm/pat.h> #include <asm/e820.h> #include <asm/cacheflush.h> #include <asm/fcntl.h> #include <asm/mtrr.h> +#include <asm/io.h> int pat_wc_enabled = 1; @@ -190,6 +193,21 @@ static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot, return 0; } +/* + * req_type typically has one of the: + * - _PAGE_CACHE_WB + * - _PAGE_CACHE_WC + * - _PAGE_CACHE_UC_MINUS + * - _PAGE_CACHE_UC + * + * req_type will have a special case value '-1', when requester want to inherit + * the memory type from mtrr (if WB), existing PAT, defaulting to UC_MINUS. + * + * If ret_type is NULL, function will return an error if it cannot reserve the + * region with req_type. If ret_type is non-null, function will return + * available type in ret_type in case of no error. In case of any error + * it will return a negative return value. + */ int reserve_memtype(u64 start, u64 end, unsigned long req_type, unsigned long *ret_type) { @@ -200,9 +218,14 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, /* Only track when pat_wc_enabled */ if (!pat_wc_enabled) { - if (ret_type) - *ret_type = req_type; - + /* This is identical to page table setting without PAT */ + if (ret_type) { + if (req_type == -1) { + *ret_type = _PAGE_CACHE_WB; + } else { + *ret_type = req_type; + } + } return 0; } @@ -214,8 +237,29 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, return 0; } - req_type &= _PAGE_CACHE_MASK; - err = pat_x_mtrr_type(start, end, req_type, &actual_type); + if (req_type == -1) { + /* + * Special case where caller wants to inherit from mtrr or + * existing pat mapping, defaulting to UC_MINUS in case of + * no match. + */ + u8 mtrr_type = mtrr_type_lookup(start, end); + if (mtrr_type == 0xFE) { /* MTRR match error */ + err = -1; + } + + if (mtrr_type == MTRR_TYPE_WRBACK) { + req_type = _PAGE_CACHE_WB; + actual_type = _PAGE_CACHE_WB; + } else { + req_type = _PAGE_CACHE_UC_MINUS; + actual_type = _PAGE_CACHE_UC_MINUS; + } + } else { + req_type &= _PAGE_CACHE_MASK; + err = pat_x_mtrr_type(start, end, req_type, &actual_type); + } + if (err) { if (ret_type) *ret_type = actual_type; @@ -241,7 +285,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, struct memtype *saved_ptr; if (parse->start >= end) { - printk("New Entry\n"); + pr_debug("New Entry\n"); list_add(&new_entry->nd, parse->nd.prev); new_entry = NULL; break; @@ -291,7 +335,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, break; } - printk("Overlap at 0x%Lx-0x%Lx\n", + pr_debug("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); @@ -343,8 +387,8 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, break; } - printk("Overlap at 0x%Lx-0x%Lx\n", - saved_ptr->start, saved_ptr->end); + pr_debug(KERN_INFO "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); new_entry = NULL; @@ -353,7 +397,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type, } if (err) { - printk( + printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, track %s, req %s\n", start, end, cattr_name(new_entry->type), cattr_name(req_type)); @@ -365,16 +409,16 @@ 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); - printk("New Entry\n"); - } + pr_debug("New Entry\n"); + } if (ret_type) { - printk( + pr_debug( "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 { - printk( + pr_debug( "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n", start, end, cattr_name(actual_type), cattr_name(req_type)); @@ -411,11 +455,142 @@ int free_memtype(u64 start, u64 end) spin_unlock(&memtype_lock); if (err) { - printk(KERN_DEBUG "%s:%d freeing invalid memtype %Lx-%Lx\n", + printk(KERN_INFO "%s:%d freeing invalid memtype %Lx-%Lx\n", current->comm, current->pid, start, end); } - printk( "free_memtype request 0x%Lx-0x%Lx\n", start, end); + pr_debug("free_memtype request 0x%Lx-0x%Lx\n", start, end); return err; } + +/* + * /dev/mem mmap interface. The memtype used for mapping varies: + * - Use UC for mappings with O_SYNC flag + * - Without O_SYNC flag, if there is any conflict in reserve_memtype, + * inherit the memtype from existing mapping. + * - Else use UC_MINUS memtype (for backward compatibility with existing + * X drivers. + */ +pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t vma_prot) +{ + return vma_prot; +} + +#ifdef CONFIG_NONPROMISC_DEVMEM +/* This check is done in drivers/char/mem.c in case of NONPROMISC_DEVMEM*/ +static inline int range_is_allowed(unsigned long pfn, unsigned long size) +{ + return 1; +} +#else +static inline int range_is_allowed(unsigned long pfn, unsigned long size) +{ + u64 from = ((u64)pfn) << PAGE_SHIFT; + u64 to = from + size; + u64 cursor = from; + + while (cursor < to) { + if (!devmem_is_allowed(pfn)) { + printk(KERN_INFO + "Program %s tried to access /dev/mem between %Lx->%Lx.\n", + current->comm, from, to); + return 0; + } + cursor += PAGE_SIZE; + pfn++; + } + return 1; +} +#endif /* CONFIG_NONPROMISC_DEVMEM */ + +int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t *vma_prot) +{ + u64 offset = ((u64) pfn) << PAGE_SHIFT; + unsigned long flags = _PAGE_CACHE_UC_MINUS; + int retval; + + if (!range_is_allowed(pfn, size)) + return 0; + + if (file->f_flags & O_SYNC) { + flags = _PAGE_CACHE_UC; + } + +#ifdef CONFIG_X86_32 + /* + * On the PPro and successors, the MTRRs are used to set + * memory types for physical addresses outside main memory, + * so blindly setting UC or PWT on those pages is wrong. + * For Pentiums and earlier, the surround logic should disable + * 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)) { + flags = _PAGE_CACHE_UC; + } +#endif + + /* + * With O_SYNC, we can only take UC mapping. Fail if we cannot. + * Without O_SYNC, we want to get + * - WB for WB-able memory and no other conflicting mappings + * - UC_MINUS for non-WB-able memory with no other conflicting mappings + * - Inherit from confliting mappings otherwise + */ + if (flags != _PAGE_CACHE_UC_MINUS) { + retval = reserve_memtype(offset, offset + size, flags, NULL); + } else { + retval = reserve_memtype(offset, offset + size, -1, &flags); + } + + if (retval < 0) + return 0; + + if (pfn <= max_pfn_mapped && + 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", + current->comm, current->pid, + cattr_name(flags), + offset, offset + size); + return 0; + } + + *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) | + flags); + return 1; +} + +void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) +{ + 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) { + printk(KERN_INFO + "%s:%d /dev/mem expected mapping type %s for %Lx-%Lx, got %s\n", + current->comm, current->pid, + cattr_name(want_flags), + addr, addr + size, + cattr_name(flags)); + } +} + +void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot) +{ + u64 addr = (u64)pfn << PAGE_SHIFT; + + free_memtype(addr, addr + size); +} + |