Revision 40509ca982c00c4b70fc00be887509feca0bff15 authored by Johan Hovold on 19 March 2013, 08:21:22 UTC, committed by Greg Kroah-Hartman on 21 March 2013, 22:59:05 UTC
Use the port wait queue and make sure to check the serial disconnected flag before accessing private port data after waking up. This is is needed as the private port data (including the wait queue itself) can be gone when waking up after a disconnect. Cc: stable <stable@vger.kernel.org> Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 parent 8edfdab
dma-contiguous.c
/*
* 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/sizes.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/mm_types.h>
#include <linux/dma-contiguous.h>
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 phys_addr_t size_bytes = CMA_SIZE_MBYTES * SZ_1M;
static phys_addr_t 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 phys_addr_t __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 phys_addr_t 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)
{
phys_addr_t 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__,
(unsigned long)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, phys_addr_t size,
phys_addr_t base, phys_addr_t limit)
{
struct cma_reserved *r = &cma_reserved[cma_reserved_count];
phys_addr_t 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 - 1, 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 {
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", (unsigned long)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", (unsigned long)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);
struct page *page = NULL;
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)
break;
pfn = cma->base_pfn + pageno;
ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
if (ret == 0) {
bitmap_set(cma->bitmap, pageno, count);
page = pfn_to_page(pfn);
break;
} else if (ret != -EBUSY) {
break;
}
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("%s(): returned %p\n", __func__, page);
return page;
}
/**
* dma_release_from_contiguous() - release allocated pages
* @dev: Pointer to device for which the pages were allocated.
* @pages: Allocated pages.
* @count: Number of allocated pages.
*
* This function releases memory allocated by dma_alloc_from_contiguous().
* It returns false when provided pages do not belong to contiguous area and
* true otherwise.
*/
bool dma_release_from_contiguous(struct device *dev, struct page *pages,
int count)
{
struct cma *cma = dev_get_cma_area(dev);
unsigned long pfn;
if (!cma || !pages)
return false;
pr_debug("%s(page %p)\n", __func__, (void *)pages);
pfn = page_to_pfn(pages);
if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
return false;
VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
mutex_lock(&cma_mutex);
bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count);
free_contig_range(pfn, count);
mutex_unlock(&cma_mutex);
return true;
}
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