qla1280: sg chaining support

Interesting hardware setup...

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/drivers/scsi/qla1280.c b/drivers/scsi/qla1280.c
index fba8aa8a81b58c8f689d136cd65435d5873f5192..1f17dec7d6fcc08f2022f940a44c294acd8ee99b 100644 (file)
--- a/drivers/scsi/qla1280.c
+++ b/drivers/scsi/qla1280.c
@@ -2775,7 +2775,7 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
        struct device_reg __iomem *reg = ha->iobase;
        struct scsi_cmnd *cmd = sp->cmd;
        cmd_a64_entry_t *pkt;
-       struct scatterlist *sg = NULL;
+       struct scatterlist *sg = NULL, *s;
        __le32 *dword_ptr;
        dma_addr_t dma_handle;
        int status = 0;
@@ -2889,13 +2889,16 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
         * Load data segments.
         */
        if (seg_cnt) {  /* If data transfer. */
+               int remseg = seg_cnt;
                /* Setup packet address segment pointer. */
                dword_ptr = (u32 *)&pkt->dseg_0_address;
 
                if (cmd->use_sg) {      /* If scatter gather */
                        /* Load command entry data segments. */
-                       for (cnt = 0; cnt < 2 && seg_cnt; cnt++, seg_cnt--) {
-                               dma_handle = sg_dma_address(sg);
+                       for_each_sg(sg, s, seg_cnt, cnt) {
+                               if (cnt == 2)
+                                       break;
+                               dma_handle = sg_dma_address(s);
 #if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_SGI_SN2)
                                if (ha->flags.use_pci_vchannel)
                                        sn_pci_set_vchan(ha->pdev,
@@ -2906,12 +2909,12 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                                        cpu_to_le32(pci_dma_lo32(dma_handle));
                                *dword_ptr++ =
                                        cpu_to_le32(pci_dma_hi32(dma_handle));
-                               *dword_ptr++ = cpu_to_le32(sg_dma_len(sg));
-                               sg++;
+                               *dword_ptr++ = cpu_to_le32(sg_dma_len(s));
                                dprintk(3, "S/G Segment phys_addr=%x %x, len=0x%x\n",
                                        cpu_to_le32(pci_dma_hi32(dma_handle)),
                                        cpu_to_le32(pci_dma_lo32(dma_handle)),
-                                       cpu_to_le32(sg_dma_len(sg)));
+                                       cpu_to_le32(sg_dma_len(sg_next(s))));
+                               remseg--;
                        }
                        dprintk(5, "qla1280_64bit_start_scsi: Scatter/gather "
                                "command packet data - b %i, t %i, l %i \n",
@@ -2926,7 +2929,9 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                        dprintk(3, "S/G Building Continuation...seg_cnt=0x%x "
                                "remains\n", seg_cnt);
 
-                       while (seg_cnt > 0) {
+                       while (remseg > 0) {
+                               /* Update sg start */
+                               sg = s;
                                /* Adjust ring index. */
                                ha->req_ring_index++;
                                if (ha->req_ring_index == REQUEST_ENTRY_CNT) {
@@ -2952,9 +2957,10 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                                        (u32 *)&((struct cont_a64_entry *) pkt)->dseg_0_address;
 
