[ARM] xsc3: add highmem support to L2 cache handling code
On xsc3, L2 cache ops are possible only on virtual addresses. The code
is rearranged so to have a linear progression requiring the least amount
of pte setups in the highmem case. To protect the virtual mapping so
created, interrupts must be disabled currently up to a page worth of
address range.
The interrupt disabling is done in a way to minimize the overhead within
the inner loop. The alternative would consist in separate code for
the highmem and non highmem compilation which is less preferable.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
diff --git a/arch/arm/mm/cache-xsc3l2.c b/arch/arm/mm/cache-xsc3l2.c
index 464de89..5d180cb 100644
--- a/arch/arm/mm/cache-xsc3l2.c
+++ b/arch/arm/mm/cache-xsc3l2.c
@@ -17,12 +17,14 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/io.h>
-
#include <asm/system.h>
#include <asm/cputype.h>
#include <asm/cacheflush.h>
+#include <asm/kmap_types.h>
+#include <asm/fixmap.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include "mm.h"
#define CR_L2 (1 << 26)
@@ -47,21 +49,11 @@
__asm__("mcr p15, 1, %0, c7, c11, 1" : : "r" (addr));
}
-static inline void xsc3_l2_clean_pa(unsigned long addr)
-{
- xsc3_l2_clean_mva(__phys_to_virt(addr));
-}
-
static inline void xsc3_l2_inv_mva(unsigned long addr)
{
__asm__("mcr p15, 1, %0, c7, c7, 1" : : "r" (addr));
}
-static inline void xsc3_l2_inv_pa(unsigned long addr)
-{
- xsc3_l2_inv_mva(__phys_to_virt(addr));
-}
-
static inline void xsc3_l2_inv_all(void)
{
unsigned long l2ctype, set_way;
@@ -79,50 +71,103 @@
dsb();
}
+#ifdef CONFIG_HIGHMEM
+#define l2_map_save_flags(x) raw_local_save_flags(x)
+#define l2_map_restore_flags(x) raw_local_irq_restore(x)
+#else
+#define l2_map_save_flags(x) ((x) = 0)
+#define l2_map_restore_flags(x) ((void)(x))
+#endif
+
+static inline unsigned long l2_map_va(unsigned long pa, unsigned long prev_va,
+ unsigned long flags)
+{
+#ifdef CONFIG_HIGHMEM
+ unsigned long va = prev_va & PAGE_MASK;
+ unsigned long pa_offset = pa << (32 - PAGE_SHIFT);
+ if (unlikely(pa_offset < (prev_va << (32 - PAGE_SHIFT)))) {
+ /*
+ * Switching to a new page. Because cache ops are
+ * using virtual addresses only, we must put a mapping
+ * in place for it. We also enable interrupts for a
+ * short while and disable them again to protect this
+ * mapping.
+ */
+ unsigned long idx;
+ raw_local_irq_restore(flags);
+ idx = KM_L2_CACHE + KM_TYPE_NR * smp_processor_id();
+ va = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+ raw_local_irq_restore(flags | PSR_I_BIT);
+ set_pte_ext(TOP_PTE(va), pfn_pte(pa >> PAGE_SHIFT, PAGE_KERNEL), 0);
+ local_flush_tlb_kernel_page(va);
+ }
+ return va + (pa_offset >> (32 - PAGE_SHIFT));
+#else
+ return __phys_to_virt(pa);
+#endif
+}
+
static void xsc3_l2_inv_range(unsigned long start, unsigned long end)
{
+ unsigned long vaddr, flags;
+
if (start == 0 && end == -1ul) {
xsc3_l2_inv_all();
return;
}
+ vaddr = -1; /* to force the first mapping */
+ l2_map_save_flags(flags);
+
/*
* Clean and invalidate partial first cache line.
*/
if (start & (CACHE_LINE_SIZE - 1)) {
- xsc3_l2_clean_pa(start & ~(CACHE_LINE_SIZE - 1));
- xsc3_l2_inv_pa(start & ~(CACHE_LINE_SIZE - 1));
+ vaddr = l2_map_va(start & ~(CACHE_LINE_SIZE - 1), vaddr, flags);
+ xsc3_l2_clean_mva(vaddr);
+ xsc3_l2_inv_mva(vaddr);
start = (start | (CACHE_LINE_SIZE - 1)) + 1;
}
/*
- * Clean and invalidate partial last cache line.
- */
- if (start < end && (end & (CACHE_LINE_SIZE - 1))) {
- xsc3_l2_clean_pa(end & ~(CACHE_LINE_SIZE - 1));
- xsc3_l2_inv_pa(end & ~(CACHE_LINE_SIZE - 1));
- end &= ~(CACHE_LINE_SIZE - 1);
- }
-
- /*
* Invalidate all full cache lines between 'start' and 'end'.
*/
- while (start < end) {
- xsc3_l2_inv_pa(start);
+ while (start < (end & ~(CACHE_LINE_SIZE - 1))) {
+ vaddr = l2_map_va(start, vaddr, flags);
+ xsc3_l2_inv_mva(vaddr);
start += CACHE_LINE_SIZE;
}
+ /*
+ * Clean and invalidate partial last cache line.
+ */
+ if (start < end) {
+ vaddr = l2_map_va(start, vaddr, flags);
+ xsc3_l2_clean_mva(vaddr);
+ xsc3_l2_inv_mva(vaddr);
+ }
+
+ l2_map_restore_flags(flags);
+
dsb();
}
static void xsc3_l2_clean_range(unsigned long start, unsigned long end)
{
+ unsigned long vaddr, flags;
+
+ vaddr = -1; /* to force the first mapping */
+ l2_map_save_flags(flags);
+
start &= ~(CACHE_LINE_SIZE - 1);
while (start < end) {
- xsc3_l2_clean_pa(start);
+ vaddr = l2_map_va(start, vaddr, flags);
+ xsc3_l2_clean_mva(vaddr);
start += CACHE_LINE_SIZE;
}
+ l2_map_restore_flags(flags);
+
dsb();
}
@@ -148,18 +193,26 @@
static void xsc3_l2_flush_range(unsigned long start, unsigned long end)
{
+ unsigned long vaddr, flags;
+
if (start == 0 && end == -1ul) {
xsc3_l2_flush_all();
return;
}
+ vaddr = -1; /* to force the first mapping */
+ l2_map_save_flags(flags);
+
start &= ~(CACHE_LINE_SIZE - 1);
while (start < end) {
- xsc3_l2_clean_pa(start);
- xsc3_l2_inv_pa(start);
+ vaddr = l2_map_va(start, vaddr, flags);
+ xsc3_l2_clean_mva(vaddr);
+ xsc3_l2_inv_mva(vaddr);
start += CACHE_LINE_SIZE;
}
+ l2_map_restore_flags(flags);
+
dsb();
}