[PATCH 3/3] dma-mapping: introduce DMA range map, supplanting dma_pfn_offset
Robin Murphy
robin.murphy at arm.com
Fri Sep 11 12:12:36 EDT 2020
(apologies to Jim - I did look through one of the previous versions
since I last commented and thought it looked OK, but never actually
replied as such)
On 2020-09-10 06:40, Christoph Hellwig wrote:
> From: Jim Quinlan <james.quinlan at broadcom.com>
>
> 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).
This is now called dma_direct_set_offset(), right?
> Signed-off-by: Jim Quinlan <james.quinlan at broadcom.com>
> [hch: various interface cleanups]
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Tested-by: Nathan Chancellor <natechancellor at gmail.com>
> ---
> arch/arm/include/asm/dma-direct.h | 9 +--
> arch/arm/mach-keystone/keystone.c | 17 ++--
> arch/sh/drivers/pci/pcie-sh7786.c | 9 ++-
> arch/x86/pci/sta2x11-fixup.c | 6 +-
> drivers/acpi/arm64/iort.c | 6 +-
> drivers/base/core.c | 2 +
> drivers/gpu/drm/sun4i/sun4i_backend.c | 8 +-
> drivers/iommu/io-pgtable-arm.c | 2 +-
> .../platform/sunxi/sun4i-csi/sun4i_csi.c | 9 ++-
> .../platform/sunxi/sun6i-csi/sun6i_csi.c | 11 ++-
> drivers/of/address.c | 73 ++++++++---------
> drivers/of/device.c | 44 ++++++----
> drivers/of/of_private.h | 11 +--
> drivers/of/unittest.c | 34 +++++---
> drivers/remoteproc/remoteproc_core.c | 4 +-
> .../staging/media/sunxi/cedrus/cedrus_hw.c | 10 ++-
> drivers/usb/core/message.c | 5 +-
> drivers/usb/core/usb.c | 3 +-
> include/linux/device.h | 4 +-
> include/linux/dma-direct.h | 52 ++++++++++--
> include/linux/dma-mapping.h | 19 ++++-
> kernel/dma/coherent.c | 7 +-
> kernel/dma/direct.c | 81 ++++++++++++++++++-
> 23 files changed, 303 insertions(+), 123 deletions(-)
>
> diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
> index de0f4ff9279615..a443d5257a21ed 100644
> --- a/arch/arm/include/asm/dma-direct.h
> +++ b/arch/arm/include/asm/dma-direct.h
> @@ -16,8 +16,8 @@
> #ifndef __arch_pfn_to_dma
> static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
> {
> - if (dev)
> - pfn -= dev->dma_pfn_offset;
> + if (dev && dev->dma_range_map)
> + pfn = PFN_DOWN(translate_phys_to_dma(dev, PFN_PHYS(pfn)));
> return (dma_addr_t)__pfn_to_bus(pfn);
> }
>
> @@ -25,9 +25,8 @@ static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
> {
> unsigned long pfn = __bus_to_pfn(addr);
>
> - if (dev)
> - pfn += dev->dma_pfn_offset;
> -
> + if (dev && dev->dma_range_map)
> + pfn = PFN_DOWN(translate_dma_to_phys(dev, PFN_PHYS(pfn)));
> return pfn;
> }
>
> diff --git a/arch/arm/mach-keystone/keystone.c b/arch/arm/mach-keystone/keystone.c
> index dcd031ba84c2e0..09a65c2dfd7327 100644
> --- a/arch/arm/mach-keystone/keystone.c
> +++ b/arch/arm/mach-keystone/keystone.c
> @@ -8,6 +8,7 @@
> */
> #include <linux/io.h>
> #include <linux/of.h>
> +#include <linux/dma-mapping.h>
> #include <linux/init.h>
> #include <linux/of_platform.h>
> #include <linux/of_address.h>
> @@ -25,8 +26,6 @@
> #include "keystone.h"
>
> #ifdef CONFIG_ARM_LPAE
> -static unsigned long keystone_dma_pfn_offset __read_mostly;
> -
> static int keystone_platform_notifier(struct notifier_block *nb,
> unsigned long event, void *data)
> {
> @@ -39,9 +38,12 @@ static int keystone_platform_notifier(struct notifier_block *nb,
> return NOTIFY_BAD;
>
> if (!dev->of_node) {
> - dev->dma_pfn_offset = keystone_dma_pfn_offset;
> - dev_err(dev, "set dma_pfn_offset%08lx\n",
> - dev->dma_pfn_offset);
> + int ret = dma_direct_set_offset(dev, KEYSTONE_HIGH_PHYS_START,
> + KEYSTONE_LOW_PHYS_START,
> + KEYSTONE_HIGH_PHYS_SIZE);
> + dev_err(dev, "set dma_offset%08llx%s\n",
> + KEYSTONE_HIGH_PHYS_START - KEYSTONE_LOW_PHYS_START,
> + ret ? " failed" : "");
FWIW I've already been thinking of some optimisations which would have
the happy side-effect of removing many of these allocation failure
scenarios, but at this point I reckon it's more practical to just get
the current implementation landed and working.
