diff options
Diffstat (limited to 'drivers/base')
30 files changed, 1758 insertions, 445 deletions
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 9aa618acfe97..9b21469482ae 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -192,4 +192,93 @@ config DMA_SHARED_BUFFER APIs extension; the file's descriptor can then be passed on to other driver. +config CMA + bool "Contiguous Memory Allocator (EXPERIMENTAL)" + depends on HAVE_DMA_CONTIGUOUS && HAVE_MEMBLOCK && EXPERIMENTAL + select MIGRATION + help + This enables the Contiguous Memory Allocator which allows drivers + to allocate big physically-contiguous blocks of memory for use with + hardware components that do not support I/O map nor scatter-gather. + + For more information see <include/linux/dma-contiguous.h>. + If unsure, say "n". + +if CMA + +config CMA_DEBUG + bool "CMA debug messages (DEVELOPMENT)" + depends on DEBUG_KERNEL + help + Turns on debug messages in CMA. This produces KERN_DEBUG + messages for every CMA call as well as various messages while + processing calls such as dma_alloc_from_contiguous(). + This option does not affect warning and error messages. + +comment "Default contiguous memory area size:" + +config CMA_SIZE_MBYTES + int "Size in Mega Bytes" + depends on !CMA_SIZE_SEL_PERCENTAGE + default 16 + help + Defines the size (in MiB) of the default memory area for Contiguous + Memory Allocator. + +config CMA_SIZE_PERCENTAGE + int "Percentage of total memory" + depends on !CMA_SIZE_SEL_MBYTES + default 10 + help + Defines the size of the default memory area for Contiguous Memory + Allocator as a percentage of the total memory in the system. + +choice + prompt "Selected region size" + default CMA_SIZE_SEL_ABSOLUTE + +config CMA_SIZE_SEL_MBYTES + bool "Use mega bytes value only" + +config CMA_SIZE_SEL_PERCENTAGE + bool "Use percentage value only" + +config CMA_SIZE_SEL_MIN + bool "Use lower value (minimum)" + +config CMA_SIZE_SEL_MAX + bool "Use higher value (maximum)" + +endchoice + +config CMA_ALIGNMENT + int "Maximum PAGE_SIZE order of alignment for contiguous buffers" + range 4 9 + default 8 + help + DMA mapping framework by default aligns all buffers to the smallest + PAGE_SIZE order which is greater than or equal to the requested buffer + size. This works well for buffers up to a few hundreds kilobytes, but + for larger buffers it just a memory waste. With this parameter you can + specify the maximum PAGE_SIZE order for contiguous buffers. Larger + buffers will be aligned only to this specified order. The order is + expressed as a power of two multiplied by the PAGE_SIZE. + + For example, if your system defaults to 4KiB pages, the order value + of 8 means that the buffers will be aligned up to 1MiB only. + + If unsure, leave the default value "8". + +config CMA_AREAS + int "Maximum count of the CMA device-private areas" + default 7 + help + CMA allows to create CMA areas for particular devices. This parameter + sets the maximum number of such device private CMA areas in the + system. + + If unsure, leave the default value "7". + +endif + endmenu diff --git a/drivers/base/Makefile b/drivers/base/Makefile index b6d1b9c4200c..5aa2d703d19f 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -6,6 +6,7 @@ obj-y := core.o bus.o dd.o syscore.o \ attribute_container.o transport_class.o \ topology.o obj-$(CONFIG_DEVTMPFS) += devtmpfs.o +obj-$(CONFIG_CMA) += dma-contiguous.o obj-y += power/ obj-$(CONFIG_HAS_DMA) += dma-mapping.o obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 26a06b801b5b..2bcef657a60c 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -21,8 +21,7 @@ #include "power/power.h" /* /sys/devices/system */ -/* FIXME: make static after drivers/base/sys.c is deleted */ -struct kset *system_kset; +static struct kset *system_kset; #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) diff --git a/drivers/base/core.c b/drivers/base/core.c index