From 629ed3f7dad2a914b3a89fad49b358e363e3e6d1 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 3 Nov 2020 10:27:29 +0100 Subject: xtensa/mm/highmem: Switch to generic kmap atomic No reason having the same code in every architecture Signed-off-by: Thomas Gleixner Cc: Chris Zankel Cc: Max Filippov Cc: Arnd Bergmann Link: https://lore.kernel.org/r/20201103095858.311016780@linutronix.de --- arch/xtensa/Kconfig | 1 + arch/xtensa/include/asm/fixmap.h | 4 ++-- arch/xtensa/include/asm/highmem.h | 12 ++++++++-- arch/xtensa/mm/highmem.c | 46 +++++---------------------------------- 4 files changed, 18 insertions(+), 45 deletions(-) (limited to 'arch/xtensa') diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index d0dfa50bd0bb..dc22ef3cf4be 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -666,6 +666,7 @@ endchoice config HIGHMEM bool "High Memory Support" depends on MMU + select KMAP_LOCAL help Linux can use the full amount of RAM in the system by default. However, the default MMUv2 setup only maps the diff --git a/arch/xtensa/include/asm/fixmap.h b/arch/xtensa/include/asm/fixmap.h index a06ffb0c61c7..92049b61c351 100644 --- a/arch/xtensa/include/asm/fixmap.h +++ b/arch/xtensa/include/asm/fixmap.h @@ -16,7 +16,7 @@ #ifdef CONFIG_HIGHMEM #include #include -#include +#include #endif /* @@ -39,7 +39,7 @@ enum fixed_addresses { /* reserved pte's for temporary kernel mappings */ FIX_KMAP_BEGIN, FIX_KMAP_END = FIX_KMAP_BEGIN + - (KM_TYPE_NR * NR_CPUS * DCACHE_N_COLORS) - 1, + (KM_MAX_IDX * NR_CPUS * DCACHE_N_COLORS) - 1, #endif __end_of_fixed_addresses }; diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h index eac503215f17..0fc3b1cebc56 100644 --- a/arch/xtensa/include/asm/highmem.h +++ b/arch/xtensa/include/asm/highmem.h @@ -16,9 +16,8 @@ #include #include #include -#include -#define PKMAP_BASE ((FIXADDR_START - \ +#define PKMAP_BASE ((FIXADDR_START - \ (LAST_PKMAP + 1) * PAGE_SIZE) & PMD_MASK) #define LAST_PKMAP (PTRS_PER_PTE * DCACHE_N_COLORS) #define LAST_PKMAP_MASK (LAST_PKMAP - 1) @@ -68,6 +67,15 @@ static inline void flush_cache_kmaps(void) flush_cache_all(); } +enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn); +#define arch_kmap_local_map_idx kmap_local_map_idx + +enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr); +#define arch_kmap_local_unmap_idx kmap_local_unmap_idx + +#define arch_kmap_local_post_unmap(vaddr) \ + local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE) + void kmap_init(void); #endif diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c index 673196fe862e..0735ca5e8f86 100644 --- a/arch/xtensa/mm/highmem.c +++ b/arch/xtensa/mm/highmem.c @@ -12,8 +12,6 @@ #include #include -static pte_t *kmap_pte; - #if DCACHE_WAY_SIZE > PAGE_SIZE unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS]; wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS]; @@ -33,59 +31,25 @@ static inline void kmap_waitqueues_init(void) static inline enum fixed_addresses kmap_idx(int type, unsigned long color) { - return (type + KM_TYPE_NR * smp_processor_id()) * DCACHE_N_COLORS + + return (type + KM_MAX_IDX * smp_processor_id()) * DCACHE_N_COLORS + color; } -void *kmap_atomic_high_prot(struct page *page, pgprot_t prot) +enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn) { - enum fixed_addresses idx; - unsigned long vaddr; - - idx = kmap_idx(kmap_atomic_idx_push(), - DCACHE_ALIAS(page_to_phys(page))); - vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); -#ifdef CONFIG_DEBUG_HIGHMEM - BUG_ON(!pte_none(*(kmap_pte + idx))); -#endif - set_pte(kmap_pte + idx, mk_pte(page, prot)); - - return (void *)vaddr; + return kmap_idx(type, DCACHE_ALIAS(pfn << PAGE_SHIFT)); } -EXPORT_SYMBOL(kmap_atomic_high_prot); -void kunmap_atomic_high(void *kvaddr) +enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr) { - if (kvaddr >= (void *)FIXADDR_START && - kvaddr < (void *)FIXADDR_TOP) { - int idx = kmap_idx(kmap_atomic_idx(), - DCACHE_ALIAS((unsigned long)kvaddr)); - - /* - * Force other mappings to Oops if they'll try to access this - * pte without first