Avoid address_space_rw() with a constant is_write argument

The address_space_rw() function allows either reads or writes
depending on the is_write argument passed to it; this is useful
when the direction of the access is determined programmatically
(as for instance when handling the KVM_EXIT_MMIO exit reason).
Under the hood it just calls either address_space_write() or
address_space_read_full().

We also use it a lot with a constant is_write argument, though,
which has two issues:
 * when reading "address_space_rw(..., 1)" this is less
   immediately clear to the reader as being a write than
   "address_space_write(...)"
 * calling address_space_rw() bypasses the optimization
   in address_space_read() that fast-paths reads of a
   fixed length

This commit was produced with the included Coccinelle script
scripts/coccinelle/exec_rw_const.cocci.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20200218112457.22712-1-peter.maydell@linaro.org>
[PMD: Update macvm_set_cr0() reported by Laurent Vivier]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

3 files changed, 50 insertions, 47 deletions

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index b4363e3186..70451934ae 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -275,8 +275,8 @@ static void dp8393x_do_load_cam(dp8393xState *s)
 
     while (s->regs[SONIC_CDC] & 0x1f) {
         /* Fill current entry */
-        address_space_rw(&s->as, dp8393x_cdp(s),
-                         MEMTXATTRS_UNSPECIFIED, s->data, size, false);
+        address_space_read(&s->as, dp8393x_cdp(s),
+                           MEMTXATTRS_UNSPECIFIED, s->data, size);
         s->cam[index][0] = dp8393x_get(s, width, 1) & 0xff;
         s->cam[index][1] = dp8393x_get(s, width, 1) >> 8;
         s->cam[index][2] = dp8393x_get(s, width, 2) & 0xff;
@@ -293,8 +293,8 @@ static void dp8393x_do_load_cam(dp8393xState *s)
     }
 
     /* Read CAM enable */
-    address_space_rw(&s->as, dp8393x_cdp(s),
-                     MEMTXATTRS_UNSPECIFIED, s->data, size, false);
+    address_space_read(&s->as, dp8393x_cdp(s),
+                       MEMTXATTRS_UNSPECIFIED, s->data, size);
     s->regs[SONIC_CE] = dp8393x_get(s, width, 0);
     DPRINTF("load cam done. cam enable mask 0x%04x\n", s->regs[SONIC_CE]);
 
@@ -311,8 +311,8 @@ static void dp8393x_do_read_rra(dp8393xState *s)
     /* Read memory */
     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
     size = sizeof(uint16_t) * 4 * width;
-    address_space_rw(&s->as, dp8393x_rrp(s),
-                     MEMTXATTRS_UNSPECIFIED, s->data, size, false);
+    address_space_read(&s->as, dp8393x_rrp(s),
+                       MEMTXATTRS_UNSPECIFIED, s->data, size);
 
     /* Update SONIC registers */
     s->regs[SONIC_CRBA0] = dp8393x_get(s, width, 0);
@@ -426,8 +426,8 @@ static void dp8393x_do_transmit_packets(dp8393xState *s)
         size = sizeof(uint16_t) * 6 * width;
         s->regs[SONIC_TTDA] = s->regs[SONIC_CTDA];
         DPRINTF("Transmit packet at %08x\n", dp8393x_ttda(s));
-        address_space_rw(&s->as, dp8393x_ttda(s) + sizeof(uint16_t) * width,
-                         MEMTXATTRS_UNSPECIFIED, s->data, size, false);
+        address_space_read(&s->as, dp8393x_ttda(s) + sizeof(uint16_t) * width,
+                           MEMTXATTRS_UNSPECIFIED, s->data, size);
         tx_len = 0;
 
         /* Update registers */
@@ -451,18 +451,19 @@ static void dp8393x_do_transmit_packets(dp8393xState *s)
             if (tx_len + len > sizeof(s->tx_buffer)) {
                 len = sizeof(s->tx_buffer) - tx_len;
             }
-            address_space_rw(&s->as, dp8393x_tsa(s),
-                             MEMTXATTRS_UNSPECIFIED,
-                             &s->tx_buffer[tx_len], len, false);
+            address_space_read(&s->as, dp8393x_tsa(s), MEMTXATTRS_UNSPECIFIED,
+                               &s->tx_buffer[tx_len], len);
             tx_len += len;
 
