Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754723AbaDMN1c (ORCPT ); Sun, 13 Apr 2014 09:27:32 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:30328 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754381AbaDMN1a (ORCPT ); Sun, 13 Apr 2014 09:27:30 -0400 Message-ID: <534A9031.5030006@huawei.com> Date: Sun, 13 Apr 2014 21:25:05 +0800 From: Liu hua User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Nicolas Pitre CC: , , , , , , , Subject: Re: [PATCH v2 2/2] ARM : change fixmap mapping region to support 32 CPUs References: <1397203252-22977-1-git-send-email-sdu.liu@huawei.com> <1397203252-22977-3-git-send-email-sdu.liu@huawei.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.58.238] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014/4/12 11:26, Nicolas Pitre wrote: > On Fri, 11 Apr 2014, Liu Hua wrote: > >> In 32-bit ARM systems, the fixmap mapping region can support >> no more than 14 CPUs(total: 896k; one CPU: 64K). And we can >> configure NR_CPUS up to 32. So there is a mismatch. >> >> This patch moves fixmapping region downwards to region >> 0xffc00000-0xffe00000 . Then the fixmap mapping region can >> support up to 32 CPUs. >> >> Signed-off-by: Liu Hua > > Comments below. > >> --- >> Documentation/arm/memory.txt | 2 +- >> arch/arm/include/asm/fixmap.h | 4 ++-- >> arch/arm/include/asm/highmem.h | 1 + >> arch/arm/mm/highmem.c | 10 +++++----- >> arch/arm/mm/mm.h | 7 +++++++ >> arch/arm/mm/mmu.c | 4 ++++ >> mm/highmem.c | 1 + >> 7 files changed, 21 insertions(+), 8 deletions(-) >> >> diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt >> index 8a361c0..4bca737 100644 >> --- a/Documentation/arm/memory.txt >> +++ b/Documentation/arm/memory.txt >> @@ -41,7 +41,7 @@ fffe8000 fffeffff DTCM mapping area for platforms with >> fffe0000 fffe7fff ITCM mapping area for platforms with >> ITCM mounted inside the CPU. >> >> -fff00000 fffdffff Fixmap mapping region. Addresses provided >> +ffc00000 ffdfffff Fixmap mapping region. Addresses provided >> by fix_to_virt() will be located here. >> >> ff000000 ffbfffff Reserved for future expansion of DMA >> diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h >> index bbae919..014a70d 100644 >> --- a/arch/arm/include/asm/fixmap.h >> +++ b/arch/arm/include/asm/fixmap.h >> @@ -13,8 +13,8 @@ >> * 0xfffe0000 and 0xfffeffff. >> */ >> >> -#define FIXADDR_START 0xfff00000UL >> -#define FIXADDR_TOP 0xfffe0000UL >> +#define FIXADDR_START 0xffc00000UL >> +#define FIXADDR_TOP 0xffe00000UL >> #define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START) >> >> #define FIX_KMAP_BEGIN 0 >> diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h >> index 91b99ab..5355795 100644 >> --- a/arch/arm/include/asm/highmem.h >> +++ b/arch/arm/include/asm/highmem.h >> @@ -18,6 +18,7 @@ >> } while (0) >> >> extern pte_t *pkmap_page_table; >> +extern pte_t *fixmap_page_table; >> >> extern void *kmap_high(struct page *page); >> extern void kunmap_high(struct page *page); >> diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c >> index 21b9e1b..9bc8988 100644 >> --- a/arch/arm/mm/highmem.c >> +++ b/arch/arm/mm/highmem.c >> @@ -69,14 +69,14 @@ void *kmap_atomic(struct page *page) >> * With debugging enabled, kunmap_atomic forces that entry to 0. >> * Make sure it was indeed properly unmapped. >> */ >> - BUG_ON(!pte_none(get_top_pte(vaddr))); >> + BUG_ON(!pte_none(*(fixmap_page_table + idx))); >> #endif >> /* >> * When debugging is off, kunmap_atomic leaves the previous mapping >> * in place, so the contained TLB flush ensures the TLB is updated >> * with the new mapping. >> */ >> - set_top_pte(vaddr, mk_pte(page, kmap_prot)); >> + set_fixmap_pte(idx, mk_pte(page, kmap_prot)); >> >> return (void *)vaddr; >> } >> @@ -95,7 +95,7 @@ void __kunmap_atomic(void *kvaddr) >> __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); >> #ifdef CONFIG_DEBUG_HIGHMEM >> BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); >> - set_top_pte(vaddr, __pte(0)); >> + set_fixmap_pte(idx, __pte(0)); >> #else >> (void) idx; /* to kill a warning */ >> #endif >> @@ -119,9 +119,9 @@ void *kmap_atomic_pfn(unsigned long pfn) >> idx = type + KM_TYPE_NR * smp_processor_id(); >> vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); >> #ifdef CONFIG_DEBUG_HIGHMEM >> - BUG_ON(!pte_none(get_top_pte(vaddr))); >> + BUG_ON(!pte_none(*(fixmap_page_table + idx))); >> #endif >> - set_top_pte(vaddr, pfn_pte(pfn, kmap_prot)); >> + set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot)); >> >> return (void *)vaddr; >> } >> diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h >> index 7ea641b..3460d73 100644 >> --- a/arch/arm/mm/mm.h >> +++ b/arch/arm/mm/mm.h >> @@ -1,6 +1,7 @@ >> #ifdef CONFIG_MMU >> #include >> #include >> +#include >> >> /* the upper-most page table pointer */ >> extern pmd_t *top_pmd; >> @@ -25,6 +26,12 @@ static inline void set_top_pte(unsigned long va, pte_t pte) >> local_flush_tlb_kernel_page(va); >> } >> >> +static inline void set_fixmap_pte(int idx, pte_t pte) >> +{ >> + unsigned long vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); >> + set_pte_ext(fixmap_page_table + idx, pte, 0); >> + local_flush_tlb_kernel_page(vaddr); >> +} > > This has no other users than the code in highmem.c so it probably should > live there. > > Other than that... > > Acked-by: Nicolas Pitre > > . > Hi Nicolas. Sure, your suggestion made my patch looks better. How about that : Thanks, Liu Hua ------------------------------------------------- Changes from v2: moved new codes to highmem.c as more as possible. unchanged Document/arm/memory.txt. In 32-bit ARM systems, the fixmap mapping region can support no more than 14 CPUs(total: 896k; one CPU: 64K). And we can configure NR_CPUS up to 32. So there is a mismatch. This patch moves fixmapping region downwards to region 0xffc00000-0xffe00000 . Then the fixmap mapping region can support up to 32 CPUs Acked-by: Nicolas Pitre Signed-off-by: Liu Hua --- arch/arm/include/asm/fixmap.h | 4 ++-- arch/arm/include/asm/highmem.h | 1 + arch/arm/mm/highmem.c | 28 ++++++++++++++++++++++------ arch/arm/mm/mmu.c | 4 ++++ 4 files changed, 29 insertions(+), 8 deletions(-) diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index bbae919..014a70d 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -13,8 +13,8 @@ * 0xfffe0000 and 0xfffeffff. */ -#define FIXADDR_START 0xfff00000UL -#define FIXADDR_TOP 0xfffe0000UL +#define FIXADDR_START 0xffc00000UL +#define FIXADDR_TOP 0xffe00000UL #define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START) #define FIX_KMAP_BEGIN 0 diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h index 91b99ab..5355795 100644 --- a/arch/arm/include/asm/highmem.h +++ b/arch/arm/include/asm/highmem.h @@ -18,6 +18,7 @@ } while (0) extern pte_t *pkmap_page_table; +extern pte_t *fixmap_page_table; extern void *kmap_high(struct page *page); extern void kunmap_high(struct page *page); diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c index 21b9e1b..fa97896 100644 --- a/arch/arm/mm/highmem.c +++ b/arch/arm/mm/highmem.c @@ -18,6 +18,22 @@ #include #include "mm.h" +pte_t *fixmap_page_table; + +static inline void set_fixmap_pte(int idx, pte_t pte) +{ + unsigned long vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + set_pte_ext(fixmap_page_table + idx, pte, 0); + local_flush_tlb_kernel_page(vaddr); +} + +static inline pte_t get_fixmap_pte(unsigned long vaddr) +{ + unsigned long idx = __virt_to_fix(vaddr); + idx -= FIX_KMAP_BEGIN; + return *(fixmap_page_table + idx); +} + void *kmap(struct page *page) { might_sleep(); @@ -69,14 +85,14 @@ void *kmap_atomic(struct page *page) * With debugging enabled, kunmap_atomic forces that entry to 0. * Make sure it was indeed properly unmapped. */ - BUG_ON(!pte_none(get_top_pte(vaddr))); + BUG_ON(!pte_none(*(fixmap_page_table + idx))); #endif /* * When debugging is off, kunmap_atomic leaves the previous mapping * in place, so the contained TLB flush ensures the TLB is updated * with the new mapping. */ - set_top_pte(vaddr, mk_pte(page, kmap_prot)); + set_fixmap_pte(idx, mk_pte(page, kmap_prot)); return (void *)vaddr; } @@ -95,7 +111,7 @@ void __kunmap_atomic(void *kvaddr) __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); #ifdef CONFIG_DEBUG_HIGHMEM BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); - set_top_pte(vaddr, __pte(0)); + set_fixmap_pte(idx, __pte(0)); #else (void) idx; /* to kill a warning */ #endif @@ -119,9 +135,9 @@ void *kmap_atomic_pfn(unsigned long pfn) idx = type + KM_TYPE_NR * smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); #ifdef CONFIG_DEBUG_HIGHMEM - BUG_ON(!pte_none(get_top_pte(vaddr))); + BUG_ON(!pte_none(*(fixmap_page_table + idx))); #endif - set_top_pte(vaddr, pfn_pte(pfn, kmap_prot)); + set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot)); return (void *)vaddr; } @@ -133,5 +149,5 @@ struct page *kmap_atomic_to_page(const void *ptr) if (vaddr < FIXADDR_START) return virt_to_page(ptr); - return pte_page(get_top_pte(vaddr)); + return pte_page(get_fixmap_pte(vaddr)); } diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index b68c6b2..09c0a16 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -35,6 +35,7 @@ #include #include #include +#include #include "mm.h" #include "tcm.h" @@ -1359,6 +1360,9 @@ static void __init kmap_init(void) #ifdef CONFIG_HIGHMEM pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE), PKMAP_BASE, _PAGE_KERNEL_TABLE); + + fixmap_page_table = early_pte_alloc(pmd_off_k(FIXADDR_START), + FIXADDR_START, _PAGE_KERNEL_TABLE); #endif } -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/