From b478491f2628114b2eae76587f22ce3789b66012 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 27 Oct 2010 17:28:46 +0100 Subject: MN10300: Allow some cacheflushes to be avoided if cache snooping is available The AM34 core is able to do cache snooping, and so can skip some of the cache flushing. Signed-off-by: David Howells --- arch/mn10300/Kconfig | 1 + arch/mn10300/include/asm/cacheflush.h | 16 ++-- arch/mn10300/kernel/kprobes.c | 4 + arch/mn10300/kernel/traps.c | 2 + arch/mn10300/mm/Kconfig.cache | 34 +++++++++ arch/mn10300/mm/Makefile | 2 + arch/mn10300/mm/cache-flush-icache.c | 137 ++++++++++++++++++++++++++++++++++ arch/mn10300/mm/cache-inv-icache.c | 119 +++++++++++++++++++++++++++++ arch/mn10300/mm/cache.c | 90 ---------------------- 9 files changed, 309 insertions(+), 96 deletions(-) create mode 100644 arch/mn10300/mm/cache-flush-icache.c create mode 100644 arch/mn10300/mm/cache-inv-icache.c (limited to 'arch/mn10300') diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig index 069e34d4c4a..21e2a534d98 100644 --- a/arch/mn10300/Kconfig +++ b/arch/mn10300/Kconfig @@ -18,6 +18,7 @@ config AM33_3 config AM34_2 def_bool n select MN10300_HAS_ATOMIC_OPS_UNIT + select MN10300_HAS_CACHE_SNOOP config MMU def_bool y diff --git a/arch/mn10300/include/asm/cacheflush.h b/arch/mn10300/include/asm/cacheflush.h index 748143f6541..faed90240de 100644 --- a/arch/mn10300/include/asm/cacheflush.h +++ b/arch/mn10300/include/asm/cacheflush.h @@ -131,18 +131,22 @@ extern void mn10300_dcache_flush_inv_range2(unsigned long start, unsigned long s /* * Physically-indexed cache management */ -#ifdef CONFIG_MN10300_CACHE_ENABLED - +#if defined(CONFIG_MN10300_CACHE_FLUSH_ICACHE) +extern void flush_icache_page(struct vm_area_struct *vma, struct page *page); +extern void flush_icache_range(unsigned long start, unsigned long end); +#elif defined(CONFIG_MN10300_CACHE_INV_ICACHE) +static inline void flush_icache_page(struct vm_area_struct *vma, + struct page *page) +{ + mn10300_icache_inv_page(page_to_phys(page)); +} extern void flush_icache_range(unsigned long start, unsigned long end); -extern void flush_icache_page(struct vm_area_struct *vma, struct page *pg); - #else - #define flush_icache_range(start, end) do {} while (0) #define flush_icache_page(vma, pg) do {} while (0) - #endif + #define flush_icache_user_range(vma, pg, adr, len) \ flush_icache_range(adr, adr + len) diff --git a/arch/mn10300/kernel/kprobes.c b/arch/mn10300/kernel/kprobes.c index 67e6389d625..0311a7fcea1 100644 --- a/arch/mn10300/kernel/kprobes.c +++ b/arch/mn10300/kernel/kprobes.c @@ -377,8 +377,10 @@ void __kprobes arch_arm_kprobe(struct kprobe *p) void __kprobes arch_disarm_kprobe(struct kprobe *p) { +#ifndef CONFIG_MN10300_CACHE_SNOOP mn10300_dcache_flush(); mn10300_icache_inv(); +#endif } void arch_remove_kprobe(struct kprobe *p) @@ -390,8 +392,10 @@ void __kprobes disarm_kprobe(struct kprobe *p, struct pt_regs *regs) { *p->addr = p->opcode; regs->pc = (unsigned long) p->addr; +#ifndef CONFIG_MN10300_CACHE_SNOOP mn10300_dcache_flush(); mn10300_icache_inv(); +#endif } static inline diff --git a/arch/mn10300/kernel/traps.c b/arch/mn10300/kernel/traps.c index a64604b512d..c7257a1304a 100644 --- a/arch/mn10300/kernel/traps.c +++ b/arch/mn10300/kernel/traps.c @@ -533,8 +533,10 @@ void __init set_intr_stub(enum exception_code code, void *handler) vector[6] = 0xcb; vector[7] = 0xcb; +#ifndef CONFIG_MN10300_CACHE_SNOOP mn10300_dcache_flush_inv(); mn10300_icache_inv(); +#endif } /* diff --git a/arch/mn10300/mm/Kconfig.cache b/arch/mn10300/mm/Kconfig.cache index 97adc06e712..653254a34f8 100644 --- a/arch/mn10300/mm/Kconfig.cache +++ b/arch/mn10300/mm/Kconfig.cache @@ -22,12 +22,26 @@ choice config MN10300_CACHE_WBACK bool "Write-Back" + help + The dcache operates in delayed write-back mode. It must be manually + flushed if writes