From f76348a360fe92063e07a8f54b0c1ea67f91e76c Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 24 Dec 2009 12:57:01 +0000 Subject: ARM: remove unnecessary cache flush This cache flush occurs when we first insert a page into the page tables, where a page did not exist previously. There can be no cache lines associated with this virtual mapping, so this cache flush is redundant. Tested-by: Mike Rapoport Tested-by: Mikael Pettersson Signed-off-by: Russell King --- arch/arm/mm/fault-armv.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index c9b97e9..82df01a 100644 --- a/arch/arm/mm/fault-armv.c +++ b/arch/arm/mm/fault-armv.c @@ -133,8 +133,6 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, flush_dcache_mmap_unlock(mapping); if (aliases) do_adjust_pte(vma, addr, pfn, ptep); - else - flush_cache_page(vma, addr, pfn); } /* -- cgit v1.1 From 8e797a7e4f588fb3b9cfe9860b00dcd3b14f8b60 Mon Sep 17 00:00:00 2001 From: Srinidhi Kasagar Date: Sat, 3 Apr 2010 19:10:45 +0100 Subject: ARM: 6027/1: ux500: enable l2x0 support This enables the l2x0 support and ensures that the secondary CPU can see the page table and secondary data at this point. Signed-off-by: srinidhi kasagar Acked-by: Linus Walleij Signed-off-by: Russell King --- arch/arm/mm/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index c4ed9f9..22c1c83 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -754,7 +754,8 @@ config CACHE_FEROCEON_L2_WRITETHROUGH config CACHE_L2X0 bool "Enable the L2x0 outer cache controller" depends on REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || MACH_REALVIEW_PB1176 || \ - REALVIEW_EB_A9MP || ARCH_MX35 || ARCH_MX31 || MACH_REALVIEW_PBX || ARCH_NOMADIK || ARCH_OMAP4 + REALVIEW_EB_A9MP || ARCH_MX35 || ARCH_MX31 || MACH_REALVIEW_PBX || \ + ARCH_NOMADIK || ARCH_OMAP4 || ARCH_U8500 default y select OUTER_CACHE help -- cgit v1.1 From a3be6327163c223c1715c8307a616941fbf8bf73 Mon Sep 17 00:00:00 2001 From: Hans Ulli Kroll Date: Tue, 27 Apr 2010 12:45:10 +0200 Subject: ARM: Gemini: fix compiler error in copypage-fa.c Fix compiler error in copypage-fs.c missing struct vm_area_struct *vma in function fa_copy_user_highpage Signed-off-by: Hans Ulli Kroll --- arch/arm/mm/copypage-fa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/copypage-fa.c b/arch/arm/mm/copypage-fa.c index b2a6008..d2852e1 100644 --- a/arch/arm/mm/copypage-fa.c +++ b/arch/arm/mm/copypage-fa.c @@ -40,7 +40,7 @@ fa_copy_user_page(void *kto, const void *kfrom) } void fa_copy_user_highpage(struct page *to, struct page *from, - unsigned long vaddr) + unsigned long vaddr, struct vm_area_struct *vma) { void *kto, *kfrom; -- cgit v1.1 From fef88f10767cfd9f9b4eebb5d5490214c5e13ad5 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 28 Feb 2010 17:26:25 +0000 Subject: ARM: Add Versatile Express CA9x4 processor support Signed-off-by: Russell King --- arch/arm/mm/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index c4ed9f9..270c8e2 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -754,7 +754,8 @@ config CACHE_FEROCEON_L2_WRITETHROUGH config CACHE_L2X0 bool "Enable the L2x0 outer cache controller" depends on REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || MACH_REALVIEW_PB1176 || \ - REALVIEW_EB_A9MP || ARCH_MX35 || ARCH_MX31 || MACH_REALVIEW_PBX || ARCH_NOMADIK || ARCH_OMAP4 + REALVIEW_EB_A9MP || ARCH_MX35 || ARCH_MX31 || MACH_REALVIEW_PBX || \ + ARCH_NOMADIK || ARCH_OMAP4 || ARCH_VEXPRESS_CA9X4 default y select OUTER_CACHE help -- cgit v1.1 From e220ba60223a9d63e70217e5b112160df8c21cea Mon Sep 17 00:00:00 2001 From: Dave Estes Date: Tue, 11 Aug 2009 17:58:49 -0400 Subject: arm: mm: qsd8x50: Fix incorrect permission faults Handle incorrectly reported permission faults for qsd8650. On permission faults, retry MVA to PA conversion. If retry detects translation fault. Report as translation fault. Cc: Jamie Lokier Signed-off-by: Dave Estes --- arch/arm/mm/Kconfig | 2 ++ arch/arm/mm/abort-ev7.S | 21 +++++++++++++++++++++ 2 files changed, 23 insertions(+) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 