From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f173.google.com (mail-ig0-f173.google.com [209.85.213.173]) by kanga.kvack.org (Postfix) with ESMTP id 2816D6B0092 for ; Tue, 10 Mar 2015 16:24:10 -0400 (EDT) Received: by igbhn18 with SMTP id hn18so7268590igb.2 for ; Tue, 10 Mar 2015 13:24:10 -0700 (PDT) Received: from g1t5424.austin.hp.com (g1t5424.austin.hp.com. [15.216.225.54]) by mx.google.com with ESMTPS id ih18si3507074igb.55.2015.03.10.13.24.09 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 10 Mar 2015 13:24:09 -0700 (PDT) From: Toshi Kani Subject: [PATCH 1/3] mm, x86: Document return values of mapping funcs Date: Tue, 10 Mar 2015 14:23:15 -0600 Message-Id: <1426018997-12936-2-git-send-email-toshi.kani@hp.com> In-Reply-To: <1426018997-12936-1-git-send-email-toshi.kani@hp.com> References: <1426018997-12936-1-git-send-email-toshi.kani@hp.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, arnd@arndb.de Cc: linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org, dave.hansen@intel.com, Elliott@hp.com, pebolle@tiscali.nl, Toshi Kani Documented the return values of KVA mapping functions, pud_set_huge(), pmd_set_huge, pud_clear_huge() and pmd_clear_huge(). Simplified the conditions to select HAVE_ARCH_HUGE_VMAP in Kconfig since X86_PAE depends on X86_32. There is no functinal change in this patch. Signed-off-by: Toshi Kani --- arch/x86/Kconfig | 2 +- arch/x86/mm/pgtable.c | 36 ++++++++++++++++++++++++++++-------- 2 files changed, 29 insertions(+), 9 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 110f6ae..ba5e78e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -99,7 +99,7 @@ config X86 select IRQ_FORCED_THREADING select HAVE_BPF_JIT if X86_64 select HAVE_ARCH_TRANSPARENT_HUGEPAGE - select HAVE_ARCH_HUGE_VMAP if X86_64 || (X86_32 && X86_PAE) + select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE select ARCH_HAS_SG_CHAIN select CLKEVT_I8253 select ARCH_HAVE_NMI_SAFE_CMPXCHG diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 0b97d2c..a0f7eeb 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -563,14 +563,19 @@ void native_set_fixmap(enum fixed_addresses idx, phys_addr_t phys, } #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +/** + * pud_set_huge - setup kernel PUD mapping + * + * MTRRs can override PAT memory types with a 4KB granularity. Therefore, + * it does not set up a huge page when the range is covered by non-WB type + * of MTRRs. 0xFF indicates that MTRRs are disabled. + * + * Return 1 on success, and 0 on no-operation. + */ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) { u8 mtrr; - /* - * Do not use a huge page when the range is covered by non-WB type - * of MTRRs. - */ mtrr = mtrr_type_lookup(addr, addr + PUD_SIZE); if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF)) return 0; @@ -584,14 +589,19 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot) return 1; } +/** + * pmd_set_huge - setup kernel PMD mapping + * + * MTRRs can override PAT memory types with a 4KB granularity. Therefore, + * it does not set up a huge page when the range is covered by non-WB type + * of MTRRs. 0xFF indicates that MTRRs are disabled. + * + * Return 1 on success, and 0 on no-operation. + */ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) { u8 mtrr; - /* - * Do not use a huge page when the range is covered by non-WB type - * of MTRRs. - */ mtrr = mtrr_type_lookup(addr, addr + PMD_SIZE); if ((mtrr != MTRR_TYPE_WRBACK) && (mtrr != 0xFF)) return 0; @@ -605,6 +615,11 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot) return 1; } +/** + * pud_clear_huge - clear kernel PUD mapping when it is set + * + * Return 1 on success, and 0 on no-operation. + */ int pud_clear_huge(pud_t *pud) { if (pud_large(*pud)) { @@ -615,6 +630,11 @@ int pud_clear_huge(pud_t *pud) return 0; } +/** + * pmd_clear_huge - clear kernel PMD mapping when it is set + * + * Return 1 on success, and 0 on no-operation. + */ int pmd_clear_huge(pmd_t *pmd) { if (pmd_large(*pmd)) { -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org