From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753528AbbCXWdZ (ORCPT ); Tue, 24 Mar 2015 18:33:25 -0400 Received: from g9t5008.houston.hp.com ([15.240.92.66]:41088 "EHLO g9t5008.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752214AbbCXW1q (ORCPT ); Tue, 24 Mar 2015 18:27:46 -0400 From: Toshi Kani To: akpm@linux-foundation.org, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com 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 Subject: [PATCH v4 1/7] mm, x86: Document return values of mapping funcs Date: Tue, 24 Mar 2015 16:08:35 -0600 Message-Id: <1427234921-19737-2-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1427234921-19737-1-git-send-email-toshi.kani@hp.com> References: <1427234921-19737-1-git-send-email-toshi.kani@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Document the return values of KVA mapping functions, pud_set_huge(), pmd_set_huge, pud_clear_huge() and pmd_clear_huge(). Simplify the conditions to select HAVE_ARCH_HUGE_VMAP in the Kconfig, since X86_PAE depends on X86_32. There is no functional 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 cb23206..2ea27da 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..4891fa1 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 + * + * MTRR can override PAT memory types with 4KB granularity. Therefore, + * it does not set up a huge page when the range is covered by a non-WB + * type of MTRR. 0xFF indicates that MTRR are disabled. + * + * Return 1 on success, and 0 when no PUD was set. + */ 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 + * + * MTRR can override PAT memory types with 4KB granularity. Therefore, + * it does not set up a huge page when the range is covered by a non-WB + * type of MTRR. 0xFF indicates that MTRR are disabled. + * + * Return 1 on success, and 0 when no PMD was set. + */ 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 when no PUD map was found. + */ 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 when no PMD map was found. + */ int pmd_clear_huge(pmd_t *pmd) { if (pmd_large(*pmd)) {