e28ce9898af4..346be8b78b24 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -25,6 +25,7 @@ #include <linux/mutex.h> #include <linux/async.h> #include <linux/pm_runtime.h> +#include <linux/netdevice.h> #include "base.h" #include "power/power.h" @@ -65,7 +66,7 @@ static inline int device_is_not_partition(struct device *dev) * @dev: struct device to get the name of * * Will return the device's driver's name if it is bound to a device. If - * the device is not bound to a device, it will return the name of the bus + * the device is not bound to a driver, it will return the name of the bus * it is attached to. If it is not attached to a bus either, an empty * string will be returned. */ @@ -878,8 +879,8 @@ EXPORT_SYMBOL_GPL(dev_set_name); * to NULL prevents an entry from being created. class->dev_kobj must * be set (or cleared) before any devices are registered to the class * otherwise device_create_sys_dev_entry() and - * device_remove_sys_dev_entry() will disagree about the the presence - * of the link. + * device_remove_sys_dev_entry() will disagree about the presence of + * the link. */ static struct kobject *device_to_dev_kobj(struct device *dev) { @@ -1843,15 +1844,60 @@ void device_shutdown(void) */ #ifdef CONFIG_PRINTK - int __dev_printk(const char *level, const struct device *dev, struct va_format *vaf) { + char dict[128]; + size_t dictlen = 0; + const char *subsys; + if (!dev) return printk("%s(NULL device *): %pV", level, vaf); - return printk("%s%s %s: %pV", - level, dev_driver_string(dev), dev_name(dev), vaf); + if (dev->class) + subsys = dev->class->name; + else if (dev->bus) + subsys = dev->bus->name; + else + goto skip; + + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, + "SUBSYSTEM=%s", subsys); + + /* + * Add device identifier DEVICE=: + * b12:8 block dev_t + * c127:3 char dev_t + * n8 netdev ifindex + * +sound:card0 subsystem:devname + */ + if (MAJOR(dev->devt)) { + char c; + + if (strcmp(subsys, "block") == 0) + c = 'b'; + else + c = 'c'; + dictlen++; + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, + "DEVICE=%c%u:%u", + c, MAJOR(dev->devt), MINOR(dev->devt)); + } else if (strcmp(subsys, "net") == 0) { + struct net_device *net = to_net_dev(dev); + + dictlen++; + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, + "DEVICE=n%u", net->ifindex); + } else { + dictlen++; + dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen, + "DEVICE=+%s:%s", subsys, dev_name(dev)); + } +skip: + return printk_emit(0, level[1] - '0', + dictlen ? dict : NULL, dictlen, + "%s %s: %pV", + dev_driver_string(dev), dev_name(dev), vaf); } EXPORT_SYMBOL(__dev_printk); diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index adf937bf4091..63452943abd1 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -330,8 +330,4 @@ void __init cpu_dev_init(void) panic("Failed to register CPU subsystem"); cpu_dev_register_generic(); - -#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) - sched_create_sysfs_power_savings_entries(cpu_subsys.dev_root); -#endif } diff --git a/drivers/base/devres.c b/drivers/base/devres.c index 524bf96c289f..2360adb7a58f 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -309,6 +309,10 @@ EXPORT_SYMBOL_GPL(devres_remove); * which @match returns 1. If @match is NULL, it's considered to * match all. If found, the resource is removed atomically and freed. * + * Note that the release function for the resource will not be called, + * only the devres-allocated data will be freed. The caller becomes + * responsible for freeing any other data. + * * RETURNS: * 0 if devres is found and freed, -ENOENT if not found. */ @@ -326,6 +330,37 @@ int devres_destroy(struct device *dev, dr_release_t release, } EXPORT_SYMBOL_GPL(devres_destroy); + +/** + * devres_release - Find a device resource and destroy it, calling release + * @dev: Device to find resource from + * @release: Look for resources associated with this release