[SCSI] megaraid_sas: add the IEEE SGE support to SAS2 controller

To increase the performance, megaraid sas driver added the IEEE SGE
support to support SAS2 controller.

Signed-off-by Bo Yang<bo.yang@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

2 files changed, 82 insertions, 7 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 5afd65121725..4c04a68bad6c 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -696,6 +696,35 @@ megasas_make_sgl64(struct megasas_instance *instance, struct scsi_cmnd *scp,
         return sge_count;
 }
 
+/**
+ * megasas_make_sgl_skinny - Prepares IEEE SGL
+ * @instance:           Adapter soft state
+ * @scp:                SCSI command from the mid-layer
+ * @mfi_sgl:            SGL to be filled in
+ *
+ * If successful, this function returns the number of SG elements. Otherwise,
+ * it returnes -1.
+ */
+static int
+megasas_make_sgl_skinny(struct megasas_instance *instance,
+                struct scsi_cmnd *scp, union megasas_sgl *mfi_sgl)
+{
+        int i;
+        int sge_count;
+        struct scatterlist *os_sgl;
+
+        sge_count = scsi_dma_map(scp);
+
+        if (sge_count) {
+                scsi_for_each_sg(scp, os_sgl, sge_count, i) {
+                        mfi_sgl->sge_skinny[i].length = sg_dma_len(os_sgl);
+                        mfi_sgl->sge_skinny[i].phys_addr =
+                                                sg_dma_address(os_sgl);
+                }
+        }
+        return sge_count;
+}
+
  /**
  * megasas_get_frame_count - Computes the number of frames
  * @frame_type          : type of frame- io or pthru frame
@@ -704,7 +733,8 @@ megasas_make_sgl64(struct megasas_instance *instance, struct scsi_cmnd *scp,
  * Returns the number of frames required for numnber of sge's (sge_count)
  */
 
-static u32 megasas_get_frame_count(u8 sge_count, u8 frame_type)
+static u32 megasas_get_frame_count(struct megasas_instance *instance,
+                        u8 sge_count, u8 frame_type)
 {
         int num_cnt;
         int sge_bytes;
@@ -714,6 +744,10 @@ static u32 megasas_get_frame_count(u8 sge_count, u8 frame_type)
         sge_sz = (IS_DMA64) ? sizeof(struct megasas_sge64) :
             sizeof(struct megasas_sge32);
 
+        if (instance->flag_ieee) {
+                sge_sz = sizeof(struct megasas_sge_skinny);
+        }
+
         /*
          * Main frame can contain 2 SGEs for 64-bit SGLs and
          * 3 SGEs for 32-bit SGLs for ldio &
@@ -721,12 +755,16 @@ static u32 megasas_get_frame_count(u8 sge_count, u8 frame_type)
          * 2 SGEs for 32-bit SGLs for pthru frame
          */
         if (unlikely(frame_type == PTHRU_FRAME)) {
-                if (IS_DMA64)
+                if (instance->flag_ieee == 1) {
+                        num_cnt = sge_count - 1;
+                } else if (IS_DMA64)
                         num_cnt = sge_count - 1;
                 else
                         num_cnt = sge_count - 2;
         } else {
-                if (IS_DMA64)
+                if (instance->flag_ieee == 1) {
+                        num_cnt = sge_count - 1;
+                } else if (IS_DMA64)
                         num_cnt = sge_count - 2;
                 else
                         num_cnt = sge_count - 3;
@@ -775,6 +813,10 @@ megasas_build_dcdb(struct megasas_instance *instance, struct scsi_cmnd *scp,
         else if (scp->sc_data_direction == PCI_DMA_NONE)
                 flags = MFI_FRAME_DIR_NONE;
 
+        if (instance->flag_ieee == 1) {
+                flags |= MFI_FRAME_IEEE;
+        }
+
         /*
          * Prepare the DCDB frame
          */
@@ -804,7 +846,11 @@ megasas_build_dcdb(struct megasas_instance *instance, struct scsi_cmnd *scp,
         /*
          * Construct SGL
          */
-        if (IS_DMA64) {
+        if (instance->flag_ieee == 1) {
+                pthru->flags |= MFI_FRAME_SGL64;
+                pthru->sge_count = megasas_make_sgl_skinny(instance, scp,
+                                                      &pthru->sgl);
+        } else if (IS_DMA64) {
                 pthru->flags |= MFI_FRAME_SGL64;
                 pthru->sge_count = megasas_make_sgl64(instance, scp,
                                                       &pthru->sgl);
@@ -823,7 +869,7 @@ megasas_build_dcdb(struct megasas_instance *instance, struct scsi_cmnd *scp,
          * 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(pthru->sge_count,
+        cmd->frame_count = megasas_get_frame_count(instance, pthru->sge_count,
                                                         PTHRU_FRAME);
 
         return cmd->frame_count;
@@ -854,6 +900,10 @@ megasas_build_ldio(struct megasas_instance *instance, struct scsi_cmnd *scp,
         else if (scp->sc_data_direction == PCI_DMA_FROMDEVICE)
                 flags = MFI_FRAME_DIR_READ;
 
