Commit 59753773 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

Merge tag 'dt-dma-properties-for-arm' of... 

Merge tag 'dt-dma-properties-for-arm' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone into depends/dma-ranges

DT support for 'dma-ranges'and 'dma-coherent' properties with ARM updates

- The 'dma-ranges' helps to take care of few DMAable system memory
        restrictions by use of dma_pfn_offset which is maintained per
        device. Arch code then uses it for dma address translations for such
        cases. We update the dma_pfn_offset accordingly during DT the device
        creation process.
- The 'dma-coherent' property is used to setup arch's coherent dma_ops.

* tag 'dt-dma-properties-for-arm' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone

:
  ARM: dma: use phys_addr_t in __dma_page_[cpu_to_dev/dev_to_cpu]
  ARM: dma: implement set_arch_dma_coherent_ops()
  ARM: dma: Use dma_pfn_offset for dma address translation
  of: configure the platform device dma parameters
  of: introduce of_dma_is_coherent() helper
  of: introduce of_dma_get_range() helper
  device: introduce per device dma_pfn_offset

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parents c9eaa447 2161c248

arch/arm/include/asm/dma-mapping.h

+24 −1
Original line number Diff line number Diff line
@@ -58,21 +58,37 @@ static inline int dma_set_mask(struct device *dev, u64 mask) 
#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;

	return (dma_addr_t)__pfn_to_bus(pfn);

}



static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)

{

	return __bus_to_pfn(addr);

	unsigned long pfn = __bus_to_pfn(addr);



	if (dev)

		pfn += dev->dma_pfn_offset;



	return pfn;

}



static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)

{

	if (dev) {

		unsigned long pfn = dma_to_pfn(dev, addr);



		return phys_to_virt(__pfn_to_phys(pfn));

	}



	return (void *)__bus_to_virt((unsigned long)addr);

}



static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)

{

	if (dev)

		return pfn_to_dma(dev, virt_to_pfn(addr));



	return (dma_addr_t)__virt_to_bus((unsigned long)(addr));

}
@@ -105,6 +121,13 @@ static inline unsigned long dma_max_pfn(struct device *dev) 
}

#define dma_max_pfn(dev) dma_max_pfn(dev)



static inline int set_arch_dma_coherent_ops(struct device *dev)

{

	set_dma_ops(dev, &arm_coherent_dma_ops);

	return 0;

}

#define set_arch_dma_coherent_ops(dev)	set_arch_dma_coherent_ops(dev)



static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)

{

	unsigned int offset = paddr & ~PAGE_MASK;

arch/arm/mm/dma-mapping.c

+2 −2
Original line number Diff line number Diff line
@@ -885,7 +885,7 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, 
static void __dma_page_cpu_to_dev(struct page *page, unsigned long off,

	size_t size, enum dma_data_direction dir)

{

	unsigned long paddr;

	phys_addr_t paddr;



	dma_cache_maint_page(page, off, size, dir, dmac_map_area);
@@ -901,7 +901,7 @@ static void __dma_page_cpu_to_dev(struct page *page, unsigned long off, 
static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,

	size_t size, enum dma_data_direction dir)

{

	unsigned long paddr = page_to_phys(page) + off;

	phys_addr_t paddr = page_to_phys(page) + off;



	/* FIXME: non-speculating: not required */

	/* don't bother invalidating if DMA to device */

drivers/of/address.c

+110 −0
Original line number Diff line number Diff line
@@ -721,3 +721,113 @@ void __iomem *of_iomap(struct device_node *np, int index) 
	return ioremap(res.start, resource_size(&res));

}

EXPORT_SYMBOL(of_iomap);



/**

 * of_dma_get_range - Get DMA range info

 * @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

 *

 * Look in bottom up direction for the first "dma-ranges" property

 * and parse it.

 *  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.

 */

int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size)

{

	struct device_node *node = of_node_get(np);

	const __be32 *ranges = NULL;

	int len, naddr, nsize, pna;

	int ret = 0;

	u64 dmaaddr;



	if (!node)

		return -EINVAL;



	while (1) {

		naddr = of_n_addr_cells(node);

		nsize = of_n_size_cells(node);

		node = of_get_next_parent(node);

		if (!node)

			break;



		ranges = of_get_property(node, "dma-ranges", &len);



		/* Ignore empty ranges, they imply no translation required */

		if (ranges && len > 0)

			break;



		/*

		 * At least empty ranges has to be defined for parent node if

		 * DMA is supported

		 */

		if (!ranges)

			break;

	}



	if (!ranges) {

		pr_debug("%s: no dma-ranges found for node(%s)\n",

			 __func__, np->full_name);

		ret = -ENODEV;

		goto out;

