From 19f703477314a5db09ffc3c0f6be9c45645f8302 Mon Sep 17 00:00:00 2001 From: Peter Maydell <peter.maydell@linaro.org> 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 <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> --- hw/dma/xlnx-zdma.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'hw/dma') diff --git a/hw/dma/xlnx-zdma.c b/hw/dma/xlnx-zdma.c index 683abbe..1c1b142 100644 --- a/hw/dma/xlnx-zdma.c +++ b/hw/dma/xlnx-zdma.c @@ -311,8 +311,7 @@ static bool zdma_load_descriptor(XlnxZDMA *s, uint64_t addr, void *buf) return false; } - address_space_rw(s->dma_as, addr, s->attr, - buf, sizeof(XlnxZDMADescr), false); + address_space_read(s->dma_as, addr, s->attr, buf, sizeof(XlnxZDMADescr)); return true; } @@ -364,7 +363,7 @@ static uint64_t zdma_update_descr_addr(XlnxZDMA *s, bool type, } else { addr = zdma_get_regaddr64(s, basereg); addr += sizeof(s->dsc_dst); - address_space_rw(s->dma_as, addr, s->attr, &next, 8, false); + address_space_read(s->dma_as, addr, s->attr, &next, 8); zdma_put_regaddr64(s, basereg, next); } return next; @@ -416,8 +415,7 @@ static void zdma_write_dst(XlnxZDMA *s, uint8_t *buf, uint32_t len) } } - address_space_rw(s->dma_as, s->dsc_dst.addr, s->attr, buf, dlen, - true); + address_space_write(s->dma_as, s->dsc_dst.addr, s->attr, buf, dlen); if (burst_type == AXI_BURST_INCR) { s->dsc_dst.addr += dlen; } @@ -493,8 +491,7 @@ static void zdma_process_descr(XlnxZDMA *s) len = s->cfg.bus_width / 8; } } else { - address_space_rw(s->dma_as, src_addr, s->attr, s->buf, len, - false); + address_space_read(s->dma_as, src_addr, s->attr, s->buf, len); if (burst_type == AXI_BURST_INCR) { src_addr += len; } -- cgit v1.1