sh: Support explicit L1 cache disabling.
This reworks the cache mode configuration in Kconfig, and allows for
explicit selection of write-back/write-through/off configurations.
All of the cache flushing routines are optimized away for the off
case.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/cpu/init.c b/arch/sh/kernel/cpu/init.c
index 9172e97..fdc245b 100644
--- a/arch/sh/kernel/cpu/init.c
+++ b/arch/sh/kernel/cpu/init.c
@@ -143,12 +143,15 @@
flags &= ~CCR_CACHE_EMODE;
#endif
-#ifdef CONFIG_SH_WRITETHROUGH
- /* Turn on Write-through caching */
+#if defined(CONFIG_CACHE_WRITETHROUGH)
+ /* Write-through */
flags |= CCR_CACHE_WT;
-#else
- /* .. or default to Write-back */
+#elif defined(CONFIG_CACHE_WRITEBACK)
+ /* Write-back */
flags |= CCR_CACHE_CB;
+#else
+ /* Off */
+ flags &= ~CCR_CACHE_ENABLE;
#endif
ctrl_outl(flags, CCR);
diff --git a/arch/sh/kernel/sh_ksyms.c b/arch/sh/kernel/sh_ksyms.c
index 37aef0a..de25070 100644
--- a/arch/sh/kernel/sh_ksyms.c
+++ b/arch/sh/kernel/sh_ksyms.c
@@ -128,7 +128,8 @@
#endif /* __GNUC__ == 4 */
#endif
-#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
+#if !defined(CONFIG_CACHE_OFF) && (defined(CONFIG_CPU_SH4) || \
+ defined(CONFIG_SH7705_CACHE_32KB))
/* needed by some modules */
EXPORT_SYMBOL(flush_cache_all);
EXPORT_SYMBOL(flush_cache_range);
@@ -136,8 +137,8 @@
EXPORT_SYMBOL(__flush_purge_region);
#endif
-#if defined(CONFIG_MMU) && (defined(CONFIG_CPU_SH4) || \
- defined(CONFIG_SH7705_CACHE_32KB))
+#if !defined(CONFIG_CACHE_OFF) && defined(CONFIG_MMU) && \
+ (defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB))
EXPORT_SYMBOL(clear_user_page);
#endif
diff --git a/arch/sh/mm/Kconfig b/arch/sh/mm/Kconfig
index 093d491..c277755 100644
--- a/arch/sh/mm/Kconfig
+++ b/arch/sh/mm/Kconfig
@@ -2,7 +2,6 @@
# Processor families
#
config CPU_SH2
- select SH_WRITETHROUGH if !CPU_SH2A
bool
config CPU_SH2A
@@ -414,8 +413,17 @@
Turn this option off for platforms that do not have a direct-mapped
cache, and you have no need to run the caches in such a configuration.
-config SH_WRITETHROUGH
- bool "Use write-through caching"
+choice
+ prompt "Cache mode"
+ default CACHE_WRITEBACK if CPU_SH2A || CPU_SH3 || CPU_SH4
+ default CACHE_WRITETHROUGH if (CPU_SH2 && !CPU_SH2A)
+
+config CACHE_WRITEBACK
+ bool "Write-back"
+ depends on CPU_SH2A || CPU_SH3 || CPU_SH4
+
+config CACHE_WRITETHROUGH
+ bool "Write-through"
help
Selecting this option will configure the caches in write-through
mode, as opposed to the default write-back configuration.
@@ -426,4 +434,9 @@
If unsure, say N.
