From 19f703477314a5db09ffc3c0f6be9c45645f8302 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 18 Feb 2020 11:24:57 +0000 Subject: Avoid address_space_rw() with a constant is_write argument MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Edgar E. Iglesias Reviewed-by: Laurent Vivier Reviewed-by: Cédric Le Goater Acked-by: Christian Borntraeger Reviewed-by: Cornelia Huck Reviewed-by: Alistair Francis Acked-by: David Gibson Message-Id: <20200218112457.22712-1-peter.maydell@linaro.org> [PMD: Update macvm_set_cr0() reported by Laurent Vivier] Signed-off-by: Philippe Mathieu-Daudé --- hw/ppc/pnv_lpc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'hw/ppc/pnv_lpc.c') 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) -- cgit v1.2.3