[PATCH 5/7] sg_ring: Convert core scsi code to sg_ring.
If nothing else, the simplification of this logic shows why I prefer
sg_ring over scatterlist chaining.
Signed-off-by: Rusty Russell <[EMAIL PROTECTED]>
diff --git a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
--- a/drivers/block/cciss_scsi.c
+++ b/drivers/block/cciss_scsi.c
@@ -1191,28 +1191,28 @@ cciss_scatter_gather(struct pci_dev *pde
struct scsi_cmnd *cmd)
{
unsigned int len;
- struct scatterlist *sg;
+ struct sg_ring *sg;
__u64 addr64;
- int use_sg, i;
+ int count = 0, i;
- BUG_ON(scsi_sg_count(cmd) > MAXSGENTRIES);
-
- use_sg = scsi_dma_map(cmd);
- if (use_sg) { /* not too many addrs? */
- scsi_for_each_sg(cmd, sg, use_sg, i) {
- addr64 = (__u64) sg_dma_address(sg);
- len = sg_dma_len(sg);
+ if (scsi_dma_map(cmd) >= 0) { /* not too many addrs? */
+ sg_ring_for_each(scsi_sgring(cmd), sg, i) {
+ addr64 = (__u64) sg_dma_address(>sg[i]);
+ len = sg_dma_len(>sg[i]);
cp->SG[i].Addr.lower =
(__u32) (addr64 & (__u64) 0x);
cp->SG[i].Addr.upper =
(__u32) ((addr64 >> 32) & (__u64)
0x);
cp->SG[i].Len = len;
cp->SG[i].Ext = 0; // we are not chaining
+ count++;
}
}
- cp->Header.SGList = (__u8) use_sg; /* no. SGs contig in this cmd */
- cp->Header.SGTotal = (__u16) use_sg; /* total sgs in this cmd list */
+ cp->Header.SGList = (__u8) count; /* no. SGs contig in this cmd */
+ cp->Header.SGTotal = (__u16) count; /* total sgs in this cmd list */
+
+ BUG_ON(count > MAXSGENTRIES);
return;
}
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -619,18 +619,17 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd
ses->data_direction = scmd->sc_data_direction;
ses->bufflen = scmd->request_bufflen;
ses->buffer = scmd->request_buffer;
- ses->use_sg = scmd->use_sg;
ses->resid = scmd->resid;
ses->result = scmd->result;
if (sense_bytes) {
scmd->request_bufflen = min_t(unsigned,
sizeof(scmd->sense_buffer), sense_bytes);
- sg_init_one(>sense_sgl, scmd->sense_buffer,
- scmd->request_bufflen);
- scmd->request_buffer = >sense_sgl;
+
+ sg_ring_single(>sense_sg.ring, scmd->sense_buffer,
+ scmd->request_bufflen);
+ scmd->request_buffer = >sense_sg;
scmd->sc_data_direction = DMA_FROM_DEVICE;
- scmd->use_sg = 1;
memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
scmd->cmnd[0] = REQUEST_SENSE;
scmd->cmnd[4] = scmd->request_bufflen;
@@ -639,7 +638,6 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd
scmd->request_buffer = NULL;
scmd->request_bufflen = 0;
scmd->sc_data_direction = DMA_NONE;
- scmd->use_sg = 0;
if (cmnd) {
memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
memcpy(scmd->cmnd, cmnd, cmnd_size);
@@ -678,7 +676,6 @@ void scsi_eh_restore_cmnd(struct scsi_cm
scmd->sc_data_direction = ses->data_direction;
scmd->request_bufflen = ses->bufflen;
scmd->request_buffer = ses->buffer;
- scmd->use_sg = ses->use_sg;
scmd->resid = ses->resid;
scmd->result = ses->result;
}
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -17,7 +17,7 @@
#include
#include
#include
-#include
+#include
#include
#include
@@ -737,21 +737,31 @@ static inline unsigned int scsi_sgtable_
return index;
}
-struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+static void free_sgring(struct sg_ring *sg)
{
struct scsi_host_sg_pool *sgp;
- struct scatterlist *sgl, *prev, *ret;
+
+ sgp = scsi_sg_pools + scsi_sgtable_index(sg->max);
+
+ mempool_free(sg, sgp->pool);
+}
+
+struct sg_ring *scsi_alloc_sgring(struct scsi_cmnd *cmd, unsigned int num,
+ gfp_t gfp_mask)
+{
+ struct scsi_host_sg_pool *sgp;
+ struct sg_ring *sg, *ret;
unsigned int index;
int this, left;
- BUG_ON(!cmd->use_sg);
+ BUG_ON(!num);
- left = cmd->use_sg;
- ret = prev = NULL;
+ left = num;
+ ret = NULL;
do {
this = left;
if (this > SCSI_MAX_SG_SEGMENTS) {
- this =
[PATCH 5/7] sg_ring: Convert core scsi code to sg_ring.
