[PATCH v3 5/6] dmaengine: pl330: Make sure microcode is privileged
From: Mitchel Humpherys <hidden>
Date: 2016-07-19 20:37:25
Also in:
linux-iommu, lkml
Subsystem:
dma generic offload engine subsystem, the rest · Maintainers:
Vinod Koul, Linus Torvalds
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 <redacted> Cc: Jassi Brar <redacted> Signed-off-by: Mitchel Humpherys <redacted> --- 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__);
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