5bd7c89..d3022da 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -572,6 +572,8 @@ config CPU_TLB_V6 config CPU_TLB_V7 bool +config VERIFY_PERMISSION_FAULT + bool endif config CPU_HAS_ASID diff --git a/arch/arm/mm/abort-ev7.S b/arch/arm/mm/abort-ev7.S index 2e6dc04..ec88b15 100644 --- a/arch/arm/mm/abort-ev7.S +++ b/arch/arm/mm/abort-ev7.S @@ -29,5 +29,26 @@ ENTRY(v7_early_abort) * V6 code adjusts the returned DFSR. * New designs should not need to patch up faults. */ + +#if defined(CONFIG_VERIFY_PERMISSION_FAULT) + /* + * Detect erroneous permission failures and fix + */ + ldr r3, =0x40d @ On permission fault + and r3, r1, r3 + cmp r3, #0x0d + movne pc, lr + + mcr p15, 0, r0, c7, c8, 0 @ Retranslate FAR + isb + mrc p15, 0, r2, c7, c4, 0 @ Read the PAR + and r3, r2, #0x7b @ On translation fault + cmp r3, #0x0b + movne pc, lr + bic r1, r1, #0xf @ Fix up FSR FS[5:0] + and r2, r2, #0x7e + orr r1, r1, r2, LSR #1 +#endif + mov pc, lr ENDPROC(v7_early_abort) -- cgit v1.1 From 66b196475031c748a5861390a4fadb915e14ccdc Mon Sep 17 00:00:00 2001 From: Haojian Zhuang Date: Wed, 28 Apr 2010 10:59:45 -0400 Subject: [ARM] mmp: enable L2 in mmp2 Enable Tauros2 L2 in mmp2. Tauros2 L2 is shared in Marvell ARM cores. Signed-off-by: Haojian Zhuang Signed-off-by: Eric Miao --- arch/arm/mm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 5bd7c89..6989126 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -769,7 +769,7 @@ config CACHE_L2X0 config CACHE_TAUROS2 bool "Enable the Tauros2 L2 cache controller" - depends on ARCH_DOVE + depends on (ARCH_DOVE || ARCH_MMP) default y select OUTER_CACHE help -- cgit v1.1 From b7072c63c1b0611042ba6ecf0152a33c7b806e67 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Sun, 2 May 2010 12:40:35 +0300 Subject: ARM: convert /proc/cpu/aligment to seq_file Convert code away from ->read_proc/->write_proc interfaces. Switch to proc_create()/proc_create_data() which makes addition of proc entries reliable wrt NULL ->proc_fops, NULL ->data and so on. Problem with ->read_proc et al is described here commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba "Fix rmmod/read/write races in /proc entries" This patch is part of an effort to remove the old simple procfs PAGE_SIZE buffer interface. Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Russell King --- arch/arm/mm/alignment.c | 53 ++++++++++++++++++++++++------------------------- 1 file changed, 26 insertions(+), 27 deletions(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index edddd66..28b7c27 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -94,36 +95,29 @@ static const char *usermode_action[] = { "signal+warn" }; -static int -proc_alignment_read(char *page, char **start, off_t off, int count, int *eof, - void *data) +static int alignment_proc_show(struct seq_file *m, void *v) { - char *p = page; - int len; - - p += sprintf(p, "User:\t\t%lu\n", ai_user); - p += sprintf(p, "System:\t\t%lu\n", ai_sys); - p += sprintf(p, "Skipped:\t%lu\n", ai_skipped); - p += sprintf(p, "Half:\t\t%lu\n", ai_half); - p += sprintf(p, "Word:\t\t%lu\n", ai_word); + seq_printf(m, "User:\t\t%lu\n", ai_user); + seq_printf(m, "System:\t\t%lu\n", ai_sys); + seq_printf(m, "Skipped:\t%lu\n", ai_skipped); + seq_printf(m, "Half:\t\t%lu\n", ai_half); + seq_printf(m, "Word:\t\t%lu\n", ai_word); if (cpu_architecture() >= CPU_ARCH_ARMv5TE) - p += sprintf(p, "DWord:\t\t%lu\n", ai_dword); - p += sprintf(p, "Multi:\t\t%lu\n", ai_multi); - p += sprintf(p, "User faults:\t%i (%s)\n", ai_usermode, + seq_printf(m, "DWord:\t\t%lu\n", ai_dword); + seq_printf(m, "Multi:\t\t%lu\n", ai_multi); + seq_printf(m, "User faults:\t%i (%s)\n", ai_usermode, usermode_action[ai_usermode]); - len = (p - page) - off; - if (len < 0) - len = 0; - - *eof = (len <= count) ? 