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>

1 files changed, 4 insertions, 4 deletions

diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c
index 5989d723c5..f150deca34 100644
--- a/hw/ppc/pnv_lpc.c
+++ b/hw/ppc/pnv_lpc.c
@@ -238,16 +238,16 @@ static bool opb_read(PnvLpcController *lpc, uint32_t addr, uint8_t *data,
                      int sz)
 {
     /* XXX Handle access size limits and FW read caching here */
-    return !address_space_rw(&lpc->opb_as, addr, MEMTXATTRS_UNSPECIFIED,
-                             data, sz, false);
+    return !address_space_read(&lpc->opb_as, addr, MEMTXATTRS_UNSPECIFIED,
+                               data, sz);
 }
 
 static bool opb_write(PnvLpcController *lpc, uint32_t addr, uint8_t *data,
                       int sz)
 {
     /* XXX Handle access size limits here */
-    return !address_space_rw(&lpc->opb_as, addr, MEMTXATTRS_UNSPECIFIED,
-                             data, sz, true);
+    return !address_space_write(&lpc->opb_as, addr, MEMTXATTRS_UNSPECIFIED,
+                                data, sz);
 }
 
 #define ECCB_CTL_READ           PPC_BIT(15)