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authorNicolas Pitre <nicolas.pitre@linaro.org>2010-12-16 14:56:34 -0500
committerNicolas Pitre <nico@fluxnic.net>2010-12-19 12:57:16 -0500
commit6d3e6d3640052cac958d61c44597cc216f6ee09f (patch)
treeba246fb50f8d637a0c6074211ddc2e74c4eb1ebe /arch/arm/mm/cache-feroceon-l2.c
parent25cbe45440ea89a3b0f6f7ed326d3d476d53068b (diff)
ARM: fix cache-feroceon-l2 after stack based kmap_atomic()
Since commit 3e4d3af501 "mm: stack based kmap_atomic()", it is actively wrong to rely on fixed kmap type indices (namely KM_L2_CACHE) as kmap_atomic() totally ignores them and a concurrent instance of it may happily reuse any slot for any purpose. Because kmap_atomic() is now able to deal with reentrancy, we can get rid of the ad hoc mapping here. While the code is made much simpler, there is a needless cache flush introduced by the usage of __kunmap_atomic(). It is not clear if the performance difference to remove that is worth the cost in code maintenance (I don't think there are that many highmem users on that platform anyway) but that should be reconsidered when/if someone cares enough to do some measurements. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm/mm/cache-feroceon-l2.c')
-rw-r--r--arch/arm/mm/cache-feroceon-l2.c37
1 files changed, 19 insertions, 18 deletions
diff --git a/arch/arm/mm/cache-feroceon-l2.c b/arch/arm/mm/cache-feroceon-l2.c
index 6e77c042d8e..e0b0e7a4ec6 100644
--- a/arch/arm/mm/cache-feroceon-l2.c
+++ b/arch/arm/mm/cache-feroceon-l2.c
@@ -13,13 +13,9 @@
*/
#include <linux/init.h>
+#include <linux/highmem.h>
#include <asm/cacheflush.h>
-#include <asm/kmap_types.h>
-#include <asm/fixmap.h>
-#include <asm/pgtable.h>
-#include <asm/tlbflush.h>
#include <plat/cache-feroceon-l2.h>
-#include "mm.h"
/*
* Low-level cache maintenance operations.
@@ -39,27 +35,30 @@
* between which we don't want to be preempted.
*/
-static inline unsigned long l2_start_va(unsigned long paddr)
+static inline unsigned long l2_get_va(unsigned long paddr)
{
#ifdef CONFIG_HIGHMEM
/*
- * Let's do our own fixmap stuff in a minimal way here.
* Because range ops can't be done on physical addresses,
* we simply install a virtual mapping for it only for the
* TLB lookup to occur, hence no need to flush the untouched
- * memory mapping. This is protected with the disabling of
- * interrupts by the caller.
+ * memory mapping afterwards (note: a cache flush may happen
+ * in some circumstances depending on the path taken in kunmap_atomic).
*/
- unsigned long idx = KM_L2_CACHE + KM_TYPE_NR * smp_processor_id();
- unsigned long vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte_ext(TOP_PTE(vaddr), pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL), 0);
- local_flush_tlb_kernel_page(vaddr);
- return vaddr + (paddr & ~PAGE_MASK);
+ void *vaddr = kmap_atomic_pfn(paddr >> PAGE_SHIFT);
+ return (unsigned long)vaddr + (paddr & ~PAGE_MASK);
#else
return __phys_to_virt(paddr);
#endif
}
+static inline void l2_put_va(unsigned long vaddr)
+{
+#ifdef CONFIG_HIGHMEM
+ kunmap_atomic((void *)vaddr);
+#endif
+}
+
static inline void l2_clean_pa(unsigned long addr)
{
__asm__("mcr p15, 1, %0, c15, c9, 3" : : "r" (addr));
@@ -76,13 +75,14 @@ static inline void l2_clean_pa_range(unsigned long start, unsigned long end)
*/
BUG_ON((start ^ end) >> PAGE_SHIFT);
- raw_local_irq_save(flags);
- va_start = l2_start_va(start);
+ va_start = l2_get_va(start);
va_end = va_start + (end - start);
+ raw_local_irq_save(flags);
__asm__("mcr p15, 1, %0, c15, c9, 4\n\t"
"mcr p15, 1, %1, c15, c9, 5"
: : "r" (va_start), "r" (va_end));
raw_local_irq_restore(flags);
+ l2_put_va(va_start);
}
static inline void l2_clean_inv_pa(unsigned long addr)
@@ -106,13 +106,14 @@ static inline void l2_inv_pa_range(unsigned long start, unsigned long end)
*/
BUG_ON((start ^ end) >> PAGE_SHIFT);
- raw_local_irq_save(flags);
- va_start = l2_start_va(start);
+ va_start = l2_get_va(start);
va_end = va_start + (end - start);
+ raw_local_irq_save(flags);
__asm__("mcr p15, 1, %0, c15, c11, 4\n\t"
"mcr p15, 1, %1, c15, c11, 5"
: : "r" (va_start), "r" (va_end));
raw_local_irq_restore(flags);
+ l2_put_va(va_start);
}
static inline void l2_inv_all(void)