From 7202fdb1b3299ec78dc1e7702260947ec20dd9e9 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Thu, 4 Jun 2015 18:55:11 +0200 Subject: [PATCH] x86/mm/pat: Remove pat_enabled() checks Now that we emulate a PAT table when PAT is disabled, there's no need for those checks anymore as the PAT abstraction will handle those cases too. Based on a conglomerate patch from Toshi Kani. Signed-off-by: Borislav Petkov Reviewed-by: Toshi Kani Cc: Andrew Morton Cc: Andy Lutomirski Cc: Elliott@hp.com Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Luis R. Rodriguez Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: arnd@arndb.de Cc: hch@lst.de Cc: hmh@hmh.eng.br Cc: jgross@suse.com Cc: konrad.wilk@oracle.com Cc: linux-mm Cc: linux-nvdimm@lists.01.org Cc: stefan.bader@canonical.com Cc: yigal@plexistor.com Link: http://lkml.kernel.org/r/1433436928-31903-4-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar --- arch/x86/mm/iomap_32.c | 12 ++++++------ arch/x86/mm/ioremap.c | 5 +---- arch/x86/mm/pageattr.c | 3 --- arch/x86/mm/pat.c | 13 +++---------- 4 files changed, 10 insertions(+), 23 deletions(-) diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index 3a2ec8790ca7..a9dc7a37e6a2 100644 --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -77,13 +77,13 @@ 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 b0da3588b452..cc0f17c5ad9f 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -292,11 +292,8 @@ EXPORT_SYMBOL_GPL(ioremap_uc); */ 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); diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index fae3c5366ac0..31b4f3fd1207 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -1572,9 +1572,6 @@ 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) diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 6dc7826e4797..f89e460c55a8 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -438,12 +438,8 @@ int reserve_memtype(u64 start, u64 end, enum page_cache_mode req_type, 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; } @@ -947,11 +943,8 @@ 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);