Hi Andy, Sorry for the delay in response. I will do what you suggest in your email. I do have one response to one of your comments below. On Thu, Jul 2, 2020 at 4:43 AM Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxxxxxx> wrote: > > 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? Someone else questioned this. There are two cases that come to mind: our overnight test which load/unloads the RC driver over and over, and a customer that does an unbind/bind of the RC driver when their EP is hung and wants to restart. Both cases are atypical and are weak arguments to justify the second copy. I will drop the copy. Thanks, Jim Quinlan Broadcom STB > > ... > > > > + 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
