This patch defines a new API for sense handling. All drivers will
be converted to this API, before the sense handling implementation will
change. API is as follows:
void scsi_eh_cpy_sense(struct scsi_cmnd *cmd, void* sense,
unsigned sense_bytes);
To be used by drivers, when they have sense-bits
and wants to send them to upper layer. Max size
need not be a concern, If upper layer does not have
enough space it will be automatically truncated.
u8 *scsi_make_sense(struct scsi_cmnd *cmd);
To be used by drivers, and scsi-midlayer. Returns a DMA-able
sense buffer. Must be returned by scsi_return_sense(). It should
never fail if .pre_allocate_sense && .sense_buffsize in host
template where properly set.
the buffer is of shost->sense_buffsize long.
void *scsi_return_sense(struct scsi_cmnd *cmd, u8 *sb);
Frees and returns the sense to the upper layer,
copying only what's necessary.
void scsi_eh_reset_sense(struct scsi_cmnd *cmd)
Should not be used or necessary.
const u8 *scsi_sense(struct scsi_cmnd *cmd)
Used by ULDs and for inspecting the returned sense, can not
be modified. It is only valid after a call to
scsi_eh_cpy_sense() or a call to scsi_return_sense(). Before
that it will/should return an empty buffer.
New members at scsi host template:
.sense_buffsize - if a driver calls scsi_make_sense() or
scsi_eh_prep_cmnd(), This value should be none
zero indicating the max sense size, the driver
supports. In most cases it should be
SCSI_SENSE_BUFFERSIZE.
If this value is zero the driver will only call
scsi_eh_cpy_sense().
.pre_allocate_sense - if a Driver calls scsi_make_sense()
in .queuecommand for every cmnd, this
should be set to true. In which case
scsi_make_sense() will not fail because
midlayer will fail the command allocation.
If the drivers calls scsi_eh_prep_cmnd()
then sense_buffsize is not Zero but this
here is set to false.
Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
---
drivers/scsi/scsi.c | 12 ++++++++++++
drivers/scsi/scsi_error.c | 7 +++++++
include/scsi/scsi_eh.h | 17 +++++++++++++++++
include/scsi/scsi_host.h | 15 +++++++++++++++
4 files changed, 51 insertions(+), 0 deletions(-)
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 98cba7d..af29ccc 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -290,6 +290,18 @@ void scsi_put_command(struct scsi_cmnd *cmd)
}
EXPORT_SYMBOL(scsi_put_command);
+u8 *scsi_make_sense(struct scsi_cmnd *cmd)
+{
+ return cmd->sense_buffer;
+}
+EXPORT_SYMBOL(scsi_make_sense);
+
+void scsi_return_sense(struct scsi_cmnd *cmd, u8 *sb)
+{
+ BUG_ON(cmd->sense_buffer != sb);
+}
+EXPORT_SYMBOL(scsi_return_sense);
+
/**
* scsi_setup_command_freelist - Setup the command freelist for a scsi host.
* @shost: host to allocate the freelist for.
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 98696ae..dc8cd2b 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -588,6 +588,13 @@ static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
scsi_try_host_reset(scmd);
}
+void scsi_eh_cpy_sense(struct scsi_cmnd *cmd, void *sense, unsigned sense_bytes)
+{
+ unsigned len = min_t(unsigned, sense_bytes, SCSI_SENSE_BUFFERSIZE);
+ memcpy(cmd->sense_buffer, sense, len);
+}
+EXPORT_SYMBOL(scsi_eh_cpy_sense);
+
/**
* scsi_eh_prep_cmnd - Save a scsi command info as part of error recory
* @scmd: SCSI command structure to hijack
diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h
index 9438ea1..ce84330 100644
--- a/include/scsi/scsi_eh.h
+++ b/include/scsi/scsi_eh.h
@@ -87,4 +87,21 @@ extern void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd,
extern void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd,
struct scsi_eh_save *ses);
+extern void scsi_eh_cpy_sense(struct scsi_cmnd *cmd, void *sense,
+ unsigned sense_bytes);
+
+extern u8 *scsi_make_sense(struct scsi_cmnd *cmd);
+extern void scsi_return_sense(struct scsi_cmnd *cmd, u8 *sb);
+
+/*FIXME: don't use, it's temporary */
+static inline void scsi_eh_reset_sense(struct scsi_cmnd *cmd)
+{
+ memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
+}
+
+static inline const u8 *scsi_sense(struct scsi_cmnd *cmd)
+{
+ return cmd->sense_buffer;
+}
+
#endif /* _SCSI_SCSI_EH_H */
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index c2dd31d..f232768 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -443,6 +443,18 @@ struct scsi_host_template {
unsigned ordered_tag:1;
/*
+ * IF sense_buffsize != 0 then this bit asks to pre-allocate a sense
+ * buffer for each command.
+ */
+ unsigned pre_allocate_sense:1;
+
+ /*
+ * IF sense_buffsize != 0 then a mem_cache_pool is allocated for the
+ * host with buffers of this size, with 1 pre-allocated buffer.
+ */
+ unsigned sense_buffsize;
+
+ /*
* Countdown for host blocking with no commands outstanding
*/
unsigned int max_host_blocked;
@@ -609,6 +621,9 @@ struct Scsi_Host {
/* Asynchronous scan in progress */
unsigned async_scan:1;
+ /* actual allocated sense_buffsize for this host */
+ unsigned sense_buffsize;
+
/*
* Optional work queue to be utilized by the transport
*/
--
1.5.3.3
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