From: Thierry Reding Date: Fri, 1 Feb 2019 13:28:29 +0000 (+0100) Subject: gpu: host1x: Use correct semantics for HOST1X_CHANNEL_DMAEND X-Git-Tag: v5.1-rc1~117^2~12^2~12 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0e43b8da154a95f4369da4068a43ad9d700f4cea;p=thirdparty%2Fkernel%2Flinux.git gpu: host1x: Use correct semantics for HOST1X_CHANNEL_DMAEND The HOST1X_CHANNEL_DMAEND is an offset relative to the value written to the HOST1X_CHANNEL_DMASTART register, but it is currently treated as an absolute address. This can cause SMMU faults if the CDMA fetches past a pushbuffer's IOMMU mapping. Properly setting the DMAEND prevents the CDMA from fetching beyond that address and avoid such issues. This is currently not observed because a whole (almost) page of essentially scratch space absorbs any excessive prefetching by CDMA. However, changing the number of slots in the push buffer can trigger these SMMU faults. Signed-off-by: Thierry Reding --- diff --git a/drivers/gpu/host1x/hw/cdma_hw.c b/drivers/gpu/host1x/hw/cdma_hw.c index 485aef5761af6..a24c090ac96fd 100644 --- a/drivers/gpu/host1x/hw/cdma_hw.c +++ b/drivers/gpu/host1x/hw/cdma_hw.c @@ -75,7 +75,7 @@ static void cdma_start(struct host1x_cdma *cdma) cdma->last_pos = cdma->push_buffer.pos; start = cdma->push_buffer.dma; - end = start + cdma->push_buffer.size + 4; + end = cdma->push_buffer.size + 4; host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP, HOST1X_CHANNEL_DMACTRL); @@ -126,7 +126,7 @@ static void cdma_timeout_restart(struct host1x_cdma *cdma, u32 getptr) HOST1X_CHANNEL_DMACTRL); start = cdma->push_buffer.dma; - end = start + cdma->push_buffer.size + 4; + end = cdma->push_buffer.size + 4; /* set base, end pointer (all of memory) */ host1x_ch_writel(ch, lower_32_bits(start), HOST1X_CHANNEL_DMASTART);