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authorDavid Howells <dhowells@redhat.com>2010-10-27 17:28:46 +0100
committerDavid Howells <dhowells@redhat.com>2010-10-27 17:28:46 +0100
commitb478491f2628114b2eae76587f22ce3789b66012 (patch)
tree038580a05fa1a3c8c9cbee0fa8743af2bba650b9 /arch/mn10300
parent9731d23710736b96786d68c2e63148ff3f22e6eb (diff)
downloadlinux-2.6.38-lt-ux500-b478491f2628114b2eae76587f22ce3789b66012.tar.gz
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 <dhowells@redhat.com>
Diffstat (limited to 'arch/mn10300')
-rw-r--r--arch/mn10300/Kconfig1
-rw-r--r--arch/mn10300/include/asm/cacheflush.h16
-rw-r--r--arch/mn10300/kernel/kprobes.c4
-rw-r--r--arch/mn10300/kernel/traps.c2
-rw-r--r--arch/mn10300/mm/Kconfig.cache34
-rw-r--r--arch/mn10300/mm/Makefile2
-rw-r--r--arch/mn10300/mm/cache-flush-icache.c137
-rw-r--r--arch/mn10300/mm/cache-inv-icache.c119
-rw-r--r--arch/mn10300/mm/cache.c90
9 files changed, 309 insertions, 96 deletions
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 <linux/module.h>
+#include <linux/mm.h>
+#include <asm/cacheflush.h>
+/**
+ * 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 <linux/module.h>
+#include <linux/mm.h>
+#include <asm/cacheflush.h>
+
+/**
+ * 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
@@ -37,96 +37,6 @@ 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
*/
asmlinkage long sys_cacheflush(unsigned long start, unsigned long end)