From 5ea3b1b2f8ad9162684431ce6188102ca4c64b7a Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Wed, 4 Jun 2014 16:06:54 -0700 Subject: cma: add placement specifier for "cma=" kernel parameter Currently, "cma=" kernel parameter is used to specify the size of CMA, but we can't specify where it is located. We want to locate CMA below 4GB for devices only supporting 32-bit addressing on 64-bit systems without iommu. This enables to specify the placement of CMA by extending "cma=" kernel parameter. Examples: 1. locate 64MB CMA below 4GB by "cma=64M@0-4G" 2. locate 64MB CMA exact at 512MB by "cma=64M@512M" Note that the DMA contiguous memory allocator on x86 assumes that page_address() works for the pages to allocate. So this change requires to limit end address of contiguous memory area upto max_pfn_mapped to prevent from locating it on highmem area by the argument of dma_contiguous_reserve(). Signed-off-by: Akinobu Mita Cc: Marek Szyprowski Cc: Konrad Rzeszutek Wilk Cc: David Woodhouse Cc: Don Dutile Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Andi Kleen Cc: Yinghai Lu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/dma-contiguous.c | 42 ++++++++++++++++++++++++++++++++---------- 1 file changed, 32 insertions(+), 10 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c index c34ec33..83969f8 100644 --- a/drivers/base/dma-contiguous.c +++ b/drivers/base/dma-contiguous.c @@ -60,11 +60,22 @@ struct cma *dma_contiguous_default_area; */ static const phys_addr_t size_bytes = CMA_SIZE_MBYTES * SZ_1M; static phys_addr_t size_cmdline = -1; +static phys_addr_t base_cmdline; +static phys_addr_t limit_cmdline; static int __init early_cma(char *p) { pr_debug("%s(%s)\n", __func__, p); size_cmdline = memparse(p, &p); + if (*p != '@') + return 0; + base_cmdline = memparse(p + 1, &p); + if (*p != '-') { + limit_cmdline = base_cmdline + size_cmdline; + return 0; + } + limit_cmdline = memparse(p + 1, &p); + return 0; } early_param("cma", early_cma); @@ -108,11 +119,18 @@ static inline __maybe_unused phys_addr_t cma_early_percent_memory(void) void __init dma_contiguous_reserve(phys_addr_t limit) { phys_addr_t selected_size = 0; + phys_addr_t selected_base = 0; + phys_addr_t selected_limit = limit; + bool fixed = false; pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit); if (size_cmdline != -1) { selected_size = size_cmdline; + selected_base = base_cmdline; + selected_limit = min_not_zero(limit_cmdline, limit); + if (base_cmdline + size_cmdline == limit_cmdline) + fixed = true; } else { #ifdef CONFIG_CMA_SIZE_SEL_MBYTES selected_size = size_bytes; @@ -129,10 +147,12 @@ void __init dma_contiguous_reserve(phys_addr_t limit) pr_debug("%s: reserving %ld MiB for global area\n", __func__, (unsigned long)selected_size / SZ_1M); - dma_contiguous_reserve_area(selected_size, 0, limit, - &dma_contiguous_default_area); + dma_contiguous_reserve_area(selected_size, selected_base, + selected_limit, + &dma_contiguous_default_area, + fixed); } -}; +} static DEFINE_MUTEX(cma_mutex); @@ -189,15 +209,20 @@ core_initcall(cma_init_reserved_areas); * @base: Base address of the reserved area optional, use 0 for any * @limit: End address of the reserved memory (optional, 0 for any). * @res_cma: Pointer to store the created cma region. + * @fixed: hint about where to place the reserved area * * 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. This function allows to create custom reserved areas for specific * devices. + * + * If @fixed is true, reserve contiguous area at exactly @base. If false, + * reserve in range from @base to @limit. */ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, - phys_addr_t limit, struct cma **res_cma) + phys_addr_t limit, struct cma **res_cma, + bool fixed) { struct cma *cma = &cma_areas[cma_area_count]; phys_addr_t alignment; @@ -223,18 +248,15 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, limit &= ~(alignment - 1); /* Reserve memory */ - if (base) { + if (base && fixed) { if (memblock_is_region_reserved(base, size) || memblock_reserve(base, size) < 0) { ret = -EBUSY; goto err; } } else { - /* - * Use __memblock_alloc_base() since - * memblock_alloc_base() panic()s. - */ - phys_addr_t addr = __memblock_alloc_base(size, alignment, limit); + phys_addr_t addr = memblock_alloc_range(size, alignment, base, + limit); if (!addr) { ret = -ENOMEM; goto err; -- cgit v1.1 From 56a3c655a3d31cb1afef25b530b5ef6a1e7ddefd Mon Sep 17 00:00:00 2001 From: Li Zhong Date: Wed, 4 Jun 2014 16:07:03 -0700 Subject: memory-hotplug: update documentation to hide information about SECTIONS and remove end_phys_index Seems we all agree that information about SECTION, e.g. section size, sections per memory block should be kept as kernel internals, and not exposed to userspace. This patch updates Documentation/memory-hotplug.txt to refer to memory blocks instead of memory sections where appropriate and added a paragraph to explain that memory blocks are made of memory sections. The documentation update is mostly provided by Nathan. Also, as end_phys_index in code is actually not the end section id, but the end memory block id, which should always be the same as phys_index. So it is removed here. Signed-off-by: Li Zhong Reviewed-by: Zhang Yanfei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/memory.c | 12 ------------ 1 file changed, 12 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/memory.c b/drivers/base/memory.c index bece691..89f752d 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -118,16 +118,6 @@ static ssize_t show_mem_start_phys_index(struct device *dev, return sprintf(buf, "%08lx\n", phys_index); } -static ssize_t show_mem_end_phys_index(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct memory_block *mem = to_memory_block(dev); - unsigned long phys_index; - - phys_index = mem->end_section_nr / sections_per_block; - return sprintf(buf, "%08lx\n", phys_index); -} - /* * Show whether the section of memory is likely to be hot-removable */ @@ -384,7 +374,6 @@ static ssize_t show_phys_device(struct device *dev, } static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL); -static DEVICE_ATTR(end_phys_index, 0444, show_mem_end_phys_index, NULL); static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state); static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL); static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL); @@ -529,7 +518,6 @@ struct memory_block *find_memory_block(struct mem_section *section) static struct attribute *memory_memblk_attrs[] = { &dev_attr_phys_index.attr, - &dev_attr_end_phys_index.attr, &dev_attr_state.attr, &dev_attr_phys_device.attr, &dev_attr_removable.attr, -- cgit v1.1 From fe54b1fd49b712cd94a1846e993a515fc9394dcb Mon Sep 17 00:00:00 2001 From: Marc Carino Date: Wed, 4 Jun 2014 16:10:01 -0700 Subject: cma: increase CMA_ALIGNMENT upper limit to 12 Some systems require a larger maximum PAGE_SIZE order for CMA allocations. To accommodate such systems, increase the upper-bound of the CMA_ALIGNMENT range to 12 (which ends up being 16MB on systems with 4K pages). Signed-off-by: Marc Carino Cc: Marek Szyprowski Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base') diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 4b7b452..23b8726 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -258,7 +258,7 @@ endchoice config CMA_ALIGNMENT int "Maximum PAGE_SIZE order of alignment for contiguous buffers" - range 4 9 + range 4 12 default 8 help DMA mapping framework by default aligns all buffers to the smallest -- cgit v1.1