Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946192AbWJSQfe (ORCPT ); Thu, 19 Oct 2006 12:35:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946194AbWJSQfe (ORCPT ); Thu, 19 Oct 2006 12:35:34 -0400 Received: from ftp.linux-mips.org ([194.74.144.162]:14048 "EHLO ftp.linux-mips.org") by vger.kernel.org with ESMTP id S1946192AbWJSQfc (ORCPT ); Thu, 19 Oct 2006 12:35:32 -0400 From: Ralf Baechle To: Linus Torvalds , Andrew Morton Cc: linux-kernel@vger.kernel.org, Atsushi Nemoto , Ralf Baechle Subject: [PATCH 3/3] MIPS: Fix COW D-cache aliasing on fork Date: Thu, 19 Oct 2006 17:35:48 +0100 Message-Id: <1161275750378-git-send-email-ralf@linux-mips.org> X-Mailer: git-send-email 1.4.2.4 In-Reply-To: <1161275748231-git-send-email-ralf@linux-mips.org> References: <1161275748231-git-send-email-ralf@linux-mips.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13985 Lines: 465 From: Atsushi Nemoto Provide a custom copy_user_highpage() to deal with aliasing issues on MIPS. It uses kmap_coherent() to map an user page for kernel with same color. Rewrite copy_to_user_page() and copy_from_user_page() with the new interfaces to avoid extra cache flushing. The main part of this patch was originally written by Ralf Baechle; Atushi Nemoto did the the debugging. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle arch/mips/mm/init.c | 213 ++++++++++++++++++++++++++++++++++++++++-- arch/mips/mm/pgtable-32.c | 7 - arch/mips/mm/pgtable-64.c | 11 ++ include/asm-mips/cacheflush.h | 19 --- include/asm-mips/fixmap.h | 14 ++ include/asm-mips/page.h | 17 +-- 6 files changed, 242 insertions(+), 39 deletions(-) Index: upstream-linus/arch/mips/mm/init.c =================================================================== --- upstream-linus.orig/arch/mips/mm/init.c 2006-10-12 18:51:03.000000000 +0100 +++ upstream-linus/arch/mips/mm/init.c 2006-10-12 18:51:18.000000000 +0100 @@ -30,11 +30,39 @@ #include #include #include +#include #include #include #include #include #include +#include + +/* CP0 hazard avoidance. */ +#define BARRIER __asm__ __volatile__(".set noreorder\n\t" \ + "nop; nop; nop; nop; nop; nop;\n\t" \ + ".set reorder\n\t") + +/* Atomicity and interruptability */ +#ifdef CONFIG_MIPS_MT_SMTC + +#include + +#define ENTER_CRITICAL(flags) \ + { \ + unsigned int mvpflags; \ + local_irq_save(flags);\ + mvpflags = dvpe() +#define EXIT_CRITICAL(flags) \ + evpe(mvpflags); \ + local_irq_restore(flags); \ + } +#else + +#define ENTER_CRITICAL(flags) local_irq_save(flags) +#define EXIT_CRITICAL(flags) local_irq_restore(flags) + +#endif /* CONFIG_MIPS_MT_SMTC */ DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); @@ -80,13 +108,183 @@ unsigned long setup_zero_pages(void) return 1UL << order; } -#ifdef CONFIG_HIGHMEM -pte_t *kmap_pte; -pgprot_t kmap_prot; +/* + * These are almost like kmap_atomic / kunmap_atmic except they take an + * additional address argument as the hint. + */ #define kmap_get_fixmap_pte(vaddr) \ pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr)) +#ifdef CONFIG_MIPS_MT_SMTC +static pte_t *kmap_coherent_pte; +static void __init kmap_coherent_init(void) +{ + unsigned long vaddr; + + /* cache the first coherent kmap pte */ + vaddr = __fix_to_virt(FIX_CMAP_BEGIN); + kmap_coherent_pte = kmap_get_fixmap_pte(vaddr); +} +#else +static inline void kmap_coherent_init(void) {} +#endif + +static inline void *kmap_coherent(struct page *page, unsigned long addr) +{ + enum fixed_addresses idx; + unsigned long