This is now the next try to fix the aio bug in our kmap/kunmap
implementation. It's basically stuff from
@James: Does this looks better? Can we get a signed-off or Acked-by from
you on this patch?
The old mail thread was named "aio: fix D-cache aliasing issues"..
Dave & James: You can see my current patch description below. I would
be happy if one of you could come up with a better one...
Tested on my C8000 and works OK.
Helge
-------------------
From: John David Anglin <dave.anglin@xxxxxxxx>
The aio-stress testcase revealed the problems in our kmap/kunmap API, that we
didn't flushed the dcache page during kmap() on PA8800/PA8900 CPUs, and always
needed to flush the kernel dcache at kunmap(), even if the CPU doesn't require
conherency (< PA8800).
Signed-off-by: John David Anglin <dave.anglin@xxxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 3.9+
diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index f0e2784..8ddab5e 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -125,42 +125,44 @@ flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vma
void mark_rodata_ro(void);
#endif
-#ifdef CONFIG_PA8X00
-/* Only pa8800, pa8900 needs this */
-
#include <asm/kmap_types.h>
#define ARCH_HAS_KMAP
-void kunmap_parisc(void *addr);
-
static inline void *kmap(struct page *page)
{
might_sleep();
+ /* Flush dcache page on CPUs that require coherency. */
+ if (parisc_requires_coherency())
+ flush_dcache_page(page);
return page_address(page);
}
static inline void kunmap(struct page *page)
{
- kunmap_parisc(page_address(page));
+ /* Always flush kernel dcache, even if CPU doesn't require conherency.
+ * Needed on CPUs < PA8800/PA8900 for AIO support. */
+ flush_kernel_dcache_page_addr(page_address(page));
}
static inline void *kmap_atomic(struct page *page)
{
pagefault_disable();
+ /* Flush dcache page on CPUs that require coherency. */
+ if (parisc_requires_coherency())
+ flush_dcache_page(page);
return page_address(page);
}
static inline void __kunmap_atomic(void *addr)
{
- kunmap_parisc(addr);
+ flush_kernel_dcache_page_addr(addr);
pagefault_enable();
}
#define kmap_atomic_prot(page, prot) kmap_atomic(page)
#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
-#endif
#endif /* _PARISC_CACHEFLUSH_H */
diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h
index cc2290a..9cbee39 100644
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -106,6 +106,7 @@ struct cpuinfo_parisc {
};
extern struct system_cpuinfo_parisc boot_cpu_data;
+extern int parisc_coherent_cpu;
DECLARE_PER_CPU(struct cpuinfo_parisc, cpu_data);
#define CPU_HVERSION ((boot_cpu_data.hversion >> 4) & 0x0FFF)
@@ -338,8 +339,7 @@ extern unsigned long get_wchan(struct task_struct *p);
static inline int parisc_requires_coherency(void)
{
#ifdef CONFIG_PA8X00
- return (boot_cpu_data.cpu_type == mako) ||
- (boot_cpu_data.cpu_type == mako2);
+ return parisc_coherent_cpu;
#else
return 0;
#endif
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index c035673..3c6899f 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -391,8 +391,6 @@ EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
void clear_user_page(void *vto, unsigned long vaddr, struct page *page)
{
clear_page_asm(vto);
- if (!parisc_requires_coherency())
- flush_kernel_dcache_page_asm(vto);
}
EXPORT_SYMBOL(clear_user_page);
@@ -401,28 +399,18 @@ void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
{
/* Copy using kernel mapping. No coherency is needed
(all in kmap/kunmap) on machines that don't support
- non-equivalent aliasing. However, the `from' page
- needs to be flushed before it can be accessed through
- the kernel mapping. */
- preempt_disable();
- flush_dcache_page_asm(__pa(vfrom), vaddr);
- preempt_enable();
+ non-equivalent aliasing. On other machines, the
+ `from' page needs to be flushed before it can be
+ accessed through the kernel mapping. */
+ if (!parisc_requires_coherency()) {
+ preempt_disable();
+ flush_dcache_page_asm(__pa(vfrom), vaddr);
+ preempt_enable();
+ }
copy_page_asm(vto, vfrom);
- if (!parisc_requires_coherency())
- flush_kernel_dcache_page_asm(vto);
}
EXPORT_SYMBOL(copy_user_page);
-#ifdef CONFIG_PA8X00
-
-void kunmap_parisc(void *addr)
-{
- if (parisc_requires_coherency())
- flush_kernel_dcache_page_addr(addr);
-}
-EXPORT_SYMBOL(kunmap_parisc);
-#endif
-
void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
{
unsigned long flags;
diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c
index b68d977..f1b8c48 100644
--- a/arch/parisc/kernel/processor.c
+++ b/arch/parisc/kernel/processor.c
@@ -45,6 +45,11 @@
struct system_cpuinfo_parisc boot_cpu_data __read_mostly;
EXPORT_SYMBOL(boot_cpu_data);
+#ifdef CONFIG_PA8X00
+int parisc_coherent_cpu __read_mostly;
+EXPORT_SYMBOL(parisc_coherent_cpu);
+#endif
+
DEFINE_PER_CPU(struct cpuinfo_parisc, cpu_data);
extern int update_cr16_clocksource(void); /* from time.c */
@@ -271,6 +276,11 @@ void __init collect_boot_cpu_data(void)
printk(KERN_INFO "model %s\n",
boot_cpu_data.pdc.sys_model_name);
+#ifdef CONFIG_PA8X00
+ parisc_coherent_cpu = (boot_cpu_data.cpu_type == mako) ||
+ (boot_cpu_data.cpu_type == mako2);
+#endif
+
boot_cpu_data.hversion = boot_cpu_data.pdc.model.hversion;
boot_cpu_data.sversion = boot_cpu_data.pdc.model.sversion;
--
To unsubscribe from this list: send the line "unsubscribe linux-parisc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
