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authorRichard Curnow <richard.curnow@st.com>2006-09-27 14:09:26 +0900
committerPaul Mundt <lethal@linux-sh.org>2006-09-27 14:09:26 +0900
commitb638d0b921dc95229af0dfd09cd24850336a2f75 (patch)
tree0ef34527a47b22421fb92ba2141052fecfe36482 /arch/sh/mm/cache-sh4.c
parentfdfc74f9fcebdda14609159d5010b758a9409acf (diff)
sh: Optimized cache handling for SH-4/SH-4A caches.
This reworks some of the SH-4 cache handling code to more easily accomodate newer-style caches (particularly for the > direct-mapped case), as well as optimizing some of the old code. Signed-off-by: Richard Curnow <richard.curnow@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/mm/cache-sh4.c')
-rw-r--r--arch/sh/mm/cache-sh4.c517
1 files changed, 430 insertions, 87 deletions
diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
index 846b63d6f5e..c036c2b4ac2 100644
--- a/arch/sh/mm/cache-sh4.c
+++ b/arch/sh/mm/cache-sh4.c
@@ -25,28 +25,95 @@
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
-extern void __flush_cache_4096(unsigned long addr, unsigned long phys,
+static void __flush_dcache_segment_1way(unsigned long start,
+ unsigned long extent);
+static void __flush_dcache_segment_2way(unsigned long start,
+ unsigned long extent);
+static void __flush_dcache_segment_4way(unsigned long start,
+ unsigned long extent);
+
+static void __flush_cache_4096(unsigned long addr, unsigned long phys,
unsigned long exec_offset);
-extern void __flush_cache_4096_all(unsigned long start);
-static void __flush_cache_4096_all_ex(unsigned long start);
-extern void __flush_dcache_all(void);
-static void __flush_dcache_all_ex(void);
+
+/*
+ * This is initialised here to ensure that it is not placed in the BSS. If
+ * that were to happen, note that cache_init gets called before the BSS is
+ * cleared, so this would get nulled out which would be hopeless.
+ */
+static void (*__flush_dcache_segment_fn)(unsigned long, unsigned long) =
+ (void (*)(unsigned long, unsigned long))0xdeadbeef;
+
+static void compute_alias(struct cache_info *c)
+{
+ c->alias_mask = ((c->sets - 1) << c->entry_shift) & ~(PAGE_SIZE - 1);
+ c->n_aliases = (c->alias_mask >> PAGE_SHIFT) + 1;
+}
+
+static void __init emit_cache_params(void)
+{
+ printk("PVR=%08x CVR=%08x PRR=%08x\n",
+ ctrl_inl(CCN_PVR),
+ ctrl_inl(CCN_CVR),
+ ctrl_inl(CCN_PRR));
+ printk("I-cache : n_ways=%d n_sets=%d way_incr=%d\n",
+ cpu_data->icache.ways,
+ cpu_data->icache.sets,
+ cpu_data->icache.way_incr);
+ printk("I-cache : entry_mask=0x%08x alias_mask=0x%08x n_aliases=%d\n",
+ cpu_data->icache.entry_mask,
+ cpu_data->icache.alias_mask,
+ cpu_data->icache.n_aliases);
+ printk("D-cache : n_ways=%d n_sets=%d way_incr=%d\n",
+ cpu_data->dcache.ways,
+ cpu_data->dcache.sets,
+ cpu_data->dcache.way_incr);
+ printk("D-cache : entry_mask=0x%08x alias_mask=0x%08x n_aliases=%d\n",
+ cpu_data->dcache.entry_mask,
+ cpu_data->dcache.alias_mask,
+ cpu_data->dcache.n_aliases);
+
+ if (!__flush_dcache_segment_fn)
+ panic("unknown number of cache ways\n");
+}
/*
* SH-4 has virtually indexed and physically tagged cache.
