Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754010AbaDOLG2 (ORCPT ); Tue, 15 Apr 2014 07:06:28 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:17670 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750972AbaDOLG0 (ORCPT ); Tue, 15 Apr 2014 07:06:26 -0400 Message-ID: <534D1243.20004@huawei.com> Date: Tue, 15 Apr 2014 19:04:35 +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: Russell King - ARM Linux , Will Deacon , , , , , , 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> <534A9031.5030006@huawei.com> <534BD488.3020606@huawei.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit 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 于 2014/4/14 21:50, Nicolas Pitre 写道: > On Mon, 14 Apr 2014, Liu hua wrote: > >> Yes, it seems that FIX_KMAP_BEGIN and FIX_KMAP_END are not as important for >> ARM than that for other architectures (MIPS PowerPC x86), whose FIX_KMAP_BEGIN >> is not 0. I will reminder this in my patch. Anyone who need them can get >> imformantion there. >> >> >> Now the new patchs are following. Maybe I sould resend the patch series >> with a new tag. If It is time to do that. Can I add this information >> "Reviewed-by: Nicolas Pitre " ? >> >> Thanks, >> Liu Hua. >> >> -----------------patch 1------------------------- >> >> Subject: [PATCH 1/2] ARM : fixmap : remove FIX_KMAP_BEGIN and FIX_KMAP_END >> >> It seems that these two variables are not used by non >> architecture specific code. And on ARM FIX_KMAP_BEGIN >> equals zero; FIX_KMAP_END is totally not used by the >> kernel. >> >> This patch removes these two variables. The code will >> become clear when I introduce a bugfix on fixmap mapping > > s/clear/clearer/ > >> region. >> >> Signed-off-by: Liu Hua >> --- >> arch/arm/include/asm/fixmap.h | 12 ++++++++---- >> arch/arm/mm/highmem.c | 6 +++--- >> 2 files changed, 11 insertions(+), 7 deletions(-) >> >> diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h >> index bbae919..8675bb9 100644 >> --- a/arch/arm/include/asm/fixmap.h >> +++ b/arch/arm/include/asm/fixmap.h >> @@ -17,9 +17,13 @@ >> #define FIXADDR_TOP 0xfffe0000UL >> #define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START) >> >> -#define FIX_KMAP_BEGIN 0 >> -#define FIX_KMAP_END (FIXADDR_SIZE >> PAGE_SHIFT) >> - >> +/* Notice : FIX_KMAP_END and FIX_KMAP_BEGIN are removed. >> + * >> + * Instead, using FIX_KMAP_NR_PTES to tell the pte number >> + * belonged to fixmap mapping region. >> + * >> + */ > > Please move this comment to the commit log instead. This is not > important enough to occupy that much space in the code. > >> +#define FIX_KMAP_NR_PTES (FIXADDR_SIZE >> PAGE_SHIFT) >> #define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT)) >> #define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT) >> >> @@ -27,7 +31,7 @@ extern void __this_fixmap_does_not_exist(void); >> >> static inline unsigned long fix_to_virt(const unsigned int idx) >> { >> - if (idx >= FIX_KMAP_END) >> + if (idx >= FIX_KMAP_NR_PTES) >> __this_fixmap_does_not_exist(); >> return __fix_to_virt(idx); >> } >> diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c >> index 21b9e1b..e05e8ad 100644 >> --- a/arch/arm/mm/highmem.c >> +++ b/arch/arm/mm/highmem.c >> @@ -63,7 +63,7 @@ void *kmap_atomic(struct page *page) >> type = kmap_atomic_idx_push(); >> >> idx = type + KM_TYPE_NR * smp_processor_id(); >> - vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); >> + vaddr = __fix_to_virt(idx); >> #ifdef CONFIG_DEBUG_HIGHMEM >> /* >> * With debugging enabled, kunmap_atomic forces that entry to 0. >> @@ -94,7 +94,7 @@ void __kunmap_atomic(void *kvaddr) >> if (cache_is_vivt()) >> __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); >> #ifdef CONFIG_DEBUG_HIGHMEM >> - BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); >> + BUG_ON(vaddr != __fix_to_virt(idx)); >> set_top_pte(vaddr, __pte(0)); >> #else >> (void) idx; /* to kill a warning */ >> @@ -117,7 +117,7 @@ void *kmap_atomic_pfn(unsigned long pfn) >> >> type = kmap_atomic_idx_push(); >> idx = type + KM_TYPE_NR * smp_processor_id(); >> - vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); >> + vaddr = __fix_to_virt(idx); >> #ifdef CONFIG_DEBUG_HIGHMEM >> BUG_ON(!pte_none(get_top_pte(vaddr))); >> #endif >> -- >> 1.9.0 > > With the above details fixed you may add: > > Reviewed-by: Nicolas Pitre > >> -----------------patch 2------------------------- >> >> >> >> Subject: [PATCH 2/2] ARM : change fixmap mapping region to support 32 CPUs >> >> 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 >> --- >> Documentation/arm/memory.txt | 2 +- >> arch/arm/include/asm/fixmap.h | 16 ++-------------- >> arch/arm/include/asm/highmem.h | 1 + >> arch/arm/mm/highmem.c | 27 +++++++++++++++++++++------ >> arch/arm/mm/mmu.c | 4 ++++ >> 5 files changed, 29 insertions(+), 21 deletions(-) >> >> diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt >> index d74e8a5..256c5e0 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 >> +fffc0000 ffdfffff Fixmap mapping region. Addresses provided >> by fix_to_virt() will be located here. >> >> fee00000 feffffff Mapping of PCI I/O space. This is a static >> diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h >> index 8675bb9..fb8a5a7 100644 >> --- a/arch/arm/include/asm/fixmap.h >> +++ b/arch/arm/include/asm/fixmap.h >> @@ -1,20 +1,8 @@ >> #ifndef _ASM_FIXMAP_H >> #define _ASM_FIXMAP_H >> >> -/* >> - * Nothing too fancy for now. >> - * >> - * On ARM we already have well known fixed virtual addresses imposed by >> - * the architecture such as the vector page which is located at 0xffff0000, >> - * therefore a second level page table is already allocated covering >> - * 0xfff00000 upwards. >> - * >> - * The cache flushing code in proc-xscale.S uses the virtual area between >> - * 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) >> >> /* Notice : FIX_KMAP_END and FIX_KMAP_BEGIN are removed. >> 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 e05e8ad..45aeaac 100644 >> --- a/arch/arm/mm/highmem.c >> +++ b/arch/arm/mm/highmem.c >> @@ -18,6 +18,21 @@ >> #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(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); >> + return *(fixmap_page_table + idx); >> +} >> + >> void *kmap(struct page *page) >> { >> might_sleep(); >> @@ -69,14 +84,14 @@ 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 +110,7 @@ void __kunmap_atomic(void *kvaddr) >> __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); >> #ifdef CONFIG_DEBUG_HIGHMEM >> BUG_ON(vaddr != __fix_to_virt(idx)); >> - set_top_pte(vaddr, __pte(0)); >> + set_fixmap_pte(idx, __pte(0)); >> #else >> (void) idx; /* to kill a warning */ >> #endif >> @@ -119,9 +134,9 @@ void *kmap_atomic_pfn(unsigned long pfn) >> idx = type + KM_TYPE_NR * smp_processor_id(); >> vaddr = __fix_to_virt(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 +148,5 @@ 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 > > Reviewed-by: Nicolas Pitre > >> >> Ok, I will send the patch series with tag "v3". If there is no bothersome details. you can add "Reviewed-by:" at than time! Thanks, Liu Hua -- 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/