From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f178.google.com (mail-ob0-f178.google.com [209.85.214.178]) by kanga.kvack.org (Postfix) with ESMTP id 332166B0072 for ; Tue, 3 Mar 2015 12:45:15 -0500 (EST) Received: by obcuz6 with SMTP id uz6so1304786obc.12 for ; Tue, 03 Mar 2015 09:45:15 -0800 (PST) Received: from g2t2353.austin.hp.com (g2t2353.austin.hp.com. [15.217.128.52]) by mx.google.com with ESMTPS id ix8si736618obc.59.2015.03.03.09.45.14 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 03 Mar 2015 09:45:14 -0800 (PST) From: Toshi Kani Subject: [PATCH v3 5/6] x86, mm: Support huge I/O mapping capability I/F Date: Tue, 3 Mar 2015 10:44:23 -0700 Message-Id: <1425404664-19675-6-git-send-email-toshi.kani@hp.com> In-Reply-To: <1425404664-19675-1-git-send-email-toshi.kani@hp.com> References: <1425404664-19675-1-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, Toshi Kani This patch implements huge I/O mapping capability interfaces for ioremap() on x86. IOREMAP_MAX_ORDER is defined to PUD_SHIFT on x86/64 and PMD_SHIFT on x86/32, which overrides the default value defined in . Signed-off-by: Toshi Kani --- arch/x86/include/asm/page_types.h | 2 ++ arch/x86/mm/ioremap.c | 23 +++++++++++++++++++++-- 2 files changed, 23 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h index 95e11f7..b526093 100644 --- a/arch/x86/include/asm/page_types.h +++ b/arch/x86/include/asm/page_types.h @@ -40,8 +40,10 @@ #ifdef CONFIG_X86_64 #include +#define IOREMAP_MAX_ORDER (PUD_SHIFT) #else #include +#define IOREMAP_MAX_ORDER (PMD_SHIFT) #endif /* CONFIG_X86_64 */ #ifndef __ASSEMBLY__ diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index fdf617c..5ead4d6 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -67,8 +67,13 @@ static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, /* * Remap an arbitrary physical address space into the kernel virtual - * address space. Needed when the kernel wants to access high addresses - * directly. + * address space. It transparently creates kernel huge I/O mapping when + * the physical address is aligned by a huge page size (1GB or 2MB) and + * the requested size is at least the huge page size. + * + * NOTE: MTRRs can override PAT memory types with a 4KB granularity. + * Therefore, the mapping code falls back to use a smaller page toward 4KB + * when a mapping range is covered by non-WB type of MTRRs. * * NOTE! We need to allow non-page-aligned mappings too: we will obviously * have to convert them into an offset in a page-aligned mapping, but the @@ -326,6 +331,20 @@ void iounmap(volatile void __iomem *addr) } EXPORT_SYMBOL(iounmap); +int arch_ioremap_pud_supported(void) +{ +#ifdef CONFIG_X86_64 + return cpu_has_gbpages; +#else + return 0; +#endif +} + +int arch_ioremap_pmd_supported(void) +{ + return cpu_has_pse; +} + /* * Convert a physical pointer to a virtual kernel pointer for /dev/mem * access -- 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