From: Toshi Kani <toshi.kani@hp.com>
To: bp@alien8.de, hpa@zytor.com, tglx@linutronix.de,
mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org,
linux-nvdimm@lists.01.org, jgross@suse.com,
stefan.bader@canonical.com, luto@amacapital.net, hmh@hmh.eng.br,
yigal@plexistor.com, konrad.wilk@oracle.com, Elliott@hp.com,
mcgrof@suse.com, hch@lst.de, Toshi Kani <toshi.kani@hp.com>
Subject: [PATCH v11 4/12] x86, mm, pat: Change reserve_memtype() for WT
Date: Fri, 29 May 2015 16:59:02 -0600 [thread overview]
Message-ID: <1432940350-1802-5-git-send-email-toshi.kani@hp.com> (raw)
In-Reply-To: <1432940350-1802-1-git-send-email-toshi.kani@hp.com>
From: Toshi Kani <toshi.kani@hp.com>
When a RAM range is requested to reserve_memtype(), it calls
reserve_ram_pages_type() to verify the requested type.
reserve_ram_pages_type() is changed 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.kani@hp.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
Patch 10/12 enhances set_page_memtype() to support WT.
---
arch/x86/mm/pat.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 3d9f125..85c9fcb 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -389,6 +389,8 @@ 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.
+ * 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 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
@@ -400,6 +402,13 @@ 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);
@@ -449,6 +458,7 @@ 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
--
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next prev parent reply other threads:[~2015-05-29 23:18 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-29 22:58 [PATCH v11 0/12] Support Write-Through mapping on x86 Toshi Kani
2015-05-29 22:58 ` [PATCH v11 1/12] x86, mm, pat: Cleanup init flags in pat_init() Toshi Kani
2015-05-29 22:59 ` [PATCH v11 2/12] x86, mm, pat: Refactor !pat_enabled handling Toshi Kani
2015-05-31 9:46 ` Borislav Petkov
2015-05-31 9:48 ` [PATCH 1/4] x86/pat: Untangle pat_init() Borislav Petkov
2015-05-31 9:48 ` [PATCH 2/4] x86/pat: Merge pat_init_cache_modes() into its caller Borislav Petkov
2015-05-31 10:15 ` Juergen Gross
2015-05-31 10:24 ` Borislav Petkov
2015-05-31 10:23 ` Borislav Petkov
2015-05-31 11:02 ` Juergen Gross
2015-06-01 18:15 ` Toshi Kani
2015-05-31 9:48 ` [PATCH 3/4] x86/pat: Emulate PAT when it is disabled Borislav Petkov
2015-05-31 9:48 ` [PATCH 4/4] x86/pat: Remove pat_enabled() checks Borislav Petkov
2015-06-01 18:26 ` Toshi Kani
2015-06-01 18:51 ` Borislav Petkov
2015-06-01 16:17 ` [PATCH 1/4] x86/pat: Untangle pat_init() Toshi Kani
2015-06-01 15:50 ` [PATCH v11 2/12] x86, mm, pat: Refactor !pat_enabled handling Toshi Kani
2015-05-29 22:59 ` [PATCH v11 3/12] x86, mm, pat: Set WT to PA7 slot of PAT MSR Toshi Kani
2015-05-29 22:59 ` Toshi Kani [this message]
2015-05-29 22:59 ` [PATCH v11 5/12] x86, asm: Change is_new_memtype_allowed() for WT Toshi Kani
2015-05-29 22:59 ` [PATCH v11 6/12] x86, mm, asm-gen: Add ioremap_wt() " Toshi Kani
2015-05-30 9:18 ` Geert Uytterhoeven
2015-05-31 0:58 ` Toshi Kani
2015-05-29 22:59 ` [PATCH v11 7/12] arch/*/asm/io.h: Add ioremap_wt() to all architectures Toshi Kani
2015-05-29 22:59 ` [PATCH v11 8/12] video/fbdev, asm/io.h: Remove ioremap_writethrough() Toshi Kani
2015-05-29 22:59 ` [PATCH v11 9/12] x86, mm, pat: Add pgprot_writethrough() for WT Toshi Kani
2015-05-29 22:59 ` [PATCH v11 10/12] x86, mm, asm: Add WT support to set_page_memtype() Toshi Kani
2015-05-29 22:59 ` [PATCH v11 11/12] x86, mm: Add set_memory_wt() for WT Toshi Kani
2015-05-29 22:59 ` [PATCH v11 12/12] drivers/block/pmem: Map NVDIMM with ioremap_wt() Toshi Kani
2015-05-30 1:18 ` Dan Williams
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