are made that subsequently need to be executed or + to be DMA'd by a device. config MN10300_CACHE_WTHRU bool "Write-Through" + help + The dcache operates in immediate write-through mode. Writes are + committed to RAM immediately in addition to being stored in the + cache. This means that the written data is immediately available for + execution or DMA. + + This is not available for use with an SMP kernel if cache flushing + and invalidation by automatic purge register is not selected. config MN10300_CACHE_DISABLED bool "Disabled" + help + The icache and dcache are disabled. endchoice @@ -64,3 +78,23 @@ config MN10300_CACHE_FLUSH_BY_TAG config MN10300_CACHE_FLUSH_BY_REG def_bool y if MN10300_CACHE_MANAGE_BY_REG && MN10300_CACHE_WBACK + + +config MN10300_HAS_CACHE_SNOOP + def_bool n + +config MN10300_CACHE_SNOOP + bool "Use CPU Cache Snooping" + depends on MN10300_CACHE_ENABLED && MN10300_HAS_CACHE_SNOOP + default y + +config MN10300_CACHE_FLUSH_ICACHE + def_bool y if MN10300_CACHE_WBACK && !MN10300_CACHE_SNOOP + help + Set if we need the dcache flushing before the icache is invalidated. + +config MN10300_CACHE_INV_ICACHE + def_bool y if MN10300_CACHE_WTHRU && !MN10300_CACHE_SNOOP + help + Set if we need the icache to be invalidated, even if the dcache is in + write-through mode and doesn't need flushing. diff --git a/arch/mn10300/mm/Makefile b/arch/mn10300/mm/Makefile index 7b997236ed2..56c5af83151 100644 --- a/arch/mn10300/mm/Makefile +++ b/arch/mn10300/mm/Makefile @@ -3,6 +3,8 @@ # cacheflush-y := cache.o +cacheflush-$(CONFIG_MN10300_CACHE_INV_ICACHE) += cache-inv-icache.o +cacheflush-$(CONFIG_MN10300_CACHE_FLUSH_ICACHE) += cache-flush-icache.o cacheflush-$(CONFIG_MN10300_CACHE_INV_BY_TAG) += cache-inv-by-tag.o cacheflush-$(CONFIG_MN10300_CACHE_INV_BY_REG) += cache-inv-by-reg.o cacheflush-$(CONFIG_MN10300_CACHE_FLUSH_BY_TAG) += cache-flush-by-tag.o diff --git a/arch/mn10300/mm/cache-flush-icache.c b/arch/mn10300/mm/cache-flush-icache.c new file mode 100644 index 00000000000..0e471e1cb2d --- /dev/null +++ b/arch/mn10300/mm/cache-flush-icache.c @@ -0,0 +1,137 @@ +/* Flush dcache and invalidate icache when the dcache is in writeback mode + * + * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#include +#include +#include +/** + * flush_icache_page - Flush a page from the dcache and invalidate the icache + * @vma: The VMA the page is part of. + * @page: The page to be flushed. + * + * Write a page back from the dcache and invalidate the icache so that we can + * run code from it that we've just written into it + */ +void flush_icache_page(struct vm_area_struct *vma, struct page *page) +{ + unsigned long start = page_to_phys(page); + + mn10300_dcache_flush_page(start); + mn10300_icache_inv_page(start); +} +EXPORT_SYMBOL(flush_icache_page); + +/** + * flush_icache_page_range - Flush dcache and invalidate icache for part of a + * single page + * @start: The starting virtual address of the page part. + * @end: The ending virtual address of the page part. + * + * Flush the dcache and invalidate the icache for part of a single page, as + * determined by the virtual addresses given. The page must be in the paged + * area. + */ +static void flush_icache_page_range(unsigned long start, unsigned long end) +{ + unsigned long addr, size, off; + struct page *page; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *ppte, pte; + + /* work out how much of the page to flush */ + off = start & ~PAGE_MASK; + size = end - start; + + /* get the physical address the page is mapped to from the page + * tables */ + pgd = pgd_offset(current->mm, start); + if (!pgd || !pgd_val(*pgd)) + return; + + pud = pud_offset(pgd, start); + if (!pud || !pud_val(*pud)) + return; + + pmd = pmd_offset(pud, start); + if (!pmd || !pmd_val(*pmd)) + return; + + ppte = pte_offset_map(pmd, start); + if (!ppte) + return; + pte = *ppte; + pte_unmap(ppte); + + if (pte_none(pte)) + return; + + page = pte_page(pte); + if (!page) + return; + + addr = page_to_phys(page); + + /* flush the dcache and invalidate the icache coverage on that + * region */ + mn10300_dcache_flush_range2(addr + off, size); + mn10300_icache_inv_range2(addr + off, size); +} + +/** + * flush_icache_range - Globally flush dcache and invalidate icache for region + * @start: The starting virtual address of the region. + * @end: The ending virtual address of the region. + * + * This is used by the kernel to globally flush some code it has just written + * from the dcache back to RAM and then to globally invalidate the icache over + * that region so that that code can be run on all CPUs in the system. + */ +void flush_icache_range(unsigned long start, unsigned long end) +{ + unsigned long start_page, end_page; + + if (end > 0x80000000UL) { + /* addresses above 0xa0000000 do not go through the cache */ + if (end > 0xa0000000UL) { + end = 0xa0000000UL; + if (start >= end) + return; + } + + /* kernel addresses between 0x80000000 and 0x9fffffff do not + * require page tables, so we just map such addresses + * directly */ + start_page = (start >= 0x80000000UL) ? start : 0x80000000UL; + mn10300_dcache_flush_range(start_page, end); + mn10300_icache_inv_range(start_page, end); + if (start_page == start) + return; + end = start_page; + } + + start_page = start & PAGE_MASK; + end_page = end & PAGE_MASK; + + if (start_page == end_page) { + /* the first and last bytes are on the same page */ + flush_icache_page_range(start, end); + } else if (start_page + 1 == end_page) { + /* split over two virtually contiguous pages */ + flush_icache_page_range(start, end_page); + flush_icache_page_range(end_page, end); + } else { + /* more than 2 pages; just flush the entire cache */ + mn10300_dcache_flush(); + mn10300_icache_inv(); + } +} +EXPORT_SYMBOL(flush_icache_range); diff --git a/arch/mn10300/mm/cache-inv-icache.c b/arch/mn10300/mm/cache-inv-icache.c new file mode 100644 index 00000000000..4a3f7afcfe5 --- /dev/null +++ b/arch/mn10300/mm/cache-inv-icache.c @@ -0,0 +1,119 @@ +/* Invalidate icache when dcache doesn't need invalidation as it's in + * write-through mode + * + * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#include +#include +#include + +/** + * flush_icache_page_range - Flush dcache and invalidate icache for part of a + * single page + * @start: The starting virtual address of the page part. + * @end: The ending virtual address of the page part. + * + * Invalidate the icache for part of a single page, as determined by the + * virtual addresses given. The page must be in the paged area. The dcache is + * not flushed as the cache must be in write-through mode to get here. + */ +static void flush_icache_page_range(unsigned long start, unsigned long end) +{ + unsigned long addr, size, off; + struct page *page; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *ppte, pte; + + /* work out how much of the page to flush */ + off = start & ~PAGE_MASK; + size = end - start; + + /* get the physical address the page is mapped to from the page + * tables */ + pgd = pgd_offset(current->mm, start); + if (!pgd || !pgd_val(*pgd)) + return; + + pud = pud_offset(pgd, start); + if (!pud || !pud_val(*pud)) + return; + + pmd = pmd_offset(pud, start); + if (!pmd || !pmd_val(*pmd)) + return; + + ppte = pte_offset_map(pmd, start); + if (!ppte) + return; + pte = *ppte; + pte_unmap(ppte); + + if (pte_none(pte)) + return; + + page = pte_page(pte); + if (!page) + return; + + addr = page_to_phys(page); + + /* invalidate the icache coverage on that region */ + mn10300_icache_inv_range2(addr + off, size); +} + +/** + * flush_icache_range - Globally flush dcache and invalidate icache for region + * @start: The starting virtual address of the region. + * @end: The ending virtual