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hyperv/vmbus: Implement orphan support for transaction API

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It will be used to fix the primary channel revocation support.

MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D8525
This commit is contained in:
sephe 2016-11-24 04:58:13 +00:00
parent a839bad498
commit 3298d7d4fd
2 changed files with 92 additions and 19 deletions
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2
sys/dev/hyperv/include/vmbus_xact.h
View File

@ -39,6 +39,8 @@ struct vmbus_xact_ctx *vmbus_xact_ctx_create(bus_dma_tag_t dtag,
size_t req_size, size_t resp_size,
size_t priv_size);
void vmbus_xact_ctx_destroy(struct vmbus_xact_ctx *ctx);
bool vmbus_xact_ctx_orphan(struct vmbus_xact_ctx *ctx);
struct vmbus_xact *vmbus_xact_get(struct vmbus_xact_ctx *ctx,
size_t req_len);
void vmbus_xact_put(struct vmbus_xact *xact);

109
sys/dev/hyperv/vmbus/vmbus_xact.c
View File

@ -61,6 +61,7 @@ struct vmbus_xact_ctx {
uint32_t xc_flags; /* VMBUS_XACT_CTXF_ */
struct vmbus_xact *xc_free;
struct vmbus_xact *xc_active;
struct vmbus_xact *xc_orphan;
};
#define VMBUS_XACT_CTXF_DESTROY 0x0001
@ -72,6 +73,9 @@ static struct vmbus_xact *vmbus_xact_get1(struct vmbus_xact_ctx *,
uint32_t);
const void *vmbus_xact_wait1(struct vmbus_xact *, size_t *,
bool);
static void vmbus_xact_save_resp(struct vmbus_xact *,
const void *, size_t);
static void vmbus_xact_ctx_free(struct vmbus_xact_ctx *);
static struct vmbus_xact *
vmbus_xact_alloc(struct vmbus_xact_ctx *ctx, bus_dma_tag_t parent_dtag)
@ -136,6 +140,9 @@ vmbus_xact_ctx_create(bus_dma_tag_t dtag, size_t req_size, size_t resp_size,
{
struct vmbus_xact_ctx *ctx;
KASSERT(req_size > 0, ("request size is 0"));
KASSERT(resp_size > 0, ("response size is 0"));
ctx = malloc(sizeof(*ctx), M_DEVBUF, M_WAITOK | M_ZERO);
ctx->xc_req_size = req_size;
ctx->xc_resp_size = resp_size;
@ -152,23 +159,44 @@ vmbus_xact_ctx_create(bus_dma_tag_t dtag, size_t req_size, size_t resp_size,
return (ctx);
}
bool
vmbus_xact_ctx_orphan(struct vmbus_xact_ctx *ctx)
{
mtx_lock(&ctx->xc_lock);
if (ctx->xc_flags & VMBUS_XACT_CTXF_DESTROY) {
mtx_unlock(&ctx->xc_lock);
return (false);
}
ctx->xc_flags |= VMBUS_XACT_CTXF_DESTROY;
mtx_unlock(&ctx->xc_lock);
wakeup(&ctx->xc_free);
wakeup(&ctx->xc_active);
ctx->xc_orphan = vmbus_xact_get1(ctx, 0);
if (ctx->xc_orphan == NULL)
panic("can't get xact");
return (true);
}
static void
vmbus_xact_ctx_free(struct vmbus_xact_ctx *ctx)
{
KASSERT(ctx->xc_flags & VMBUS_XACT_CTXF_DESTROY,
("xact ctx was not orphaned"));
KASSERT(ctx->xc_orphan != NULL, ("no orphaned xact"));
vmbus_xact_free(ctx->xc_orphan);
mtx_destroy(&ctx->xc_lock);
free(ctx, M_DEVBUF);
}
void
vmbus_xact_ctx_destroy(struct vmbus_xact_ctx *ctx)
{
struct vmbus_xact *xact;
mtx_lock(&ctx->xc_lock);
ctx->xc_flags |= VMBUS_XACT_CTXF_DESTROY;
mtx_unlock(&ctx->xc_lock);
wakeup(&ctx->xc_free);
xact = vmbus_xact_get1(ctx, 0);
if (xact == NULL)
panic("can't get xact");
vmbus_xact_free(xact);
mtx_destroy(&ctx->xc_lock);
free(ctx, M_DEVBUF);
vmbus_xact_ctx_orphan(ctx);
vmbus_xact_ctx_free(ctx);
}
struct vmbus_xact *
@ -259,7 +287,8 @@ vmbus_xact_wait1(struct vmbus_xact *xact, size_t *resp_len,
mtx_lock(&ctx->xc_lock);
KASSERT(ctx->xc_active == xact, ("xact mismatch"));
while (xact->x_resp == NULL) {
while (xact->x_resp == NULL &&
(ctx->xc_flags & VMBUS_XACT_CTXF_DESTROY) == 0) {
if (can_sleep) {
mtx_sleep(&ctx->xc_active, &ctx->xc_lock, 0,
"wxact", 0);
@ -269,6 +298,20 @@ vmbus_xact_wait1(struct vmbus_xact *xact, size_t *resp_len,
mtx_lock(&ctx->xc_lock);
}
}
KASSERT(ctx->xc_active == xact, ("xact trashed"));
if ((ctx->xc_flags & VMBUS_XACT_CTXF_DESTROY) && xact->x_resp == NULL) {
uint8_t b = 0;
/*
* Orphaned and no response was received yet; fake up
* an one byte response.
*/
printf("vmbus: xact ctx was orphaned w/ pending xact\n");
vmbus_xact_save_resp(ctx->xc_active, &b, sizeof(b));
}
KASSERT(xact->x_resp != NULL, ("no response"));
ctx->xc_active = NULL;
resp = xact->x_resp;
@ -317,19 +360,47 @@ void
vmbus_xact_wakeup(struct vmbus_xact *xact, const void *data, size_t dlen)
{
struct vmbus_xact_ctx *ctx = xact->x_ctx;
int do_wakeup = 0;
mtx_lock(&ctx->xc_lock);
vmbus_xact_save_resp(xact, data, dlen);
/*
* NOTE:
* xc_active could be NULL, if the ctx has been orphaned.
*/
if (ctx->xc_active != NULL) {
vmbus_xact_save_resp(xact, data, dlen);
do_wakeup = 1;
} else {
KASSERT(ctx->xc_flags & VMBUS_XACT_CTXF_DESTROY,
("no active xact pending"));
printf("vmbus: drop xact response\n");
}
mtx_unlock(&ctx->xc_lock);
wakeup(&ctx->xc_active);
if (do_wakeup)
wakeup(&ctx->xc_active);
}
void
vmbus_xact_ctx_wakeup(struct vmbus_xact_ctx *ctx, const void *data, size_t dlen)
{
int do_wakeup = 0;
mtx_lock(&ctx->xc_lock);
KASSERT(ctx->xc_active != NULL, ("no pending xact"));
vmbus_xact_save_resp(ctx->xc_active, data, dlen);
/*
* NOTE:
* xc_active could be NULL, if the ctx has been orphaned.
*/
if (ctx->xc_active != NULL) {
vmbus_xact_save_resp(ctx->xc_active, data, dlen);
do_wakeup = 1;
} else {
KASSERT(ctx->xc_flags & VMBUS_XACT_CTXF_DESTROY,
("no active xact pending"));
printf("vmbus: drop xact response\n");
}
mtx_unlock(&ctx->xc_lock);
wakeup(&ctx->xc_active);
if (do_wakeup)
wakeup(&ctx->xc_active);
}