function + * @match: Match function (optional) + * @match_data: Data for the match function + * + * Find the latest devres of @dev associated with @release and for + * which @match returns 1. If @match is NULL, it's considered to + * match all. If found, the resource is removed atomically, the + * release function called and the resource freed. + * + * RETURNS: + * 0 if devres is found and freed, -ENOENT if not found. + */ +int devres_release(struct device *dev, dr_release_t release, + dr_match_t match, void *match_data) +{ + void *res; + + res = devres_remove(dev, release, match, match_data); + if (unlikely(!res)) + return -ENOENT; + + (*release)(dev, res); + devres_free(res); + return 0; +} +EXPORT_SYMBOL_GPL(devres_release); + static int remove_nodes(struct device *dev, struct list_head *first, struct list_head *end, struct list_head *todo) diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index 8493536ea55b..765c3a28077a 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -7,9 +7,9 @@ * devtmpfs, a tmpfs-based filesystem is created. Every driver-core * device which requests a device node, will add a node in this * filesystem. - * By default, all devices are named after the the name of the - * device, owned by root and have a default mode of 0600. Subsystems - * can overwrite the default setting if needed. + * By default, all devices are named after the name of the device, + * owned by root and have a default mode of 0600. Subsystems can + * overwrite the default setting if needed. */ #include <linux/kernel.h> diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 20258e179211..24e88fe29ec1 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -312,7 +312,7 @@ EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific * preparations. Coherency is only guaranteed in the specified range for the * specified access direction. - * @dma_buf: [in] buffer to prepare cpu access for. + * @dmabuf: [in] buffer to prepare cpu access for. * @start: [in] start of range for cpu access. * @len: [in] length of range for cpu access. * @direction: [in] length of range for cpu access. @@ -339,7 +339,7 @@ EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access); * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific * actions. Coherency is only guaranteed in the specified range for the * specified access direction. - * @dma_buf: [in] buffer to complete cpu access for. + * @dmabuf: [in] buffer to complete cpu access for. * @start: [in] start of range for cpu access. * @len: [in] length of range for cpu access. * @direction: [in] length of range for cpu access. @@ -359,7 +359,7 @@ EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); /** * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address * space. The same restrictions as for kmap_atomic and friends apply. - * @dma_buf: [in] buffer to map page from. + * @dmabuf: [in] buffer to map page from. * @page_num: [in] page in PAGE_SIZE units to map. * * This call must always succeed, any necessary preparations that might fail @@ -375,7 +375,7 @@ EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); /** * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic. - * @dma_buf: [in] buffer to unmap page from. + * @dmabuf: [in] buffer to unmap page from. * @page_num: [in] page in PAGE_SIZE units to unmap. * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap_atomic. * @@ -394,7 +394,7 @@ EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic); /** * dma_buf_kmap - Map a page of the buffer object into kernel address space. The * same restrictions as for kmap and friends apply. - * @dma_buf: [in] buffer to map page from. + * @dmabuf: [in] buffer to map page from. * @page_num: [in] page in PAGE_SIZE units to map. * * This call must always succeed, any necessary preparations that might fail @@ -410,7 +410,7 @@ EXPORT_SYMBOL_GPL(dma_buf_kmap); /** * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap. - * @dma_buf: [in] buffer to unmap page from. + * @dmabuf: [in] buffer to unmap page from. * @page_num: [in] page in PAGE_SIZE units to unmap. * @vaddr: [in] kernel space pointer obtained from dma_buf_kmap. * diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c index bb0025c510b3..1b85949e3d2f 100644 --- a/drivers/base/dma-coherent.c +++ b/drivers/base/dma-coherent.c @@ -10,6 +10,7 @@ struct dma_coherent_mem { void *virt_base; dma_addr_t device_base; + phys_addr_t pfn_base; int size; int flags; unsigned long *bitmap; @@ -44,6 +45,7 @@ int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr, dev->dma_mem->virt_base = mem_base; dev->dma_mem->device_base = device_addr; + dev->dma_mem->pfn_base = PFN_DOWN(bus_addr); dev->dma_mem->size = pages; dev->dma_mem->flags = flags; @@ -176,3 +178,43 @@ int dma_release_from_coherent(struct device *dev, int order, void *vaddr) return 0; } EXPORT_SYMBOL(dma_release_from_coherent); + +/** + * dma_mmap_from_coherent() - try to mmap the memory allocated from + * per-device coherent memory pool to userspace + * @dev: device from which the memory was allocated + * @vma: vm_area for the userspace memory + * @vaddr: cpu address returned by dma_alloc_from_coherent + * @size: size of the memory buffer allocated by dma_alloc_from_coherent + * + * This checks whether the memory was allocated from the per-device + * coherent memory pool and if so, maps that memory to the provided vma. + * + * Returns 1 if we correctly mapped the memory, or 0 if + * dma_release_coherent() should proceed with mapping memory from + * generic pools. + */ +int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma, + void *vaddr, size_t size, int *ret) +{ + struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; + + if (mem && vaddr >= mem->virt_base && vaddr + size <= + (mem->virt_base + (mem->size << PAGE_SHIFT))) { + unsigned long off = vma->vm_pgoff; + int start = (vaddr - mem->virt_base) >> PAGE_SHIFT; + int user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + int count = size >> PAGE_SHIFT; + + *ret = -ENXIO; + if (off < count && user_count <= count - off) { + unsigned pfn = mem->pfn_base + start + off; + *ret = remap_pfn_range(vma, vma->vm_start, pfn, + user_count << PAGE_SHIFT, + vma->vm_page_prot); + } + return 1; + } + return 0; +} +EXPORT_SYMBOL(dma_mmap_from_coherent); diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c new file mode 100644 index 000000000000..78efb0306a44 --- /dev/null +++ b/drivers/base/dma-contiguous.c @@ -0,0 +1,401 @@ +/* + * Contiguous Memory Allocator for DMA mapping framework + * Copyright (c) 2010-2011 by Samsung Electronics. + * Written by: + * Marek Szyprowski <m.szyprowski@samsung.com> + * Michal Nazarewicz <mina86@mina86.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License or (at your optional) any later version of the license. + */ + +#define pr_fmt(fmt) "cma: " fmt + +#ifdef CONFIG_CMA_DEBUG +#ifndef DEBUG +# define DEBUG +#endif +#endif + +#include <asm/page.h> +#include <asm/dma-contiguous.h> + +#include <linux/memblock.h> +#include <linux/err.h> +#include <linux/mm.h> +#include <linux/mutex.h> +#include <linux/page-isolation.h> +#include <linux/slab.h> +#include <linux/swap.h> +#include <linux/mm_types.h> +#include <linux/dma-contiguous.h> + +#ifndef SZ_1M +#define SZ_1M (1 << 20) +#endif + +struct cma { + unsigned long base_pfn; + unsigned long count; + unsigned long *bitmap; +}; + +struct cma *dma_contiguous_default_area; + +#ifdef CONFIG_CMA_SIZE_MBYTES +#define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES +#else +#define CMA_SIZE_MBYTES 0 +#endif + +/* + * Default global CMA area size can be defined in kernel's .config. + * This is usefull mainly for distro maintainers to create a kernel + * that works correctly for most supported systems. + * The size can be set in bytes or as a percentage of the total memory + * in the system. + * + * Users, who