From mboxrd@z Thu Jan 1 00:00:00 1970 From: mitchelh@codeaurora.org (Mitchel Humpherys) Date: Wed, 27 Jul 2016 16:42:07 -0700 Subject: [PATCH v5 5/6] dmaengine: pl330: Make sure microcode is privileged In-Reply-To: <20160727234208.2101-1-mitchelh@codeaurora.org> References: <20160727234208.2101-1-mitchelh@codeaurora.org> Message-ID: <20160727234208.2101-6-mitchelh@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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 Cc: Vinod Koul Reviewed-by: Robin Murphy Tested-by: Robin Murphy Signed-off-by: Mitchel Humpherys --- Notes: v3..v4 - Reworked against the new dma attrs format. 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 4fc3ffbd5ca0..8cd624fc3760 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 Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project