Commit-ID: 0d69bdff451a10aa48f80509e8bf18fb24683c06 Gitweb: http://git.kernel.org/tip/0d69bdff451a10aa48f80509e8bf18fb24683c06 Author: Toshi Kani <toshi.k...@hp.com> AuthorDate: Thu, 4 Jun 2015 18:55:13 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Sun, 7 Jun 2015 15:28:55 +0200
x86/mm/pat: Change reserve_memtype() for Write-Through type When a target range is in RAM, reserve_ram_pages_type() verifies the requested type. Change it to fail WT and WP requests with -EINVAL since set_page_memtype() is limited to handle three types: WB, WC and UC-. Signed-off-by: Toshi Kani <toshi.k...@hp.com> Signed-off-by: Borislav Petkov <b...@suse.de> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Andy Lutomirski <l...@amacapital.net> Cc: elli...@hp.com Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Luis R. Rodriguez <mcg...@suse.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: a...@arndb.de Cc: h...@lst.de Cc: h...@hmh.eng.br Cc: jgr...@suse.com Cc: konrad.w...@oracle.com Cc: linux-mm <linux...@kvack.org> Cc: linux-nvd...@lists.01.org Cc: stefan.ba...@canonical.com Cc: yi...@plexistor.com Link: http://lkml.kernel.org/r/1433436928-31903-6-git-send-email...@alien8.de Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/mm/pat.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 59ab1a0f..6311193 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -401,9 +401,12 @@ 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 three types, WB, WC and UC-. WT and WP requests + * fail with -EINVAL, and UC gets redirected to UC-. + * + * 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, @@ -412,6 +415,13 @@ static int reserve_ram_pages_type(u64 start, u64 end, struct page *page; u64 pfn; + if ((req_type == _PAGE_CACHE_MODE_WT) || + (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); @@ -461,6 +471,7 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