	}



	len /= sizeof(u32);



	pna = of_n_addr_cells(node);



	/* dma-ranges format:

	 * DMA addr	: naddr cells

	 * CPU addr	: pna cells

	 * size		: nsize cells

	 */

	dmaaddr = of_read_number(ranges, naddr);

	*paddr = of_translate_dma_address(np, ranges);

	if (*paddr == OF_BAD_ADDR) {

		pr_err("%s: translation of DMA address(%pad) to CPU address failed node(%s)\n",

		       __func__, dma_addr, np->full_name);

		ret = -EINVAL;

		goto out;

	}

	*dma_addr = dmaaddr;



	*size = of_read_number(ranges + naddr + pna, nsize);



	pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",

		 *dma_addr, *paddr, *size);



out:

	of_node_put(node);



	return ret;

}

EXPORT_SYMBOL_GPL(of_dma_get_range);



/**

 * of_dma_is_coherent - Check if device is coherent

 * @np:	device node

 *

 * It returns true if "dma-coherent" property was found

 * for this device in DT.

 */

bool of_dma_is_coherent(struct device_node *np)

{

	struct device_node *node = of_node_get(np);



	while (node) {

		if (of_property_read_bool(node, "dma-coherent")) {

			of_node_put(node);

			return true;

		}

		node = of_get_next_parent(node);

	}

	of_node_put(node);

	return false;

}

EXPORT_SYMBOL_GPL(of_dma_is_coherent);
 
 No newline at end of file

drivers/of/platform.c

+59 −6
Original line number Diff line number Diff line
@@ -186,6 +186,64 @@ struct platform_device *of_device_alloc(struct device_node *np, 
}

EXPORT_SYMBOL(of_device_alloc);



/**

 * of_dma_configure - Setup DMA configuration

 * @dev:	Device to apply DMA configuration

 *

 * Try to get devices's DMA configuration from DT and update it

 * accordingly.

 *

 * In case if platform code need to use own special DMA configuration,it

 * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event

 * to fix up DMA configuration.

 */

static void of_dma_configure(struct platform_device *pdev)

{

	u64 dma_addr, paddr, size;

	int ret;

	struct device *dev = &pdev->dev;



#if defined(CONFIG_MICROBLAZE)

	pdev->archdata.dma_mask = 0xffffffffUL;

#endif



	/*

	 * Set default dma-mask to 32 bit. Drivers are expected to setup

	 * the correct supported dma_mask.

	 */

	dev->coherent_dma_mask = DMA_BIT_MASK(32);



	/*

	 * Set it to coherent_dma_mask by default if the architecture

	 * code has not set it.

	 */

	if (!dev->dma_mask)

		dev->dma_mask = &dev->coherent_dma_mask;



	/*

	 * if dma-coherent property exist, call arch hook to setup

	 * dma coherent operations.

	 */

	if (of_dma_is_coherent(dev->of_node)) {

		set_arch_dma_coherent_ops(dev);

		dev_dbg(dev, "device is dma coherent\n");

	}



	/*

	 * if dma-ranges property doesn't exist - just return else

	 * setup the dma offset

	 */

	ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size);

	if (ret < 0) {

		dev_dbg(dev, "no dma range information to setup\n");

		return;

	}



	/* DMA ranges found. Calculate and set dma_pfn_offset */

	dev->dma_pfn_offset = PFN_DOWN(paddr - dma_addr);

	dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", dev->dma_pfn_offset);

}



/**

 * of_platform_device_create_pdata - Alloc, initialize and register an of_device

 * @np: pointer to node to create device for
@@ -211,12 +269,7 @@ static struct platform_device *of_platform_device_create_pdata( 
	if (!dev)

		return NULL;



#if defined(CONFIG_MICROBLAZE)

	dev->archdata.dma_mask = 0xffffffffUL;

#endif

	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

	if (!dev->dev.dma_mask)

		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;

	of_dma_configure(dev);

	dev->dev.bus = &platform_bus_type;

	dev->dev.platform_data = platform_data;

include/linux/device.h

+2 −0
Original line number Diff line number Diff line
@@ -691,6 +691,7 @@ struct acpi_dev_node { 
 * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all

 * 		hardware supports 64-bit addresses for consistent allocations

 * 		such descriptors.

 * @dma_pfn_offset: offset of DMA memory range relatively 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).
@@ -756,6 +757,7 @@ struct device { 
					     not all hardware supports

					     64 bit addresses for consistent

					     allocations such descriptors. */

	unsigned long	dma_pfn_offset;



	struct device_dma_parameters *dma_parms;

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