[IA64] improve flush_icache_range()
Check with PAL to see what the i-cache line size is for
each level of the cache, and so use the correct stride
when flushing the cache.
Acked-by: David Mosberger
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index 2693e15..7fc891a 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -20,6 +20,7 @@
* 02/01/00 R.Seth fixed get_cpuinfo for SMP
* 01/07/99 S.Eranian added the support for command line argument
* 06/24/99 W.Drummond added boot_cpu_data.
+ * 05/28/05 Z. Menyhart Dynamic stride size for "flush_icache_range()"
*/
#include <linux/config.h>
#include <linux/module.h>
@@ -83,6 +84,13 @@
unsigned int num_io_spaces;
/*
+ * "flush_icache_range()" needs to know what processor dependent stride size to use
+ * when it makes i-cache(s) coherent with d-caches.
+ */
+#define I_CACHE_STRIDE_SHIFT 5 /* Safest way to go: 32 bytes by 32 bytes */
+unsigned long ia64_i_cache_stride_shift = ~0;
+
+/*
* The merge_mask variable needs to be set to (max(iommu_page_size(iommu)) - 1). This
* mask specifies a mask of address bits that must be 0 in order for two buffers to be
* mergeable by the I/O MMU (i.e., the end address of the first buffer and the start
@@ -626,6 +634,12 @@
/* start_kernel() requires this... */
}
+/*
+ * Calculate the max. cache line size.
+ *
+ * In addition, the minimum of the i-cache stride sizes is calculated for
+ * "flush_icache_range()".
+ */
static void
get_max_cacheline_size (void)
{
@@ -639,6 +653,8 @@
printk(KERN_ERR "%s: ia64_pal_cache_summary() failed (status=%ld)\n",
__FUNCTION__, status);
max = SMP_CACHE_BYTES;
+ /* Safest setup for "flush_icache_range()" */
+ ia64_i_cache_stride_shift = I_CACHE_STRIDE_SHIFT;
goto out;
}
@@ -647,14 +663,31 @@
&cci);
if (status != 0) {
printk(KERN_ERR
- "%s: ia64_pal_cache_config_info(l=%lu) failed (status=%ld)\n",
+ "%s: ia64_pal_cache_config_info(l=%lu, 2) failed (status=%ld)\n",
__FUNCTION__, l, status);
max = SMP_CACHE_BYTES;
+ /* The safest setup for "flush_icache_range()" */
+ cci.pcci_stride = I_CACHE_STRIDE_SHIFT;
+ cci.pcci_unified = 1;
}
line_size = 1 << cci.pcci_line_size;
if (line_size > max)
max = line_size;
- }
+ if (!cci.pcci_unified) {
+ status = ia64_pal_cache_config_info(l,
+ /* cache_type (instruction)= */ 1,
+ &cci);
+ if (status != 0) {
+ printk(KERN_ERR
+ "%s: ia64_pal_cache_config_info(l=%lu, 1) failed (status=%ld)\n",
+ __FUNCTION__, l, status);
+ /* The safest setup for "flush_icache_range()" */
+ cci.pcci_stride = I_CACHE_STRIDE_SHIFT;
+ }
+ }
+ if (cci.pcci_stride < ia64_i_cache_stride_shift)
+ ia64_i_cache_stride_shift = cci.pcci_stride;
+ }
out:
if (max > ia64_max_cacheline_size)
ia64_max_cacheline_size = max;