On Wed, Jul 01, 2020 at 05:21:38PM -0400, Jim Quinlan wrote: > The new field 'dma_range_map' in struct device is used to facilitate the > use of single or multiple offsets between mapping regions of cpu addrs and > dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only > capable of holding a single uniform offset and had no region bounds > checking. > > The function of_dma_get_range() has been modified so that it takes a single > argument -- the device node -- and returns a map, NULL, or an error code. > The map is an array that holds the information regarding the DMA regions. > Each range entry contains the address offset, the cpu_start address, the > dma_start address, and the size of the region. > > of_dma_configure() is the typical manner to set range offsets but there are > a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel > driver code. These cases now invoke the function > dma_attach_offset_range(dev, cpu_addr, dma_addr, size). ... > + if (dev && dev->dma_range_map) > + pfn -= (unsigned long)PFN_DOWN(dma_offset_from_phys_addr(dev, PFN_PHYS(pfn))); Instead of casting use PHYS_PFN() and it will be consistent with latter in the same line. > + if (dev && dev->dma_range_map) > + pfn += (unsigned long)PFN_DOWN(dma_offset_from_dma_addr(dev, addr)); Ditto. ... > + dev_err(dev, "set dma_offset%08llx%s\n", KEYSTONE_HIGH_PHYS_START > + - KEYSTONE_LOW_PHYS_START, ret ? " failed" : ""); Please, avoid such indentation. Better split it to the three lines, argument per line (expect dev which will go on the first one). This applies to all similar places. ... > unsigned long pfn = (dma_handle >> PAGE_SHIFT); PHYS_PFN() / PFN_DOWN() ? > + if (!WARN_ON(!dev) && dev->dma_range_map) > + pfn += (unsigned long)PFN_DOWN(dma_offset_from_dma_addr(dev, dma_handle)); PHYS_PFN() ? ... > + r = kcalloc(num_ranges + 1, sizeof(struct bus_dma_region), GFP_KERNEL); sizeof(*r) ? > + if (!r) > + return ERR_PTR(-ENOMEM); ... > + ret = IS_ERR(map) ? PTR_ERR(map) : 0; PTR_ERR_OR_ZERO() ... > + /* We want the offset map to be device-managed, so alloc & copy */ > + dev->dma_range_map = devm_kcalloc(dev, num_ranges + 1, sizeof(*r), > + GFP_KERNEL); The question is how many times per device lifetime this can be called? ... > + if (!dev->dma_range_map) > + return -ENOMEM; > + memcpy((void *)dev->dma_range_map, map, sizeof(*r) * num_ranges + 1); If it's continuous, perhaps kmemdup() ? ... > + rc = IS_ERR(map) ? PTR_ERR(map) : 0; PTR_ERR_OR_ZERO() ... > + = dma_offset_from_phys_addr(dev, PFN_PHYS(mem->pfn_base)); > + > + return (dma_addr_t)PFN_PHYS(mem->pfn_base) - dma_offset; Looking at this more, I think you need to introduce in the same header (pfn.h) something like: #define PFN_DMA_ADDR() #define DMA_ADDR_PFN() -- With Best Regards, Andy Shevchenko _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
