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-rw-r--r--drivers/scsi/megaraid/megaraid_sas.c72
1 files changed, 47 insertions, 25 deletions
diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 38733b6009a..e177fc5c5dd 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -495,6 +495,46 @@ megasas_make_sgl64(struct megasas_instance *instance, struct scsi_cmnd *scp,
return sge_count;
}
+ /**
+ * megasas_get_frame_count - Computes the number of frames
+ * @sge_count : number of sg elements
+ *
+ * Returns the number of frames required for numnber of sge's (sge_count)
+ */
+
+u32 megasas_get_frame_count(u8 sge_count)
+{
+ int num_cnt;
+ int sge_bytes;
+ u32 sge_sz;
+ u32 frame_count=0;
+
+ sge_sz = (IS_DMA64) ? sizeof(struct megasas_sge64) :
+ sizeof(struct megasas_sge32);
+
+ /*
+ * Main frame can contain 2 SGEs for 64-bit SGLs and
+ * 3 SGEs for 32-bit SGLs
+ */
+ if (IS_DMA64)
+ num_cnt = sge_count - 2;
+ else
+ num_cnt = sge_count - 3;
+
+ if(num_cnt>0){
+ sge_bytes = sge_sz * num_cnt;
+
+ frame_count = (sge_bytes / MEGAMFI_FRAME_SIZE) +
+ ((sge_bytes % MEGAMFI_FRAME_SIZE) ? 1 : 0) ;
+ }
+ /* Main frame */
+ frame_count +=1;
+
+ if (frame_count > 7)
+ frame_count = 8;
+ return frame_count;
+}
+
/**
* megasas_build_dcdb - Prepares a direct cdb (DCDB) command
* @instance: Adapter soft state
@@ -508,8 +548,6 @@ static int
megasas_build_dcdb(struct megasas_instance *instance, struct scsi_cmnd *scp,
struct megasas_cmd *cmd)
{
- u32 sge_sz;
- int sge_bytes;
u32 is_logical;
u32 device_id;
u16 flags = 0;
@@ -544,9 +582,6 @@ megasas_build_dcdb(struct megasas_instance *instance, struct scsi_cmnd *scp,
/*
* Construct SGL
*/
- sge_sz = (IS_DMA64) ? sizeof(struct megasas_sge64) :
- sizeof(struct megasas_sge32);
-
if (IS_DMA64) {
pthru->flags |= MFI_FRAME_SGL64;
pthru->sge_count = megasas_make_sgl64(instance, scp,
@@ -562,17 +597,11 @@ megasas_build_dcdb(struct megasas_instance *instance, struct scsi_cmnd *scp,
pthru->sense_buf_phys_addr_hi = 0;
pthru->sense_buf_phys_addr_lo = cmd->sense_phys_addr;
- sge_bytes = sge_sz * pthru->sge_count;
-
/*
* Compute the total number of frames this command consumes. FW uses
* this number to pull sufficient number of frames from host memory.
*/
- cmd->frame_count = (sge_bytes / MEGAMFI_FRAME_SIZE) +
- ((sge_bytes % MEGAMFI_FRAME_SIZE) ? 1 : 0) + 1;
-
- if (cmd->frame_count > 7)
- cmd->frame_count = 8;
+ cmd->frame_count = megasas_get_frame_count(pthru->sge_count);
return cmd->frame_count;
}
@@ -589,8 +618,6 @@ static int
megasas_build_ldio(struct megasas_instance *instance, struct scsi_cmnd *scp,
struct megasas_cmd *cmd)
{
- u32 sge_sz;
- int sge_bytes;
u32 device_id;
u8 sc = scp->cmnd[0];
u16 flags = 0;
@@ -605,7 +632,7 @@ megasas_build_ldio(struct megasas_instance *instance, struct scsi_cmnd *scp,
flags = MFI_FRAME_DIR_READ;
/*
- * Preare the Logical IO frame: 2nd bit is zero for all read cmds
+ * Prepare the Logical IO frame: 2nd bit is zero for all read cmds
*/
ldio->cmd = (sc & 0x02) ? MFI_CMD_LD_WRITE : MFI_CMD_LD_READ;
ldio->cmd_status = 0x0;
@@ -674,9 +701,6 @@ megasas_build_ldio(struct megasas_instance *instance, struct scsi_cmnd *scp,
/*
* Construct SGL
*/
- sge_sz = (IS_DMA64) ? sizeof(struct megasas_sge64) :
- sizeof(struct megasas_sge32);
-
if (IS_DMA64) {
ldio->flags |= MFI_FRAME_SGL64;
ldio->sge_count = megasas_make_sgl64(instance, scp, &ldio->sgl);
@@ -690,13 +714,11 @@ megasas_build_ldio(struct megasas_instance *instance, struct scsi_cmnd *scp,
ldio->sense_buf_phys_addr_hi = 0;
ldio->sense_buf_phys_addr_lo = cmd->sense_phys_addr;
- sge_bytes = sge_sz * ldio->sge_count;
-
- cmd->frame_count = (sge_bytes / MEGAMFI_FRAME_SIZE) +
- ((sge_bytes % MEGAMFI_FRAME_SIZE) ? 1 : 0) + 1;
-
- if (cmd->frame_count > 7)
- cmd->frame_count = 8;
+ /*
+ * Compute the total number of frames this command consumes. FW uses
+ * this number to pull sufficient number of frames from host memory.
+ */
+ cmd->frame_count = megasas_get_frame_count(ldio->sge_count);
return cmd->frame_count;
}