[RFC v2 PATCH 1/4] block: add a flag to identify PM request

Lin Ming
2012-05-17T15:47:18Z

Add a flag REQ_PM to identify the request is PM related.
As an example, modify scsi code to use this flag.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
---
drivers/scsi/scsi_lib.c | 25 ++++++++++++++++++++++---
drivers/scsi/sd.c | 9 +++++----
include/linux/blk_types.h | 2 ++
include/scsi/scsi_device.h | 4 ++++
4 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ead6405..5a1eb5a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -256,10 +256,10 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
EXPORT_SYMBOL(scsi_execute);

-int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
+static int __scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
int data_direction, void *buffer, unsigned bufflen,
struct scsi_sense_hdr *sshdr, int timeout, int retries,
- int *resid)
+ int *resid, int flags)
{
char *sense = NULL;
int result;
@@ -270,15 +270,34 @@ int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
return DRIVER_ERROR << 24;
}
result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen,
- sense, timeout, retries, 0, resid);
+ sense, timeout, retries, flags, resid);
if (sshdr)
scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr);

kfree(sense);
return result;
}
+
+int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
+ int data_direction, void *buffer, unsigned bufflen,
+ struct scsi_sense_hdr *sshdr, int timeout, int retries,
+ int *resid)
+{
+ return __scsi_execute_req(sdev, cmd, data_direction, buffer, bufflen,
+ sshdr, timeout, retries, resid, 0);
+}
EXPORT_SYMBOL(scsi_execute_req);

+int scsi_execute_req_flag(struct scsi_device *sdev, const unsigned char *cmd,
+ int data_direction, void *buffer, unsigned bufflen,
+ struct scsi_sense_hdr *sshdr, int timeout, int retries,
+ int *resid, int flags)
+{
+ return __scsi_execute_req(sdev, cmd, data_direction, buffer, bufflen,
+ sshdr, timeout, retries, resid, flags);
+}
+EXPORT_SYMBOL(scsi_execute_req_flag);
+
/*
* Function: scsi_init_cmd_errh()
*
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 5ba5c2a..1205a8b 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1269,8 +1269,9 @@ static int sd_sync_cache(struct scsi_disk *sdkp)
* Leave the rest of the command zero to indicate
* flush everything.
*/
- res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
- SD_FLUSH_TIMEOUT, SD_MAX_RETRIES, NULL);
+ res = scsi_execute_req_flag(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
+ SD_FLUSH_TIMEOUT, SD_MAX_RETRIES, NULL,
+ REQ_PM);
if (res == 0)
break;
}
@@ -2812,8 +2813,8 @@ static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
if (!scsi_device_online(sdp))
return -ENODEV;

- res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
- SD_TIMEOUT, SD_MAX_RETRIES, NULL);
+ res = scsi_execute_req_flag(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
+ SD_TIMEOUT, SD_MAX_RETRIES, NULL, REQ_PM);
if (res) {
sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
sd_print_result(sdkp, res);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 4053cbd..a75f854 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -150,6 +150,7 @@ enum rq_flag_bits {
__REQ_FLUSH_SEQ, /* request for flush sequence */
__REQ_IO_STAT, /* account I/O stat */
__REQ_MIXED_MERGE, /* merge of different types, fail separately */
+ __REQ_PM, /* runtime pm request */
__REQ_NR_BITS, /* stops here */
};

@@ -191,5 +192,6 @@ enum rq_flag_bits {
#define REQ_IO_STAT (1 << __REQ_IO_STAT)
#define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE)
#define REQ_SECURE (1 << __REQ_SECURE)
+#define REQ_PM (1 << __REQ_PM)

#endif /* __LINUX_BLK_TYPES_H */
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 6efb2e1..7735b46 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -387,6 +387,10 @@ extern int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
int data_direction, void *buffer, unsigned bufflen,
struct scsi_sense_hdr *, int timeout, int retries,
int *resid);
+extern int scsi_execute_req_flag(struct scsi_device *sdev, const unsigned char *cmd,
+ int data_direction, void *buffer, unsigned bufflen,
+ struct scsi_sense_hdr *, int timeout, int retries,
+ int *resid, int flags);

#ifdef CONFIG_PM_RUNTIME
extern int scsi_autopm_get_device(struct scsi_device *);
--
1.7.2.5