> }
> return NOTIFY_OK;
> }
> @@ -54,11 +56,8 @@ static struct notifier_block platform_nb = {
> static void __init keystone_init(void)
> {
> #ifdef CONFIG_ARM_LPAE
> - if (PHYS_OFFSET >= KEYSTONE_HIGH_PHYS_START) {
> - keystone_dma_pfn_offset = PFN_DOWN(KEYSTONE_HIGH_PHYS_START -
> - KEYSTONE_LOW_PHYS_START);
> + if (PHYS_OFFSET >= KEYSTONE_HIGH_PHYS_START)
> bus_register_notifier(&platform_bus_type, &platform_nb);
> - }
> #endif
> keystone_pm_runtime_init();
> }
> diff --git a/arch/sh/drivers/pci/pcie-sh7786.c b/arch/sh/drivers/pci/pcie-sh7786.c
> index e0b568aaa7014c..4468289ab2cac7 100644
> --- a/arch/sh/drivers/pci/pcie-sh7786.c
> +++ b/arch/sh/drivers/pci/pcie-sh7786.c
> @@ -12,6 +12,7 @@
> #include <linux/io.h>
> #include <linux/async.h>
> #include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> #include <linux/slab.h>
> #include <linux/clk.h>
> #include <linux/sh_clk.h>
> @@ -31,6 +32,8 @@ struct sh7786_pcie_port {
> static struct sh7786_pcie_port *sh7786_pcie_ports;
> static unsigned int nr_ports;
> static unsigned long dma_pfn_offset;
> +size_t memsize;
> +u64 memstart;
>
> static struct sh7786_pcie_hwops {
> int (*core_init)(void);
> @@ -301,7 +304,6 @@ static int __init pcie_init(struct sh7786_pcie_port *port)
> struct pci_channel *chan = port->hose;
> unsigned int data;
> phys_addr_t memstart, memend;
> - size_t memsize;
> int ret, i, win;
>
> /* Begin initialization */
> @@ -368,8 +370,6 @@ static int __init pcie_init(struct sh7786_pcie_port *port)
> memstart = ALIGN_DOWN(memstart, memsize);
> memsize = roundup_pow_of_two(memend - memstart);
>
> - dma_pfn_offset = memstart >> PAGE_SHIFT;
> -
> /*
> * If there's more than 512MB of memory, we need to roll over to
> * LAR1/LAMR1.
> @@ -487,7 +487,8 @@ int pcibios_map_platform_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
>
> void pcibios_bus_add_device(struct pci_dev *pdev)
> {
> - pdev->dev.dma_pfn_offset = dma_pfn_offset;
> + dma_direct_set_offset(&pdev->dev, __pa(memory_start),
> + __pa(memory_start) - memstart, memsize);
> }
>
> static int __init sh7786_pcie_core_init(void)
> diff --git a/arch/x86/pci/sta2x11-fixup.c b/arch/x86/pci/sta2x11-fixup.c
> index c313d784efabb9..324a207f99956b 100644
> --- a/arch/x86/pci/sta2x11-fixup.c
> +++ b/arch/x86/pci/sta2x11-fixup.c
> @@ -133,7 +133,7 @@ static void sta2x11_map_ep(struct pci_dev *pdev)
> struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
> struct device *dev = &pdev->dev;
> u32 amba_base, max_amba_addr;
> - int i;
> + int i, ret;
>
> if (!instance)
> return;
> @@ -141,7 +141,9 @@ static void sta2x11_map_ep(struct pci_dev *pdev)
> pci_read_config_dword(pdev, AHB_BASE(0), &amba_base);
> max_amba_addr = amba_base + STA2X11_AMBA_SIZE - 1;
>
> - dev->dma_pfn_offset = PFN_DOWN(-amba_base);
> + ret = dma_direct_set_offset(dev, 0, amba_base, STA2X11_AMBA_SIZE);
> + if (ret)
> + dev_err(dev, "sta2x11: could not set DMA offset\n");
>
> dev->bus_dma_limit = max_amba_addr;
> pci_set_consistent_dma_mask(pdev, max_amba_addr);
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index ec782e4a0fe419..de18c07ca02cc4 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -18,6 +18,7 @@
> #include <linux/pci.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
> +#include <linux/dma-mapping.h>
>
> #define IORT_TYPE_MASK(type) (1 << (type))
> #define IORT_MSI_TYPE (1 << ACPI_IORT_NODE_ITS_GROUP)
> @@ -1184,8 +1185,9 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
> *dma_addr = dmaaddr;
> *dma_size = size;
>
> - dev->dma_pfn_offset = PFN_DOWN(offset);
> - dev_dbg(dev, "dma_pfn_offset(%#08llx)\n", offset);
> + ret = dma_direct_set_offset(dev, dmaaddr + offset, dmaaddr, size);
> +
> + dev_dbg(dev, "dma_offset(%#08llx)%s\n", offset, ret ? " failed!" : "");
> }
>
> static void __init acpi_iort_register_irq(int hwirq, const char *name,
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index f6f620aa94086d..b893056e39459c 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -1792,6 +1792,8 @@ static void device_release(struct kobject *kobj)
> */
> devres_release_all(dev);