vaddr, flags, entrylo; + unsigned long old_ctx; + pte_t pte; + unsigned int tlbidx; + + inc_preempt_count(); + idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1); +#ifdef CONFIG_MIPS_MT_SMTC + idx += FIX_N_COLOURS * smp_processor_id(); +#endif + vaddr = __fix_to_virt(FIX_CMAP_END - idx); + pte = mk_pte(page, PAGE_KERNEL); +#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32_R1) + entrylo = pte.pte_high; +#else + entrylo = pte_val(pte) >> 6; +#endif + + ENTER_CRITICAL(flags); + old_ctx = read_c0_entryhi(); + write_c0_entryhi(vaddr & (PAGE_MASK << 1)); + write_c0_entrylo0(entrylo); + write_c0_entrylo1(entrylo); +#ifdef CONFIG_MIPS_MT_SMTC + set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte); + /* preload TLB instead of local_flush_tlb_one() */ + mtc0_tlbw_hazard(); + tlb_probe(); + BARRIER; + tlbidx = read_c0_index(); + mtc0_tlbw_hazard(); + if (tlbidx < 0) + tlb_write_random(); + else + tlb_write_indexed(); +#else + tlbidx = read_c0_wired(); + write_c0_wired(tlbidx + 1); + write_c0_index(tlbidx); + mtc0_tlbw_hazard(); + tlb_write_indexed(); +#endif + tlbw_use_hazard(); + write_c0_entryhi(old_ctx); + EXIT_CRITICAL(flags); + + return (void*) vaddr; +} + +#define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1))) + +static inline void kunmap_coherent(struct page *page) +{ +#ifndef CONFIG_MIPS_MT_SMTC + unsigned int wired; + unsigned long flags, old_ctx; + + ENTER_CRITICAL(flags); + old_ctx = read_c0_entryhi(); + wired = read_c0_wired() - 1; + write_c0_wired(wired); + write_c0_index(wired); + write_c0_entryhi(UNIQUE_ENTRYHI(wired)); + write_c0_entrylo0(0); + write_c0_entrylo1(0); + mtc0_tlbw_hazard(); + tlb_write_indexed(); + write_c0_entryhi(old_ctx); + EXIT_CRITICAL(flags); +#endif + dec_preempt_count(); + preempt_check_resched(); +} + +void copy_user_highpage(struct page *to, struct page *from, + unsigned long vaddr, struct vm_area_struct *vma) +{ + void *vfrom, *vto; + + vto = kmap_atomic(to, KM_USER1); + if (cpu_has_dc_aliases) { + vfrom = kmap_coherent(from, vaddr); + copy_page(vto, vfrom); + kunmap_coherent(from); + } else { + vfrom = kmap_atomic(from, KM_USER0); + copy_page(vto, vfrom); + kunmap_atomic(vfrom, KM_USER0); + } + if (((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc) || + pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK)) + flush_data_cache_page((unsigned long)vto); + kunmap_atomic(vto, KM_USER1); + /* Make sure this page is cleared on other CPU's too before using it */ + smp_wmb(); +} + +EXPORT_SYMBOL(copy_user_highpage); + +void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, + struct page *to) +{ + if (cpu_has_dc_aliases) { + struct page *from = virt_to_page(vfrom); + vfrom = kmap_coherent(from, vaddr); + copy_page(vto, vfrom); + kunmap_coherent(from); + } else + copy_page(vto, vfrom); + if (!cpu_has_ic_fills_f_dc || + pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK)) + flush_data_cache_page((unsigned long)vto); +} + +EXPORT_SYMBOL(copy_user_page); + +void copy_to_user_page(struct vm_area_struct *vma, + struct page *page, unsigned long vaddr, void *dst, const void *src, + unsigned long len) +{ + if (cpu_has_dc_aliases) { + void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK); + memcpy(vto, src, len); + kunmap_coherent(page); + } else + memcpy(dst, src, len); + if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc) + flush_cache_page(vma, vaddr, page_to_pfn(page)); +} + +EXPORT_SYMBOL(copy_to_user_page); + +void copy_from_user_page(struct