Messages in this thread | | | Date | Thu, 4 Aug 2022 19:26:27 +0100 | Subject | Re: [PATCH] ACPI / scan: Support multiple dma windows with different offsets | From | Robin Murphy <> |
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On 04/08/2022 2:27 pm, Lorenzo Pieralisi wrote: > [+Robin] > > On Thu, Aug 04, 2022 at 05:59:23PM +0800, Jianmin Lv wrote: >> Hi, all >> >> Can anybody help to review the patch, or I missed somebody else? > > I will review the patch - added Robin since it affects the DMA > ranges handling.
Thanks Lorenzo!
> > Lorenzo > >> Thanks! >> >> On 2022/7/31 下午4:17, Jianmin Lv wrote: >>> For DT, of_dma_get_range returns bus_dma_region typed dma regions, >>> which makes multiple dma windows with different offset available >>> for translation between dma address and cpu address. >>> >>> But for ACPI, acpi_dma_get_range doesn't return similar dma regions, >>> causing no path for setting dev->dma_range_map conveniently. So the >>> patch changes acpi_dma_get_range and returns bus_dma_region typed >>> dma regions according to of_dma_get_range. >>> >>> After changing acpi_dma_get_range, original part of internal code >>> only available for ARM is moved to acpi_arch_dma_setup for remaining >>> unchanged.
This seems a bit silly. If we've finally done the work to parse a proper dma_range_map, we can use it; no need to artificially maintain the old dma_pfn_offset limitation. TBH I wouldn't even preserve the dmaaddr and size calculations as they are either, just set dev->bus_dma_limit based on the highest entry in the map, and pass 0 and U64_MAX to arch_setup_dma_ops() since those are basically meaningless now (I plan to remove them entirely once I unpick the IOMMU setup).
Thanks, Robin.
>>> Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn> >>> >>> diff --git a/drivers/acpi/arm64/dma.c b/drivers/acpi/arm64/dma.c >>> index f16739a..840f918 100644 >>> --- a/drivers/acpi/arm64/dma.c >>> +++ b/drivers/acpi/arm64/dma.c >>> @@ -9,6 +9,7 @@ void acpi_arch_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size) >>> int ret; >>> u64 end, mask; >>> u64 dmaaddr = 0, size = 0, offset = 0; >>> + const struct bus_dma_region *map = NULL; >>> /* >>> * If @dev is expected to be DMA-capable then the bus code that created >>> @@ -26,10 +27,37 @@ void acpi_arch_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size) >>> else >>> size = 1ULL << 32; >>> - ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size); >>> + ret = acpi_dma_get_range(dev, &map); >>> if (ret == -ENODEV) >>> ret = iort_dma_get_ranges(dev, &size); >>> if (!ret) { >>> + const struct bus_dma_region *r = map; >>> + u64 len, dma_start, dma_end = 0; >>> + >>> + /* determine the overall bounds of all dma regions */ >>> + for (dma_start = U64_MAX; r->size; r++) { >>> + if (offset && r->offset != offset) { >>> + dev_warn(dev, "Can't handle multiple windows with different offsets\n"); >>> + return; >>> + } >>> + offset = r->offset; >>> + >>> + /* Take lower and upper limits */ >>> + if (r->dma_start < dma_start) >>> + dma_start = r->dma_start; >>> + if (r->dma_start + r->size - 1 > dma_end) >>> + dma_end = r->dma_start + r->size - 1; >>> + } >>> + >>> + if (dma_start >= dma_end) { >>> + dev_dbg(dev, "Invalid DMA regions configuration\n"); >>> + return; >>> + } >>> + >>> + dmaaddr = dma_start; >>> + len = dma_end - dma_start; >>> + size = max(len, len + 1); >>> + >>> /* >>> * Limit coherent and dma mask based on size retrieved from >>> * firmware. >>> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c >>> index 762b61f..8961b51 100644 >>> --- a/drivers/acpi/scan.c >>> +++ b/drivers/acpi/scan.c >>> @@ -20,6 +20,7 @@ >>> #include <linux/platform_data/x86/apple.h> >>> #include <linux/pgtable.h> >>> #include <linux/crc32.h> >>> +#include <linux/dma-direct.h> >>> #include "internal.h" >>> @@ -1492,15 +1493,15 @@ enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev) >>> * >>> * Return 0 on success, < 0 on failure. >>> */ >>> -int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset, >>> - u64 *size) >>> +int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map) >>> { >>> struct acpi_device *adev; >>> LIST_HEAD(list); >>> struct resource_entry *rentry; >>> int ret; >>> struct device *dma_dev = dev; >>> - u64 len, dma_start = U64_MAX, dma_end = 0, dma_offset = 0; >>> + int num_ranges = 0; >>> + struct bus_dma_region *r; >>> /* >>> * Walk the device tree chasing an ACPI companion with a _DMA >>> @@ -1525,31 +1526,31 @@ int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset, >>> ret = acpi_dev_get_dma_resources(adev, &list); >>> if (ret > 0) { >>> + list_for_each_entry(rentry, &list, node) >>> + num_ranges++; >>> + >>> + r = kcalloc(num_ranges + 1, sizeof(*r), GFP_KERNEL); >>> + if (!r) { >>> + ret = -ENOMEM; >>> + goto out; >>> + } >>> + >>> + *map = r; >>> + >>> list_for_each_entry(rentry, &list, node) { >>> - if (dma_offset && rentry->offset != dma_offset) { >>> + if (rentry->res->start >= rentry->res->end) { >>> ret = -EINVAL; >>> - dev_warn(dma_dev, "Can't handle multiple windows with different offsets\n"); >>> + dev_dbg(dma_dev, "Invalid DMA regions configuration\n"); >>> goto out; >>> } >>> - dma_offset = rentry->offset; >>> - >>> - /* Take lower and upper limits */ >>> - if (rentry->res->start < dma_start) >>> - dma_start = rentry->res->start; >>> - if (rentry->res->end > dma_end) >>> - dma_end = rentry->res->end; >>> - } >>> - if (dma_start >= dma_end) { >>> - ret = -EINVAL; >>> - dev_dbg(dma_dev, "Invalid DMA regions configuration\n"); >>> - goto out; >>> + r->cpu_start = rentry->res->start; >>> + r->dma_start = rentry->res->start - rentry->offset; >>> + r->size = rentry->res->end - rentry->res->start + 1; >>> + r->offset = rentry->offset; >>> + r++; >>> } >>> - *dma_addr = dma_start - dma_offset; >>> - len = dma_end - dma_start; >>> - *size = max(len, len + 1); >>> - *offset = dma_offset; >>> } >>> out: >>> acpi_dev_free_resource_list(&list); >>> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h >>> index 0dc1ea0b..e106073 100644 >>> --- a/include/acpi/acpi_bus.h >>> +++ b/include/acpi/acpi_bus.h >>> @@ -611,8 +611,7 @@ struct acpi_pci_root { >>> int acpi_iommu_fwspec_init(struct device *dev, u32 id, >>> struct fwnode_handle *fwnode, >>> const struct iommu_ops *ops); >>> -int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset, >>> - u64 *size); >>> +int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map); >>> int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr, >>> const u32 *input_id); >>> static inline int acpi_dma_configure(struct device *dev, >>> diff --git a/include/linux/acpi.h b/include/linux/acpi.h >>> index 44975c1..f806092 100644 >>> --- a/include/linux/acpi.h >>> +++ b/include/linux/acpi.h >>> @@ -974,8 +974,7 @@ static inline enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev) >>> return DEV_DMA_NOT_SUPPORTED; >>> } >>> -static inline int acpi_dma_get_range(struct device *dev, u64 *dma_addr, >>> - u64 *offset, u64 *size) >>> +static inline int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map) >>> { >>> return -ENODEV; >>> } >>> >>
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