+config CACHE_OFF
+ bool "Off"
+
+endchoice
+
endmenu
diff --git a/arch/sh/mm/Makefile b/arch/sh/mm/Makefile
index 4061e89..e73d7f9 100644
--- a/arch/sh/mm/Makefile
+++ b/arch/sh/mm/Makefile
@@ -4,9 +4,10 @@
obj-y := init.o extable.o consistent.o
-obj-$(CONFIG_CPU_SH2) += cache-sh2.o
-obj-$(CONFIG_CPU_SH3) += cache-sh3.o
-obj-$(CONFIG_CPU_SH4) += cache-sh4.o
+cache-$(CONFIG_CPU_SH2) := cache-sh2.o
+cache-$(CONFIG_CPU_SH3) := cache-sh3.o
+cache-$(CONFIG_CPU_SH4) := cache-sh4.o pg-sh4.o
+cache-$(CONFIG_CACHE_OFF) :=
mmu-y := tlb-nommu.o pg-nommu.o
mmu-$(CONFIG_CPU_SH3) += fault-nommu.o
@@ -14,7 +15,7 @@
mmu-$(CONFIG_MMU) := fault.o clear_page.o copy_page.o tlb-flush.o \
ioremap.o
-obj-y += $(mmu-y)
+obj-y += $(cache-y) $(mmu-y)
ifdef CONFIG_DEBUG_FS
obj-$(CONFIG_CPU_SH4) += cache-debugfs.o
@@ -22,7 +23,7 @@
ifdef CONFIG_MMU
obj-$(CONFIG_CPU_SH3) += tlb-sh3.o
-obj-$(CONFIG_CPU_SH4) += tlb-sh4.o pg-sh4.o
+obj-$(CONFIG_CPU_SH4) += tlb-sh4.o
obj-$(CONFIG_SH7705_CACHE_32KB) += pg-sh7705.o
endif
diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
index a08a4a9..7d43758 100644
--- a/arch/sh/mm/pmb.c
+++ b/arch/sh/mm/pmb.c
@@ -145,7 +145,7 @@
ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos));
-#ifdef CONFIG_SH_WRITETHROUGH
+#ifdef CONFIG_CACHE_WRITETHROUGH
/*
* When we are in 32-bit address extended mode, CCR.CB becomes
* invalid, so care must be taken to manually adjust cacheable
diff --git a/arch/sh/mm/tlb-sh4.c b/arch/sh/mm/tlb-sh4.c
index f74cf66..13fde8c 100644
--- a/arch/sh/mm/tlb-sh4.c
+++ b/arch/sh/mm/tlb-sh4.c
@@ -34,22 +34,27 @@
unsigned long flags;
unsigned long pteval;
unsigned long vpn;
- struct page *page;
- unsigned long pfn;
/* Ptrace may call this routine. */
if (vma && current->active_mm != vma->vm_mm)
return;
- pfn = pte_pfn(pte);
- if (pfn_valid(pfn)) {
- page = pfn_to_page(pfn);
- if (!test_bit(PG_mapped, &page->flags)) {
- unsigned long phys = pte_val(pte) & PTE_PHYS_MASK;
- __flush_wback_region((void *)P1SEGADDR(phys), PAGE_SIZE);
- __set_bit(PG_mapped, &page->flags);
+#ifndef CONFIG_CACHE_OFF
+ {
+ unsigned long pfn = pte_pfn(pte);
+
+ if (pfn_valid(pfn)) {
+ struct page *page = pfn_to_page(pfn);
+
+ if (!test_bit(PG_mapped, &page->flags)) {
+ unsigned long phys = pte_val(pte) & PTE_PHYS_MASK;
+ __flush_wback_region((void *)P1SEGADDR(phys),
+ PAGE_SIZE);
+ __set_bit(PG_mapped, &page->flags);
+ }
}
}
+#endif
local_irq_save(flags);
@@ -66,7 +71,7 @@
/* Set PTEL register */
pteval &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
-#ifdef CONFIG_SH_WRITETHROUGH
+#ifdef CONFIG_CACHE_WRITETHROUGH
pteval |= _PAGE_WT;
#endif
/* conveniently, we want all the software flags to be 0 anyway */
diff --git a/include/asm-sh/cacheflush.h b/include/asm-sh/cacheflush.h
index 07f62ec..aa558da 100644
--- a/include/asm-sh/cacheflush.h
+++ b/include/asm-sh/cacheflush.h
@@ -1,16 +1,47 @@
#ifndef __ASM_SH_CACHEFLUSH_H
#define __ASM_SH_CACHEFLUSH_H
+
#ifdef __KERNEL__
-#include <linux/mm.h>
+#ifdef CONFIG_CACHE_OFF
+/*
+ * Nothing to do when the cache is disabled, initial flush and explicit
+ * disabling is handled at CPU init time.
