[SCSI] megaraid_sas: replace pci_alloc_consitent with dma_alloc_coherent in ioctl path

Replaced pci_alloc_consistent with dma_alloc_coherent from the ioctl path.
This is to avoid situations where ioctl fails for lack of memory
(when system under heavy stress).
Signed-off-by: NSumant Patro <sumant.patro@lsi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/megaraid/megaraid_sas.c

@@ -2711,9 +2711,9 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
 	 * For each user buffer, create a mirror buffer and copy in
 	 */
 	for (i = 0; i < ioc->sge_count; i++) {
-		kbuff_arr[i] = pci_alloc_consistent(instance->pdev,
+		kbuff_arr[i] = dma_alloc_coherent(&instance->pdev->dev,
 						    ioc->sgl[i].iov_len,
-						    &buf_handle);
+						    &buf_handle, GFP_KERNEL);
 		if (!kbuff_arr[i]) {
 			printk(KERN_DEBUG "megasas: Failed to alloc "
 			       "kernel SGL buffer for IOCTL \n");
@@ -2740,8 +2740,8 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
 	}
 
 	if (ioc->sense_len) {
-		sense = pci_alloc_consistent(instance->pdev, ioc->sense_len,
-					     &sense_handle);
+		sense = dma_alloc_coherent(&instance->pdev->dev, ioc->sense_len,
+					     &sense_handle, GFP_KERNEL);
 		if (!sense) {
 			error = -ENOMEM;
 			goto out;
@@ -2800,12 +2800,12 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
 
       out:
 	if (sense) {
-		pci_free_consistent(instance->pdev, ioc->sense_len,
+		dma_free_coherent(&instance->pdev->dev, ioc->sense_len,
 				    sense, sense_handle);
 	}
 
 	for (i = 0; i < ioc->sge_count && kbuff_arr[i]; i++) {
-		pci_free_consistent(instance->pdev,
+		dma_free_coherent(&instance->pdev->dev,
 				    kern_sge32[i].length,
 				    kbuff_arr[i], kern_sge32[i].phys_addr);
 	}