>
> + kfree(dev->dma_range_map);
> +
> if (dev->release)
> dev->release(dev);
> else if (dev->type && dev->type->release)
> diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
> index 072ea113e6be55..05e9f0d28196d9 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_backend.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
> @@ -11,6 +11,7 @@
> #include <linux/module.h>
> #include <linux/of_device.h>
> #include <linux/of_graph.h>
> +#include <linux/dma-mapping.h>
> #include <linux/platform_device.h>
> #include <linux/reset.h>
>
> @@ -811,8 +812,13 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
> * because of an old DT, we need to set the DMA offset by hand
> * on our device since the RAM mapping is at 0 for the DMA bus,
> * unlike the CPU.
> + *
> + * XXX(hch): this has no business in a driver and needs to move
> + * to the device tree.
As the context implies, this has actually grown a proper DT description
of the funky interconnect layout (see 564d6fd611f9 and the linked patch
series), and this is just an ugly fallback path to prevent regressions
with old DTBs that are already out there. So unless you can fire up the
time machine to fix those, this extra comment is really just beating a
dead horse :(
> */
> - drm->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
> + ret = dma_direct_set_offset(drm->dev, PHYS_OFFSET, 0, SZ_4G);
> + if (ret)
> + return ret;
> }
>
> backend->engine.node = dev->of_node;
> diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
> index dc7bcf858b6d2d..d77e881516a4ab 100644
> --- a/drivers/iommu/io-pgtable-arm.c
> +++ b/drivers/iommu/io-pgtable-arm.c
> @@ -751,7 +751,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
> if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS)
> return NULL;
>
> - if (!selftest_running && cfg->iommu_dev->dma_pfn_offset) {
> + if (!selftest_running && cfg->iommu_dev->dma_range_map) {
> dev_err(cfg->iommu_dev, "Cannot accommodate DMA offset for IOMMU page tables\n");
> return NULL;
> }
> diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
> index 5319eb1ab30927..307997ee7f96a2 100644
> --- a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
> +++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
> @@ -7,6 +7,7 @@
> */
>
> #include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> #include <linux/interrupt.h>
> #include <linux/module.h>
> #include <linux/mutex.h>
> @@ -182,8 +183,14 @@ static int sun4i_csi_probe(struct platform_device *pdev)
> if (ret)
> return ret;
> } else {
> + /*
> + * XXX(hch): this has no business in a driver and needs to move
> + * to the device tree.
> + */
Again, the top half of that "else" does already handle the proper DT
case and document this as a fallback :(
> #ifdef PHYS_PFN_OFFSET
Strictly that probably deserves updating too, but PHYS_PFN_OFFSET
implies PHYS_OFFSET so there should be no functional issue, just semantics.
> - csi->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
> + ret = dma_direct_set_offset(csi->dev, PHYS_OFFSET, 0, SZ_4G);
> + if (ret)
> + return ret;
> #endif
> }
>
> diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> index 28e89340fed981..e69e14379fc6e4 100644
> --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> @@ -899,8 +899,15 @@ static int sun6i_csi_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> sdev->dev = &pdev->dev;
> - /* The DMA bus has the memory mapped at 0 */
> - sdev->dev->dma_pfn_offset = PHYS_OFFSET >> PAGE_SHIFT;
> + /*
> + * The DMA bus has the memory mapped at 0.
> + *
> + * XXX(hch): this has no business in a driver and needs to move
> + * to the device tree.
> + */
Apparently this one *does* want updating to use the MBUS interconnect
bindings - as does the cedrus instance below - so no complaint there :)
Other than those few trivial nitpicks, I think I've stared at this patch
enough times now that even if there are any bugs left I'm not going to
see them... let's try to get it thrown at linux-next and everyone's CI
systems :)
Reviewed-by: Robin Murphy <robin.murphy at arm.com>
Cheers,
Robin.
