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mmc: block: Issue a cache flush only when it's enabled

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In command queueing mode, the cache isn't flushed via the mmc_flush_cache()
function, but instead by issuing a CMDQ_TASK_MGMT (CMD48) with a
FLUSH_CACHE opcode. In this path, we need to check if cache has been
enabled, before deciding to flush the cache, along the lines of what's
being done in mmc_flush_cache().

To fix this problem, let's add a new bus ops callback ->cache_enabled() and
implement it for the mmc bus type. In this way, the mmc block device driver
can call it to know whether cache flushing should be done.

Fixes: 1e8e55b670 (mmc: block: Add CQE support)
Cc: stable@vger.kernel.org
Reported-by: Brendan Peter <bpeter@lytx.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Tested-by: Brendan Peter <bpeter@lytx.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20210425060207.2591-2-avri.altman@wdc.com
Link: https://lore.kernel.org/r/20210425060207.2591-3-avri.altman@wdc.com
[Ulf: Squashed the two patches and made some minor updates]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Avri Altman 2021-04-25 09:02:06 +03:00 committed by Ulf Hansson
parent 2f156712be
commit 97fce126e2
4 changed files with 21 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

4
drivers/mmc/core/block.c
View file

@ -2237,6 +2237,10 @@ enum mmc_issued mmc_blk_mq_issue_rq(struct mmc_queue *mq, struct request *req)
case MMC_ISSUE_ASYNC: case MMC_ISSUE_ASYNC:
switch (req_op(req)) { switch (req_op(req)) {
case REQ_OP_FLUSH: case REQ_OP_FLUSH:
if (!mmc_cache_enabled(host)) {
blk_mq_end_request(req, BLK_STS_OK);
return MMC_REQ_FINISHED;
}
ret = mmc_blk_cqe_issue_flush(mq, req); ret = mmc_blk_cqe_issue_flush(mq, req);
break; break;
case REQ_OP_READ: case REQ_OP_READ:

9
drivers/mmc/core/core.h
View file

@ -29,6 +29,7 @@ struct mmc_bus_ops {
int (*shutdown)(struct mmc_host *); int (*shutdown)(struct mmc_host *);
int (*hw_reset)(struct mmc_host *); int (*hw_reset)(struct mmc_host *);
int (*sw_reset)(struct mmc_host *); int (*sw_reset)(struct mmc_host *);
bool (*cache_enabled)(struct mmc_host *);
}; };
void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops); void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
@ -163,4 +164,12 @@ static inline void mmc_post_req(struct mmc_host *host, struct mmc_request *mrq,
host->ops->post_req(host, mrq, err); host->ops->post_req(host, mrq, err);
} }
static inline bool mmc_cache_enabled(struct mmc_host *host)
{
if (host->bus_ops->cache_enabled)
return host->bus_ops->cache_enabled(host);
return false;
}
#endif #endif

7
drivers/mmc/core/mmc.c
View file

@ -2029,6 +2029,12 @@ static void mmc_detect(struct mmc_host *host)
} }
} }
static bool _mmc_cache_enabled(struct mmc_host *host)
{
return host->card->ext_csd.cache_size > 0 &&
host->card->ext_csd.cache_ctrl & 1;
}
static int _mmc_suspend(struct mmc_host *host, bool is_suspend) static int _mmc_suspend(struct mmc_host *host, bool is_suspend)
{ {
int err = 0; int err = 0;
@ -2208,6 +2214,7 @@ static const struct mmc_bus_ops mmc_ops = {
.alive = mmc_alive, .alive = mmc_alive,
.shutdown = mmc_shutdown, .shutdown = mmc_shutdown,
.hw_reset = _mmc_hw_reset, .hw_reset = _mmc_hw_reset,
.cache_enabled = _mmc_cache_enabled,
}; };
/* /*

4
drivers/mmc/core/mmc_ops.c
View file

@ -968,9 +968,7 @@ int mmc_flush_cache(struct mmc_card *card)
{ {
int err = 0; int err = 0;
if (mmc_card_mmc(card) && if (mmc_cache_enabled(card->host)) {
(card->ext_csd.cache_size > 0) &&
(card->ext_csd.cache_ctrl & 1)) {
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_FLUSH_CACHE, 1, EXT_CSD_FLUSH_CACHE, 1,
MMC_CACHE_FLUSH_TIMEOUT_MS); MMC_CACHE_FLUSH_TIMEOUT_MS);