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 c01fd52f451387fa0360bcf0b43fc1ac93d2e606..e2345afa5df57bcd57ece08c08ac07a4922cf5bf 100644 (file)
--- 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;
                }