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path: root/drivers/scsi/scsi_lib.c
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Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c28
1 files changed, 20 insertions, 8 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b6e6d801768b..1a7e8d811a08 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -34,6 +34,13 @@
#define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools)
#define SG_MEMPOOL_SIZE 2
+/*
+ * The maximum number of SG segments that we will put inside a scatterlist
+ * (unless chaining is used). Should ideally fit inside a single page, to
+ * avoid a higher order allocation.
+ */
+#define SCSI_MAX_SG_SEGMENTS 128
+
struct scsi_host_sg_pool {
size_t size;
char *name;
@@ -45,9 +52,15 @@ struct scsi_host_sg_pool {
static struct scsi_host_sg_pool scsi_sg_pools[] = {
SP(8),
SP(16),
+#if (SCSI_MAX_SG_SEGMENTS > 16)
SP(32),
+#if (SCSI_MAX_SG_SEGMENTS > 32)
SP(64),
+#if (SCSI_MAX_SG_SEGMENTS > 64)
SP(128),
+#endif
+#endif
+#endif
};
#undef SP
@@ -685,13 +698,6 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate,
}
/*
- * The maximum number of SG segments that we will put inside a scatterlist
- * (unless chaining is used). Should ideally fit inside a single page, to
- * avoid a higher order allocation.
- */
-#define SCSI_MAX_SG_SEGMENTS 128
-
-/*
* Like SCSI_MAX_SG_SEGMENTS, but for archs that have sg chaining. This limit
* is totally arbitrary, a setting of 2048 will get you at least 8mb ios.
*/
@@ -708,15 +714,21 @@ static inline unsigned int scsi_sgtable_index(unsigned short nents)
case 9 ... 16:
index = 1;
break;
+#if (SCSI_MAX_SG_SEGMENTS > 16)
case 17 ... 32:
index = 2;
break;
+#if (SCSI_MAX_SG_SEGMENTS > 32)
case 33 ... 64:
index = 3;
break;
- case 65 ... SCSI_MAX_SG_SEGMENTS:
+#if (SCSI_MAX_SG_SEGMENTS > 64)
+ case 65 ... 128:
index = 4;
break;
+#endif
+#endif
+#endif
default:
printk(KERN_ERR "scsi: bad segment count=%d\n", nents);
BUG();
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