> + ret = dma_direct_set_offset(sdev->dev, PHYS_OFFSET, 0, SZ_4G);
> + if (ret)
> + return ret;
>
> ret = sun6i_csi_resource_request(sdev, pdev);
> if (ret)
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index da4f7341323f22..a49ef87aaaf21c 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -13,6 +13,7 @@
> #include <linux/sizes.h>
> #include <linux/slab.h>
> #include <linux/string.h>
> +#include <linux/dma-direct.h> /* for bus_dma_region */
>
> #include "of_private.h"
>
> @@ -937,33 +938,33 @@ void __iomem *of_io_request_and_map(struct device_node *np, int index,
> }
> EXPORT_SYMBOL(of_io_request_and_map);
>
> +#ifdef CONFIG_HAS_DMA
> /**
> - * of_dma_get_range - Get DMA range info
> + * of_dma_get_range - Get DMA range info and put it into a map array
> * @np: device node to get DMA range info
> - * @dma_addr: pointer to store initial DMA address of DMA range
> - * @paddr: pointer to store initial CPU address of DMA range
> - * @size: pointer to store size of DMA range
> + * @map: dma range structure to return
> *
> * Look in bottom up direction for the first "dma-ranges" property
> - * and parse it.
> - * dma-ranges format:
> + * and parse it. Put the information into a DMA offset map array.
> + *
> + * dma-ranges format:
> * DMA addr (dma_addr) : naddr cells
> * CPU addr (phys_addr_t) : pna cells
> * size : nsize cells
> *
> - * It returns -ENODEV if "dma-ranges" property was not found
> - * for this device in DT.
> + * It returns -ENODEV if "dma-ranges" property was not found for this
> + * device in the DT.
> */
> -int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size)
> +int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
> {
> struct device_node *node = of_node_get(np);
> const __be32 *ranges = NULL;
> - int len;
> - int ret = 0;
> bool found_dma_ranges = false;
> struct of_range_parser parser;
> struct of_range range;
> - u64 dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
> + struct bus_dma_region *r;
> + int len, num_ranges = 0;
> + int ret = 0;
>
> while (node) {
> ranges = of_get_property(node, "dma-ranges", &len);
> @@ -989,49 +990,39 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
> }
>
> of_dma_range_parser_init(&parser, node);
> + for_each_of_range(&parser, &range)
> + num_ranges++;
> +
> + r = kcalloc(num_ranges + 1, sizeof(*r), GFP_KERNEL);
> + if (!r) {
> + ret = -ENOMEM;
> + goto out;
> + }
>
> + /*
> + * Record all info in the generic DMA ranges array for struct device.
> + */
> + *map = r;
> + of_dma_range_parser_init(&parser, node);
> for_each_of_range(&parser, &range) {
> pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
> range.bus_addr, range.cpu_addr, range.size);
> -
> - if (dma_offset && range.cpu_addr - range.bus_addr != dma_offset) {
> - pr_warn("Can't handle multiple dma-ranges with different offsets on node(%pOF)\n", node);
> - /* Don't error out as we'd break some existing DTs */
> - continue;
> - }
> if (range.cpu_addr == OF_BAD_ADDR) {
> pr_err("translation of DMA address(%llx) to CPU address failed node(%pOF)\n",
> range.bus_addr, node);
> continue;
> }
> - dma_offset = range.cpu_addr - range.bus_addr;
> -
> - /* Take lower and upper limits */
> - if (range.bus_addr < dma_start)
> - dma_start = range.bus_addr;
> - if (range.bus_addr + range.size > dma_end)
> - dma_end = range.bus_addr + range.size;
> - }
> -
> - if (dma_start >= dma_end) {
> - ret = -EINVAL;
> - pr_debug("Invalid DMA ranges configuration on node(%pOF)\n",
> - node);
> - goto out;
> + r->cpu_start = range.cpu_addr;
> + r->dma_start = range.bus_addr;
> + r->size = range.size;
> + r->offset = range.cpu_addr - range.bus_addr;
> + r++;
> }
> -
> - *dma_addr = dma_start;
> - *size = dma_end - dma_start;
> - *paddr = dma_start + dma_offset;
> -
> - pr_debug("final: dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
> - *dma_addr, *paddr, *size);
> -
> out:
> of_node_put(node);
> -
> return ret;
> }
> +#endif /* CONFIG_HAS_DMA */
>
> /**
> * of_dma_is_coherent - Check if device is coherent
> diff --git a/drivers/of/device.c b/drivers/of/device.c
> index b439c1e054349b..6e3ae7ebc33eeb 100644
> --- a/drivers/of/device.c
