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authorChris Metcalf <cmetcalf@tilera.com>2011-05-02 15:54:32 -0400
committerChris Metcalf <cmetcalf@tilera.com>2011-05-04 14:40:46 -0400
commitdbb434214e34014dc7acb0e7811c37471df26a72 (patch)
treec7402998f41a967107fe3e7bec11b66c3b6a9afe /arch/tile/lib
parent43d9ebba93b4e775f89efc1eeeed3075a4ab4741 (diff)
arch/tile: disable GX prefetcher during cache flush
Otherwise, it's possible to end up with the prefetcher pulling data into cache that the code believes has been flushed. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Diffstat (limited to 'arch/tile/lib')
-rw-r--r--arch/tile/lib/cacheflush.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/tile/lib/cacheflush.c b/arch/tile/lib/cacheflush.c
index 35c1d8ca5f3..8928aace7a6 100644
--- a/arch/tile/lib/cacheflush.c
+++ b/arch/tile/lib/cacheflush.c
@@ -15,6 +15,7 @@
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <arch/icache.h>
+#include <arch/spr_def.h>
void __flush_icache_range(unsigned long start, unsigned long end)
@@ -39,6 +40,18 @@ void finv_buffer_remote(void *buffer, size_t size, int hfh)
char *p, *base;
size_t step_size, load_count;
const unsigned long STRIPE_WIDTH = 8192;
+#ifdef __tilegx__
+ /*
+ * On TILE-Gx, we must disable the dstream prefetcher before doing
+ * a cache flush; otherwise, we could end up with data in the cache
+ * that we don't want there. Note that normally we'd do an mf
+ * after the SPR write to disabling the prefetcher, but we do one
+ * below, before any further loads, so there's no need to do it
+ * here.
+ */
+ uint_reg_t old_dstream_pf = __insn_mfspr(SPR_DSTREAM_PF);
+ __insn_mtspr(SPR_DSTREAM_PF, 0);
+#endif
/*
* Flush and invalidate the buffer out of the local L1/L2
@@ -122,4 +135,9 @@ void finv_buffer_remote(void *buffer, size_t size, int hfh)
/* Wait for the load+inv's (and thus finvs) to have completed. */
__insn_mf();
+
+#ifdef __tilegx__
+ /* Reenable the prefetcher. */
+ __insn_mtspr(SPR_DSTREAM_PF, old_dstream_pf);
+#endif
}