[PATCH 6/6] dma-mapping: introduce DMA range map, supplanting dma_pfn_offset

From: Christoph Hellwig
Date: Wed Sep 16 2020 - 02:30:39 EST

From: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>

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_direct_set_offset(dev, cpu_addr, dma_addr, size).

Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
[hch: various interface cleanups]
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
---
arch/arm/include/asm/dma-direct.h | 9 +--
arch/arm/mach-keystone/keystone.c | 17 ++---
arch/arm/mach-omap1/include/mach/memory.h | 4 +
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 | 24 +++++-
.../staging/media/sunxi/cedrus/cedrus_hw.c | 10 ++-
include/linux/device.h | 4 +-
include/linux/dma-direct.h | 54 ++++++++++++--
include/linux/dma-mapping.h | 9 ++-
kernel/dma/coherent.c | 7 +-
kernel/dma/direct.c | 51 ++++++++++++-
22 files changed, 285 insertions(+), 119 deletions(-)

diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
index fbcf4367b5cb1a..436544aeb83405 100644
--- a/arch/arm/include/asm/dma-direct.h
+++ b/arch/arm/include/asm/dma-direct.h
@@ -12,8 +12,8 @@
#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);
}

@@ -21,9 +21,8 @@ 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" : "");
}
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/arm/mach-omap1/include/mach/memory.h b/arch/arm/mach-omap1/include/mach/memory.h
index e43697c3297bf2..1142560e0078f5 100644
--- a/arch/arm/mach-omap1/include/mach/memory.h
+++ b/arch/arm/mach-omap1/include/mach/memory.h
@@ -41,6 +41,10 @@
__phys_to_pfn(__dma); \
})

+#define __arch_dma_to_virt(dev, addr) ({ (void *) (is_lbus_device(dev) ? \
+ lbus_to_virt(addr) : \
+ __phys_to_virt(addr)); })
+
#define __arch_virt_to_dma(dev, addr) ({ unsigned long __addr = (unsigned long)(addr); \
(dma_addr_t) (is_lbus_device(dev) ? \
virt_to_lbus(__addr) : \
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.
*/
- 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.
+ */
#ifdef PHYS_PFN_OFFSET
- 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.
+ */
+ 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@70000000",
- 0x0, 0x20000000, 0x40000000);
+ 0x0, 0x20000000);
of_unittest_dma_ranges_one("/testcase-data/address-tests/bus@80000000/device@1000",
- 0x100000000, 0x20000000, 0x2000000000);
+ 0x100000000, 0x20000000);
of_unittest_dma_ranges_one("/testcase-data/address-tests/pci@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..8157dd491d2819 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -23,6 +23,7 @@
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h> /* XXX: pokes into bus_dma_range */
#include <linux/firmware.h>
#include <linux/string.h>
#include <linux/debugfs.h>
@@ -458,6 +459,25 @@ static void rproc_rvdev_release(struct device *dev)
kfree(rvdev);
}

+static int copy_dma_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;
+}
+
/**
* rproc_handle_vdev() - handle a vdev fw resource
* @rproc: the remote processor
@@ -529,7 +549,9 @@ 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 = copy_dma_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/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 805010ea5346f9..c6b21acba7a459 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -14,6 +14,41 @@

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 (phys_addr_t)-1;
+}
+
#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
#include <asm/dma-direct.h>
#ifndef phys_to_dma_unencrypted
@@ -23,9 +58,9 @@ extern unsigned int zone_dma_bits;
static inline dma_addr_t phys_to_dma_unencrypted(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;
}

/*
@@ -39,10 +74,14 @@ static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
return __sme_set(phys_to_dma_unencrypted(dev, 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 +
- ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
+ phys_addr_t paddr;
+
+ if (dev->dma_range_map)
+ paddr = translate_dma_to_phys(dev, dma_addr);
+ else
+ paddr = dma_addr;

return __sme_clr(paddr);
}
@@ -64,7 +103,8 @@ 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..bb138ac6f5e63e 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -730,4 +730,11 @@ static inline int dma_mmap_wc(struct device *dev,
#define dma_unmap_len_set(PTR, LEN_NAME, VAL) do { } while (0)
#endif

-#endif
+/*
+ * Legacy interface to set up the dma offset map. Drivers really should not
+ * actually use it, but we have a few legacy cases left.
+ */
+int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
+ dma_addr_t dma_start, u64 size);
+
+#endif /* _LINUX_DMA_MAPPING_H */
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
index f85d14bbfcbe03..c0685196fb6d42 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 54db9cfdaecc6d..750659f7447c4b 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
@@ -66,8 +67,12 @@ 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);
}

/*
@@ -461,3 +466,45 @@ 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);
--
2.28.0