[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>

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);

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;