1 : 0; - *start = page + off; + return 0; +} - return len; +static int alignment_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, alignment_proc_show, NULL); } -static int proc_alignment_write(struct file *file, const char __user *buffer, - unsigned long count, void *data) +static ssize_t alignment_proc_write(struct file *file, const char __user *buffer, + size_t count, loff_t *pos) { char mode; @@ -136,6 +130,13 @@ static int proc_alignment_write(struct file *file, const char __user *buffer, return count; } +static const struct file_operations alignment_proc_fops = { + .open = alignment_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = alignment_proc_write, +}; #endif /* CONFIG_PROC_FS */ union offset_union { @@ -901,12 +902,10 @@ static int __init alignment_init(void) #ifdef CONFIG_PROC_FS struct proc_dir_entry *res; - res = create_proc_entry("cpu/alignment", S_IWUSR | S_IRUGO, NULL); + res = proc_create("cpu/alignment", S_IWUSR | S_IRUGO, NULL, + &alignment_proc_fops); if (!res) return -ENOMEM; - - res->read_proc = proc_alignment_read; - res->write_proc = proc_alignment_write; #endif /* -- cgit v1.1 From ceb683d3bc36f213aeef0c5d79e6fbb1e16bd459 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 25 Mar 2010 18:47:20 +0000 Subject: ARM: Ensure meminfo is sorted prior to sanity_check_meminfo Acked-by: Tony Lindgren Signed-off-by: Russell King --- arch/arm/mm/init.c | 10 ---------- arch/arm/mm/mmu.c | 10 ++++++++++ 2 files changed, 10 insertions(+), 10 deletions(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 7829cb5..8bbb9a9 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include @@ -387,21 +386,12 @@ static void arm_memory_present(struct meminfo *mi, int node) } #endif -static int __init meminfo_cmp(const void *_a, const void *_b) -{ - const struct membank *a = _a, *b = _b; - long cmp = bank_pfn_start(a) - bank_pfn_start(b); - return cmp < 0 ? -1 : cmp > 0 ? 1 : 0; -} - void __init bootmem_init(void) { struct meminfo *mi = &meminfo; unsigned long min, max_low, max_high; int node, initrd_node; - sort(&mi->bank, mi->nr_banks, sizeof(mi->bank[0]), meminfo_cmp, NULL); - /* * Locate which node contains the ramdisk image, if any. */ diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 9d4da6a..9154719 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -1013,6 +1014,13 @@ static void __init kmap_init(void) #endif } +static int __init meminfo_cmp(const void *_a, const void *_b) +{ + const struct membank *a = _a, *b = _b; + long cmp = bank_pfn_start(a) - bank_pfn_start(b); + return cmp < 0 ? -1 : cmp > 0 ? 1 : 0; +} + /* * paging_init() sets up the page tables, initialises the zone memory * maps, and sets up the zero page, bad page and bad page tables. @@ -1021,6 +1029,8 @@ void __init paging_init(struct machine_desc *mdesc) { void *zero_page; + sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL); + build_mem_type_table(); sanity_check_meminfo(); prepare_page_table(); -- cgit v1.1 From a2227120eead4ea7d2ea04d8ce0947f1dd23dedf Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 25 Mar 2010 18:56:05 +0000 Subject: ARM: Move memory mapping into mmu.c Acked-by: Tony Lindgren Signed-off-by: Russell King --- arch/arm/mm/init.c | 24 ------------------------ arch/arm/mm/mm.h | 3 --- arch/arm/mm/mmu.c | 29 ++++++++++++++++++++++++++++- 3 files changed, 28 insertions(+), 28 deletions(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 8bbb9a9..105d1d4 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -225,20 +225,6 @@ static int __init check_initrd(struct meminfo *mi) return initrd_node; } -static inline void map_memory_bank(struct membank *bank) -{ -#ifdef CONFIG_MMU - struct map_desc map; - - map.pfn = bank_pfn_start(bank); - map.virtual = __phys_to_virt(bank_phys_start(bank)); - map.length = bank_phys_size(bank); - map.type = MT_MEMORY; - - create_mapping(&map); -#endif -} - static void __init bootmem_init_node(int node, struct meminfo *mi, unsigned long start_pfn, unsigned long end_pfn) { @@ -248,16 +234,6 @@ static void __init bootmem_init_node(int node, struct meminfo *mi, int i; /* - * Map the memory banks for this node. - */ - for_each_nodebank(i, mi, node) { - struct membank *bank = &mi->bank[i]; - - if (!bank->highmem) - map_memory_bank(bank); - } - - /* * Allocate the bootmem bitmap page. */ boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn); diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h index a888363..815d08e 100644 --- a/arch/arm/mm/mm.h +++ b/arch/arm/mm/mm.h @@ -28,10 +28,7 @@ extern void __flush_dcache_page(struct address_space *mapping, struct page *page #endif -struct map_desc; -struct meminfo; struct pglist_data; -void __init create_mapping(struct map_desc *md); void __init bootmem_init(void); void reserve_node_zero(struct pglist_data *pgdat); diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 9154719..6985200 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -600,7 +600,7 @@ static void __init create_36bit_mapping(struct map_desc *md, * offsets, and we take full advantage of sections and * supersections. */ -void __init create_mapping(struct map_desc *md) +static void __init create_mapping(struct map_desc *md) { unsigned long phys, addr, length, end; const struct mem_type *type; @@ -1014,6 +1014,32 @@ static void __init kmap_init(void) #endif } +static inline void map_memory_bank(struct membank *bank) +{ + struct map_desc map; + + map.pfn = bank_pfn_start(bank); + map.virtual = __phys_to_virt(bank_phys_start(bank)); + map.length = bank_phys_size(bank); + map.type = MT_MEMORY; + + create_mapping(&map); +} + +static void __init map_lowmem(void) +{ + struct meminfo *mi = &meminfo; + int i; + + /* Map all the lowmem memory banks. */ + for (i = 0; i < mi->nr_banks; i++) { + struct membank *bank = &mi->bank[i]; + + if (!bank->highmem) + map_memory_bank(bank); + } +} + static int __init meminfo_cmp(const void *_a, const void *_b) { const struct membank *a = _a, *b = _b; @@ -1034,6 +1060,7 @@ void __init paging_init(struct machine_desc *mdesc) build_mem_type_table(); sanity_check_meminfo(); prepare_page_table(); + map_lowmem(); bootmem_init(); devicemaps_init(mdesc); kmap_init(); -- cgit v1.1 From 64039be8226b9f6c80c704d94ac9891eee4a274c Mon Sep 17 00:00:00 2001 From: Jason McMullan Date: Wed, 5 May 2010 18:59:37 +0100 Subject: ARM: 6094/1: Extend cache-l2x0 to support the 16-way PL310 The L310 cache controller's interface is almost identical to the L210. One major difference is that the PL310 can have up to 16 ways. This change uses the cache's part ID and the Associativity bits in the AUX_CTRL register to determine the number of ways. Also, this version prints out the CACHE_ID and AUX_CTRL registers. Acked-by: Will Deacon Acked-by: Acked-by: Catalin Marinas Signed-off-by: Jason S. McMullan Signed-off-by: Russell King --- arch/arm/mm/cache-l2x0.c | 39 ++++++++++++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 5 deletions(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index 0733463..78f0fc8 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c @@ -27,6 +27,7 @@ static void __iomem *l2x0_base; static DEFINE_SPINLOCK(l2x0_lock); +static uint32_t l2x0_way_mask; /* Bitmask of active ways */ static inline void cache_wait(void __iomem *reg, unsigned long mask) { @@ -99,8 +100,8 @@ static inline void l2x0_inv_all(void) /* invalidate all ways */ spin_lock_irqsave(&l2x0_lock, flags); - writel(0xff, l2x0_base + L2X0_INV_WAY); - cache_wait(l2x0_base + L2X0_INV_WAY, 0xff); + writel(l2x0_way_mask, l2x0_base + L2X0_INV_WAY); + cache_wait(l2x0_base + L2X0_INV_WAY, l2x0_way_mask); cache_sync(); spin_unlock_irqrestore(&l2x0_lock, flags); } @@ -199,9 +200,37 @@ static void l2x0_flush_range(unsigned long start, unsigned long end) void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask) { __u32 aux; + __u32 cache_id; + int ways; + const char *type; l2x0_base = base; + cache_id = readl(l2x0_base + L2X0_CACHE_ID); + aux = readl(l2x0_base + L2X0_AUX_CTRL); + + /* Determine the number of ways */ + switch (cache_id & L2X0_CACHE_ID_PART_MASK) { + case L2X0_CACHE_ID_PART_L310: + if (aux & (1 << 16)) + ways = 16; + else + ways = 8; + type = "L310"; + break; + case L2X0_CACHE_ID_PART_L210: + ways = (aux >> 13) & 0xf; + type = "L210"; + break; + default: + /* Assume unknown chips have 8 ways */ + ways = 8; + type = "L2x0 series"; + break; + } + + l2x0_way_mask = (1 << ways) - 1; + /* * Check if l2x0 controller is already enabled. * If you are booting from non-secure mode @@ -210,8 +239,6 @@ void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask) if (!