If nothing else, the simplification of this logic shows why I prefer
sg_ring over scatterlist chaining.
Signed-off-by: Rusty Russell [EMAIL PROTECTED]
diff --git a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
--- a/drivers/block/cciss_scsi.c
+++ b/drivers/block/cciss_scsi.c
@@ -1191,28 +1191,28 @@ cciss_scatter_gather(struct pci_dev *pde
struct scsi_cmnd *cmd)
{
unsigned int len;
- struct scatterlist *sg;
+ struct sg_ring *sg;
__u64 addr64;
- int use_sg, i;
+ int count = 0, i;
- BUG_ON(scsi_sg_count(cmd) MAXSGENTRIES);
-
- use_sg = scsi_dma_map(cmd);
- if (use_sg) { /* not too many addrs? */
- scsi_for_each_sg(cmd, sg, use_sg, i) {
- addr64 = (__u64) sg_dma_address(sg);
- len = sg_dma_len(sg);
+ if (scsi_dma_map(cmd) = 0) { /* not too many addrs? */
+ sg_ring_for_each(scsi_sgring(cmd), sg, i) {
+ addr64 = (__u64) sg_dma_address(sg-sg[i]);
+ len = sg_dma_len(sg-sg[i]);
cp-SG[i].Addr.lower =
(__u32) (addr64 (__u64) 0x);
cp-SG[i].Addr.upper =
(__u32) ((addr64 32) (__u64)
0x);
cp-SG[i].Len = len;
cp-SG[i].Ext = 0; // we are not chaining
+ count++;
}
}
- cp-Header.SGList = (__u8) use_sg; /* no. SGs contig in this cmd */
- cp-Header.SGTotal = (__u16) use_sg; /* total sgs in this cmd list */
+ cp-Header.SGList = (__u8) count; /* no. SGs contig in this cmd */
+ cp-Header.SGTotal = (__u16) count; /* total sgs in this cmd list */
+
+ BUG_ON(count MAXSGENTRIES);
return;
}
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -619,18 +619,17 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd
ses-data_direction = scmd-sc_data_direction;
ses-bufflen = scmd-request_bufflen;
ses-buffer = scmd-request_buffer;
- ses-use_sg = scmd-use_sg;
ses-resid = scmd-resid;
ses-result = scmd-result;
if (sense_bytes) {
scmd-request_bufflen = min_t(unsigned,
sizeof(scmd-sense_buffer), sense_bytes);
- sg_init_one(ses-sense_sgl, scmd-sense_buffer,
- scmd-request_bufflen);
- scmd-request_buffer = ses-sense_sgl;
+
+ sg_ring_single(ses-sense_sg.ring, scmd-sense_buffer,
+ scmd-request_bufflen);
+ scmd-request_buffer = ses-sense_sg;
scmd-sc_data_direction = DMA_FROM_DEVICE;
- scmd-use_sg = 1;
memset(scmd-cmnd, 0, sizeof(scmd-cmnd));
scmd-cmnd[0] = REQUEST_SENSE;
scmd-cmnd[4] = scmd-request_bufflen;
@@ -639,7 +638,6 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd
scmd-request_buffer = NULL;
scmd-request_bufflen = 0;
scmd-sc_data_direction = DMA_NONE;
- scmd-use_sg = 0;
if (cmnd) {
memset(scmd-cmnd, 0, sizeof(scmd-cmnd));
memcpy(scmd-cmnd, cmnd, cmnd_size);
@@ -678,7 +676,6 @@ void scsi_eh_restore_cmnd(struct scsi_cm
scmd-sc_data_direction = ses-data_direction;
scmd-request_bufflen = ses-bufflen;
scmd-request_buffer = ses-buffer;
- scmd-use_sg = ses-use_sg;
scmd-resid = ses-resid;
scmd-result = ses-result;
}
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -17,7 +17,7 @@
#include linux/pci.h
#include linux/delay.h
#include linux/hardirq.h
-#include linux/scatterlist.h
+#include linux/sg_ring.h
#include scsi/scsi.h
#include scsi/scsi_cmnd.h
@@ -737,21 +737,31 @@ static inline unsigned int scsi_sgtable_
return index;
}
-struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+static void free_sgring(struct sg_ring *sg)
{
struct scsi_host_sg_pool *sgp;
- struct scatterlist *sgl, *prev, *ret;
+
+ sgp = scsi_sg_pools + scsi_sgtable_index(sg-max);
+
+ mempool_free(sg, sgp-pool);
+}
+
+struct sg_ring *scsi_alloc_sgring(struct scsi_cmnd *cmd, unsigned int num,
+ gfp_t gfp_mask)
+{
+ struct scsi_host_sg_pool *sgp;
+ struct sg_ring *sg, *ret;
unsigned int index;
int this, left;
- BUG_ON(!cmd-use_sg);
+ BUG_ON(!num);
- left = cmd-use_sg;
- ret = prev = NULL;
+ left = num;
+ ret = NULL;
do {
this = left;
if (this
