Messages in this thread Patch in this message | | | From | Borislav Petkov <> | Subject | [PATCH 4/4] x86/pat: Remove pat_enabled() checks | Date | Sun, 31 May 2015 11:48:06 +0200 |
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From: Borislav Petkov <bp@suse.de>
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 <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: arnd@arndb.de Cc: Elliott@hp.com Cc: hch@lst.de Cc: hmh@hmh.eng.br Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: jgross@suse.com Cc: konrad.wilk@oracle.com Cc: linux-mm <linux-mm@kvack.org> Cc: linux-nvdimm@lists.01.org Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: stefan.bader@canonical.com Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: x86-ml <x86@kernel.org> Cc: yigal@plexistor.com --- 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 70d221fe2eb4..94aae76a5e06 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -1571,9 +1571,6 @@ 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 62171cb2b0cb..e65555e0fe3d 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -432,12 +432,8 @@ 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; } @@ -941,11 +937,8 @@ 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); -- 2.3.5
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