Message ID | 20240524182702.1317935-2-dave.stevenson@raspberrypi.com (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | BCM2835 DMA mapping cleanups and fixes | expand |
On Fri, May 24, 2024 at 07:26:45PM +0100, Dave Stevenson wrote: > From: Serge Semin <Sergey.Semin@baikalelectronics.ru> > > A basic device-specific linear memory mapping was introduced back in > commit ("dma: Take into account dma_pfn_offset") as a single-valued offset > preserved in the device.dma_pfn_offset field, which was initialized for > instance by means of the "dma-ranges" DT property. Afterwards the > functionality was extended to support more than one device-specific region > defined in the device.dma_range_map list of maps. But all of these > improvements concerned a single pointer, page or sg DMA-mapping methods, > while the system resource mapping function turned to miss the > corresponding modification. Thus the dma_direct_map_resource() method now > just casts the CPU physical address to the device DMA address with no > dma-ranges-based mapping taking into account, which is obviously wrong. > Let's fix it by using the phys_to_dma_direct() method to get the > device-specific bus address from the passed memory resource for the case > of the directly mapped DMA. My memory is getting a little bad, but as dma_direct_map_resource is mostly used for (non-PCIe) peer to peer transfers, any kind of mapping from the host address should be excluded. (dma_direct_map_resource in general is a horrible interface and I'd prefer everyone to switch to the map_sg based P2P support, but we have plenty of users for it unfortunately)
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 4d543b1e9d57..916a16959575 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -509,7 +509,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, size_t size, enum dma_data_direction dir, unsigned long attrs) { - dma_addr_t dma_addr = paddr; + dma_addr_t dma_addr = phys_to_dma_direct(dev, paddr); if (unlikely(!dma_capable(dev, dma_addr, size, false))) { dev_err_once(dev,