*/
-struct semaphore p3map_sem[4];
+/* Worst case assumed to be 64k cache, direct-mapped i.e. 4 synonym bits. */
+#define MAX_P3_SEMAPHORES 16
+
+struct semaphore p3map_sem[MAX_P3_SEMAPHORES];
void __init p3_cache_init(void)
{
- if (remap_area_pages(P3SEG, 0, PAGE_SIZE*4, _PAGE_CACHABLE))
+ int i;
+
+ compute_alias(&cpu_data->icache);
+ compute_alias(&cpu_data->dcache);
+
+ switch (cpu_data->dcache.ways) {
+ case 1:
+ __flush_dcache_segment_fn = __flush_dcache_segment_1way;
+ break;
+ case 2:
+ __flush_dcache_segment_fn = __flush_dcache_segment_2way;
+ break;
+ case 4:
+ __flush_dcache_segment_fn = __flush_dcache_segment_4way;
+ break;
+ default:
+ __flush_dcache_segment_fn = NULL;
+ break;
+ }
+
+ emit_cache_params();
+
+ if (remap_area_pages(P3SEG, 0, PAGE_SIZE * 4, _PAGE_CACHABLE))
panic("%s failed.", __FUNCTION__);
- sema_init (&p3map_sem[0], 1);
- sema_init (&p3map_sem[1], 1);
- sema_init (&p3map_sem[2], 1);
- sema_init (&p3map_sem[3], 1);
+ for (i = 0; i < cpu_data->dcache.n_aliases; i++)
+ sema_init(&p3map_sem[i], 1);
}
/*
@@ -91,7 +158,6 @@ void __flush_purge_region(void *start, int size)
}
}
-
/*
* No write back please
*/
@@ -110,46 +176,6 @@ void __flush_invalidate_region(void *start, int size)
}
}
-static void __flush_dcache_all_ex(void)
-{
- unsigned long addr, end_addr, entry_offset;
-
- end_addr = CACHE_OC_ADDRESS_ARRAY +
- (cpu_data->dcache.sets << cpu_data->dcache.entry_shift) *
- cpu_data->dcache.ways;
-
- entry_offset = 1 << cpu_data->dcache.entry_shift;
- for (addr = CACHE_OC_ADDRESS_ARRAY;
- addr < end_addr;
- addr += entry_offset) {
- ctrl_outl(0, addr);
- }
-}
-
-static void __flush_cache_4096_all_ex(unsigned long start)
-{
- unsigned long addr, entry_offset;
- int i;
-
- entry_offset = 1 << cpu_data->dcache.entry_shift;
- for (i = 0; i < cpu_data->dcache.ways;
- i++, start += cpu_data->dcache.way_incr) {
- for (addr = CACHE_OC_ADDRESS_ARRAY + start;
- addr < CACHE_OC_ADDRESS_ARRAY + 4096 + start;
- addr += entry_offset) {
- ctrl_outl(0, addr);
- }
- }
-}
-
-void flush_cache_4096_all(unsigned long start)
-{
- if (cpu_data->dcache.ways == 1)
- __flush_cache_4096_all(start);
- else
- __flush_cache_4096_all_ex(start);
-}
-
/*
* Write back the range of D-cache, and purge the I-cache.
*
@@ -180,9 +206,11 @@ void flush_cache_sigtramp(unsigned long addr)
local_irq_save(flags);
jump_to_P2();
+
for (i = 0; i < cpu_data->icache.ways;
i++, index += cpu_data->icache.way_incr)
ctrl_outl(0, index); /* Clear out Valid-bit */
+
back_to_P1();
wmb();
local_irq_restore(flags);
@@ -194,8 +222,8 @@ static inline void flush_cache_4096(unsigned long start,
unsigned long flags;
/*
- * SH7751, SH7751R, and ST40 have no restriction to handle cache.
- * (While SH7750 must do that at P2 area.)
+ * All types of SH-4 require PC to be in P2 to operate on the I-cache.
+ * Some types of SH-4 require PC to be in P2 to operate on the D-cache.