(readl(l2x0_base + L2X0_CTRL) & 1)) { /* l2x0 controller is disabled */ - - aux = readl(l2x0_base + L2X0_AUX_CTRL); aux &= aux_mask; aux |= aux_val; writel(aux, l2x0_base + L2X0_AUX_CTRL); @@ -226,5 +253,7 @@ void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask) outer_cache.clean_range = l2x0_clean_range; outer_cache.flush_range = l2x0_flush_range; - printk(KERN_INFO "L2X0 cache controller enabled\n"); + printk(KERN_INFO "%s cache controller enabled\n", type); + printk(KERN_INFO "l2x0: %d ways, CACHE_ID 0x%08x, AUX_CTRL 0x%08x\n", + ways, cache_id, aux); } -- cgit v1.1 From 8c0b742ca7a7d21de0ddc87eda6ef0b282e4de18 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Sat, 15 May 2010 09:57:06 +0100 Subject: ARM: 6134/1: Handle instruction cache maintenance fault properly Between "clean D line..." and "invalidate I line" operations in v7_coherent_user_range(), the memory page may get swapped out. And the fault on "invalidate I line" could not be properly handled causing the oops. In ARMv6 "external abort on linefetch" replaced by "instruction cache maintenance fault". Let's handle it as translation fault. It fixes the issue. I'm not sure if it's reasonable to check arch version in run-time. Let's do it in compile time for now. Reviewed-by: Catalin Marinas Signed-off-by: Siarhei Siamashka Signed-off-by: Kirill A. Shutemov Signed-off-by: Russell King --- arch/arm/mm/fault.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 9d40c34..92f5801 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -463,7 +463,12 @@ static struct fsr_info { { do_bad, SIGILL, BUS_ADRALN, "alignment exception" }, { do_bad, SIGKILL, 0, "terminal exception" }, { do_bad, SIGILL, BUS_ADRALN, "alignment exception" }, +/* Do we need runtime check ? */ +#if __LINUX_ARM_ARCH__ < 6 { do_bad, SIGBUS, 0, "external abort on linefetch" }, +#else + { do_translation_fault, SIGSEGV, SEGV_MAPERR, "I-cache maintenance fault" }, +#endif { do_translation_fault, SIGSEGV, SEGV_MAPERR, "section translation fault" }, { do_bad, SIGBUS, 0, "external abort on linefetch" }, { do_page_fault, SIGSEGV, SEGV_MAPERR, "page translation fault" }, -- cgit v1.1 From 47ab0dee661dbd5aca67abe44a333e471134fbf9 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 15 May 2010 11:02:43 +0100 Subject: ARM: Optionally allow ARMv6 to use 'normal, bufferable' memory for DMA Provide a configuration option to allow the ARMv6 to use normal bufferable memory for coherent DMA. This option is forced to 'y' for ARMv7, and offered as a configuration option on ARMv6. Enabling this option requires drivers to have the necessary barriers to ensure that data in DMA coherent memory is visible prior to the DMA operation commencing. Reviewed-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/mm/Kconfig | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index c4ed9f9..573528d 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -781,3 +781,22 @@ config ARM_L1_CACHE_SHIFT int default 6 if ARM_L1_CACHE_SHIFT_6 default 5 + +config ARM_DMA_MEM_BUFFERABLE + bool "Use non-cacheable memory for DMA" if CPU_V6 && !CPU_V7 + default y if CPU_V6 || CPU_V7 + help + Historically, the kernel has used strongly ordered mappings to + provide DMA coherent memory. With the advent of ARMv7, mapping + memory with differing types results in unpredictable behaviour, + so on these CPUs, this option is forced on. + + Multiple mappings with differing attributes is also unpredictable + on ARMv6 CPUs, but since they do not have aggressive speculative + prefetch, no harm appears to occur. + + However, drivers may be missing the necessary barriers for ARMv6, + and therefore turning this on may result in unpredictable driver + behaviour. Therefore, we offer this as an option. + + You are recommended say 'Y' here and debug any affected drivers. -- cgit v1.1