mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2025-01-13 03:46:32 +07:00
614f0388f5
This wraps single ioctl() commands into block requests using the custom block layer request types REQ_OP_DRV_IN and REQ_OP_DRV_OUT. By doing this we are loosening the grip on the big host lock, since two calls to mmc_get_card()/mmc_put_card() are removed. We are storing the ioctl() in/out argument as a pointer in the per-request struct mmc_blk_request container. Since we now let the block layer allocate this data, blk_get_request() will allocate it for us and we can immediately dereference it and use it to pass the argument into the block layer. We refactor the if/else/if/else ladder in mmc_blk_issue_rq() as part of the job, keeping some extra attention to the case when a NULL req is passed into this function and making that pipeline flush more explicit. Tested on the ux500 with the userspace: mmc extcsd read /dev/mmcblk3 resulting in a successful EXTCSD info dump back to the console. This commit fixes a starvation issue in the MMC/SD stack that can be easily provoked in the following way by issueing the following commands in sequence: > dd if=/dev/mmcblk3 of=/dev/null bs=1M & > mmc extcs read /dev/mmcblk3 Before this patch, the extcsd read command would hang (starve) while waiting for the dd command to finish since the block layer was holding the card/host lock. After this patch, the extcsd ioctl() command is nicely interpersed with the rest of the block commands and we can issue a bunch of ioctl()s from userspace while there is some busy block IO going on without any problems. Conversely userspace ioctl()s can no longer starve the block layer by holding the card/host lock. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Avri Altman <Avri.Altman@sandisk.com>
79 lines
1.9 KiB
C
79 lines
1.9 KiB
C
#ifndef MMC_QUEUE_H
|
|
#define MMC_QUEUE_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/blk-mq.h>
|
|
#include <linux/mmc/core.h>
|
|
#include <linux/mmc/host.h>
|
|
|
|
static inline struct mmc_queue_req *req_to_mmc_queue_req(struct request *rq)
|
|
{
|
|
return blk_mq_rq_to_pdu(rq);
|
|
}
|
|
|
|
static inline bool mmc_req_is_special(struct request *req)
|
|
{
|
|
return req &&
|
|
(req_op(req) == REQ_OP_FLUSH ||
|
|
req_op(req) == REQ_OP_DISCARD ||
|
|
req_op(req) == REQ_OP_SECURE_ERASE);
|
|
}
|
|
|
|
struct task_struct;
|
|
struct mmc_blk_data;
|
|
struct mmc_blk_ioc_data;
|
|
|
|
struct mmc_blk_request {
|
|
struct mmc_request mrq;
|
|
struct mmc_command sbc;
|
|
struct mmc_command cmd;
|
|
struct mmc_command stop;
|
|
struct mmc_data data;
|
|
int retune_retry_done;
|
|
};
|
|
|
|
struct mmc_queue_req {
|
|
struct request *req;
|
|
struct mmc_blk_request brq;
|
|
struct scatterlist *sg;
|
|
char *bounce_buf;
|
|
struct scatterlist *bounce_sg;
|
|
unsigned int bounce_sg_len;
|
|
struct mmc_async_req areq;
|
|
int ioc_result;
|
|
struct mmc_blk_ioc_data *idata;
|
|
};
|
|
|
|
struct mmc_queue {
|
|
struct mmc_card *card;
|
|
struct task_struct *thread;
|
|
struct semaphore thread_sem;
|
|
bool suspended;
|
|
bool asleep;
|
|
struct mmc_blk_data *blkdata;
|
|
struct request_queue *queue;
|
|
/*
|
|
* FIXME: this counter is not a very reliable way of keeping
|
|
* track of how many requests that are ongoing. Switch to just
|
|
* letting the block core keep track of requests and per-request
|
|
* associated mmc_queue_req data.
|
|
*/
|
|
int qcnt;
|
|
};
|
|
|
|
extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,
|
|
const char *);
|
|
extern void mmc_cleanup_queue(struct mmc_queue *);
|
|
extern void mmc_queue_suspend(struct mmc_queue *);
|
|
extern void mmc_queue_resume(struct mmc_queue *);
|
|
|
|
extern unsigned int mmc_queue_map_sg(struct mmc_queue *,
|
|
struct mmc_queue_req *);
|
|
extern void mmc_queue_bounce_pre(struct mmc_queue_req *);
|
|
extern void mmc_queue_bounce_post(struct mmc_queue_req *);
|
|
|
|
extern int mmc_access_rpmb(struct mmc_queue *);
|
|
|
|
#endif
|