> +++ b/drivers/of/device.c
> @@ -5,7 +5,7 @@
> #include <linux/of_device.h>
> #include <linux/of_address.h>
> #include <linux/of_iommu.h>
> -#include <linux/dma-mapping.h>
> +#include <linux/dma-direct.h> /* for bus_dma_region */
> #include <linux/init.h>
> #include <linux/module.h>
> #include <linux/mod_devicetable.h>
> @@ -90,14 +90,14 @@ int of_device_add(struct platform_device *ofdev)
> int of_dma_configure_id(struct device *dev, struct device_node *np,
> bool force_dma, const u32 *id)
> {
> - u64 dma_addr, paddr, size = 0;
> - int ret;
> - bool coherent;
> - unsigned long offset;
> const struct iommu_ops *iommu;
> - u64 mask, end;
> + const struct bus_dma_region *map = NULL;
> + dma_addr_t dma_start = 0;
> + u64 mask, end, size = 0;
> + bool coherent;
> + int ret;
>
> - ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
> + ret = of_dma_get_range(np, &map);
> if (ret < 0) {
> /*
> * For legacy reasons, we have to assume some devices need
> @@ -106,26 +106,35 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
> */
> if (!force_dma)
> return ret == -ENODEV ? 0 : ret;
> -
> - dma_addr = offset = 0;
> } else {
> - offset = PFN_DOWN(paddr - dma_addr);
> + const struct bus_dma_region *r = map;
> + dma_addr_t dma_end = 0;
> +
> + /* Determine the overall bounds of all DMA regions */
> + for (dma_start = ~(dma_addr_t)0; r->size; r++) {
> + /* Take lower and upper limits */
> + if (r->dma_start < dma_start)
> + dma_start = r->dma_start;
> + if (r->dma_start + r->size > dma_end)
> + dma_end = r->dma_start + r->size;
> + }
> + size = dma_end - dma_start;
>
> /*
> * Add a work around to treat the size as mask + 1 in case
> * it is defined in DT as a mask.
> */
> if (size & 1) {
> - dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
> + dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
> size);
> size = size + 1;
> }
>
> if (!size) {
> dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
> + kfree(map);
> return -EINVAL;
> }
> - dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
> }
>
> /*
> @@ -144,13 +153,11 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
> else if (!size)
> size = 1ULL << 32;
>
> - dev->dma_pfn_offset = offset;
> -
> /*
> * Limit coherent and dma mask based on size and default mask
> * set by the driver.
> */
> - end = dma_addr + size - 1;
> + end = dma_start + size - 1;
> mask = DMA_BIT_MASK(ilog2(end) + 1);
> dev->coherent_dma_mask &= mask;
> *dev->dma_mask &= mask;
> @@ -163,14 +170,17 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
> coherent ? " " : " not ");
>
> iommu = of_iommu_configure(dev, np, id);
> - if (PTR_ERR(iommu) == -EPROBE_DEFER)
> + if (PTR_ERR(iommu) == -EPROBE_DEFER) {
> + kfree(map);
> return -EPROBE_DEFER;
> + }
>
> dev_dbg(dev, "device is%sbehind an iommu\n",
> iommu ? " " : " not ");
>
> - arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
> + arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
>
> + dev->dma_range_map = map;
> return 0;
> }
> EXPORT_SYMBOL_GPL(of_dma_configure_id);
> diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
> index edc682249c0015..d9e6a324de0a77 100644
> --- a/drivers/of/of_private.h
> +++ b/drivers/of/of_private.h
> @@ -157,12 +157,13 @@ extern void __of_sysfs_remove_bin_file(struct device_node *np,
> extern int of_bus_n_addr_cells(struct device_node *np);
> extern int of_bus_n_size_cells(struct device_node *np);
>
> -#ifdef CONFIG_OF_ADDRESS
> -extern int of_dma_get_range(struct device_node *np, u64 *dma_addr,
> - u64 *paddr, u64 *size);
> +struct bus_dma_region;
> +#if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA)
> +int of_dma_get_range(struct device_node *np,
> + const struct bus_dma_region **map);
> #else
> -static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr,
> - u64 *paddr, u64 *size)
> +static inline int of_dma_get_range(struct device_node *np,
> + const struct bus_dma_region **map)
> {
> return -ENODEV;
> }
> diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
> index 9b7e84bdc7d446..06cc988faf78b3 100644
> --- a/drivers/of/unittest.c
> +++ b/drivers/of/unittest.c
> @@ -7,6 +7,7 @@
>
> #include <linux/memblock.h>
