The point of writing a macro embedded in a 'do { ... } while (0)' loop (particularly if the macro has multiple statements or would otherwise end with an 'if' statement) is so that the macro can be used as a drop-in statement with the caller supplying the trailing ';'. Although our coding style frowns on brace-less 'if': if (cond) statement; else something else; that is the classic case where failure to use do/while(0) wrapping would cause the 'else' to pair with any embedded 'if' in the macro rather than the intended outer 'if'. But conversely, if the macro includes an embedded ';', then the same brace-less coding style would now have two statements, making the 'else' a syntax error rather than pairing with the outer 'if'. Thus, even though our coding style with required braces is not impacted, ending a macro with ';' makes our code harder to port to projects that use brace-less styles. The change should have no semantic impact. I was not able to fully compile-test all of the changes (as some of them are examples of the ugly bit-rotting debug print statements that are completely elided by default, and I didn't want to recompile with the necessary -D witnesses - cleaning those up is left as a bite-sized task for another day); I did, however, audit that for all files touched, all callers of the changed macros DID supply a trailing ';' at the callsite, and did not appear to be used as part of a brace-less conditional. Found mechanically via: $ git grep -B1 'while (0);' | grep -A1 \\\\ Signed-off-by: Eric Blake <eblake@redhat.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20171201232433.25193-7-eblake@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
174 lines
5 KiB
C
174 lines
5 KiB
C
/*
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* dpcd.c
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*
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* Copyright (C) 2015 : GreenSocs Ltd
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* http://www.greensocs.com/ , email: info@greensocs.com
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*
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* Developed by :
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* Frederic Konrad <fred.konrad@greensocs.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License, or
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* (at your option)any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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/*
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* This is a simple AUX slave which emulates a connected screen.
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*/
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#include "qemu/osdep.h"
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#include "qemu/log.h"
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#include "hw/misc/auxbus.h"
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#include "hw/display/dpcd.h"
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#ifndef DEBUG_DPCD
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#define DEBUG_DPCD 0
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#endif
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#define DPRINTF(fmt, ...) do { \
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if (DEBUG_DPCD) { \
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qemu_log("dpcd: " fmt, ## __VA_ARGS__); \
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} \
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} while (0)
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#define DPCD_READABLE_AREA 0x600
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struct DPCDState {
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/*< private >*/
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AUXSlave parent_obj;
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/*< public >*/
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/*
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* The DCPD is 0x7FFFF length but read as 0 after offset 0x5FF.
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*/
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uint8_t dpcd_info[DPCD_READABLE_AREA];
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MemoryRegion iomem;
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};
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static uint64_t dpcd_read(void *opaque, hwaddr offset, unsigned size)
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{
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uint8_t ret;
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DPCDState *e = DPCD(opaque);
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if (offset < DPCD_READABLE_AREA) {
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ret = e->dpcd_info[offset];
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} else {
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qemu_log_mask(LOG_GUEST_ERROR, "dpcd: Bad offset 0x%" HWADDR_PRIX "\n",
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offset);
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ret = 0;
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}
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DPRINTF("read 0x%" PRIX8 " @0x%" HWADDR_PRIX "\n", ret, offset);
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return ret;
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}
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static void dpcd_write(void *opaque, hwaddr offset, uint64_t value,
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unsigned size)
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{
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DPCDState *e = DPCD(opaque);
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DPRINTF("write 0x%" PRIX8 " @0x%" HWADDR_PRIX "\n", (uint8_t)value, offset);
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if (offset < DPCD_READABLE_AREA) {
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e->dpcd_info[offset] = value;
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} else {
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qemu_log_mask(LOG_GUEST_ERROR, "dpcd: Bad offset 0x%" HWADDR_PRIX "\n",
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offset);
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}
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}
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static const MemoryRegionOps aux_ops = {
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.read = dpcd_read,
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.write = dpcd_write,
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.valid = {
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.min_access_size = 1,
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.max_access_size = 1,
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},
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.impl = {
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.min_access_size = 1,
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.max_access_size = 1,
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},
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};
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static void dpcd_reset(DeviceState *dev)
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{
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DPCDState *s = DPCD(dev);
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memset(&(s->dpcd_info), 0, sizeof(s->dpcd_info));
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s->dpcd_info[DPCD_REVISION] = DPCD_REV_1_0;
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s->dpcd_info[DPCD_MAX_LINK_RATE] = DPCD_5_4GBPS;
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s->dpcd_info[DPCD_MAX_LANE_COUNT] = DPCD_FOUR_LANES;
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s->dpcd_info[DPCD_RECEIVE_PORT0_CAP_0] = DPCD_EDID_PRESENT;
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/* buffer size */
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s->dpcd_info[DPCD_RECEIVE_PORT0_CAP_1] = 0xFF;
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s->dpcd_info[DPCD_LANE0_1_STATUS] = DPCD_LANE0_CR_DONE
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| DPCD_LANE0_CHANNEL_EQ_DONE
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| DPCD_LANE0_SYMBOL_LOCKED
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| DPCD_LANE1_CR_DONE
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| DPCD_LANE1_CHANNEL_EQ_DONE
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| DPCD_LANE1_SYMBOL_LOCKED;
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s->dpcd_info[DPCD_LANE2_3_STATUS] = DPCD_LANE2_CR_DONE
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| DPCD_LANE2_CHANNEL_EQ_DONE
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| DPCD_LANE2_SYMBOL_LOCKED
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| DPCD_LANE3_CR_DONE
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| DPCD_LANE3_CHANNEL_EQ_DONE
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| DPCD_LANE3_SYMBOL_LOCKED;
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s->dpcd_info[DPCD_LANE_ALIGN_STATUS_UPDATED] = DPCD_INTERLANE_ALIGN_DONE;
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s->dpcd_info[DPCD_SINK_STATUS] = DPCD_RECEIVE_PORT_0_STATUS;
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}
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static void dpcd_init(Object *obj)
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{
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DPCDState *s = DPCD(obj);
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memory_region_init_io(&s->iomem, obj, &aux_ops, s, TYPE_DPCD, 0x7FFFF);
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aux_init_mmio(AUX_SLAVE(obj), &s->iomem);
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}
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static const VMStateDescription vmstate_dpcd = {
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.name = TYPE_DPCD,
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.version_id = 0,
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.minimum_version_id = 0,
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.fields = (VMStateField[]) {
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VMSTATE_UINT8_ARRAY_V(dpcd_info, DPCDState, DPCD_READABLE_AREA, 0),
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VMSTATE_END_OF_LIST()
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}
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};
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static void dpcd_class_init(ObjectClass *oc, void *data)
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{
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DeviceClass *dc = DEVICE_CLASS(oc);
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dc->reset = dpcd_reset;
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dc->vmsd = &vmstate_dpcd;
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}
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static const TypeInfo dpcd_info = {
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.name = TYPE_DPCD,
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.parent = TYPE_AUX_SLAVE,
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.instance_size = sizeof(DPCDState),
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.class_init = dpcd_class_init,
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.instance_init = dpcd_init,
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};
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static void dpcd_register_types(void)
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{
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type_register_static(&dpcd_info);
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}
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type_init(dpcd_register_types)
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