vm_area_struct *vma, + struct page *page, unsigned long vaddr, void *dst, const void *src, + unsigned long len) +{ + if (cpu_has_dc_aliases) { + void *vfrom = + kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK); + memcpy(dst, vfrom, len); + kunmap_coherent(page); + } else + memcpy(dst, src, len); +} + +EXPORT_SYMBOL(copy_from_user_page); + + +#ifdef CONFIG_HIGHMEM +pte_t *kmap_pte; +pgprot_t kmap_prot; + static void __init kmap_init(void) { unsigned long kmap_vstart; @@ -97,11 +295,12 @@ static void __init kmap_init(void) kmap_prot = PAGE_KERNEL; } +#endif /* CONFIG_HIGHMEM */ -#ifdef CONFIG_32BIT void __init fixrange_init(unsigned long start, unsigned long end, pgd_t *pgd_base) { +#if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC) pgd_t *pgd; pud_t *pud; pmd_t *pmd; @@ -122,7 +321,7 @@ void __init fixrange_init(unsigned long for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) { if (pmd_none(*pmd)) { pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); - set_pmd(pmd, __pmd(pte)); + set_pmd(pmd, __pmd((unsigned long)pte)); if (pte != pte_offset_kernel(pmd, 0)) BUG(); } @@ -132,9 +331,8 @@ void __init fixrange_init(unsigned long } j = 0; } +#endif } -#endif /* CONFIG_32BIT */ -#endif /* CONFIG_HIGHMEM */ #ifndef CONFIG_NEED_MULTIPLE_NODES extern void pagetable_init(void); @@ -175,6 +373,7 @@ void __init paging_init(void) #ifdef CONFIG_HIGHMEM kmap_init(); #endif + kmap_coherent_init(); max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; low = max_low_pfn; Index: upstream-linus/arch/mips/mm/pgtable-32.c =================================================================== --- upstream-linus.orig/arch/mips/mm/pgtable-32.c 2006-10-12 18:51:03.000000000 +0100 +++ upstream-linus/arch/mips/mm/pgtable-32.c 2006-10-12 18:51:18.000000000 +0100 @@ -31,9 +31,10 @@ void pgd_init(unsigned long page) void __init pagetable_init(void) { -#ifdef CONFIG_HIGHMEM unsigned long vaddr; - pgd_t *pgd, *pgd_base; + pgd_t *pgd_base; +#ifdef CONFIG_HIGHMEM + pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte; @@ -44,7 +45,6 @@ void __init pagetable_init(void) pgd_init((unsigned long)swapper_pg_dir + sizeof(pgd_t) * USER_PTRS_PER_PGD); -#ifdef CONFIG_HIGHMEM pgd_base = swapper_pg_dir; /* @@ -53,6 +53,7 @@ void __init pagetable_init(void) vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; fixrange_init(vaddr, 0, pgd_base); +#ifdef CONFIG_HIGHMEM /* * Permanent kmaps: */ Index: upstream-linus/arch/mips/mm/pgtable-64.c =================================================================== --- upstream-linus.orig/arch/mips/mm/pgtable-64.c 2006-10-12 18:51:03.000000000 +0100 +++ upstream-linus/arch/mips/mm/pgtable-64.c 2006-10-12 18:51:18.000000000 +0100 @@ -8,6 +8,7 @@ */ #include #include +#include #include void pgd_init(unsigned long page) @@ -52,7 +53,17 @@ void pmd_init(unsigned long addr, unsign void __init pagetable_init(void) { + unsigned long vaddr; + pgd_t *pgd_base; + /* Initialize the entire pgd. */ pgd_init((unsigned long)swapper_pg_dir); pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table); + + pgd_base = swapper_pg_dir; + /* + * Fixed mappings: + */ + vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; + fixrange_init(vaddr, 0, pgd_base); } Index: upstream-linus/include/asm-mips/cacheflush.h =================================================================== --- upstream-linus.orig/include/asm-mips/cacheflush.h 2006-10-12 18:51:03.000000000 +0100 +++ upstream-linus/include/asm-mips/cacheflush.h 