remap it. Keeping stale mappings around - * is a bad idea also, in case the page changes cacheability - * attributes or becomes a protected page in a hypervisor. - */ - pte_clear(&init_mm, kvaddr, kmap_pte + idx); - local_flush_tlb_kernel_range((unsigned long)kvaddr, - (unsigned long)kvaddr + PAGE_SIZE); - - kmap_atomic_idx_pop(); - } + return kmap_idx(type, DCACHE_ALIAS(addr)); } -EXPORT_SYMBOL(kunmap_atomic_high); void __init kmap_init(void) { - unsigned long kmap_vstart; - /* Check if this memory layout is broken because PKMAP overlaps * page table. */ BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE); - /* cache the first kmap pte */ - kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); - kmap_pte = virt_to_kpte(kmap_vstart); kmap_waitqueues_init(); } -- cgit v1.2.3 From 1eb0616c2df5b78c301eaa7bd2ee859f43915001 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 16 Nov 2020 11:32:53 -0800 Subject: xtensa/mm/highmem: Make generic kmap_atomic() work correctly The conversion to the generic kmap_atomic() implementation missed the fact that xtensa's fixmap works bottom up while all other implementations work top down. There is no real reason why xtensa needs to work that way. Cure it by: - Using the generic fix_to_virt()/virt_to_fix() functions which work top down - Adjusting the mapping defines - Using the generic index calculation for the non cache aliasing case - Making the cache colour offset reverse so the effective index is correct While at it, remove the outdated and misleading comment above the fixmap enum which originates from the initial copy&pasta of this code from i386. [ Max: Fixed the off by one in the index calculation ] Fixes: 629ed3f7dad2 ("xtensa/mm/highmem: Switch to generic kmap atomic") Reported-by: Max Filippov Signed-off-by: Thomas Gleixner Signed-off-by: Max Filippov Signed-off-by: Thomas Gleixner Tested-by: Max Filippov Link: https://lore.kernel.org/r/20201116193253.23875-1-jcmvbkbc@gmail.com --- arch/xtensa/include/asm/fixmap.h | 55 +++++---------------------------------- arch/xtensa/include/asm/highmem.h | 15 ++++++----- arch/xtensa/mm/highmem.c | 18 ++++++++----- arch/xtensa/mm/init.c | 4 +-- arch/xtensa/mm/mmu.c | 3 ++- 5 files changed, 31 insertions(+), 64 deletions(-) (limited to 'arch/xtensa') diff --git a/arch/xtensa/include/asm/fixmap.h b/arch/xtensa/include/asm/fixmap.h index 92049b61c351..1c65dc1d3397 100644 --- a/arch/xtensa/include/asm/fixmap.h +++ b/arch/xtensa/include/asm/fixmap.h @@ -17,63 +17,22 @@ #include #include #include -#endif -/* - * Here we define all the compile-time 'special' virtual - * addresses. The point is to have a constant address at - * compile time, but to set the physical address only - * in the boot process. We allocate these special addresses - * from the start of the consistent memory region upwards. - * Also this lets us do fail-safe vmalloc(), we - * can guarantee that these special addresses and - * vmalloc()-ed addresses never overlap. - * - * these 'compile-time allocated' memory buffers are - * fixed-size 4k pages. (or larger if used with an increment - * higher than 1) use fixmap_set(idx,phys) to associate - * physical memory with fixmap indices. - */ +/* The map slots for temporary mappings via kmap_atomic/local(). */ enum fixed_addresses { -#ifdef CONFIG_HIGHMEM - /* reserved pte's for temporary kernel mappings */ FIX_KMAP_BEGIN, FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS * DCACHE_N_COLORS) - 1, -#endif __end_of_fixed_addresses }; -#define FIXADDR_TOP (XCHAL_KSEG_CACHED_VADDR - PAGE_SIZE) +#define FIXADDR_END (XCHAL_KSEG_CACHED_VADDR - PAGE_SIZE) #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) -#define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK) +/* Enforce that FIXADDR_START is PMD aligned to handle cache aliasing */ +#define FIXADDR_START ((FIXADDR_END - FIXADDR_SIZE) & PMD_MASK) +#define FIXADDR_TOP (FIXADDR_START + FIXADDR_SIZE - PAGE_SIZE) -#define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT)) -#define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT) - -#ifndef __ASSEMBLY__ -/* - * 'index to address' translation. If anyone tries to use the idx - * directly without translation, we catch the bug with a NULL-deference - * kernel oops. Illegal ranges of incoming indices are caught too. - */ -static __always_inline unsigned long fix_to_virt(const unsigned int idx) -{ - /* Check if this memory layout is broken because fixmap overlaps page - * table. - */ - BUILD_BUG_ON(FIXADDR_START < - TLBTEMP_BASE_1 + TLBTEMP_SIZE); - BUILD_BUG_ON(idx >= __end_of_fixed_addresses); - return __fix_to_virt(idx); -} - -static inline unsigned long virt_to_fix(const unsigned long vaddr) -{ - BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); - return __virt_to_fix(vaddr); -} - -#endif +#include +#endif /* CONFIG_HIGHMEM */ #endif diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h index 0fc3b1cebc56..34b8b620e7f1 100644 --- a/arch/xtensa/include/asm/highmem.h +++ b/arch/xtensa/include/asm/highmem.h @@ -12,6 +12,7 @@ #ifndef _XTENSA_HIGHMEM_H #define _XTENSA_HIGHMEM_H +#ifdef CONFIG_HIGHMEM #include #include #include @@ -58,6 +59,13 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color) { return pkmap_map_wait_arr + color; } + +enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn); +#define arch_kmap_local_map_idx kmap_local_map_idx + +enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr); +#define arch_kmap_local_unmap_idx kmap_local_unmap_idx + #endif extern pte_t *pkmap_page_table; @@ -67,15 +75,10 @@ static inline void flush_cache_kmaps(void) flush_cache_all(); } -enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn); -#define arch_kmap_local_map_idx kmap_local_map_idx - -enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr); -#define arch_kmap_local_unmap_idx kmap_local_unmap_idx - #define arch_kmap_local_post_unmap(vaddr) \ local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE) void kmap_init(void); +#endif /* CONFIG_HIGHMEM */ #endif diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c index 0735ca5e8f86..35c4f7d4a333 100644 --- a/arch/xtensa/mm/highmem.c +++ b/arch/xtensa/mm/highmem.c @@ -23,16 +23,16 @@ static void __init kmap_waitqueues_init(void) for (i = 0; i < ARRAY_SIZE(pkmap_map_wait_arr); ++i) init_waitqueue_head(pkmap_map_wait_arr + i); } -#else -static inline void kmap_waitqueues_init(void) -{ -} -#endif static inline enum fixed_addresses kmap_idx(int type, unsigned long color) { - return (type + KM_MAX_IDX * smp_processor_id()) * DCACHE_N_COLORS + - color; + int idx = (type + KM_MAX_IDX * smp_processor_id()) * DCACHE_N_COLORS; + + /* + * The fixmap operates top down, so the color offset needs to be + * reverse as well. + */ + return idx + DCACHE_N_COLORS - 1 - color; } enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn) @@ -45,6 +45,10 @@ enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr) return kmap_idx(type, DCACHE_ALIAS(addr)); } +#else +static inline void kmap_waitqueues_init(void) { } +#endif + void __init kmap_init(void) { /* Check if this memory layout is broken because PKMAP overlaps diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c index c6fc83efee0c..0f85666bcbeb 100644 --- a/arch/xtensa/mm/init.c +++ b/arch/xtensa/mm/init.c @@ -147,8 +147,8 @@ void __init mem_init(void) #ifdef CONFIG_HIGHMEM PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE, (LAST_PKMAP*PAGE_SIZE) >> 10, - FIXADDR_START, FIXADDR_TOP, - (FIXADDR_TOP - FIXADDR_START) >> 10, + FIXADDR_START, FIXADDR_END, + (FIXADDR_END - FIXADDR_START) >> 10, #endif PAGE_OFFSET, PAGE_OFFSET + (max_low_pfn - min_low_pfn) * PAGE_SIZE, diff --git a/arch/xtensa/mm/mmu.c b/arch/xtensa/mm/mmu.c index fd2193df8a14..7e4d97dc8bd8 100644 --- a/arch/xtensa/mm/mmu.c +++ b/arch/xtensa/mm/mmu.c @@ -52,7 +52,8 @@ static void * __init init_pmd(unsigned long vaddr, unsigned long n_pages) static void __init fixedrange_init(void) { - init_pmd(__fix_to_virt(0), __end_of_fixed_addresses); + BUILD_BUG_ON(FIXADDR_START < TLBTEMP_BASE_1 + TLBTEMP_SIZE); + init_pmd(FIXADDR_START, __end_of_fixed_addresses); } #endif -- cgit v1.2.3