*/
if ((cpu_data->flags & CPU_HAS_P2_FLUSH_BUG)
|| start < CACHE_OC_ADDRESS_ARRAY) {
@@ -217,12 +245,13 @@ void flush_dcache_page(struct page *page)
{
if (test_bit(PG_mapped, &page->flags)) {
unsigned long phys = PHYSADDR(page_address(page));
+ unsigned long addr = CACHE_OC_ADDRESS_ARRAY;
+ int i, n;
/* Loop all the D-cache */
- flush_cache_4096(CACHE_OC_ADDRESS_ARRAY, phys);
- flush_cache_4096(CACHE_OC_ADDRESS_ARRAY | 0x1000, phys);
- flush_cache_4096(CACHE_OC_ADDRESS_ARRAY | 0x2000, phys);
- flush_cache_4096(CACHE_OC_ADDRESS_ARRAY | 0x3000, phys);
+ n = cpu_data->dcache.n_aliases;
+ for (i = 0; i < n; i++, addr += PAGE_SIZE)
+ flush_cache_4096(addr, phys);
}
wmb();
@@ -246,10 +275,7 @@ static inline void flush_icache_all(void)
void flush_dcache_all(void)
{
- if (cpu_data->dcache.ways == 1)
- __flush_dcache_all();
- else
- __flush_dcache_all_ex();
+ (*__flush_dcache_segment_fn)(0UL, cpu_data->dcache.way_size);
wmb();
}
@@ -261,6 +287,16 @@ void flush_cache_all(void)
void flush_cache_mm(struct mm_struct *mm)
{
+ /*
+ * Note : (RPC) since the caches are physically tagged, the only point
+ * of flush_cache_mm for SH-4 is to get rid of aliases from the
+ * D-cache. The assumption elsewhere, e.g. flush_cache_range, is that
+ * lines can stay resident so long as the virtual address they were
+ * accessed with (hence cache set) is in accord with the physical
+ * address (i.e. tag). It's no different here. So I reckon we don't
+ * need to flush the I-cache, since aliases don't matter for that. We
+ * should try that.
+ */
flush_cache_all();
}
@@ -273,24 +309,36 @@ void flush_cache_mm(struct mm_struct *mm)
void flush_cache_page(struct vm_area_struct *vma, unsigned long address, unsigned long pfn)
{
unsigned long phys = pfn << PAGE_SHIFT;
+ unsigned int alias_mask;
+
+ alias_mask = cpu_data->dcache.alias_mask;
/* We only need to flush D-cache when we have alias */
- if ((address^phys) & CACHE_ALIAS) {
+ if ((address^phys) & alias_mask) {
/* Loop 4K of the D-cache */
flush_cache_4096(
- CACHE_OC_ADDRESS_ARRAY | (address & CACHE_ALIAS),
+ CACHE_OC_ADDRESS_ARRAY | (address & alias_mask),
phys);
/* Loop another 4K of the D-cache */
flush_cache_4096(
- CACHE_OC_ADDRESS_ARRAY | (phys & CACHE_ALIAS),
+ CACHE_OC_ADDRESS_ARRAY | (phys & alias_mask),
phys);
}
- if (vma->vm_flags & VM_EXEC)
- /* Loop 4K (half) of the I-cache */
+ alias_mask = cpu_data->icache.alias_mask;
+ if (vma->vm_flags & VM_EXEC) {
+ /*
+ * Evict entries from the portion of the cache from which code
+ * may have been executed at this address (virtual). There's
+ * no need to evict from the portion corresponding to the
+ * physical address as for the D-cache, because we know the
+ * kernel has never executed the code through its identity
+ * translation.
+ */
flush_cache_4096(
- CACHE_IC_ADDRESS_ARRAY | (address & 0x1000),
+ CACHE_IC_ADDRESS_ARRAY | (address & alias_mask),
phys);
+ }
}
/*
@@ -305,14 +353,28 @@ void flush_cache_page(struct vm_area_struct *vma, unsigned long address, unsigne
void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
- unsigned long p = start & PAGE_MASK;
+ unsigned long d = 0, p = start & PAGE_MASK;
+ unsigned long alias_mask = cpu_data->dcache.alias_mask;
+ unsigned long n_aliases = cpu_data->dcache.n_aliases;
+ unsigned long select_bit;
+ unsigned long all_aliases_mask;
+ unsigned long addr_offset;
+ unsigned long phys;
pgd_t *dir;
pmd_t *pmd;
pud_t *pud;
pte_t *pte;
pte_t entry;
- unsigned long phys;
- unsigned long d = 0;
+ int i;
+
+ /*
+ * If cache is only 4k-per-way, there are never any 'aliases'. Since
+ * the cache is physically tagged, the data can just be left in there.