> #include <linux/clk.h>
> +#include <linux/dma-direct.h> /* to test phys_to_dma/dma_to_phys */
> #include <linux/err.h>
> #include <linux/errno.h>
> #include <linux/hashtable.h>
> @@ -869,10 +870,11 @@ static void __init of_unittest_changeset(void)
> }
>
> static void __init of_unittest_dma_ranges_one(const char *path,
> - u64 expect_dma_addr, u64 expect_paddr, u64 expect_size)
> + u64 expect_dma_addr, u64 expect_paddr)
> {
> +#ifdef CONFIG_HAS_DMA
> struct device_node *np;
> - u64 dma_addr, paddr, size;
> + const struct bus_dma_region *map = NULL;
> int rc;
>
> np = of_find_node_by_path(path);
> @@ -881,28 +883,40 @@ static void __init of_unittest_dma_ranges_one(const char *path,
> return;
> }
>
> - rc = of_dma_get_range(np, &dma_addr, &paddr, &size);
> + rc = of_dma_get_range(np, &map);
>
> unittest(!rc, "of_dma_get_range failed on node %pOF rc=%i\n", np, rc);
> +
> if (!rc) {
> - unittest(size == expect_size,
> - "of_dma_get_range wrong size on node %pOF size=%llx\n", np, size);
> + phys_addr_t paddr;
> + dma_addr_t dma_addr;
> + struct device dev_bogus;
> +
> + dev_bogus.dma_range_map = map;
> + paddr = dma_to_phys(&dev_bogus, expect_dma_addr);
> + dma_addr = phys_to_dma(&dev_bogus, expect_paddr);
> +
> unittest(paddr == expect_paddr,
> - "of_dma_get_range wrong phys addr (%llx) on node %pOF", paddr, np);
> + "of_dma_get_range: wrong phys addr %pap (expecting %llx) on node %pOF\n",
> + &paddr, expect_paddr, np);
> unittest(dma_addr == expect_dma_addr,
> - "of_dma_get_range wrong DMA addr (%llx) on node %pOF", dma_addr, np);
> + "of_dma_get_range: wrong DMA addr %pad (expecting %llx) on node %pOF\n",
> + &dma_addr, expect_dma_addr, np);
> +
> + kfree(map);
> }
> of_node_put(np);
> +#endif
> }
>
> static void __init of_unittest_parse_dma_ranges(void)
> {
> of_unittest_dma_ranges_one("/testcase-data/address-tests/device at 70000000",
> - 0x0, 0x20000000, 0x40000000);
> + 0x0, 0x20000000);
> of_unittest_dma_ranges_one("/testcase-data/address-tests/bus at 80000000/device at 1000",
> - 0x100000000, 0x20000000, 0x2000000000);
> + 0x100000000, 0x20000000);
> of_unittest_dma_ranges_one("/testcase-data/address-tests/pci at 90000000",
> - 0x80000000, 0x20000000, 0x10000000);
> + 0x80000000, 0x20000000);
> }
>
> static void __init of_unittest_pci_dma_ranges(void)
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 7f90eeea67e279..bc412fb164a3fe 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -529,7 +529,9 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
> /* Initialise vdev subdevice */
> snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
> rvdev->dev.parent = &rproc->dev;
> - rvdev->dev.dma_pfn_offset = rproc->dev.parent->dma_pfn_offset;
> + ret = dma_direct_copy_range_map(&rvdev->dev, rproc->dev.parent);
> + if (ret)
> + return ret;
> rvdev->dev.release = rproc_rvdev_release;
> dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
> dev_set_drvdata(&rvdev->dev, rvdev);
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> index 1744e6fcc99980..bcf050a04ffc45 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> @@ -227,11 +227,17 @@ int cedrus_hw_probe(struct cedrus_dev *dev)
> * the RAM offset to the physcal addresses.
> *
> * This information will eventually be obtained from device-tree.
> + *
> + * XXX(hch): this has no business in a driver and needs to move
> + * to the device tree.
> */
>
> #ifdef PHYS_PFN_OFFSET
> - if (!(variant->quirks & CEDRUS_QUIRK_NO_DMA_OFFSET))
> - dev->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
> + if (!(variant->quirks & CEDRUS_QUIRK_NO_DMA_OFFSET)) {
> + ret = dma_direct_set_offset(dev->dev, PHYS_OFFSET, 0, SZ_4G);
> + if (ret)
> + return ret;
> + }
> #endif
>
> ret = of_reserved_mem_device_init(dev->dev);
> diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
> index 6197938dcc2d8f..935ee98e049f65 100644
> --- a/drivers/usb/core/message.c
> +++ b/drivers/usb/core/message.c
> @@ -1956,10 +1956,11 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
> intf->dev.groups = usb_interface_groups;
> /*
> * Please refer to usb_alloc_dev() to see why we set
> - * dma_mask and dma_pfn_offset.