2006-10-12 18:51:18.000000000 +0100 @@ -55,24 +55,13 @@ extern void (*flush_icache_range)(unsign #define flush_cache_vmap(start, end) flush_cache_all() #define flush_cache_vunmap(start, end) flush_cache_all() -static inline void copy_to_user_page(struct vm_area_struct *vma, +extern void copy_to_user_page(struct vm_area_struct *vma, struct page *page, unsigned long vaddr, void *dst, const void *src, - unsigned long len) -{ - if (cpu_has_dc_aliases) - flush_cache_page(vma, vaddr, page_to_pfn(page)); - memcpy(dst, src, len); - __flush_icache_page(vma, page); -} + unsigned long len); -static inline void copy_from_user_page(struct vm_area_struct *vma, +extern void copy_from_user_page(struct vm_area_struct *vma, struct page *page, unsigned long vaddr, void *dst, const void *src, - unsigned long len) -{ - if (cpu_has_dc_aliases) - flush_cache_page(vma, vaddr, page_to_pfn(page)); - memcpy(dst, src, len); -} + unsigned long len); extern void (*flush_cache_sigtramp)(unsigned long addr); extern void (*flush_icache_all)(void); Index: upstream-linus/include/asm-mips/fixmap.h =================================================================== --- upstream-linus.orig/include/asm-mips/fixmap.h 2006-10-12 18:51:03.000000000 +0100 +++ upstream-linus/include/asm-mips/fixmap.h 2006-10-12 18:51:18.000000000 +0100 @@ -45,8 +45,16 @@ * fix-mapped? */ enum fixed_addresses { +#define FIX_N_COLOURS 8 + FIX_CMAP_BEGIN, +#ifdef CONFIG_MIPS_MT_SMTC + FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS), +#else + FIX_CMAP_END = FIX_CMAP_BEGIN + FIX_N_COLOURS, +#endif #ifdef CONFIG_HIGHMEM - FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ + /* reserved pte's for temporary kernel mappings */ + FIX_KMAP_BEGIN = FIX_CMAP_END + 1, FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, #endif __end_of_fixed_addresses @@ -70,9 +78,9 @@ extern void __set_fixmap (enum fixed_add * at the top of mem.. */ #if defined(CONFIG_CPU_TX39XX) || defined(CONFIG_CPU_TX49XX) -#define FIXADDR_TOP (0xff000000UL - 0x2000) +#define FIXADDR_TOP ((unsigned long)(long)(int)(0xff000000 - 0x20000)) #else -#define FIXADDR_TOP (0xffffe000UL) +#define FIXADDR_TOP ((unsigned long)(long)(int)0xfffe0000) #endif #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) Index: upstream-linus/include/asm-mips/page.h =================================================================== --- upstream-linus.orig/include/asm-mips/page.h 2006-10-12 18:51:03.000000000 +0100 +++ upstream-linus/include/asm-mips/page.h 2006-10-12 18:51:18.000000000 +0100 @@ -34,8 +34,6 @@ #ifndef __ASSEMBLY__ -#include - extern void clear_page(void * page); extern void copy_page(void * to, void * from); @@ -59,16 +57,13 @@ static inline void clear_user_page(void flush_data_cache_page((unsigned long)addr); } -static inline void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, - struct page *to) -{ - extern void (*flush_data_cache_page)(unsigned long addr); +extern void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, + struct page *to); +struct vm_area_struct; +extern void copy_user_highpage(struct page *to, struct page *from, + unsigned long vaddr, struct vm_area_struct *vma); - copy_page(vto, vfrom); - if (!cpu_has_ic_fills_f_dc || - pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK)) - flush_data_cache_page((unsigned long)vto); -} +#define __HAVE_ARCH_COPY_USER_HIGHPAGE /* * These are used to make use of C type-checking.. - 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/