util: Enhance flush_icache_range with separate data pointer

We are shortly going to have a split rw/rx jit buffer.  Depending
on the host, we need to flush the dcache at the rw data pointer and
flush the icache at the rx code pointer.

For now, the two passed pointers are identical, so there is no
effective change in behaviour.

Reviewed-by: Joelle van Dyne <j@getutm.app>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

2 files changed, 27 insertions, 19 deletions

diff --git a/util/cacheflush.c b/util/cacheflush.c
index 2881832..92805ef 100644
--- a/util/cacheflush.c
+++ b/util/cacheflush.c
@@ -21,29 +21,32 @@
 #include <sys/cachectl.h>
 #endif
 
-void flush_icache_range(uintptr_t start, uintptr_t stop)
+void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
 {
-    cacheflush((void *)start, stop - start, ICACHE);
+    if (rx != rw) {
+        cacheflush((void *)rw, len, DCACHE);
+    }
+    cacheflush((void *)rx, len, ICACHE);
 }
 
 #elif defined(__powerpc__)
 
-void flush_icache_range(uintptr_t start, uintptr_t stop)
+void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
 {
-    uintptr_t p, start1, stop1;
+    uintptr_t p, b, e;
     size_t dsize = qemu_dcache_linesize;
     size_t isize = qemu_icache_linesize;
 
-    start1 = start & ~(dsize - 1);
-    stop1 = (stop + dsize - 1) & ~(dsize - 1);
-    for (p = start1; p < stop1; p += dsize) {
+    b = rw & ~(dsize - 1);
+    e = (rw + len + dsize - 1) & ~(dsize - 1);
+    for (p = b; p < e; p += dsize) {
         asm volatile ("dcbst 0,%0" : : "r"(p) : "memory");
     }
     asm volatile ("sync" : : : "memory");
 
-    start &= start & ~(isize - 1);
-    stop1 = (stop + isize - 1) & ~(isize - 1);
-    for (p = start1; p < stop1; p += isize) {
+    b = rx & ~(isize - 1);
+    e = (rx + len + isize - 1) & ~(isize - 1);
+    for (p = b; p < e; p += isize) {
         asm volatile ("icbi 0,%0" : : "r"(p) : "memory");
     }
     asm volatile ("sync" : : : "memory");
@@ -52,20 +55,23 @@ void flush_icache_range(uintptr_t start, uintptr_t stop)
 
 #elif defined(__sparc__)
 
-void flush_icache_range(uintptr_t start, uintptr_t stop)
+void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
 {
-    uintptr_t p;
-
-    for (p = start & -8; p < ((stop + 7) & -8); p += 8) {
+    /* No additional data flush to the RW virtual address required. */
+    uintptr_t p, end = (rx + len + 7) & -8;
+    for (p = rx & -8; p < end; p += 8) {
         __asm__ __volatile__("flush\t%0" : : "r" (p));
     }
 }
 
 #else
 
-void flush_icache_range(uintptr_t start, uintptr_t stop)
+void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
 {
-    __builtin___clear_cache((char *)start, (char *)stop);
+    if (rw != rx) {
+        __builtin___clear_cache((char *)rw, (char *)rw + len);
+    }
+    __builtin___clear_cache((char *)rx, (char *)rx + len);
 }
 
 #endif
diff --git a/util/cacheinfo.c b/util/cacheinfo.c
index 7804c18..b182f0b 100644
--- a/util/cacheinfo.c
+++ b/util/cacheinfo.c
@@ -166,9 +166,11 @@ static void fallback_cache_info(int *isize, int *dsize)
         *isize = *dsize;
     } else {
 #if defined(_ARCH_PPC)
-        /* For PPC, we're going to use the icache size computed for
-           flush_icache_range.  Which means that we must use the
-           architecture minimum.  */
+        /*
+         * For PPC, we're going to use the cache sizes computed for
+         * flush_idcache_range.  Which means that we must use the
+         * architecture minimum.
+         */
         *isize = *dsize = 16;
 #else
         /* Otherwise, 64 bytes is not uncommon.  */