Loading Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt +10 −0 Original line number Diff line number Diff line Loading @@ -59,6 +59,16 @@ no-map (optional) - empty property of the region as part of its standard mapping of system memory, nor permit speculative access to it under any circumstances other than under the control of the device driver using the region. no-map-fixup (optional) - empty property - Indicates the operating system must reserve the memory region and keep virtual mapping. Upon first allocation the actual allocated region is removed for any virtual mapping and behaves as "no-map" while the remaining memory is returned back to the system for normal use. One would like to use this property where he is not sure about how much region size must be reserved, so he gives it a max size which then is shrink once (first) allocation is done. This property is for some specific use cases, if unsure please don't use it. This property cannot be used together with "no-map" attribute. reusable (optional) - empty property - The operating system can use the memory in this region with the limitation that the device driver(s) owning the region need to be Loading drivers/base/dma-removed.c +164 −0 Original line number Diff line number Diff line Loading @@ -7,10 +7,12 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/bootmem.h> #include <linux/module.h> #include <linux/mm.h> #include <linux/gfp.h> #include <linux/errno.h> #include <linux/ioport.h> #include <linux/list.h> #include <linux/init.h> #include <linux/device.h> Loading @@ -24,11 +26,14 @@ #include <linux/vmalloc.h> #include <linux/sizes.h> #include <linux/spinlock.h> #include <asm/dma-contiguous.h> #include <asm/tlbflush.h> struct removed_region { phys_addr_t base; int nr_pages; unsigned long *bitmap; int fixup; struct mutex lock; }; Loading Loading @@ -72,6 +77,140 @@ static int dma_assign_removed_region(struct device *dev, return 0; } static void adapt_iomem_resource(unsigned long base_pfn, unsigned long end_pfn) { struct resource *res, *conflict; resource_size_t cstart, cend; res = kzalloc(sizeof(*res), GFP_KERNEL); if (!res) return; res->name = "System RAM"; res->start = __pfn_to_phys(base_pfn); res->end = __pfn_to_phys(end_pfn) - 1; res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; conflict = request_resource_conflict(&iomem_resource, res); if (!conflict) { pr_err("Removed memory: no conflict resource found\n"); kfree(res); goto done; } cstart = conflict->start; cend = conflict->end; if ((cstart == res->start) && (cend == res->end)) { release_resource(conflict); } else if ((res->start >= cstart) && (res->start <= cend)) { if (res->start == cstart) { adjust_resource(conflict, res->end + 1, cend - res->end); } else if (res->end == cend) { adjust_resource(conflict, cstart, res->start - cstart); } else { adjust_resource(conflict, cstart, res->start - cstart); res->start = res->end + 1; res->end = cend; request_resource(&iomem_resource, res); goto done; } } else { pr_err("Removed memory: incorrect resource conflict start=%llx end=%llx\n", (unsigned long long) conflict->start, (unsigned long long) conflict->end); } kfree(res); done: return; } #ifdef CONFIG_FLATMEM static void free_memmap(unsigned long start_pfn, unsigned long end_pfn) { struct page *start_pg, *end_pg; unsigned long pg, pgend; /* * Convert start_pfn/end_pfn to a struct page pointer. */ start_pg = pfn_to_page(start_pfn - 1) + 1; end_pg = pfn_to_page(end_pfn - 1) + 1; /* * Convert to physical addresses, and round start upwards and end * downwards. */ pg = (unsigned long)PAGE_ALIGN(__pa(start_pg)); pgend = (unsigned long)__pa(end_pg) & PAGE_MASK; /* * If there are free pages between these, free the section of the * memmap array. */ if (pg < pgend) free_bootmem_late(pg, pgend - pg); } #else static void free_memmap(unsigned long start_pfn, unsigned long end_pfn) { } #endif static int _clear_pte(pte_t *pte, pgtable_t token, unsigned long addr, void *data) { pte_clear(&init_mm, addr, pte); return 0; } static void clear_mapping(unsigned long addr, unsigned long size) { apply_to_page_range(&init_mm, addr, size, _clear_pte, NULL); /* ensure ptes are updated */ mb(); flush_tlb_kernel_range(addr, addr + size); } static void removed_region_fixup(struct removed_region *dma_mem, int index) { unsigned long fixup_size; unsigned long base_pfn; if (index > dma_mem->nr_pages) return; /* carve-out */ memblock_free(dma_mem->base, dma_mem->nr_pages * PAGE_SIZE); memblock_remove(dma_mem->base, index * PAGE_SIZE); /* clear page-mappings */ base_pfn = dma_mem->base >> PAGE_SHIFT; if (!PageHighMem(pfn_to_page(base_pfn))) { clear_mapping((unsigned long) phys_to_virt(dma_mem->base), index * PAGE_SIZE); } /* free page objects */ free_memmap(base_pfn, base_pfn + index); /* return remaining area to system */ fixup_size = (dma_mem->nr_pages - index) * PAGE_SIZE; free_bootmem_late(dma_mem->base + index * PAGE_SIZE, fixup_size); /* * release freed resource region so as to show up under iomem resource * list */ adapt_iomem_resource(base_pfn, base_pfn + index); /* limit the fixup region */ dma_mem->nr_pages = index; } void *removed_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs) { Loading Loading @@ -108,6 +247,11 @@ void *removed_alloc(struct device *dev, size_t size, dma_addr_t *handle, bitmap_set(dma_mem->bitmap, pageno, nbits); if (dma_mem->fixup) { removed_region_fixup(dma_mem, pageno + nbits); dma_mem->fixup = 0; } if (no_kernel_mapping && skip_zeroing) { addr = (void *)NO_KERNEL_MAPPING_DUMMY; goto out; Loading Loading @@ -254,6 +398,7 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) &rmem->base, (unsigned long)rmem->size / SZ_1M); return -EINVAL; } mem->fixup = rmem->fixup; set_dma_ops(dev, &removed_dma_ops); rmem->priv = mem; dma_assign_removed_region(dev, mem); Loading @@ -273,6 +418,25 @@ static const struct reserved_mem_ops removed_mem_ops = { static int __init removed_dma_setup(struct reserved_mem *rmem) { unsigned long node = rmem->fdt_node; int nomap, fixup; nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; fixup = of_get_flat_dt_prop(node, "no-map-fixup", NULL) != NULL; if (nomap && fixup) { pr_err("Removed memory: nomap & nomap-fixup can't co-exist\n"); return -EINVAL; } rmem->fixup = fixup; if (rmem->fixup) { /* Architecture specific contiguous memory fixup only for * no-map-fixup to split mappings */ dma_contiguous_early_fixup(rmem->base, rmem->size); } rmem->ops = &removed_mem_ops; pr_info("Removed memory: created DMA memory pool at %pa, size %ld MiB\n", &rmem->base, (unsigned long)rmem->size / SZ_1M); Loading include/linux/of_reserved_mem.h +1 −0 Original line number Diff line number Diff line Loading @@ -13,6 +13,7 @@ struct reserved_mem { phys_addr_t base; phys_addr_t size; void *priv; int fixup; }; struct reserved_mem_ops { Loading Loading
Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt +10 −0 Original line number Diff line number Diff line Loading @@ -59,6 +59,16 @@ no-map (optional) - empty property of the region as part of its standard mapping of system memory, nor permit speculative access to it under any circumstances other than under the control of the device driver using the region. no-map-fixup (optional) - empty property - Indicates the operating system must reserve the memory region and keep virtual mapping. Upon first allocation the actual allocated region is removed for any virtual mapping and behaves as "no-map" while the remaining memory is returned back to the system for normal use. One would like to use this property where he is not sure about how much region size must be reserved, so he gives it a max size which then is shrink once (first) allocation is done. This property is for some specific use cases, if unsure please don't use it. This property cannot be used together with "no-map" attribute. reusable (optional) - empty property - The operating system can use the memory in this region with the limitation that the device driver(s) owning the region need to be Loading
drivers/base/dma-removed.c +164 −0 Original line number Diff line number Diff line Loading @@ -7,10 +7,12 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/bootmem.h> #include <linux/module.h> #include <linux/mm.h> #include <linux/gfp.h> #include <linux/errno.h> #include <linux/ioport.h> #include <linux/list.h> #include <linux/init.h> #include <linux/device.h> Loading @@ -24,11 +26,14 @@ #include <linux/vmalloc.h> #include <linux/sizes.h> #include <linux/spinlock.h> #include <asm/dma-contiguous.h> #include <asm/tlbflush.h> struct removed_region { phys_addr_t base; int nr_pages; unsigned long *bitmap; int fixup; struct mutex lock; }; Loading Loading @@ -72,6 +77,140 @@ static int dma_assign_removed_region(struct device *dev, return 0; } static void adapt_iomem_resource(unsigned long base_pfn, unsigned long end_pfn) { struct resource *res, *conflict; resource_size_t cstart, cend; res = kzalloc(sizeof(*res), GFP_KERNEL); if (!res) return; res->name = "System RAM"; res->start = __pfn_to_phys(base_pfn); res->end = __pfn_to_phys(end_pfn) - 