+ */
+ if (n_aliases == 0)
+ return;
+
+ all_aliases_mask = (1 << n_aliases) - 1;
/*
* Don't bother with the lookup and alias check if we have a
@@ -335,39 +397,52 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
do {
if (pmd_none(*pmd) || pmd_bad(*pmd)) {
- p &= ~((1 << PMD_SHIFT) -1);
+ p &= ~((1 << PMD_SHIFT) - 1);
p += (1 << PMD_SHIFT);
pmd++;
+
continue;
}
+
pte = pte_offset_kernel(pmd, p);
+
do {
entry = *pte;
+
if ((pte_val(entry) & _PAGE_PRESENT)) {
- phys = pte_val(entry)&PTE_PHYS_MASK;
- if ((p^phys) & CACHE_ALIAS) {
- d |= 1 << ((p & CACHE_ALIAS)>>12);
- d |= 1 << ((phys & CACHE_ALIAS)>>12);
- if (d == 0x0f)
+ phys = pte_val(entry) & PTE_PHYS_MASK;
+
+ if ((p ^ phys) & alias_mask) {
+ d |= 1 << ((p & alias_mask) >> PAGE_SHIFT);
+ d |= 1 << ((phys & alias_mask) >> PAGE_SHIFT);
+
+ if (d == all_aliases_mask)
goto loop_exit;
}
}
+
pte++;
p += PAGE_SIZE;
} while (p < end && ((unsigned long)pte & ~PAGE_MASK));
pmd++;
} while (p < end);
- loop_exit:
- if (d & 1)
- flush_cache_4096_all(0);
- if (d & 2)
- flush_cache_4096_all(0x1000);
- if (d & 4)
- flush_cache_4096_all(0x2000);
- if (d & 8)
- flush_cache_4096_all(0x3000);
- if (vma->vm_flags & VM_EXEC)
+
+loop_exit:
+ for (i = 0, select_bit = 0x1, addr_offset = 0x0; i < n_aliases;
+ i++, select_bit <<= 1, addr_offset += PAGE_SIZE)
+ if (d & select_bit) {
+ (*__flush_dcache_segment_fn)(addr_offset, PAGE_SIZE);
+ wmb();
+ }
+
+ if (vma->vm_flags & VM_EXEC) {
+ /*
+ * TODO: Is this required??? Need to look at how I-cache
+ * coherency is assured when new programs are loaded to see if
+ * this matters.
+ */
flush_icache_all();
+ }
}
/*
@@ -384,3 +459,271 @@ void flush_icache_user_range(struct vm_area_struct *vma,
mb();
}
+/**
+ * __flush_cache_4096
+ *
+ * @addr: address in memory mapped cache array
+ * @phys: P1 address to flush (has to match tags if addr has 'A' bit
+ * set i.e. associative write)
+ * @exec_offset: set to 0x20000000 if flush has to be executed from P2
+ * region else 0x0
+ *
+ * The offset into the cache array implied by 'addr' selects the
+ * 'colour' of the virtual address range that will be flushed. The
+ * operation (purge/write-back) is selected by the lower 2 bits of
+ * 'phys'.
+ */
+static void __flush_cache_4096(unsigned long addr, unsigned long phys,
+ unsigned long exec_offset)
+{
+ int way_count;
+ unsigned long base_addr = addr;
+ struct cache_info *dcache;
+ unsigned long way_incr;
+ unsigned long a, ea, p;
+ unsigned long temp_pc;
+
+ dcache = &cpu_data->dcache;
+ /* Write this way for better assembly. */
+ way_count = dcache->ways;
+ way_incr = dcache->way_incr;
+
+ /*
+ * Apply exec_offset (i.e. branch to P2 if required.).
+ *
+ * FIXME:
+ *
+ * If I write "=r" for the (temp_pc), it puts this in r6 hence
+ * trashing exec_offset before it's been added on - why? Hence
+ * "=&r" as a 'workaround'
+ */
+ asm volatile("mov.l 1f, %0\n\t"
+ "add %1, %0\n\t"
+ "jmp @%0\n\t"
+ "nop\n\t"
+ ".balign 4\n\t"
+ "1: .long 2f\n\t"
+ "2:\n" : "=&r" (temp_pc) : "r" (exec_offset));
+
+ /*
+ * We know there will be >=1 iteration, so write as do-while to avoid
+ * pointless nead-of-loop check for 0 iterations.