> + * dma_mask and dma_range_map.
> */
> intf->dev.dma_mask = dev->dev.dma_mask;
> - intf->dev.dma_pfn_offset = dev->dev.dma_pfn_offset;
> + if (dma_direct_copy_range_map(&intf->dev, &dev->dev))
> + dev_err(&dev->dev, "failed to copy DMA map\n");
> INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
> intf->minor = -1;
> device_initialize(&intf->dev);
> diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
> index bafc113f2b3ef3..23d451f6894d70 100644
> --- a/drivers/usb/core/usb.c
> +++ b/drivers/usb/core/usb.c
> @@ -610,7 +610,8 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
> * mask for the entire HCD, so don't do that.
> */
> dev->dev.dma_mask = bus->sysdev->dma_mask;
> - dev->dev.dma_pfn_offset = bus->sysdev->dma_pfn_offset;
> + if (dma_direct_copy_range_map(&dev->dev, bus->sysdev))
> + dev_err(&dev->dev, "failed to copy DMA map\n");
> set_dev_node(&dev->dev, dev_to_node(bus->sysdev));
> dev->state = USB_STATE_ATTACHED;
> dev->lpm_disable_count = 1;
> diff --git a/include/linux/device.h b/include/linux/device.h
> index ca18da4768e3e8..1c78621fc3c01f 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -466,7 +466,7 @@ struct dev_links_info {
> * such descriptors.
> * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
> * DMA limit than the device itself supports.
> - * @dma_pfn_offset: offset of DMA memory range relatively of RAM
> + * @dma_range_map: map for DMA memory ranges relative to that of RAM
> * @dma_parms: A low level driver may set these to teach IOMMU code about
> * segment limitations.
> * @dma_pools: Dma pools (if dma'ble device).
> @@ -561,7 +561,7 @@ struct device {
> 64 bit addresses for consistent
> allocations such descriptors. */
> u64 bus_dma_limit; /* upstream dma constraint */
> - unsigned long dma_pfn_offset;
> + const struct bus_dma_region *dma_range_map;
>
> struct device_dma_parameters *dma_parms;
>
> diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
> index 6e87225600ae35..715dcb7d64d5a4 100644
> --- a/include/linux/dma-direct.h
> +++ b/include/linux/dma-direct.h
> @@ -14,21 +14,56 @@
>
> extern unsigned int zone_dma_bits;
>
> +/*
> + * Record the mapping of CPU physical to DMA addresses for a given region.
> + */
> +struct bus_dma_region {
> + phys_addr_t cpu_start;
> + dma_addr_t dma_start;
> + u64 size;
> + u64 offset;
> +};
> +
> +static inline dma_addr_t translate_phys_to_dma(struct device *dev,
> + phys_addr_t paddr)
> +{
> + const struct bus_dma_region *m;
> +
> + for (m = dev->dma_range_map; m->size; m++)
> + if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size)
> + return (dma_addr_t)paddr - m->offset;
> +
> + /* make sure dma_capable fails when no translation is available */
> + return DMA_MAPPING_ERROR;
> +}
> +
> +static inline phys_addr_t translate_dma_to_phys(struct device *dev,
> + dma_addr_t dma_addr)
> +{
> + const struct bus_dma_region *m;
> +
> + for (m = dev->dma_range_map; m->size; m++)
> + if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size)
> + return (phys_addr_t)dma_addr + m->offset;
> +
> + return 0;
> +}
> +
> #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
> #include <asm/dma-direct.h>
> #else
> static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
> {
> - dma_addr_t dev_addr = (dma_addr_t)paddr;
> -
> - return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
> + if (dev->dma_range_map)
> + return translate_phys_to_dma(dev, paddr);
> + return paddr;
> }
>
> -static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
> +static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
> {
> - phys_addr_t paddr = (phys_addr_t)dev_addr;
> -
> - return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
> + if (dev->dma_range_map)
> + return translate_dma_to_phys(dev, dma_addr);
> + return dma_addr;
> }
> #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
>
> @@ -64,7 +99,8 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
>
> if (!dev->dma_mask)
> return false;
> -
> + if (addr == DMA_MAPPING_ERROR)
> + return false;
> if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
> min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
> return false;
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index df0bff2ea750e0..e8fcb19c9112f8 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -730,4 +730,21 @@ static inline int dma_mmap_wc(struct device *dev,
> #define dma_unmap_len_set(PTR, LEN_NAME, VAL) do { } while (0)
> #endif
>
> -#endif
> +/*
> + * These interfaces deal with the offset ranges for the direct mapping.
> + * Drivers really should not use them, but we have a few legacy cases
> + * that need them left.
