Module Name: src
Committed By: jakllsch
Date: Thu Jun 7 23:32:30 UTC 2018
Modified Files:
src/sys/dev/pci: ld_virtio.c
Log Message:
Make ld_virtio aware of a possible device-side write cache.
To generate a diff of this commit:
cvs rdiff -u -r1.19 -r1.20 src/sys/dev/pci/ld_virtio.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/pci/ld_virtio.c
diff -u src/sys/dev/pci/ld_virtio.c:1.19 src/sys/dev/pci/ld_virtio.c:1.20
--- src/sys/dev/pci/ld_virtio.c:1.19 Sun Jun 3 19:50:20 2018
+++ src/sys/dev/pci/ld_virtio.c Thu Jun 7 23:32:30 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: ld_virtio.c,v 1.19 2018/06/03 19:50:20 jakllsch Exp $ */
+/* $NetBSD: ld_virtio.c,v 1.20 2018/06/07 23:32:30 jakllsch Exp $ */
/*
* Copyright (c) 2010 Minoura Makoto.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ld_virtio.c,v 1.19 2018/06/03 19:50:20 jakllsch Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ld_virtio.c,v 1.20 2018/06/07 23:32:30 jakllsch Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -120,6 +120,7 @@ struct virtio_blk_req {
struct virtio_blk_req_hdr vr_hdr;
uint8_t vr_status;
struct buf *vr_bp;
+#define DUMMY_VR_BP ((void *)1)
bus_dmamap_t vr_cmdsts;
bus_dmamap_t vr_payload;
};
@@ -135,6 +136,13 @@ struct ld_virtio_softc {
bus_dma_segment_t sc_reqs_seg;
int sc_readonly;
+
+ enum {
+ SYNC_FREE, SYNC_BUSY, SYNC_DONE
+ } sc_sync_use;
+ kcondvar_t sc_sync_wait;
+ kmutex_t sc_sync_wait_lock;
+ uint8_t sc_sync_status;
};
static int ld_virtio_match(device_t, cfdata_t, void *);
@@ -158,6 +166,7 @@ ld_virtio_match(device_t parent, cfdata_
static int ld_virtio_vq_done(struct virtqueue *);
static int ld_virtio_dump(struct ld_softc *, void *, int, int);
static int ld_virtio_start(struct ld_softc *, struct buf *);
+static int ld_virtio_ioctl(struct ld_softc *, u_long, void *, int32_t, bool);
static int
ld_virtio_alloc_reqs(struct ld_virtio_softc *sc, int qsize)
@@ -270,7 +279,8 @@ ld_virtio_attach(device_t parent, device
virtio_child_attach_start(vsc, self, IPL_BIO, &sc->sc_vq,
NULL, virtio_vq_intr, 0,
(VIRTIO_BLK_F_SIZE_MAX | VIRTIO_BLK_F_SEG_MAX |
- VIRTIO_BLK_F_GEOMETRY | VIRTIO_BLK_F_RO | VIRTIO_BLK_F_BLK_SIZE),
+ VIRTIO_BLK_F_GEOMETRY | VIRTIO_BLK_F_RO | VIRTIO_BLK_F_BLK_SIZE |
+ VIRTIO_BLK_F_FLUSH | VIRTIO_BLK_F_CONFIG_WCE),
VIRTIO_BLK_FLAG_BITS);
features = virtio_features(vsc);
@@ -344,13 +354,18 @@ ld_virtio_attach(device_t parent, device
ld->sc_nsectors = virtio_read_device_config_1(vsc,
VIRTIO_BLK_CONFIG_GEOMETRY_S);
}
- ld->sc_maxqueuecnt = qsize;
+ ld->sc_maxqueuecnt = qsize - 1; /* reserve slot for dumps, flushes */
if (ld_virtio_alloc_reqs(sc, qsize) < 0)
goto err;
+ cv_init(&sc->sc_sync_wait, "vblksync");
+ mutex_init(&sc->sc_sync_wait_lock, MUTEX_DEFAULT, IPL_BIO);
+ sc->sc_sync_use = SYNC_FREE;
+
ld->sc_dump = ld_virtio_dump;
ld->sc_start = ld_virtio_start;
+ ld->sc_ioctl = ld_virtio_ioctl;
ld->sc_flags = LDF_ENABLED | LDF_MPSAFE;
ldattach(ld, BUFQ_DISK_DEFAULT_STRAT);
@@ -443,14 +458,23 @@ ld_virtio_vq_done1(struct ld_virtio_soft
bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
0, sizeof(struct virtio_blk_req_hdr),
BUS_DMASYNC_POSTWRITE);
+ bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
+ sizeof(struct virtio_blk_req_hdr), sizeof(uint8_t),
+ BUS_DMASYNC_POSTREAD);
+ if (bp == DUMMY_VR_BP) {
+ mutex_enter(&sc->sc_sync_wait_lock);
+ sc->sc_sync_status = vr->vr_status;
+ sc->sc_sync_use = SYNC_DONE;
+ cv_signal(&sc->sc_sync_wait);
+ mutex_exit(&sc->sc_sync_wait_lock);
+ virtio_dequeue_commit(vsc, vq, slot);
+ return;
+ }
bus_dmamap_sync(virtio_dmat(vsc), vr->vr_payload,
0, bp->b_bcount,
(bp->b_flags & B_READ)?BUS_DMASYNC_POSTREAD
:BUS_DMASYNC_POSTWRITE);
bus_dmamap_unload(virtio_dmat(vsc), vr->vr_payload);
- bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
- sizeof(struct virtio_blk_req_hdr), sizeof(uint8_t),
- BUS_DMASYNC_POSTREAD);
if (vr->vr_status != VIRTIO_BLK_S_OK) {
bp->b_error = EIO;
@@ -609,6 +633,150 @@ ld_virtio_detach(device_t self, int flag
return 0;
}
+static int
+ld_virtio_flush(struct ld_softc *ld, bool poll)
+{
+ struct ld_virtio_softc * const sc = device_private(ld->sc_dv);
+ struct virtio_softc * const vsc = sc->sc_virtio;
+ const uint32_t features = virtio_features(vsc);
+ struct virtqueue *vq = &sc->sc_vq;
+ struct virtio_blk_req *vr;
+ int slot;
+ int r;
+
+ if ((features & VIRTIO_BLK_F_FLUSH) == 0)
+ return 0;
+
+ mutex_enter(&sc->sc_sync_wait_lock);
+ while (sc->sc_sync_use != SYNC_FREE) {
+ if (poll) {
+ mutex_exit(&sc->sc_sync_wait_lock);
+ ld_virtio_vq_done(vq);
+ mutex_enter(&sc->sc_sync_wait_lock);
+ continue;
+ }
+ cv_wait(&sc->sc_sync_wait, &sc->sc_sync_wait_lock);
+ }
+ sc->sc_sync_use = SYNC_BUSY;
+ mutex_exit(&sc->sc_sync_wait_lock);
+
+ r = virtio_enqueue_prep(vsc, vq, &slot);
+ if (r != 0) {
+ return r;
+ }
+
+ vr = &sc->sc_reqs[slot];
+ KASSERT(vr->vr_bp == NULL);
+
+ r = virtio_enqueue_reserve(vsc, vq, slot, VIRTIO_BLK_MIN_SEGMENTS);
+ if (r != 0) {
+ return r;
+ }
+
+ vr->vr_bp = DUMMY_VR_BP;
+ vr->vr_hdr.type = VIRTIO_BLK_T_FLUSH;
+ vr->vr_hdr.ioprio = 0;
+ vr->vr_hdr.sector = 0;
+
+ bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
+ 0, sizeof(struct virtio_blk_req_hdr),
+ BUS_DMASYNC_PREWRITE);
+ bus_dmamap_sync(virtio_dmat(vsc), vr->vr_cmdsts,
+ offsetof(struct virtio_blk_req, vr_status),
+ sizeof(uint8_t),
+ BUS_DMASYNC_PREREAD);
+
+ virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
+ 0, sizeof(struct virtio_blk_req_hdr),
+ true);
+ virtio_enqueue_p(vsc, vq, slot, vr->vr_cmdsts,
+ offsetof(struct virtio_blk_req, vr_status),
+ sizeof(uint8_t),
+ false);
+ virtio_enqueue_commit(vsc, vq, slot, true);
+
+ mutex_enter(&sc->sc_sync_wait_lock);
+ while (sc->sc_sync_use != SYNC_DONE) {
+ if (poll) {
+ mutex_exit(&sc->sc_sync_wait_lock);
+ ld_virtio_vq_done(vq);
+ mutex_enter(&sc->sc_sync_wait_lock);
+ continue;
+ }
+ cv_wait(&sc->sc_sync_wait, &sc->sc_sync_wait_lock);
+ }
+
+ if (sc->sc_sync_status == VIRTIO_BLK_S_OK)
+ r = 0;
+ else
+ r = EIO;
+
+ sc->sc_sync_use = SYNC_FREE;
+ cv_signal(&sc->sc_sync_wait);
+ mutex_exit(&sc->sc_sync_wait_lock);
+
+ return r;
+}
+
+static int
+ld_virtio_getcache(struct ld_softc *ld, int *bitsp)
+{
+ struct ld_virtio_softc * const sc = device_private(ld->sc_dv);
+ struct virtio_softc * const vsc = sc->sc_virtio;
+ const uint32_t features = virtio_features(vsc);
+
+ *bitsp = DKCACHE_READ;
+ if ((features & VIRTIO_BLK_F_CONFIG_WCE) != 0)
+ *bitsp |= DKCACHE_WCHANGE;
+ if (virtio_read_device_config_1(vsc,
+ VIRTIO_BLK_CONFIG_WRITEBACK) != 0x00)
+ *bitsp |= DKCACHE_WRITE;
+
+ return 0;
+}
+
+static int
+ld_virtio_setcache(struct ld_softc *ld, int bits)
+{
+ struct ld_virtio_softc * const sc = device_private(ld->sc_dv);
+ struct virtio_softc * const vsc = sc->sc_virtio;
+ const uint8_t wce = (bits & DKCACHE_WRITE) ? 0x01 : 0x00;
+
+ virtio_write_device_config_1(vsc,
+ VIRTIO_BLK_CONFIG_WRITEBACK, wce);
+ if (virtio_read_device_config_1(vsc,
+ VIRTIO_BLK_CONFIG_WRITEBACK) != wce)
+ return EIO;
+
+ return 0;
+}
+
+static int
+ld_virtio_ioctl(struct ld_softc *ld, u_long cmd, void *addr, int32_t flag, bool poll)
+{
+ int error;
+
+ switch (cmd) {
+ case DIOCCACHESYNC:
+ error = ld_virtio_flush(ld, poll);
+ break;
+
+ case DIOCGCACHE:
+ error = ld_virtio_getcache(ld, (int *)addr);
+ break;
+
+ case DIOCSCACHE:
+ error = ld_virtio_setcache(ld, *(int *)addr);
+ break;
+
+ default:
+ error = EPASSTHROUGH;
+ break;
+ }
+
+ return error;
+}
+
MODULE(MODULE_CLASS_DRIVER, ld_virtio, "ld,virtio");
#ifdef _MODULE