             i++;
             if (i != s->regs[SONIC_TFC]) {
                 /* Read next fragment details */
                 size = sizeof(uint16_t) * 3 * width;
-                address_space_rw(&s->as,
-                    dp8393x_ttda(s) + sizeof(uint16_t) * (4 + 3 * i) * width,
-                                 MEMTXATTRS_UNSPECIFIED, s->data, size, false);
+                address_space_read(&s->as,
+                                   dp8393x_ttda(s)
+                                   + sizeof(uint16_t) * width * (4 + 3 * i),
+                                   MEMTXATTRS_UNSPECIFIED, s->data,
+                                   size);
                 s->regs[SONIC_TSA0] = dp8393x_get(s, width, 0);
                 s->regs[SONIC_TSA1] = dp8393x_get(s, width, 1);
                 s->regs[SONIC_TFS] = dp8393x_get(s, width, 2);
@@ -495,18 +496,18 @@ static void dp8393x_do_transmit_packets(dp8393xState *s)
         dp8393x_put(s, width, 0,
                     s->regs[SONIC_TCR] & 0x0fff); /* status */
         size = sizeof(uint16_t) * width;
-        address_space_rw(&s->as,
-                         dp8393x_ttda(s),
-                         MEMTXATTRS_UNSPECIFIED, s->data, size, true);
+        address_space_write(&s->as, dp8393x_ttda(s),
+                            MEMTXATTRS_UNSPECIFIED, s->data, size);
 
         if (!(s->regs[SONIC_CR] & SONIC_CR_HTX)) {
             /* Read footer of packet */
             size = sizeof(uint16_t) * width;
-            address_space_rw(&s->as,
-                             dp8393x_ttda(s) +
-                             sizeof(uint16_t) *
-                             (4 + 3 * s->regs[SONIC_TFC]) * width,
-                             MEMTXATTRS_UNSPECIFIED, s->data, size, false);
+            address_space_read(&s->as,
+                               dp8393x_ttda(s)
+                               + sizeof(uint16_t) * width
+                                 * (4 + 3 * s->regs[SONIC_TFC]),
+                               MEMTXATTRS_UNSPECIFIED, s->data,
+                               size);
             s->regs[SONIC_CTDA] = dp8393x_get(s, width, 0) & ~0x1;
             if (dp8393x_get(s, width, 0) & 0x1) {
                 /* EOL detected */
@@ -768,8 +769,8 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
         /* Are we still in resource exhaustion? */
         size = sizeof(uint16_t) * 1 * width;
         address = dp8393x_crda(s) + sizeof(uint16_t) * 5 * width;
-        address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
-                         s->data, size, false);
+        address_space_read(&s->as, address, MEMTXATTRS_UNSPECIFIED,
+                           s->data, size);
         if (dp8393x_get(s, width, 0) & 0x1) {
             /* Still EOL ; stop reception */
             return -1;
@@ -788,10 +789,11 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
     /* Put packet into RBA */
     DPRINTF("Receive packet at %08x\n", dp8393x_crba(s));
     address = dp8393x_crba(s);
-    address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED, buf, rx_len);
+    address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
+                        buf, rx_len);
     address += rx_len;
-    address_space_rw(&s->as, address,
-                     MEMTXATTRS_UNSPECIFIED, &checksum, 4, true);
+    address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
+                        &checksum, 4);
     rx_len += 4;
     s->regs[SONIC_CRBA1] = address >> 16;
     s->regs[SONIC_CRBA0] = address & 0xffff;
@@ -819,13 +821,15 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
     dp8393x_put(s, width, 3, s->regs[SONIC_TRBA1]); /* pkt_ptr1 */
     dp8393x_put(s, width, 4, s->regs[SONIC_RSC]); /* seq_no */
     size = sizeof(uint16_t) * 5 * width;
-    address_space_rw(&s->as, dp8393x_crda(s),
-                     MEMTXATTRS_UNSPECIFIED, s->data, size, true);
+    address_space_write(&s->as, dp8393x_crda(s),
+                        MEMTXATTRS_UNSPECIFIED,
+                        s->data, size);
 
     /* Move to next descriptor */
     size = sizeof(uint16_t) * width;
-    address_space_rw(&s->as, dp8393x_crda(s) + sizeof(uint16_t) * 5 * width,
-                     MEMTXATTRS_UNSPECIFIED, s->data, size, false);
+    address_space_read(&s->as,
+                       dp8393x_crda(s) + sizeof(uint16_t) * 5 * width,
+                       MEMTXATTRS_UNSPECIFIED, s->data, size);
     s->regs[SONIC_LLFA] = dp8393x_get(s, width, 0);
     if (s->regs[SONIC_LLFA] & 0x1) {
         /* EOL detected */
@@ -838,8 +842,8 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
             offset += sizeof(uint16_t);
         }
         s->data[0] = 0;
-        address_space_rw(&s->as, offset, MEMTXATTRS_UNSPECIFIED,
-                         s->data, sizeof(uint16_t), true);
+        address_space_write(&s->as, offset, MEMTXATTRS_UNSPECIFIED,
+                            s->data, sizeof(uint16_t));
         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
         s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
         s->regs[SONIC_RSC] = (s->regs[SONIC_RSC] & 0xff00) | (((s->regs[SONIC_RSC] & 0x00ff) + 1) & 0x00ff);
diff --git a/hw/net/i82596.c b/hw/net/i82596.c
index 11537f72d1..fe9f2390a9 100644
--- a/hw/net/i82596.c
+++ b/hw/net/i82596.c
@@ -148,8 +148,8 @@ static void i82596_transmit(I82596State *s, uint32_t addr)
 
