2 * iommu.c: IOMMU specific routines for memory management.
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1995,2002 Pete Zaitcev (zaitcev@yahoo.com)
6 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
7 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
10 #include <linux/config.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/highmem.h> /* pte_offset_map => kmap_atomic */
17 #include <asm/scatterlist.h>
18 #include <asm/pgalloc.h>
19 #include <asm/pgtable.h>
24 #include <asm/cacheflush.h>
25 #include <asm/tlbflush.h>
26 #include <asm/bitext.h>
27 #include <asm/iommu.h>
31 * This can be sized dynamically, but we will do this
32 * only when we have a guidance about actual I/O pressures.
34 #define IOMMU_RNGE IOMMU_RNGE_256MB
35 #define IOMMU_START 0xF0000000
36 #define IOMMU_WINSIZE (256*1024*1024U)
37 #define IOMMU_NPTES (IOMMU_WINSIZE/PAGE_SIZE) /* 64K PTEs, 265KB */
38 #define IOMMU_ORDER 6 /* 4096 * (1<<6) */
41 extern int viking_mxcc_present;
42 BTFIXUPDEF_CALL(void, flush_page_for_dma, unsigned long)
43 #define flush_page_for_dma(page) BTFIXUP_CALL(flush_page_for_dma)(page)
44 extern int flush_page_for_dma_global;
45 static int viking_flush;
47 extern void viking_flush_page(unsigned long page);
48 extern void viking_mxcc_flush_page(unsigned long page);
51 * Values precomputed according to CPU type.
53 static unsigned int ioperm_noc; /* Consistent mapping iopte flags */
54 static pgprot_t dvma_prot; /* Consistent mapping pte flags */
56 #define IOPERM (IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID)
57 #define MKIOPTE(pfn, perm) (((((pfn)<<8) & IOPTE_PAGE) | (perm)) & ~IOPTE_WAZ)
60 iommu_init(int iommund, struct sbus_bus *sbus)
62 unsigned int impl, vers;
64 struct iommu_struct *iommu;
65 struct linux_prom_registers iommu_promregs[PROMREG_MAX];
67 unsigned long *bitmap;
69 iommu = kmalloc(sizeof(struct iommu_struct), GFP_ATOMIC);
71 prom_printf("Unable to allocate iommu structure\n");
74 prom_getproperty(iommund, "reg", (void *) iommu_promregs,
75 sizeof(iommu_promregs));
76 memset(&r, 0, sizeof(r));
77 r.flags = iommu_promregs[0].which_io;
78 r.start = iommu_promregs[0].phys_addr;
79 iommu->regs = (struct iommu_regs *)
80 sbus_ioremap(&r, 0, PAGE_SIZE * 3, "iommu_regs");
82 prom_printf("Cannot map IOMMU registers\n");
85 impl = (iommu->regs->control & IOMMU_CTRL_IMPL) >> 28;
86 vers = (iommu->regs->control & IOMMU_CTRL_VERS) >> 24;
87 tmp = iommu->regs->control;
88 tmp &= ~(IOMMU_CTRL_RNGE);
89 tmp |= (IOMMU_RNGE_256MB | IOMMU_CTRL_ENAB);
90 iommu->regs->control = tmp;
91 iommu_invalidate(iommu->regs);
92 iommu->start = IOMMU_START;
93 iommu->end = 0xffffffff;
95 /* Allocate IOMMU page table */
96 /* Stupid alignment constraints give me a headache.
