1 // SPDX-License-Identifier: GPL-2.0
3 ** PARISC 1.1 Dynamic DMA mapping support.
4 ** This implementation is for PA-RISC platforms that do not support
5 ** I/O TLBs (aka DMA address translation hardware).
6 ** See Documentation/DMA-API-HOWTO.txt for interface definitions.
8 ** (c) Copyright 1999,2000 Hewlett-Packard Company
9 ** (c) Copyright 2000 Grant Grundler
10 ** (c) Copyright 2000 Philipp Rumpf <prumpf@tux.org>
11 ** (c) Copyright 2000 John Marvin
13 ** "leveraged" from 2.3.47: arch/ia64/kernel/pci-dma.c.
14 ** (I assume it's from David Mosberger-Tang but there was no Copyright)
16 ** AFAIK, all PA7100LC and PA7300LC platforms can use this code.
21 #include <linux/init.h>
22 #include <linux/gfp.h>
24 #include <linux/proc_fs.h>
25 #include <linux/seq_file.h>
26 #include <linux/string.h>
27 #include <linux/types.h>
28 #include <linux/dma-direct.h>
29 #include <linux/dma-noncoherent.h>
31 #include <asm/cacheflush.h>
32 #include <asm/dma.h> /* for DMA_CHUNK_SIZE */
34 #include <asm/page.h> /* get_order */
35 #include <asm/pgalloc.h>
36 #include <linux/uaccess.h>
37 #include <asm/tlbflush.h> /* for purge_tlb_*() macros */
39 static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL;
40 static unsigned long pcxl_used_bytes __read_mostly = 0;
41 static unsigned long pcxl_used_pages __read_mostly = 0;
43 extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */
44 static DEFINE_SPINLOCK(pcxl_res_lock);
45 static char *pcxl_res_map;
46 static int pcxl_res_hint;
47 static int pcxl_res_size;
49 #ifdef DEBUG_PCXL_RESOURCE
50 #define DBG_RES(x...) printk(x)
57 ** Dump a hex representation of the resource map.
62 void dump_resmap(void)
64 u_long *res_ptr = (unsigned long *)pcxl_res_map;
68 for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
69 printk("%08lx ", *res_ptr);
74 static inline void dump_resmap(void) {;}
77 static inline int map_pte_uncached(pte_t * pte,
79 unsigned long size, unsigned long *paddr_ptr)
82 unsigned long orig_vaddr = vaddr;
92 printk(KERN_ERR "map_pte_uncached: page already exists\n");
93 purge_tlb_start(flags);
94 set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
95 pdtlb_kernel(orig_vaddr);
98 orig_vaddr += PAGE_SIZE;
99 (*paddr_ptr) += PAGE_SIZE;
101 } while (vaddr < end);
105 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
106 unsigned long size, unsigned long *paddr_ptr)
109 unsigned long orig_vaddr = vaddr;
111 vaddr &= ~PGDIR_MASK;
113 if (end > PGDIR_SIZE)
116 pte_t * pte = pte_alloc_kernel(pmd, vaddr);
119 if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
121 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
122 orig_vaddr += PMD_SIZE;
124 } while (vaddr < end);
128 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
132 unsigned long end = vaddr + size;
134 dir = pgd_offset_k(vaddr);
140 p4d = p4d_offset(dir, vaddr);
141 pud = pud_offset(p4d, vaddr);
142 pmd = pmd_alloc(NULL, pud, vaddr);
146 if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
148 vaddr = vaddr + PGDIR_SIZE;
150 } while (vaddr && (vaddr < end));
154 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
159 unsigned long orig_vaddr = vaddr;
168 pte = pte_offset_map(pmd, vaddr);
177 pte_clear(&init_mm, vaddr, pte);
178 purge_tlb_start(flags);
179 pdtlb_kernel(orig_vaddr);
180 purge_tlb_end(flags);
182 orig_vaddr += PAGE_SIZE;
184 if (pte_none(page) || pte_present(page))
186 printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
187 } while (vaddr < end);
190 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
195 unsigned long orig_vaddr = vaddr;
204 pmd = pmd_offset(dir, vaddr);
205 vaddr &= ~PGDIR_MASK;
207 if (end > PGDIR_SIZE)
210 unmap_uncached_pte(pmd, orig_vaddr, end - vaddr);
211 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
212 orig_vaddr += PMD_SIZE;
214 } while (vaddr < end);
217 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
220 unsigned long end = vaddr + size;
222 dir = pgd_offset_k(vaddr);
224 unmap_uncached_pmd(dir, vaddr, end - vaddr);
225 vaddr = vaddr + PGDIR_SIZE;
227 } while (vaddr && (vaddr < end));
230 #define PCXL_SEARCH_LOOP(idx, mask, size) \
231 for(; res_ptr < res_end; ++res_ptr) \
233 if(0 == ((*res_ptr) & mask)) { \
235 idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \
236 pcxl_res_hint = idx + (size >> 3); \
237 goto resource_found; \
241 #define PCXL_FIND_FREE_MAPPING(idx, mask, size) { \
242 u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \
243 u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \
244 PCXL_SEARCH_LOOP(idx, mask, size); \
245 res_ptr = (u##size *)&pcxl_res_map[0]; \
246 PCXL_SEARCH_LOOP(idx, mask, size); \
250 pcxl_alloc_range(size_t size)
254 unsigned int pages_needed = size >> PAGE_SHIFT;
257 mask >>= BITS_PER_LONG - pages_needed;
259 DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n",
260 size, pages_needed, mask);
