From: VMware, Inc <>
Date: Thu, 17 Dec 2009 21:29:40 +0000 (-0800)
Subject: Use kernel pages for SGL's.
X-Git-Tag: 2009.12.16-217847~46
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c8791c64ad032e6717f7a06d70d18153795bc892;p=thirdparty%2Fopen-vm-tools.git

Use kernel pages for SGL's.

SGL pages don't need to reside in the scarce DMA addressable space, we
can instead allocate generic kernel pages for these and use the
map/unmap API's to consistently access these pages.

Signed-off-by: Marcelo Vanzin <mvanzin@vmware.com>
---

diff --git a/open-vm-tools/modules/linux/pvscsi/pvscsi.c b/open-vm-tools/modules/linux/pvscsi/pvscsi.c
index c01fd52f4..e2345afa5 100644
--- a/open-vm-tools/modules/linux/pvscsi/pvscsi.c
+++ b/open-vm-tools/modules/linux/pvscsi/pvscsi.c
@@ -410,6 +410,8 @@ static void pvscsi_map_buffers(struct pvscsi_adapter *adapter,
 			pvscsi_create_sg(ctx, sg, segs);
 
 			e->flags |= PVSCSI_FLAG_CMD_WITH_SG_LIST;
+			ctx->sglPA = pci_map_single(adapter->dev, ctx->sgl,
+						    PAGE_SIZE, PCI_DMA_TODEVICE);
 			e->dataAddr = ctx->sglPA;
 		} else
 			e->dataAddr = sg_dma_address(sg);
@@ -422,7 +424,7 @@ static void pvscsi_map_buffers(struct pvscsi_adapter *adapter,
 }
 
 static void pvscsi_unmap_buffers(const struct pvscsi_adapter *adapter,
-				 const struct pvscsi_ctx *ctx)
+				 struct pvscsi_ctx *ctx)
 {
 	struct scsi_cmnd *cmd;
 	unsigned bufflen;
@@ -433,10 +435,15 @@ static void pvscsi_unmap_buffers(const struct pvscsi_adapter *adapter,
 	if (bufflen != 0) {
 		unsigned count = scsi_sg_count(cmd);
 
-		if (count != 0)
+		if (count != 0) {
 			pci_unmap_sg(adapter->dev, scsi_sglist(cmd), count,
 				     cmd->sc_data_direction);
-		else
+			if (ctx->sglPA) {
+				pci_unmap_single(adapter->dev, ctx->sglPA,
+						 PAGE_SIZE, PCI_DMA_TODEVICE);
+				ctx->sglPA = 0;
+			}
+		} else
 			pci_unmap_single(adapter->dev, ctx->dataPA, bufflen,
 					 cmd->sc_data_direction);
 	}
@@ -1104,8 +1111,7 @@ static void pvscsi_free_sgls(const struct pvscsi_adapter *adapter)
 	unsigned i;
 
 	for (i = 0; i < adapter->req_depth; ++i, ++ctx)
-		pci_free_consistent(adapter->dev, PAGE_SIZE, ctx->sgl,
-				    ctx->sglPA);
+		free_page((unsigned long)ctx->sgl);
 }
 
 static int pvscsi_setup_msix(const struct pvscsi_adapter *adapter, int *irq)
@@ -1204,15 +1210,13 @@ static int __devinit pvscsi_allocate_sg(struct pvscsi_adapter *adapter)
 	ASSERT_ON_COMPILE(sizeof(struct pvscsi_sg_list) <= PAGE_SIZE);
 
 	for (i = 0; i < adapter->req_depth; ++i, ++ctx) {
-		ctx->sgl = pci_alloc_consistent(adapter->dev, PAGE_SIZE,
-						&ctx->sglPA);
+		ctx->sgl = (void *)__get_free_page(GFP_KERNEL);
+		ctx->sglPA = 0;
 		BUG_ON(ctx->sglPA & ~PAGE_MASK);
 		if (!ctx->sgl) {
 			for (; i >= 0; --i, --ctx) {
-				pci_free_consistent(adapter->dev, PAGE_SIZE,
-						    ctx->sgl, ctx->sglPA);
+				free_page((unsigned long)ctx->sgl);
 				ctx->sgl = NULL;
-				ctx->sglPA = 0;
 			}
 			return -ENOMEM;
 		}