address of the region. + * + * This is used by the kernel to globally flush some code it has just written + * from the dcache back to RAM and then to globally invalidate the icache over + * that region so that that code can be run on all CPUs in the system. + */ +void flush_icache_range(unsigned long start, unsigned long end) +{ + unsigned long start_page, end_page; + + if (end > 0x80000000UL) { + /* addresses above 0xa0000000 do not go through the cache */ + if (end > 0xa0000000UL) { + end = 0xa0000000UL; + if (start >= end) + return; + } + + /* kernel addresses between 0x80000000 and 0x9fffffff do not + * require page tables, so we just map such addresses + * directly */ + start_page = (start >= 0x80000000UL) ? start : 0x80000000UL; + mn10300_dcache_flush_range(start_page, end); + mn10300_icache_inv_range(start_page, end); + if (start_page == start) + return; + end = start_page; + } + + start_page = start & PAGE_MASK; + end_page = end & PAGE_MASK; + + if (start_page == end_page) { + /* the first and last bytes are on the same page */ + flush_icache_page_range(start, end); + } else if (start_page + 1 == end_page) { + /* split over two virtually contiguous pages */ + flush_icache_page_range(start, end_page); + flush_icache_page_range(end_page, end); + } else { + /* more than 2 pages; just flush the entire cache */ + mn10300_icache_inv(); + } +} +EXPORT_SYMBOL(flush_icache_range); diff --git a/arch/mn10300/mm/cache.c b/arch/mn10300/mm/cache.c index 9261217e8d2..bc35826f135 100644 --- a/arch/mn10300/mm/cache.c +++ b/arch/mn10300/mm/cache.c @@ -36,96 +36,6 @@ EXPORT_SYMBOL(mn10300_dcache_flush_range2); EXPORT_SYMBOL(mn10300_dcache_flush_page); #endif -/* - * write a page back from the dcache and invalidate the icache so that we can - * run code from it that we've just written into it - */ -void flush_icache_page(struct vm_area_struct *vma, struct page *page) -{ - mn10300_dcache_flush_page(page_to_phys(page)); - mn10300_icache_inv(); -} -EXPORT_SYMBOL(flush_icache_page); - -/* - * write some code we've just written back from the dcache and invalidate the - * icache so that we can run that code - */ -void flush_icache_range(unsigned long start, unsigned long end) -{ -#ifdef CONFIG_MN10300_CACHE_WBACK - unsigned long addr, size, base, off; - struct page *page; - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t *ppte, pte; - - if (end > 0x80000000UL) { - /* addresses above 0xa0000000 do not go through the cache */ - if (end > 0xa0000000UL) { - end = 0xa0000000UL; - if (start >= end) - return; - } - - /* kernel addresses between 0x80000000 and 0x9fffffff do not - * require page tables, so we just map such addresses directly */ - base = (start >= 0x80000000UL) ? start : 0x80000000UL; - mn10300_dcache_flush_range(base, end); - if (base == start) - goto invalidate; - end = base; - } - - for (; start < end; start += size) { - /* work out how much of the page to flush */ - off = start & (PAGE_SIZE - 1); - - size = end - start; - if (size > PAGE_SIZE - off) - size = PAGE_SIZE - off; - - /* get the physical address the page is mapped to from the page - * tables */ - pgd = pgd_offset(current->mm, start); - if (!pgd || !pgd_val(*pgd)) - continue; - - pud = pud_offset(pgd, start); - if (!pud || !pud_val(*pud)) - continue; - - pmd = pmd_offset(pud, start); - if (!pmd || !pmd_val(*pmd)) - continue; - - ppte = pte_offset_map(pmd, start); - if (!ppte) - continue; - pte = *ppte; - pte_unmap(ppte); - - if (pte_none(pte)) - continue; - - page = pte_page(pte); - if (!page) - continue; - - addr = page_to_phys(page); - - /* flush the dcache and invalidate the icache coverage on that - * region */ - mn10300_dcache_flush_range2(addr + off, size); - } -#endif - -invalidate: - mn10300_icache_inv(); -} -EXPORT_SYMBOL(flush_icache_range); - /* * allow userspace to flush the instruction cache */ -- cgit v1.2.3