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-rw-r--r--util/cacheflush.c25
1 files changed, 23 insertions, 2 deletions
diff --git a/util/cacheflush.c b/util/cacheflush.c
index 01b6cb7583..2c2c73e085 100644
--- a/util/cacheflush.c
+++ b/util/cacheflush.c
@@ -117,6 +117,10 @@ static void sys_cache_info(int *isize, int *dsize)
* Architecture (+ OS) specific cache detection mechanisms.
*/
+#if defined(__powerpc__)
+static bool have_coherent_icache;
+#endif
+
#if defined(__aarch64__) && !defined(CONFIG_DARWIN)
/* Apple does not expose CTR_EL0, so we must use system interfaces. */
static uint64_t save_ctr_el0;
@@ -156,6 +160,7 @@ static void arch_cache_info(int *isize, int *dsize)
if (*dsize == 0) {
*dsize = qemu_getauxval(AT_DCACHEBSIZE);
}
+ have_coherent_icache = qemu_getauxval(AT_HWCAP) & PPC_FEATURE_ICACHE_SNOOP;
}
#else
@@ -298,8 +303,24 @@ void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
{
uintptr_t p, b, e;
- size_t dsize = qemu_dcache_linesize;
- size_t isize = qemu_icache_linesize;
+ size_t dsize, isize;
+
+ /*
+ * Some processors have coherent caches and support a simplified
+ * flushing procedure. See
+ * POWER9 UM, 4.6.2.2 Instruction Cache Block Invalidate (icbi)
+ * https://ibm.ent.box.com/s/tmklq90ze7aj8f4n32er1mu3sy9u8k3k
+ */
+ if (have_coherent_icache) {
+ asm volatile ("sync\n\t"
+ "icbi 0,%0\n\t"
+ "isync"
+ : : "r"(rx) : "memory");
+ return;
+ }
+
+ dsize = qemu_dcache_linesize;
+ isize = qemu_icache_linesize;
b = rw & ~(dsize - 1);
e = (rw + len + dsize - 1) & ~(dsize - 1);