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[RESEND PATCH V6 5/6] dmaengine: pl330: Make sure microcode is privileged

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From: Mitchel Humpherys <mitchelh@codeaurora.org>

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@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
---

[V6] No change

 drivers/dma/pl330.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 030fe05..1a8bac2 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1854,14 +1854,16 @@ static int dmac_alloc_resources(struct pl330_dmac *pl330)
 {
 	int chans = pl330->pcfg.num_chan;
 	int ret;
+	unsigned long dma_attrs = DMA_ATTR_PRIVILEGED;
 
 	/*
 	 * 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,
+				dma_attrs);
 	if (!pl330->mcode_cpu) {
 		dev_err(pl330->ddma.dev, "%s:%d Can't allocate memory!\n",
 			__func__, __LINE__);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

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[RESEND PATCH V6 0/6] Add support for privileged mappings Sricharan R <sricharan@codeaurora.org> - 2016-12-02 16:00 +0100
  [RESEND PATCH V6 2/6] iommu/io-pgtable-arm: add support for the IOMMU_PRIV flag Sricharan R <sricharan@codeaurora.org> - 2016-12-02 16:00 +0100
  [RESEND PATCH V6 4/6] arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED Sricharan R <sricharan@codeaurora.org> - 2016-12-02 16:00 +0100
  [RESEND PATCH V6 3/6] common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute Sricharan R <sricharan@codeaurora.org> - 2016-12-02 16:00 +0100
  [PATCH V6 6/6] iommu/arm-smmu: Set privileged attribute to 'default' instead of 'unprivileged' Sricharan R <sricharan@codeaurora.org> - 2016-12-02 16:00 +0100
    Re: [PATCH V6 6/6] iommu/arm-smmu: Set privileged attribute to  'default' instead of 'unprivileged' Will Deacon <will.deacon@arm.com> - 2016-12-06 18:40 +0100
  [RESEND PATCH V6 1/6] iommu: add IOMMU_PRIV attribute Sricharan R <sricharan@codeaurora.org> - 2016-12-02 16:00 +0100
  [RESEND PATCH V6 5/6] dmaengine: pl330: Make sure microcode is privileged Sricharan R <sricharan@codeaurora.org> - 2016-12-02 16:00 +0100
    Re: [RESEND PATCH V6 5/6] dmaengine: pl330: Make sure microcode is  privileged Vinod Koul <vinod.koul@intel.com> - 2016-12-06 06:00 +0100
  Re: [RESEND PATCH V6 0/6] Add support for privileged mappings Robin Murphy <robin.murphy@arm.com> - 2016-12-02 17:20 +0100
    RE: [RESEND PATCH V6 0/6] Add support for privileged mappings "Sricharan" <sricharan@codeaurora.org> - 2016-12-04 08:50 +0100
      Re: [RESEND PATCH V6 0/6] Add support for privileged mappings Robin Murphy <robin.murphy@arm.com> - 2016-12-06 20:20 +0100
        RE: [RESEND PATCH V6 0/6] Add support for privileged mappings "Sricharan" <sricharan@codeaurora.org> - 2016-12-07 10:50 +0100

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