1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * DMA coherent memory allocation.
5 * Copyright (C) 2002 - 2005 Tensilica Inc.
6 * Copyright (C) 2015 Cadence Design Systems Inc.
8 * Based on version for i386.
10 * Chris Zankel <chris@zankel.net>
11 * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
14 #include <linux/dma-contiguous.h>
15 #include <linux/dma-noncoherent.h>
16 #include <linux/dma-direct.h>
17 #include <linux/gfp.h>
18 #include <linux/highmem.h>
20 #include <linux/types.h>
21 #include <asm/cacheflush.h>
23 #include <asm/platform.h>
25 static void do_cache_op(phys_addr_t paddr, size_t size,
26 void (*fn)(unsigned long, unsigned long))
28 unsigned long off = paddr & (PAGE_SIZE - 1);
29 unsigned long pfn = PFN_DOWN(paddr);
30 struct page *page = pfn_to_page(pfn);
32 if (!PageHighMem(page))
33 fn((unsigned long)phys_to_virt(paddr), size);
36 size_t sz = min_t(size_t, size, PAGE_SIZE - off);
37 void *vaddr = kmap_atomic(page);
39 fn((unsigned long)vaddr + off, sz);
47 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
48 enum dma_data_direction dir)
51 case DMA_BIDIRECTIONAL:
53 do_cache_op(paddr, size, __invalidate_dcache_range);
65 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
66 enum dma_data_direction dir)
69 case DMA_BIDIRECTIONAL:
71 if (XCHAL_DCACHE_IS_WRITEBACK)
72 do_cache_op(paddr, size, __flush_dcache_range);
85 bool platform_vaddr_cached(const void *p)
87 unsigned long addr = (unsigned long)p;
89 return addr >= XCHAL_KSEG_CACHED_VADDR &&
90 addr - XCHAL_KSEG_CACHED_VADDR < XCHAL_KSEG_SIZE;
93 bool platform_vaddr_uncached(const void *p)
95 unsigned long addr = (unsigned long)p;
97 return addr >= XCHAL_KSEG_BYPASS_VADDR &&
98 addr - XCHAL_KSEG_BYPASS_VADDR < XCHAL_KSEG_SIZE;
101 void *platform_vaddr_to_uncached(void *p)
103 return p + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR;
106 void *platform_vaddr_to_cached(void *p)
108 return p + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
111 bool __attribute__((weak)) platform_vaddr_cached(const void *p)
113 WARN_ONCE(1, "Default %s implementation is used\n", __func__);
117 bool __attribute__((weak)) platform_vaddr_uncached(const void *p)
119 WARN_ONCE(1, "Default %s implementation is used\n", __func__);
123 void __attribute__((weak)) *platform_vaddr_to_uncached(void *p)
125 WARN_ONCE(1, "Default %s implementation is used\n", __func__);
129 void __attribute__((weak)) *platform_vaddr_to_cached(void *p)
131 WARN_ONCE(1, "Default %s implementation is used\n", __func__);
137 * Note: We assume that the full memory space is always mapped to 'kseg'
138 * Otherwise we have to use page attributes (not implemented).
141 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
142 gfp_t flag, unsigned long attrs)
144 unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
145 struct page *page = NULL;
147 /* ignore region speicifiers */
149 flag &= ~(__GFP_DMA | __GFP_HIGHMEM);
151 if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
154 if (gfpflags_allow_blocking(flag))
155 page = dma_alloc_from_contiguous(dev, count, get_order(size),
156 flag & __GFP_NOWARN);
159 page = alloc_pages(flag | __GFP_ZERO, get_order(size));
164 *handle = phys_to_dma(dev, page_to_phys(page));
167 if (PageHighMem(page)) {
170 p = dma_common_contiguous_remap(page, size,
171 pgprot_noncached(PAGE_KERNEL),
172 __builtin_return_address(0));
174 if (!dma_release_from_contiguous(dev, page, count))
175 __free_pages(page, get_order(size));
180 BUG_ON(!platform_vaddr_cached(page_address(page)));
181 __invalidate_dcache_range((unsigned long)page_address(page), size);
182 return platform_vaddr_to_uncached(page_address(page));
185 void arch_dma_free(struct device *dev, size_t size, void *vaddr,
186 dma_addr_t dma_handle, unsigned long attrs)
188 unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
191 if (platform_vaddr_uncached(vaddr)) {
192 page = virt_to_page(platform_vaddr_to_cached(vaddr));
195 dma_common_free_remap(vaddr, size);
197 page = pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_handle)));
200 if (!dma_release_from_contiguous(dev, page, count))
201 __free_pages(page, get_order(size));