+ */
+ do {
+ ea = base_addr + PAGE_SIZE;
+ a = base_addr;
+ p = phys;
+
+ do {
+ *(volatile unsigned long *)a = p;
+ /*
+ * Next line: intentionally not p+32, saves an add, p
+ * will do since only the cache tag bits need to
+ * match.
+ */
+ *(volatile unsigned long *)(a+32) = p;
+ a += 64;
+ p += 64;
+ } while (a < ea);
+
+ base_addr += way_incr;
+ } while (--way_count != 0);
+}
+
+/*
+ * Break the 1, 2 and 4 way variants of this out into separate functions to
+ * avoid nearly all the overhead of having the conditional stuff in the function
+ * bodies (+ the 1 and 2 way cases avoid saving any registers too).
+ */
+static void __flush_dcache_segment_1way(unsigned long start,
+ unsigned long extent_per_way)
+{
+ unsigned long orig_sr, sr_with_bl;
+ unsigned long base_addr;
+ unsigned long way_incr, linesz, way_size;
+ struct cache_info *dcache;
+ register unsigned long a0, a0e;
+
+ asm volatile("stc sr, %0" : "=r" (orig_sr));
+ sr_with_bl = orig_sr | (1<<28);
+ base_addr = ((unsigned long)&empty_zero_page[0]);
+
+ /*
+ * The previous code aligned base_addr to 16k, i.e. the way_size of all
+ * existing SH-4 D-caches. Whilst I don't see a need to have this
+ * aligned to any better than the cache line size (which it will be
+ * anyway by construction), let's align it to at least the way_size of
+ * any existing or conceivable SH-4 D-cache. -- RPC
+ */
+ base_addr = ((base_addr >> 16) << 16);
+ base_addr |= start;
+
+ dcache = &cpu_data->dcache;
+ linesz = dcache->linesz;
+ way_incr = dcache->way_incr;
+ way_size = dcache->way_size;
+
+ a0 = base_addr;
+ a0e = base_addr + extent_per_way;
+ do {
+ asm volatile("ldc %0, sr" : : "r" (sr_with_bl));
+ asm volatile("movca.l r0, @%0\n\t"
+ "ocbi @%0" : : "r" (a0));
+ a0 += linesz;
+ asm volatile("movca.l r0, @%0\n\t"
+ "ocbi @%0" : : "r" (a0));
+ a0 += linesz;
+ asm volatile("movca.l r0, @%0\n\t"
+ "ocbi @%0" : : "r" (a0));
+ a0 += linesz;
+ asm volatile("movca.l r0, @%0\n\t"
+ "ocbi @%0" : : "r" (a0));
+ asm volatile("ldc %0, sr" : : "r" (orig_sr));
+ a0 += linesz;
+ } while (a0 < a0e);
+}
+
+static void __flush_dcache_segment_2way(unsigned long start,
+ unsigned long extent_per_way)
+{
+ unsigned long orig_sr, sr_with_bl;
+ unsigned long base_addr;
+ unsigned long way_incr, linesz, way_size;
+ struct cache_info *dcache;
+ register unsigned long a0, a1, a0e;
+
+ asm volatile("stc sr, %0" : "=r" (orig_sr));
+ sr_with_bl = orig_sr | (1<<28);
+ base_addr = ((unsigned long)&empty_zero_page[0]);
+
+ /* See comment under 1-way above */
+ base_addr = ((base_addr >> 16) << 16);
+ base_addr |= start;
+
+ dcache = &cpu_data->dcache;
+ linesz = dcache->linesz;
+ way_incr = dcache->way_incr;
+ way_size = dcache->way_size;
+
+ a0 = base_addr;
+ a1 = a0 + way_incr;
+ a0e = base_addr + extent_per_way;
