[PATCH v3 5/6] dmaengine: pl330: Make sure microcode is privileged

[Mitchel Humpherys]

The PL330 performs privileged instruction fetches.  This can result in
SMMU permission faults on SMMUs that implement the ARMv8 VMSA, which
specifies that mappings that are writeable at one execution level shall
not be executable at any higher-privileged level.  Fix this by using the
DMA_ATTR_PRIVILEGED attribute, which will ensure that the microcode
IOMMU mapping is only accessible to the privileged level.

Cc: Dan Williams <dan.j.williams at intel.com>
Cc: Jassi Brar <jassi.brar at samsung.com>
Signed-off-by: Mitchel Humpherys <mitchelh at codeaurora.org>
---
 drivers/dma/pl330.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 372b4359da97..7297cd1d03c8 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1854,14 +1854,17 @@ static int dmac_alloc_resources(struct pl330_dmac *pl330)
 {
 	int chans = pl330->pcfg.num_chan;
 	int ret;
+	DEFINE_DMA_ATTRS(attrs);
 
+	dma_set_attr(DMA_ATTR_PRIVILEGED, &attrs);
 	/*
 	 * Alloc MicroCode buffer for 'chans' Channel threads.
 	 * A channel's buffer offset is (Channel_Id * MCODE_BUFF_PERCHAN)
 	 */
-	pl330->mcode_cpu = dma_alloc_coherent(pl330->ddma.dev,
+	pl330->mcode_cpu = dma_alloc_attrs(pl330->ddma.dev,
 				chans * pl330->mcbufsz,
-				&pl330->mcode_bus, GFP_KERNEL);
+				&pl330->mcode_bus, GFP_KERNEL,
+				&attrs);
 	if (!pl330->mcode_cpu) {
 		dev_err(pl330->ddma.dev, "%s:%d Can't allocate memory!\n",
 			__func__, __LINE__);
-- 
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project