> + */
> +int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
> + dma_addr_t dma_start, u64 size);
> +#ifdef CONFIG_HAS_DMA
> +int dma_direct_copy_range_map(struct device *to, struct device *from);
> +#else
> +static inline int dma_direct_copy_range_map(struct device *to,
> + struct device *from)
> +{
> + return 0;
> +}
> +#endif /* CONFIG_HAS_DMA */
> +
> +#endif /* _LINUX_DMA_MAPPING_H */
> diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
> index 2a0c4985f38e41..029fdc3eb670ae 100644
> --- a/kernel/dma/coherent.c
> +++ b/kernel/dma/coherent.c
> @@ -7,7 +7,7 @@
> #include <linux/slab.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> -#include <linux/dma-mapping.h>
> +#include <linux/dma-direct.h>
>
> struct dma_coherent_mem {
> void *virt_base;
> @@ -32,9 +32,8 @@ static inline dma_addr_t dma_get_device_base(struct device *dev,
> struct dma_coherent_mem * mem)
> {
> if (mem->use_dev_dma_pfn_offset)
> - return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT;
> - else
> - return mem->device_base;
> + return phys_to_dma(dev, PFN_PHYS(mem->pfn_base));
> + return mem->device_base;
> }
>
> static int dma_init_coherent_memory(phys_addr_t phys_addr,
> diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
> index db6ef07aec3b37..fc815f7375e282 100644
> --- a/kernel/dma/direct.c
> +++ b/kernel/dma/direct.c
> @@ -13,6 +13,7 @@
> #include <linux/pfn.h>
> #include <linux/vmalloc.h>
> #include <linux/set_memory.h>
> +#include <linux/slab.h>
>
> /*
> * Most architectures use ZONE_DMA for the first 16 Megabytes, but some use it
> @@ -70,8 +71,12 @@ static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
>
> static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
> {
> - return phys_to_dma_direct(dev, phys) + size - 1 <=
> - min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
> + dma_addr_t dma_addr = phys_to_dma_direct(dev, phys);
> +
> + if (dma_addr == DMA_MAPPING_ERROR)
> + return false;
> + return dma_addr + size - 1 <=
> + min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
> }
>
> /*
> @@ -476,3 +481,75 @@ bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr)
> return !dev_is_dma_coherent(dev) ||
> is_swiotlb_buffer(dma_to_phys(dev, dma_addr));
> }
> +
> +/**
> + * dma_direct_set_offset - Assign scalar offset for a single DMA range.
> + * @dev: device pointer; needed to "own" the alloced memory.
> + * @cpu_start: beginning of memory region covered by this offset.
> + * @dma_start: beginning of DMA/PCI region covered by this offset.
> + * @size: size of the region.
> + *
> + * This is for the simple case of a uniform offset which cannot
> + * be discovered by "dma-ranges".
> + *
> + * It returns -ENOMEM if out of memory, -EINVAL if a map
> + * already exists, 0 otherwise.
> + *
> + * Note: any call to this from a driver is a bug. The mapping needs
> + * to be described by the device tree or other firmware interfaces.
> + */
> +int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
> + dma_addr_t dma_start, u64 size)
> +{
> + struct bus_dma_region *map;
> + u64 offset = (u64)cpu_start - (u64)dma_start;
> +
> + if (dev->dma_range_map) {
> + dev_err(dev, "attempt to add DMA range to existing map\n");
> + return -EINVAL;
> + }
> +
> + if (!offset)
> + return 0;
> +
> + map = kcalloc(2, sizeof(*map), GFP_KERNEL);
> + if (!map)
> + return -ENOMEM;
> + map[0].cpu_start = cpu_start;
> + map[0].dma_start = dma_start;
> + map[0].offset = offset;
> + map[0].size = size;
> + dev->dma_range_map = map;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(dma_direct_set_offset);
> +
> +/**
> + * dma_direct_copy_range_map - Copy the dma_range from one device to another
> + * @to: device to copy to
> + * @from: device to copy from
> + *
> + * Note: this should not be used in any new code. Drivers should never try
> + * to inherit DMA parameters from other devices but just use those other
> + * devices in the DMA mapping functions.
> + */
> +int dma_direct_copy_range_map(struct device *to, struct device *from)
> +{
> + const struct bus_dma_region *map = from->dma_range_map, *new_map, *r;
> + int num_ranges = 0;
> +
> + if (!map)
> + return 0;
> +
> + for (r = map; r->size; r++)
> + num_ranges++;
> +
> + new_map = kmemdup(map, array_size(num_ranges + 1, sizeof(*map)),
> + GFP_KERNEL);
> + if (!new_map)
> + return -ENOMEM;
> + to->dma_range_map = new_map;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(dma_direct_copy_range_map);
>
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