1; res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; conflict = request_resource_conflict(&iomem_resource, res); if (!conflict) { pr_err("Removed memory: no conflict resource found\n"); kfree(res); goto done; } cstart = conflict->start; cend = conflict->end; if ((cstart == res->start) && (cend == res->end)) { release_resource(conflict); } else if ((res->start >= cstart) && (res->start <= cend)) { if (res->start == cstart) { adjust_resource(conflict, res->end + 1, cend - res->end); } else if (res->end == cend) { adjust_resource(conflict, cstart, res->start - cstart); } else { adjust_resource(conflict, cstart, res->start - cstart); res->start = res->end + 1; res->end = cend; request_resource(&iomem_resource, res); goto done; } } else { pr_err("Removed memory: incorrect resource conflict start=%llx end=%llx\n", (unsigned long long) conflict->start, (unsigned long long) conflict->end); } kfree(res); done: return; } #ifdef CONFIG_FLATMEM static void free_memmap(unsigned long start_pfn, unsigned long end_pfn) { struct page *start_pg, *end_pg; unsigned long pg, pgend; /* * Convert start_pfn/end_pfn to a struct page pointer. */ start_pg = pfn_to_page(start_pfn - 1) + 1; end_pg = pfn_to_page(end_pfn - 1) + 1; /* * Convert to physical addresses, and round start upwards and end * downwards. */ pg = (unsigned long)PAGE_ALIGN(__pa(start_pg)); pgend = (unsigned long)__pa(end_pg) & PAGE_MASK; /* * If there are free pages between these, free the section of the * memmap array. */ if (pg < pgend) free_bootmem_late(pg, pgend - pg); } #else static void free_memmap(unsigned long start_pfn, unsigned long end_pfn) { } #endif static int _clear_pte(pte_t *pte, pgtable_t token, unsigned long addr, void *data) { pte_clear(&init_mm, addr, pte); return 0; } static void clear_mapping(unsigned long addr, unsigned long size) { apply_to_page_range(&init_mm, addr, size, _clear_pte, NULL); /* ensure ptes are updated */ mb(); flush_tlb_kernel_range(addr, addr + size); } static void removed_region_fixup(struct removed_region *dma_mem, int index) { unsigned long fixup_size; unsigned long base_pfn; if (index > dma_mem->nr_pages) return; /* carve-out */ memblock_free(dma_mem->base, dma_mem->nr_pages * PAGE_SIZE); memblock_remove(dma_mem->base, index * PAGE_SIZE); /* clear page-mappings */ base_pfn = dma_mem->base >> PAGE_SHIFT; if (!PageHighMem(pfn_to_page(base_pfn))) { clear_mapping((unsigned long) phys_to_virt(dma_mem->base), index * PAGE_SIZE); } /* free page objects */ free_memmap(base_pfn, base_pfn + index); /* return remaining area to system */ fixup_size = (dma_mem->nr_pages - index) * PAGE_SIZE; free_bootmem_late(dma_mem->base + index * PAGE_SIZE, fixup_size); /* * release freed resource region so as to show up under iomem resource * list */ adapt_iomem_resource(base_pfn, base_pfn + index); /* limit the fixup region */ dma_mem->nr_pages = index; } void *removed_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs) { Loading Loading @@ -108,6 +247,11 @@ void *removed_alloc(struct device *dev, size_t size, dma_addr_t *handle, bitmap_set(dma_mem->bitmap, pageno, nbits); if (dma_mem->fixup) { removed_region_fixup(dma_mem, pageno + nbits); dma_mem->fixup = 0; } if (no_kernel_mapping && skip_zeroing) { addr = (void *)NO_KERNEL_MAPPING_DUMMY; goto out; Loading Loading @@ -254,6 +398,7 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) &rmem->base, (unsigned long)rmem->size / SZ_1M); return -EINVAL; } mem->fixup = rmem->fixup; set_dma_ops(dev, &removed_dma_ops); rmem->priv = mem; dma_assign_removed_region(dev, mem); Loading @@ -273,6 +418,25 @@ static const struct reserved_mem_ops removed_mem_ops = { static int __init removed_dma_setup(struct reserved_mem *rmem) { unsigned long node = rmem->fdt_node; int nomap, fixup; nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; fixup = of_get_flat_dt_prop(node, "no-map-fixup", NULL) != NULL; if (nomap && fixup) { pr_err("Removed memory: nomap & nomap-fixup can't co-exist\n"); return -EINVAL; } rmem->fixup = fixup; if (rmem->fixup) { /* Architecture specific contiguous memory fixup only for * no-map-fixup to split mappings */ dma_contiguous_early_fixup(rmem->base, rmem->size); } rmem->ops = &removed_mem_ops; pr_info("Removed memory: created DMA memory pool at %pa, size %ld MiB\n", &rmem->base, (unsigned long)rmem->size / SZ_1M); Loading
include/linux/of_reserved_mem.h +1 −0 Original line number Diff line number Diff line Loading @@ -13,6 +13,7 @@ struct reserved_mem { phys_addr_t base; phys_addr_t size; void *priv; int fixup; }; struct reserved_mem_ops { Loading
