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>

9 files changed, 51 insertions, 30 deletions

diff --git a/include/qemu/cacheflush.h b/include/qemu/cacheflush.h
index 58ae488..ae20bcd 100644
--- a/include/qemu/cacheflush.h
+++ b/include/qemu/cacheflush.h
@@ -8,16 +8,27 @@
 #ifndef QEMU_CACHEFLUSH_H
 #define QEMU_CACHEFLUSH_H
 
+/**
+ * flush_idcache_range:
+ * @rx: instruction address
+ * @rw: data address
+ * @len: length to flush
+ *
+ * Flush @len bytes of the data cache at @rw and the icache at @rx
+ * to bring them in sync.  The two addresses may be different virtual
+ * mappings of the same physical page(s).
+ */
+
 #if defined(__i386__) || defined(__x86_64__) || defined(__s390__)
 
-static inline void flush_icache_range(uintptr_t start, uintptr_t stop)
+static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
 {
     /* icache is coherent and does not require flushing. */
 }
 
 #else
 
-void flush_icache_range(uintptr_t start, uintptr_t stop);
+void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len);
 
 #endif
 
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 8b9ffc41..6301f4f 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -2946,7 +2946,7 @@ static inline MemTxResult address_space_write_rom_internal(AddressSpace *as,
                 invalidate_and_set_dirty(mr, addr1, l);
                 break;
             case FLUSH_CACHE:
-                flush_icache_range((uintptr_t)ram_ptr, (uintptr_t)ram_ptr + l);
+                flush_idcache_range((uintptr_t)ram_ptr, (uintptr_t)ram_ptr, l);
                 break;
             }
         }
diff --git a/tcg/aarch64/tcg-target.c.inc b/tcg/aarch64/tcg-target.c.inc
index 26f71cb..83af310 100644
--- a/tcg/aarch64/tcg-target.c.inc
+++ b/tcg/aarch64/tcg-target.c.inc
@@ -1363,7 +1363,7 @@ void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_addr,
     }
     pair = (uint64_t)i2 << 32 | i1;
     qatomic_set((uint64_t *)jmp_addr, pair);
-    flush_icache_range(jmp_addr, jmp_addr + 8);
+    flush_idcache_range(jmp_addr, jmp_addr, 8);
 }
 
 static inline void tcg_out_goto_label(TCGContext *s, TCGLabel *l)
diff --git a/tcg/mips/tcg-target.c.inc b/tcg/mips/tcg-target.c.inc
index 41be574..c255ecb 100644
--- a/tcg/mips/tcg-target.c.inc
+++ b/tcg/mips/tcg-target.c.inc
@@ -2660,7 +2660,7 @@ void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_addr,
                               uintptr_t addr)
 {
     qatomic_set((uint32_t *)jmp_addr, deposit32(OPC_J, 0, 26, addr >> 2));
-    flush_icache_range(jmp_addr, jmp_addr + 4);
+    flush_idcache_range(jmp_addr, jmp_addr, 4);
 }
 
 typedef struct {
diff --git a/tcg/ppc/tcg-target.c.inc b/tcg/ppc/tcg-target.c.inc
index 0d068ec..b756281 100644
--- a/tcg/ppc/tcg-target.c.inc
+++ b/tcg/ppc/tcg-target.c.inc
@@ -1753,12 +1753,12 @@ void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_addr,
         /* As per the enclosing if, this is ppc64.  Avoid the _Static_assert
            within qatomic_set that would fail to build a ppc32 host.  */
         qatomic_set__nocheck((uint64_t *)jmp_addr, pair);
-        flush_icache_range(jmp_addr, jmp_addr + 8);
+        flush_idcache_range(jmp_addr, jmp_addr, 8);
     } else {
         intptr_t diff = addr - jmp_addr;
         tcg_debug_assert(in_range_b(diff));
         qatomic_set((uint32_t *)jmp_addr, B | (diff & 0x3fffffc));
-        flush_icache_range(jmp_addr, jmp_addr + 4);
+        flush_idcache_range(jmp_addr, jmp_addr, 4);
     }
 }
 
diff --git a/tcg/sparc/tcg-target.c.inc b/tcg/sparc/tcg-target.c.inc
index 6775bd3..6e2d755 100644
--- a/tcg/sparc/tcg-target.c.inc
+++ b/tcg/sparc/tcg-target.c.inc
@@ -1836,7 +1836,7 @@ void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_addr,
     if (!USE_REG_TB) {
         qatomic_set((uint32_t *)jmp_addr,
 		    deposit32(CALL, 0, 30, br_disp >> 2));
-        flush_icache_range(jmp_addr, jmp_addr + 4);
+        flush_idcache_range(jmp_addr, jmp_addr, 4);
         return;
     }
 
@@ -1860,5 +1860,5 @@ void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_addr,
     }
 
     qatomic_set((uint64_t *)jmp_addr, deposit64(i2, 32, 32, i1));
-    flush_icache_range(jmp_addr, jmp_addr + 8);
+    flush_idcache_range(jmp_addr, jmp_addr, 8);
 }
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 9bdc450..759a41d 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1079,7 +1079,8 @@ void tcg_prologue_init(TCGContext *s)
 
     buf1 = s->code_ptr;
 #ifndef CONFIG_TCG_INTERPRETER
-    flush_icache_range((uintptr_t)buf0, (uintptr_t)buf1);
+    flush_idcache_range((uintptr_t)buf0, (uintptr_t)buf0,
+                        tcg_ptr_byte_diff(buf1, buf0));
 #endif
 
     /* Deduct the prologue from the buffer.  */
@@ -4328,7 +4329,8 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb)
 
 #ifndef CONFIG_TCG_INTERPRETER
     /* flush instruction cache */
-    flush_icache_range((uintptr_t)s->code_buf, (uintptr_t)s->code_ptr);
+    flush_idcache_range((uintptr_t)s->code_buf, (uintptr_t)s->code_buf,
+                        tcg_ptr_byte_diff(s->code_ptr, s->code_buf));
 #endif
 
     return tcg_current_code_size(s);
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.  */