+        if (instance->flag_ieee == 1) {
+                flags |= MFI_FRAME_IEEE;
+        }
+
         /*
          * Prepare the Logical IO frame: 2nd bit is zero for all read cmds
          */
@@ -924,7 +974,11 @@ megasas_build_ldio(struct megasas_instance *instance, struct scsi_cmnd *scp,
         /*
          * Construct SGL
          */
-        if (IS_DMA64) {
+        if (instance->flag_ieee) {
+                ldio->flags |= MFI_FRAME_SGL64;
+                ldio->sge_count = megasas_make_sgl_skinny(instance, scp,
+                                              &ldio->sgl);
+        } else if (IS_DMA64) {
                 ldio->flags |= MFI_FRAME_SGL64;
                 ldio->sge_count = megasas_make_sgl64(instance, scp, &ldio->sgl);
         } else
@@ -941,7 +995,8 @@ megasas_build_ldio(struct megasas_instance *instance, struct scsi_cmnd *scp,
          * 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, IO_FRAME);
+        cmd->frame_count = megasas_get_frame_count(instance,
+                        ldio->sge_count, IO_FRAME);
 
         return cmd->frame_count;
 }
@@ -1929,6 +1984,10 @@ static int megasas_create_frame_pool(struct megasas_instance *instance)
         sge_sz = (IS_DMA64) ? sizeof(struct megasas_sge64) :
             sizeof(struct megasas_sge32);
 
+        if (instance->flag_ieee) {
+                sge_sz = sizeof(struct megasas_sge_skinny);
+        }
+
         /*
          * Calculated the number of 64byte frames required for SGL
          */
@@ -2725,6 +2784,11 @@ megasas_register_aen(struct megasas_instance *instance, u32 seq_num,
         dcmd->sgl.sge32[0].phys_addr = (u32) instance->evt_detail_h;
         dcmd->sgl.sge32[0].length = sizeof(struct megasas_evt_detail);
 
+        if (instance->aen_cmd != NULL) {
+                megasas_return_cmd(instance, cmd);
+                return 0;
+        }
+
         /*
          * Store reference to the cmd used to register for AEN. When an
          * application wants us to register for AEN, we have to abort this
@@ -2895,6 +2959,7 @@ megasas_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
         *instance->producer = 0;
         *instance->consumer = 0;
         megasas_poll_wait_aen = 0;
+        instance->flag_ieee = 0;
 
         instance->evt_detail = pci_alloc_consistent(pdev,
                                                     sizeof(struct
@@ -2933,6 +2998,7 @@ megasas_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
         if ((instance->pdev->device == PCI_DEVICE_ID_LSI_SAS0073SKINNY) ||
                 (instance->pdev->device == PCI_DEVICE_ID_LSI_SAS0071SKINNY)) {
+                instance->flag_ieee = 1;
                 sema_init(&instance->ioctl_sem, MEGASAS_SKINNY_INT_CMDS);
         } else
                 sema_init(&instance->ioctl_sem, MEGASAS_INT_CMDS);
diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index 4c78cd32e757..a1fd44bc1817 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -96,6 +96,7 @@
 #define MFI_FRAME_DIR_WRITE                     0x0008
 #define MFI_FRAME_DIR_READ                      0x0010
 #define MFI_FRAME_DIR_BOTH                      0x0018
+#define MFI_FRAME_IEEE                          0x0020
 
 /*
  * Definition for cmd_status
@@ -732,10 +733,17 @@ struct megasas_sge64 {
 
 } __attribute__ ((packed));
 
+struct megasas_sge_skinny {
+        u64 phys_addr;
+        u32 length;
+        u32 flag;
+} __packed;
+
 union megasas_sgl {
 
         struct megasas_sge32 sge32[1];
         struct megasas_sge64 sge64[1];
+        struct megasas_sge_skinny sge_skinny[1];
 
 } __attribute__ ((packed));
 
@@ -1210,6 +1218,7 @@ struct megasas_instance {
 
         u8 flag;
         u8 unload;
+        u8 flag_ieee;
         unsigned long last_time;
 
         struct timer_list io_completion_timer;