+ do {
+ asm volatile("ldc %0, sr" : : "r" (sr_with_bl));
+ asm volatile("movca.l r0, @%0\n\t"
+ "movca.l r0, @%1\n\t"
+ "ocbi @%0\n\t"
+ "ocbi @%1" : :
+ "r" (a0), "r" (a1));
+ a0 += linesz;
+ a1 += linesz;
+ asm volatile("movca.l r0, @%0\n\t"
+ "movca.l r0, @%1\n\t"
+ "ocbi @%0\n\t"
+ "ocbi @%1" : :
+ "r" (a0), "r" (a1));
+ a0 += linesz;
+ a1 += linesz;
+ asm volatile("movca.l r0, @%0\n\t"
+ "movca.l r0, @%1\n\t"
+ "ocbi @%0\n\t"
+ "ocbi @%1" : :
+ "r" (a0), "r" (a1));
+ a0 += linesz;
+ a1 += linesz;
+ asm volatile("movca.l r0, @%0\n\t"
+ "movca.l r0, @%1\n\t"
+ "ocbi @%0\n\t"
+ "ocbi @%1" : :
+ "r" (a0), "r" (a1));
+ asm volatile("ldc %0, sr" : : "r" (orig_sr));
+ a0 += linesz;
+ a1 += linesz;
+ } while (a0 < a0e);
+}
+
+static void __flush_dcache_segment_4way(unsigned long start,
+ unsigned long extent_per_way)
+{
+ unsigned long orig_sr, sr_with_bl;
+ unsigned long base_addr;
+ unsigned long way_incr, linesz, way_size;
+ struct cache_info *dcache;
+ register unsigned long a0, a1, a2, a3, a0e;
+
+ asm volatile("stc sr, %0" : "=r" (orig_sr));
+ sr_with_bl = orig_sr | (1<<28);
+ base_addr = ((unsigned long)&empty_zero_page[0]);
+
+ /* See comment under 1-way above */
+ base_addr = ((base_addr >> 16) << 16);
+ base_addr |= start;
+
+ dcache = &cpu_data->dcache;
+ linesz = dcache->linesz;
+ way_incr = dcache->way_incr;
+ way_size = dcache->way_size;
+
+ a0 = base_addr;
+ a1 = a0 + way_incr;
+ a2 = a1 + way_incr;
+ a3 = a2 + way_incr;
+ a0e = base_addr + extent_per_way;
+ do {
+ asm volatile("ldc %0, sr" : : "r" (sr_with_bl));
+ asm volatile("movca.l r0, @%0\n\t"
+ "movca.l r0, @%1\n\t"
+ "movca.l r0, @%2\n\t"
+ "movca.l r0, @%3\n\t"
+ "ocbi @%0\n\t"
+ "ocbi @%1\n\t"
+ "ocbi @%2\n\t"
+ "ocbi @%3\n\t" : :
+ "r" (a0), "r" (a1), "r" (a2), "r" (a3));
+ a0 += linesz;
+ a1 += linesz;
+ a2 += linesz;
+ a3 += linesz;
+ asm volatile("movca.l r0, @%0\n\t"
+ "movca.l r0, @%1\n\t"
+ "movca.l r0, @%2\n\t"
+ "movca.l r0, @%3\n\t"
+ "ocbi @%0\n\t"
+ "ocbi @%1\n\t"
+ "ocbi @%2\n\t"
+ "ocbi @%3\n\t" : :
+ "r" (a0), "r" (a1), "r" (a2), "r" (a3));
+ a0 += linesz;
+ a1 += linesz;
+ a2 += linesz;
+ a3 += linesz;
+ asm volatile("movca.l r0, @%0\n\t"
+ "movca.l r0, @%1\n\t"
+ "movca.l r0, @%2\n\t"
+ "movca.l r0, @%3\n\t"
+ "ocbi @%0\n\t"
+ "ocbi @%1\n\t"
+ "ocbi @%2\n\t"
+ "ocbi @%3\n\t" : :
+ "r" (a0), "r" (a1), "r" (a2), "r" (a3));
+ a0 += linesz;
+ a1 += linesz;
+ a2 += linesz;
+ a3 += linesz;
+ asm volatile("movca.l r0, @%0\n\t"
+ "movca.l r0, @%1\n\t"
+ "movca.l r0, @%2\n\t"
+ "movca.l r0, @%3\n\t"
+ "ocbi @%0\n\t"
+ "ocbi @%1\n\t"
+ "ocbi @%2\n\t"
+ "ocbi @%3\n\t" : :
+ "r" (a0), "r" (a1), "r" (a2), "r" (a3));
+ asm volatile("ldc %0, sr" : : "r" (orig_sr));
+ a0 += linesz;
+ a1 += linesz;
+ a2 += linesz;
+ a3 += linesz;
+ } while (a0 < a0e);
+}
+