                                /* Load continuation entry data segments. */
-                               for (cnt = 0; cnt < 5 && seg_cnt;
-                                    cnt++, seg_cnt--) {
-                                       dma_handle = sg_dma_address(sg);
+                               for_each_sg(sg, s, remseg, cnt) {
+                                       if (cnt == 5)
+                                               break;
+                                       dma_handle = sg_dma_address(s);
 #if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_SGI_SN2)
                                if (ha->flags.use_pci_vchannel)
                                        sn_pci_set_vchan(ha->pdev, 
@@ -2966,12 +2972,12 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                                        *dword_ptr++ =
                                                cpu_to_le32(pci_dma_hi32(dma_handle));
                                        *dword_ptr++ =
-                                               cpu_to_le32(sg_dma_len(sg));
+                                               cpu_to_le32(sg_dma_len(s));
                                        dprintk(3, "S/G Segment Cont. phys_addr=%x %x, len=0x%x\n",
                                                cpu_to_le32(pci_dma_hi32(dma_handle)),
                                                cpu_to_le32(pci_dma_lo32(dma_handle)),
-                                               cpu_to_le32(sg_dma_len(sg)));
-                                       sg++;
+                                               cpu_to_le32(sg_dma_len(s)));
+                                       remseg--;
                                }
                                dprintk(5, "qla1280_64bit_start_scsi: "
                                        "continuation packet data - b %i, t "
@@ -3062,7 +3068,7 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
        struct device_reg __iomem *reg = ha->iobase;
        struct scsi_cmnd *cmd = sp->cmd;
        struct cmd_entry *pkt;
-       struct scatterlist *sg = NULL;
+       struct scatterlist *sg = NULL, *s;
        __le32 *dword_ptr;
        int status = 0;
        int cnt;
@@ -3188,6 +3194,7 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
         * Load data segments.
         */
        if (seg_cnt) {
+               int remseg = seg_cnt;
                /* Setup packet address segment pointer. */
                dword_ptr = &pkt->dseg_0_address;
 
@@ -3196,22 +3203,25 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                        qla1280_dump_buffer(1, (char *)sg, 4 * 16);
 
                        /* Load command entry data segments. */
-                       for (cnt = 0; cnt < 4 && seg_cnt; cnt++, seg_cnt--) {
+                       for_each_sg(sg, s, seg_cnt, cnt) {
+                               if (cnt == 4)
+                                       break;
                                *dword_ptr++ =
-                                       cpu_to_le32(pci_dma_lo32(sg_dma_address(sg)));
-                               *dword_ptr++ =
-                                       cpu_to_le32(sg_dma_len(sg));
+                                       cpu_to_le32(pci_dma_lo32(sg_dma_address(s)));
+                               *dword_ptr++ = cpu_to_le32(sg_dma_len(s));
                                dprintk(3, "S/G Segment phys_addr=0x%lx, len=0x%x\n",
-                                       (pci_dma_lo32(sg_dma_address(sg))),
-                                       (sg_dma_len(sg)));
-                               sg++;
+                                       (pci_dma_lo32(sg_dma_address(s))),
+                                       (sg_dma_len(s)));
+                               remseg--;
                        }
                        /*
                         * Build continuation packets.
                         */
                        dprintk(3, "S/G Building Continuation"
                                "...seg_cnt=0x%x remains\n", seg_cnt);
-                       while (seg_cnt > 0) {
+                       while (remseg > 0) {
+                               /* Continue from end point */
+                               sg = s;
                                /* Adjust ring index. */
                                ha->req_ring_index++;
                                if (ha->req_ring_index == REQUEST_ENTRY_CNT) {
@@ -3239,18 +3249,16 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
                                        &((struct cont_entry *) pkt)->dseg_0_address;
 
                                /* Load continuation entry data segments. */
-                               for (cnt = 0; cnt < 7 && seg_cnt;
-                                    cnt++, seg_cnt--) {
+                               for_each_sg(sg, s, remseg, cnt) {
                                        *dword_ptr++ =
-                                               cpu_to_le32(pci_dma_lo32(sg_dma_address(sg)));
+                                               cpu_to_le32(pci_dma_lo32(sg_dma_address(s)));
                                        *dword_ptr++ =
-                                               cpu_to_le32(sg_dma_len(sg));
+                                               cpu_to_le32(sg_dma_len(s));
                                        dprintk(1,
                                                "S/G Segment Cont. phys_addr=0x%x, "
                                                "len=0x%x\n",
-                                               cpu_to_le32(pci_dma_lo32(sg_dma_address(sg))),
-                                               cpu_to_le32(sg_dma_len(sg)));
-                                       sg++;
+                                               cpu_to_le32(pci_dma_lo32(sg_dma_address(s))),
+                                               cpu_to_le32(sg_dma_len(s)));
                                }
                                dprintk(5, "qla1280_32bit_start_scsi: "
                                        "continuation packet data - "