+ *
+ * See arch/sh/kernel/cpu/init.c:cache_init().
+ */
+#define p3_cache_init() do { } while (0)
+#define flush_cache_all() do { } while (0)
+#define flush_cache_mm(mm) do { } while (0)
+#define flush_cache_dup_mm(mm) do { } while (0)
+#define flush_cache_range(vma, start, end) do { } while (0)
+#define flush_cache_page(vma, vmaddr, pfn) do { } while (0)
+#define flush_dcache_page(page) do { } while (0)
+#define flush_icache_range(start, end) do { } while (0)
+#define flush_icache_page(vma,pg) do { } while (0)
+#define flush_dcache_mmap_lock(mapping) do { } while (0)
+#define flush_dcache_mmap_unlock(mapping) do { } while (0)
+#define flush_cache_sigtramp(vaddr) do { } while (0)
+#define flush_icache_user_range(vma,pg,adr,len) do { } while (0)
+#define __flush_wback_region(start, size) do { (void)(start); } while (0)
+#define __flush_purge_region(start, size) do { (void)(start); } while (0)
+#define __flush_invalidate_region(start, size) do { (void)(start); } while (0)
+#else
#include <asm/cpu/cacheflush.h>
+/*
+ * Consistent DMA requires that the __flush_xxx() primitives must be set
+ * for any of the enabled non-coherent caches (most of the UP CPUs),
+ * regardless of PIPT or VIPT cache configurations.
+ */
+
/* Flush (write-back only) a region (smaller than a page) */
extern void __flush_wback_region(void *start, int size);
/* Flush (write-back & invalidate) a region (smaller than a page) */
extern void __flush_purge_region(void *start, int size);
/* Flush (invalidate only) a region (smaller than a page) */
extern void __flush_invalidate_region(void *start, int size);
+#endif
#define flush_cache_vmap(start, end) flush_cache_all()
#define flush_cache_vunmap(start, end) flush_cache_all()
diff --git a/include/asm-sh/page.h b/include/asm-sh/page.h
index 6bc9bba..48b718e 100644
--- a/include/asm-sh/page.h
+++ b/include/asm-sh/page.h
@@ -70,14 +70,14 @@
extern void copy_page_nommu(void *to, void *from);
#endif
-#if defined(CONFIG_MMU) && (defined(CONFIG_CPU_SH4) || \
- defined(CONFIG_SH7705_CACHE_32KB))
+#if !defined(CONFIG_CACHE_OFF) && defined(CONFIG_MMU) && \
+ (defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB))
struct page;
extern void clear_user_page(void *to, unsigned long address, struct page *pg);
extern void copy_user_page(void *to, void *from, unsigned long address, struct page *pg);
extern void __clear_user_page(void *to, void *orig_to);
extern void __copy_user_page(void *to, void *from, void *orig_to);
-#elif defined(CONFIG_CPU_SH2) || defined(CONFIG_CPU_SH3) || !defined(CONFIG_MMU)
+#else
#define clear_user_page(page, vaddr, pg) clear_page(page)
#define copy_user_page(to, from, vaddr, pg) copy_page(to, from)
#endif
diff --git a/include/asm-sh/pgtable.h b/include/asm-sh/pgtable.h
index e3fae12..54ad503 100644
--- a/include/asm-sh/pgtable.h
+++ b/include/asm-sh/pgtable.h
@@ -563,7 +563,8 @@
extern unsigned int kobjsize(const void *objp);
#endif /* !CONFIG_MMU */
-#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
+#if !defined(CONFIG_CACHE_OFF) && (defined(CONFIG_CPU_SH4) || \
+ defined(CONFIG_SH7705_CACHE_32KB))
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
extern pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
#endif