262 spin_lock_irqsave(&pcxl_res_lock, flags);
264 if(pages_needed <= 8) {
265 PCXL_FIND_FREE_MAPPING(res_idx, mask, 8);
266 } else if(pages_needed <= 16) {
267 PCXL_FIND_FREE_MAPPING(res_idx, mask, 16);
268 } else if(pages_needed <= 32) {
269 PCXL_FIND_FREE_MAPPING(res_idx, mask, 32);
271 panic("%s: pcxl_alloc_range() Too many pages to map.\n",
276 panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
281 DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
282 res_idx, mask, pcxl_res_hint);
284 pcxl_used_pages += pages_needed;
285 pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
287 spin_unlock_irqrestore(&pcxl_res_lock, flags);
292 ** return the corresponding vaddr in the pcxl dma map
294 return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
297 #define PCXL_FREE_MAPPINGS(idx, m, size) \
298 u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \
299 /* BUG_ON((*res_ptr & m) != m); */ \
303 ** clear bits in the pcxl resource map
306 pcxl_free_range(unsigned long vaddr, size_t size)
309 unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3);
310 unsigned int pages_mapped = size >> PAGE_SHIFT;
313 mask >>= BITS_PER_LONG - pages_mapped;
315 DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n",
316 res_idx, size, pages_mapped, mask);
318 spin_lock_irqsave(&pcxl_res_lock, flags);
320 if(pages_mapped <= 8) {
321 PCXL_FREE_MAPPINGS(res_idx, mask, 8);
322 } else if(pages_mapped <= 16) {
323 PCXL_FREE_MAPPINGS(res_idx, mask, 16);
324 } else if(pages_mapped <= 32) {
325 PCXL_FREE_MAPPINGS(res_idx, mask, 32);
327 panic("%s: pcxl_free_range() Too many pages to unmap.\n",
331 pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
332 pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
334 spin_unlock_irqrestore(&pcxl_res_lock, flags);
339 static int proc_pcxl_dma_show(struct seq_file *m, void *v)
343 unsigned long *res_ptr = (u_long *)pcxl_res_map;
345 unsigned long total_pages = pcxl_res_size << 3; /* 8 bits per byte */
347 seq_printf(m, "\nDMA Mapping Area size : %d bytes (%ld pages)\n",
348 PCXL_DMA_MAP_SIZE, total_pages);
350 seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size);
352 seq_puts(m, " total: free: used: % used:\n");
353 seq_printf(m, "blocks %8d %8ld %8ld %8ld%%\n", pcxl_res_size,
354 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
355 (pcxl_used_bytes * 100) / pcxl_res_size);
357 seq_printf(m, "pages %8ld %8ld %8ld %8ld%%\n", total_pages,
358 total_pages - pcxl_used_pages, pcxl_used_pages,
359 (pcxl_used_pages * 100 / total_pages));
362 seq_puts(m, "\nResource bitmap:");
364 for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) {
367 seq_printf(m, "%s %08lx", buf, *res_ptr);
377 if (pcxl_dma_start == 0)
380 pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3);
382 pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL,
383 get_order(pcxl_res_size));
384 memset(pcxl_res_map, 0, pcxl_res_size);
385 proc_gsc_root = proc_mkdir("gsc", NULL);
388 "pcxl_dma_init: Unable to create gsc /proc dir entry\n");
390 struct proc_dir_entry* ent;
391 ent = proc_create_single("pcxl_dma", 0, proc_gsc_root,
395 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n");
400 __initcall(pcxl_dma_init);
402 void *arch_dma_alloc(struct device *dev, size_t size,
403 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
409 if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl)
412 order = get_order(size);
413 size = 1 << (order + PAGE_SHIFT);
414 vaddr = pcxl_alloc_range(size);
415 paddr = __get_free_pages(gfp | __GFP_ZERO, order);
416 flush_kernel_dcache_range(paddr, size);
418 map_uncached_pages(vaddr, size, paddr);
419 *dma_handle = (dma_addr_t) paddr;
422 /* This probably isn't needed to support EISA cards.
423 ** ISA cards will certainly only support 24-bit DMA addressing.
424 ** Not clear if we can, want, or need to support ISA.
426 if (!dev || *dev->coherent_dma_mask < 0xffffffff)
429 return (void *)vaddr;
432 void arch_dma_free(struct device *dev, size_t size, void *vaddr,
433 dma_addr_t dma_handle, unsigned long attrs)
435 int order = get_order(size);
437 WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 &&
438 boot_cpu_data.cpu_type != pcxl);
440 size = 1 << (order + PAGE_SHIFT);
441 unmap_uncached_pages((unsigned long)vaddr, size);
442 pcxl_free_range((unsigned long)vaddr, size);
444 free_pages((unsigned long)__va(dma_handle), order);
447 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
448 enum dma_data_direction dir)
450 flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size);
453 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
454 enum dma_data_direction dir)
456 flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size);
459 void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
460 enum dma_data_direction direction)
462 flush_kernel_dcache_range((unsigned long)vaddr, size);