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>
This commit is contained in:
Paul Mundt 2007-07-31 17:07:28 +09:00
parent ac919986d7
commit e7bd34a15b
9 changed files with 86 additions and 31 deletions

View file

@ -143,12 +143,15 @@ static void __init cache_init(void)
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);

View file

@ -128,7 +128,8 @@ DECLARE_EXPORT(__movstrSI12_i4);
#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_dcache_page);
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

View file

@ -2,7 +2,6 @@
# Processor families
#
config CPU_SH2
select SH_WRITETHROUGH if !CPU_SH2A
bool
config CPU_SH2A
@ -414,8 +413,17 @@ config SH_DIRECT_MAPPED
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 @@ config SH_WRITETHROUGH
If unsure, say N.
config CACHE_OFF
bool "Off"
endchoice
endmenu

View file

@ -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-$(CONFIG_CPU_SH4) += fault-nommu.o
mmu-$(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 @@ endif
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

View file

@ -145,7 +145,7 @@ int __set_pmb_entry(unsigned long vpn, unsigned long ppn,
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

View file

@ -34,22 +34,27 @@ void update_mmu_cache(struct vm_area_struct * vma,
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 @@ void update_mmu_cache(struct vm_area_struct * vma,
/* 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 */

View file

@ -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()

View file

@ -70,14 +70,14 @@ extern void clear_page_nommu(void *to);
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

View file

@ -563,7 +563,8 @@ struct mm_struct;
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