         if (s->nic && len) {
             assert(len <= sizeof(s->tx_buffer));
-            address_space_rw(&address_space_memory, tba,
-                             MEMTXATTRS_UNSPECIFIED, s->tx_buffer, len, false);
+            address_space_read(&address_space_memory, tba,
+                               MEMTXATTRS_UNSPECIFIED, s->tx_buffer, len);
             DBG(PRINT_PKTHDR("Send", &s->tx_buffer));
             DBG(printf("Sending %d bytes\n", len));
             qemu_send_packet(qemu_get_queue(s->nic), s->tx_buffer, len);
@@ -172,8 +172,8 @@ static void set_individual_address(I82596State *s, uint32_t addr)
 
     nc = qemu_get_queue(s->nic);
     m = s->conf.macaddr.a;
-    address_space_rw(&address_space_memory, addr + 8,
-                     MEMTXATTRS_UNSPECIFIED, m, ETH_ALEN, false);
+    address_space_read(&address_space_memory, addr + 8,
+                       MEMTXATTRS_UNSPECIFIED, m, ETH_ALEN);
     qemu_format_nic_info_str(nc, m);
     trace_i82596_new_mac(nc->info_str);
 }
@@ -190,9 +190,8 @@ static void set_multicast_list(I82596State *s, uint32_t addr)
     }
     for (i = 0; i < mc_count; i++) {
         uint8_t multicast_addr[ETH_ALEN];
-        address_space_rw(&address_space_memory,
-            addr + i * ETH_ALEN, MEMTXATTRS_UNSPECIFIED,
-                         multicast_addr, ETH_ALEN, false);
+        address_space_read(&address_space_memory, addr + i * ETH_ALEN,
+                           MEMTXATTRS_UNSPECIFIED, multicast_addr, ETH_ALEN);
         DBG(printf("Add multicast entry " MAC_FMT "\n",
                     MAC_ARG(multicast_addr)));
         unsigned mcast_idx = (net_crc32(multicast_addr, ETH_ALEN) &
@@ -260,9 +259,8 @@ static void command_loop(I82596State *s)
             byte_cnt = MAX(byte_cnt, 4);
             byte_cnt = MIN(byte_cnt, sizeof(s->config));
             /* copy byte_cnt max. */
-            address_space_rw(&address_space_memory, s->cmd_p + 8,
-                             MEMTXATTRS_UNSPECIFIED, s->config, byte_cnt,
-                             false);
+            address_space_read(&address_space_memory, s->cmd_p + 8,
+                               MEMTXATTRS_UNSPECIFIED, s->config, byte_cnt);
             /* config byte according to page 35ff */
             s->config[2] &= 0x82; /* mask valid bits */
             s->config[2] |= 0x40;
@@ -647,8 +645,8 @@ ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz)
             buf += num;
             len -= num;
             if (len == 0) { /* copy crc */
-                address_space_rw(&address_space_memory, rba - 4,
-                                 MEMTXATTRS_UNSPECIFIED, crc_ptr, 4, true);
+                address_space_write(&address_space_memory, rba - 4,
+                                    MEMTXATTRS_UNSPECIFIED, crc_ptr, 4);
             }
 
             num |= 0x4000; /* set F BIT */
diff --git a/hw/net/lasi_i82596.c b/hw/net/lasi_i82596.c
index 8bff419378..52637a562d 100644
--- a/hw/net/lasi_i82596.c
+++ b/hw/net/lasi_i82596.c
@@ -55,8 +55,9 @@ static void lasi_82596_mem_write(void *opaque, hwaddr addr,
          * Provided for SeaBIOS only. Write MAC of Network card to addr @val.
          * Needed for the PDC_LAN_STATION_ID_READ PDC call.
          */
-        address_space_rw(&address_space_memory, val, MEMTXATTRS_UNSPECIFIED,
-                         d->state.conf.macaddr.a, ETH_ALEN, true);
+        address_space_write(&address_space_memory, val,
+                            MEMTXATTRS_UNSPECIFIED, d->state.conf.macaddr.a,
+                            ETH_ALEN);
         break;
     }
 }