rcu: Use automatic rc_read unlock in core memory/exec code

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-6-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

1 files changed, 65 insertions, 73 deletions

diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index e96e621..ad158bb 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -193,30 +193,29 @@ static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
     page = start >> TARGET_PAGE_BITS;
 
-    rcu_read_lock();
-
-    blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
+    WITH_RCU_READ_LOCK_GUARD() {
+        blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
+
+        idx = page / DIRTY_MEMORY_BLOCK_SIZE;
+        offset = page % DIRTY_MEMORY_BLOCK_SIZE;
+        base = page - offset;
+        while (page < end) {
+            unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
+            unsigned long num = next - base;
+            unsigned long found = find_next_bit(blocks->blocks[idx],
+                                                num, offset);
+            if (found < num) {
+                dirty = true;
+                break;
+            }
 
-    idx = page / DIRTY_MEMORY_BLOCK_SIZE;
-    offset = page % DIRTY_MEMORY_BLOCK_SIZE;
-    base = page - offset;
-    while (page < end) {
-        unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
-        unsigned long num = next - base;
-        unsigned long found = find_next_bit(blocks->blocks[idx], num, offset);
-        if (found < num) {
-            dirty = true;
-            break;
+            page = next;
+            idx++;
+            offset = 0;
+            base += DIRTY_MEMORY_BLOCK_SIZE;
         }
-
-        page = next;
-        idx++;
-        offset = 0;
-        base += DIRTY_MEMORY_BLOCK_SIZE;
     }
 
-    rcu_read_unlock();
-
     return dirty;
 }
 
@@ -234,7 +233,7 @@ static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
     page = start >> TARGET_PAGE_BITS;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
 
     blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
 
@@ -256,8 +255,6 @@ static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
         base += DIRTY_MEMORY_BLOCK_SIZE;
     }
 
-    rcu_read_unlock();
-
     return dirty;
 }
 
@@ -309,13 +306,11 @@ static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
 
-    rcu_read_lock();
+    RCU_READ_LOCK_GUARD();
 
     blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
 
     set_bit_atomic(offset, blocks->blocks[idx]);
-
-    rcu_read_unlock();
 }
 
 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
@@ -334,39 +329,37 @@ static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
     page = start >> TARGET_PAGE_BITS;
 
-    rcu_read_lock();
+    WITH_RCU_READ_LOCK_GUARD() {
+        for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
+            blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i]);
+        }
 
-    for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
-        blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i]);
-    }
+        idx = page / DIRTY_MEMORY_BLOCK_SIZE;
+        offset = page % DIRTY_MEMORY_BLOCK_SIZE;
+        base = page - offset;
+        while (page < end) {
+            unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
 
-    idx = page / DIRTY_MEMORY_BLOCK_SIZE;
-    offset = page % DIRTY_MEMORY_BLOCK_SIZE;
-    base = page - offset;
-    while (page < end) {
-        unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
+            if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
+                bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
+                                  offset, next - page);
+            }
+            if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
+                bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
+                                  offset, next - page);
+            }
+            if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
+                bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
+                                  offset, next - page);
+            }
 
-        if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
-            bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
-                              offset, next - page);
+            page = next;
+            idx++;
+            offset = 0;
+            base += DIRTY_MEMORY_BLOCK_SIZE;
         }
-        if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
-            bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
-                              offset, next - page);
-        }
-        if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
-            bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
-                              offset, next - page);
-        }
-
-        page = next;
-        idx++;
-        offset = 0;
-        base += DIRTY_MEMORY_BLOCK_SIZE;
     }
 
-    rcu_read_unlock();
-
     xen_hvm_modified_memory(start, length);
 }
 
@@ -396,36 +389,35 @@ static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
                           DIRTY_MEMORY_BLOCK_SIZE);
 
-        rcu_read_lock();
+        WITH_RCU_READ_LOCK_GUARD() {
+            for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
+                blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
+            }
 
-        for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
-            blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
-        }
+            for (k = 0; k < nr; k++) {
+                if (bitmap[k]) {
+                    unsigned long temp = leul_to_cpu(bitmap[k]);
 
-        for (k = 0; k < nr; k++) {
-            if (bitmap[k]) {
-                unsigned long temp = leul_to_cpu(bitmap[k]);
+                    atomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
 
-                atomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
+                    if (global_dirty_log) {
+                        atomic_or(&blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
+                                  temp);
+                    }
 
-                if (global_dirty_log) {
-                    atomic_or(&blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
-                              temp);
+                    if (tcg_enabled()) {
+                        atomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
+                                  temp);
+                    }
                 }
 
-                if (tcg_enabled()) {
-                    atomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset], temp);
+                if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
+                    offset = 0;
+                    idx++;
                 }
             }
-
-            if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
-                offset = 0;
-                idx++;
-            }
         }
 
-        rcu_read_unlock();
-
         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
     } else {
         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;