want to set the size of global CMA area for their system + * should use cma= kernel parameter. + */ +static const unsigned long size_bytes = CMA_SIZE_MBYTES * SZ_1M; +static long size_cmdline = -1; + +static int __init early_cma(char *p) +{ + pr_debug("%s(%s)\n", __func__, p); + size_cmdline = memparse(p, &p); + return 0; +} +early_param("cma", early_cma); + +#ifdef CONFIG_CMA_SIZE_PERCENTAGE + +static unsigned long __init __maybe_unused cma_early_percent_memory(void) +{ + struct memblock_region *reg; + unsigned long total_pages = 0; + + /* + * We cannot use memblock_phys_mem_size() here, because + * memblock_analyze() has not been called yet. + */ + for_each_memblock(memory, reg) + total_pages += memblock_region_memory_end_pfn(reg) - + memblock_region_memory_base_pfn(reg); + + return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT; +} + +#else + +static inline __maybe_unused unsigned long cma_early_percent_memory(void) +{ + return 0; +} + +#endif + +/** + * dma_contiguous_reserve() - reserve area for contiguous memory handling + * @limit: End address of the reserved memory (optional, 0 for any). + * + * This function reserves memory from early allocator. It should be + * called by arch specific code once the early allocator (memblock or bootmem) + * has been activated and all other subsystems have already allocated/reserved + * memory. + */ +void __init dma_contiguous_reserve(phys_addr_t limit) +{ + unsigned long selected_size = 0; + + pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit); + + if (size_cmdline != -1) { + selected_size = size_cmdline; + } else { +#ifdef CONFIG_CMA_SIZE_SEL_MBYTES + selected_size = size_bytes; +#elif defined(CONFIG_CMA_SIZE_SEL_PERCENTAGE) + selected_size = cma_early_percent_memory(); +#elif defined(CONFIG_CMA_SIZE_SEL_MIN) + selected_size = min(size_bytes, cma_early_percent_memory()); +#elif defined(CONFIG_CMA_SIZE_SEL_MAX) + selected_size = max(size_bytes, cma_early_percent_memory()); +#endif + } + + if (selected_size) { + pr_debug("%s: reserving %ld MiB for global area\n", __func__, + selected_size / SZ_1M); + + dma_declare_contiguous(NULL, selected_size, 0, limit); + } +}; + +static DEFINE_MUTEX(cma_mutex); + +static __init int cma_activate_area(unsigned long base_pfn, unsigned long count) +{ + unsigned long pfn = base_pfn; + unsigned i = count >> pageblock_order; + struct zone *zone; + + WARN_ON_ONCE(!pfn_valid(pfn)); + zone = page_zone(pfn_to_page(pfn)); + + do { + unsigned j; + base_pfn = pfn; + for (j = pageblock_nr_pages; j; --j, pfn++) { + WARN_ON_ONCE(!pfn_valid(pfn)); + if (page_zone(pfn_to_page(pfn)) != zone) + return -EINVAL; + } + init_cma_reserved_pageblock(pfn_to_page(base_pfn)); + } while (--i); + return 0; +} + +static __init struct cma *cma_create_area(unsigned long base_pfn, + unsigned long count) +{ + int bitmap_size = BITS_TO_LONGS(count) * sizeof(long); + struct cma *cma; + int ret = -ENOMEM; + + pr_debug("%s(base %08lx, count %lx)\n", __func__, base_pfn, count); + + cma = kmalloc(sizeof *cma, GFP_KERNEL); + if (!cma) + return ERR_PTR(-ENOMEM); + + cma->base_pfn = base_pfn; + cma->count = count; + cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL); + + if (!cma->bitmap) + goto no_mem; + + ret = cma_activate_area(base_pfn, count); + if (ret) + goto error; + + pr_debug("%s: returned %p\n", __func__, (void *)cma); + return cma; + +error: + kfree(cma->bitmap); +no_mem: + kfree(cma); + return ERR_PTR(ret); +} + +static struct cma_reserved { + phys_addr_t start; + unsigned long size; + struct device *dev; +} cma_reserved[MAX_CMA_AREAS] __initdata; +static unsigned cma_reserved_count __initdata; + +static int __init cma_init_reserved_areas(void) +{ + struct cma_reserved *r = cma_reserved; + unsigned i = cma_reserved_count; + + pr_debug("%s()\n", __func__); + + for (; i; --i, ++r) { + struct cma *cma; + cma = cma_create_area(PFN_DOWN(r->start), + r->size >> PAGE_SHIFT); + if (!IS_ERR(cma)) + dev_set_cma_area(r->dev, cma); + } + return 0; +} +core_initcall(cma_init_reserved_areas); + +/** + * dma_declare_contiguous() - reserve area for contiguous memory handling + * for particular device + * @dev: Pointer to device structure. + * @size: Size of the reserved memory. + * @base: Start address of the reserved memory (optional, 0 for any). + * @limit: End address of the reserved memory (optional, 0 for any). + * + * This function reserves memory for specified device. It should be + * called by board specific code when early allocator (memblock or bootmem) + * is still activate. + */ +int __init dma_declare_contiguous(struct device *dev, unsigned long size, + phys_addr_t base, phys_addr_t limit) +{ + struct cma_reserved *r = &cma_reserved[cma_reserved_count]; + unsigned long alignment; + + pr_debug("%s(size %lx, base %08lx, limit %08lx)\n", __func__, + (unsigned long)size, (unsigned long)base, + (unsigned long)limit); + + /* Sanity checks */ + if (cma_reserved_count == ARRAY_SIZE(cma_reserved)) { + pr_err("Not enough slots for CMA reserved regions!\n"); + return -ENOSPC; + } + + if (!size) + return -EINVAL; + + /* Sanitise input arguments */ + alignment = PAGE_SIZE << max(MAX_ORDER, pageblock_order); + base = ALIGN(base, alignment); + size = ALIGN(size, alignment); + limit &= ~(alignment - 1); + + /* Reserve memory */ + if (base) { + if (memblock_is_region_reserved(base, size) || + memblock_reserve(base, size) < 0) { + base = -EBUSY; + goto err; + } + } else { + /* + * Use __memblock_alloc_base() since + * memblock_alloc_base() panic()s. + */ + phys_addr_t addr = __memblock_alloc_base(size, alignment, limit); + if (!addr) { + base = -ENOMEM; + goto err; + } else if (addr + size > ~(unsigned long)0) { + memblock_free(addr, size); + base = -EINVAL; + goto err; + } else { + base = addr; + } + } + + /* + * Each reserved area must be initialised later, when more kernel + * subsystems (like slab allocator) are available. + */ + r->start = base; + r->size = size; + r->dev = dev; + cma_reserved_count++; + pr_info("CMA: reserved %ld MiB at %08lx\n", size / SZ_1M, + (unsigned long)base); + + /* Architecture specific contiguous memory fixup. */ + dma_contiguous_early_fixup(base, size); + return 0; +err: + pr_err("CMA: failed to reserve %ld MiB\n", size / SZ_1M); + return base; +} + +/** + * dma_alloc_from_contiguous() - allocate pages from contiguous area + * @dev: Pointer to device for which the allocation is performed. + * @count: Requested number of pages. + * @align: Requested alignment of pages (in PAGE_SIZE order). + * + * This function allocates memory buffer for specified device. It uses + * device specific contiguous memory area if available or the default + * global one. Requires architecture specific get_dev_cma_area() helper + * function. + */ +struct page *dma_alloc_from_contiguous(struct device *dev, int count, + unsigned int align) +{ + unsigned long mask, pfn, pageno, start = 0; + struct cma *cma = dev_get_cma_area(dev); + int ret; + + if (!cma || !cma->count) + return NULL; + + if (align > CONFIG_CMA_ALIGNMENT) + align = CONFIG_CMA_ALIGNMENT; + + pr_debug("%s(cma %p, count %d, align %d)\n", __func__, (void *)cma, + count, align); + + if (!count) + return NULL; + + mask = (1 << align) - 1; + + mutex_lock(&cma_mutex); + + for (;;) { + pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count, + start, count, mask); + if (pageno >= cma->count) { + ret = -ENOMEM; + goto error; + } + + pfn = cma->base_pfn + pageno; + ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA); + if (ret == 0) { + bitmap_set(cma->bitmap, pageno, count); + break; + } else if (ret != -EBUSY) { + goto error; + } + pr_debug("%s(): memory range at %p is busy, retrying\n", + __func__, pfn_to_page(pfn)); + /* try again with a bit different memory target */ + start = pageno + mask + 1; + } + + mutex_unlock(&cma_mutex); + + pr_debug |