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authorAaron Sierra <asierra@xes-inc.com>2018-10-12 23:35:03 +0300
committerJon Mason <jdmason@kudzu.us>2018-11-01 04:20:05 +0300
commitfc5d1829f9bf3d8275322727c0e9a8baf268b7c6 (patch)
tree882b53242929fc4cc4ff3736ac52fcc5de1f0782 /drivers/ntb/ntb_transport.c
parent846429bc998f4c42d9961c139ce82d0f76a51d35 (diff)
downloadlinux-fc5d1829f9bf3d8275322727c0e9a8baf268b7c6.tar.xz
NTB: transport: Try harder to alloc an aligned MW buffer
Be a little wasteful if the (likely CMA) message window buffer is not suitably aligned after our first attempt; allocate a buffer twice as big as we need and manually align our MW buffer within it. This was needed on Intel Broadwell DE platforms with intel_iommu=off Signed-off-by: Aaron Sierra <asierra@xes-inc.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
Diffstat (limited to 'drivers/ntb/ntb_transport.c')
-rw-r--r--drivers/ntb/ntb_transport.c86
1 files changed, 63 insertions, 23 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index c643b9cf750b..3bfdb4562408 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -194,6 +194,8 @@ struct ntb_transport_mw {
void __iomem *vbase;
size_t xlat_size;
size_t buff_size;
+ size_t alloc_size;
+ void *alloc_addr;
void *virt_addr;
dma_addr_t dma_addr;
};
@@ -672,13 +674,59 @@ static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
return;
ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
- dma_free_coherent(&pdev->dev, mw->buff_size,
- mw->virt_addr, mw->dma_addr);
+ dma_free_coherent(&pdev->dev, mw->alloc_size,
+ mw->alloc_addr, mw->dma_addr);
mw->xlat_size = 0;
mw->buff_size = 0;
+ mw->alloc_size = 0;
+ mw->alloc_addr = NULL;
mw->virt_addr = NULL;
}
+static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw,
+ struct device *dma_dev, size_t align)
+{
+ dma_addr_t dma_addr;
+ void *alloc_addr, *virt_addr;
+ int rc;
+
+ alloc_addr = dma_alloc_coherent(dma_dev, mw->alloc_size,
+ &dma_addr, GFP_KERNEL);
+ if (!alloc_addr) {
+ dev_err(dma_dev, "Unable to alloc MW buff of size %zu\n",
+ mw->alloc_size);
+ return -ENOMEM;
+ }
+ virt_addr = alloc_addr;
+
+ /*
+ * we must ensure that the memory address allocated is BAR size
+ * aligned in order for the XLAT register to take the value. This
+ * is a requirement of the hardware. It is recommended to setup CMA
+ * for BAR sizes equal or greater than 4MB.
+ */
+ if (!IS_ALIGNED(dma_addr, align)) {
+ if (mw->alloc_size > mw->buff_size) {
+ virt_addr = PTR_ALIGN(alloc_addr, align);
+ dma_addr = ALIGN(dma_addr, align);
+ } else {
+ rc = -ENOMEM;
+ goto err;
+ }
+ }
+
+ mw->alloc_addr = alloc_addr;
+ mw->virt_addr = virt_addr;
+ mw->dma_addr = dma_addr;
+
+ return 0;
+
+err:
+ dma_free_coherent(dma_dev, mw->alloc_size, alloc_addr, dma_addr);
+
+ return rc;
+}
+
static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
resource_size_t size)
{
@@ -710,28 +758,20 @@ static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
/* Alloc memory for receiving data. Must be aligned */
mw->xlat_size = xlat_size;
mw->buff_size = buff_size;
+ mw->alloc_size = buff_size;
- mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,
- &mw->dma_addr, GFP_KERNEL);
- if (!mw->virt_addr) {
- mw->xlat_size = 0;
- mw->buff_size = 0;
- dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
- buff_size);
- return -ENOMEM;
- }
-
- /*
- * we must ensure that the memory address allocated is BAR size
- * aligned in order for the XLAT register to take the value. This
- * is a requirement of the hardware. It is recommended to setup CMA
- * for BAR sizes equal or greater than 4MB.
- */
- if (!IS_ALIGNED(mw->dma_addr, xlat_align)) {
- dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",
- &mw->dma_addr);
- ntb_free_mw(nt, num_mw);
- return -ENOMEM;
+ rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
+ if (rc) {
+ mw->alloc_size *= 2;
+ rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);
+ if (rc) {
+ dev_err(&pdev->dev,
+ "Unable to alloc aligned MW buff\n");
+ mw->xlat_size = 0;
+ mw->buff_size = 0;
+ mw->alloc_size = 0;
+ return rc;
+ }
}
/* Notify HW the memory location of the receive buffer */