97 We need 256K or 512K or 1M or 2M area aligned to
98 its size and current gfp will fortunately give
100 tmp = __get_free_pages(GFP_KERNEL, IOMMU_ORDER);
102 prom_printf("Unable to allocate iommu table [0x%08x]\n",
103 IOMMU_NPTES*sizeof(iopte_t));
106 iommu->page_table = (iopte_t *)tmp;
108 /* Initialize new table. */
109 memset(iommu->page_table, 0, IOMMU_NPTES*sizeof(iopte_t));
112 iommu->regs->base = __pa((unsigned long) iommu->page_table) >> 4;
113 iommu_invalidate(iommu->regs);
115 bitmap = kmalloc(IOMMU_NPTES>>3, GFP_KERNEL);
117 prom_printf("Unable to allocate iommu bitmap [%d]\n",
118 (int)(IOMMU_NPTES>>3));
121 bit_map_init(&iommu->usemap, bitmap, IOMMU_NPTES);
123 printk("IOMMU: impl %d vers %d table 0x%p[%d B] map [%d b]\n",
124 impl, vers, iommu->page_table,
125 (int)(IOMMU_NPTES*sizeof(iopte_t)), (int)IOMMU_NPTES);
130 /* This begs to be btfixup-ed by srmmu. */
131 static void iommu_viking_flush_iotlb(iopte_t *iopte, unsigned int niopte)
136 start = (unsigned long)iopte & PAGE_MASK;
137 end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
138 if (viking_mxcc_present) {
140 viking_mxcc_flush_page(start);
143 } else if (viking_flush) {
145 viking_flush_page(start);
151 static u32 iommu_get_one(struct page *page, int npages, struct sbus_bus *sbus)
153 struct iommu_struct *iommu = sbus->iommu;
155 iopte_t *iopte, *iopte0;
156 unsigned int busa, busa0;
159 ioptex = bit_map_string_get(&iommu->usemap, npages, 1);
162 busa0 = iommu->start + (ioptex << PAGE_SHIFT);
163 iopte0 = &iommu->page_table[ioptex];
167 for (i = 0; i < npages; i++) {
168 iopte_val(*iopte) = MKIOPTE(page_to_pfn(page), IOPERM);
169 iommu_invalidate_page(iommu->regs, busa);
175 iommu_viking_flush_iotlb(iopte0, npages);
180 static u32 iommu_get_scsi_one(char *vaddr, unsigned int len,
181 struct sbus_bus *sbus)
188 off = (unsigned long)vaddr & ~PAGE_MASK;
189 npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
190 page = virt_to_page((unsigned long)vaddr & PAGE_MASK);
191 busa = iommu_get_one(page, npages, sbus);
195 static __u32 iommu_get_scsi_one_noflush(char *vaddr, unsigned long len, struct sbus_bus *sbus)
197 return iommu_get_scsi_one(vaddr, len, sbus);
200 static __u32 iommu_get_scsi_one_gflush(char *vaddr, unsigned long len, struct sbus_bus *sbus)
202 flush_page_for_dma(0);
203 return iommu_get_scsi_one(vaddr, len, sbus);
206 static __u32 iommu_get_scsi_one_pflush(char *vaddr, unsigned long len, struct sbus_bus *sbus)
208 unsigned long page = ((unsigned long) vaddr) & PAGE_MASK;
210 while(page < ((unsigned long)(vaddr + len))) {
211 flush_page_for_dma(page);
214 return iommu_get_scsi_one(vaddr, len, sbus);
217 static void iommu_get_scsi_sgl_noflush(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
223 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
224 sg->dvma_address = iommu_get_one(sg->page, n, sbus) + sg->offset;
225 sg->dvma_length = (__u32) sg->length;
230 static void iommu_get_scsi_sgl_gflush(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
234 flush_page_for_dma(0);
237 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
238 sg->dvma_address = iommu_get_one(sg->page, n, sbus) + sg->offset;
239 sg->dvma_length = (__u32) sg->length;
244 static void iommu_get_scsi_sgl_pflush(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
246 unsigned long page, oldpage = 0;
252 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
255 * We expect unmapped highmem pages to be not in the cache.
256 * XXX Is this a good assumption?
257 * XXX What if someone else unmaps it here and races us?
259 if ((page = (unsigned long) page_address(sg->page)) != 0) {
260 for (i = 0; i < n; i++) {
261 if (page != oldpage) { /* Already flushed? */
262 flush_page_for_dma(page);
269 sg->dvma_address = iommu_get_one(sg->page, n, sbus) + sg->offset;
270 sg->dvma_length = (__u32) sg->length;
275 static void iommu_release_one(u32 busa, int npages, struct sbus_bus *sbus)
277 struct iommu_struct *iommu = sbus->iommu;
281 if (busa < iommu->start)
283 ioptex = (busa - iommu->start) >> PAGE_SHIFT;
284 for (i = 0; i < npages; i++) {
285 iopte_val(iommu->page_table[ioptex + i]) = 0;
286 iommu_invalidate_page(iommu->regs, busa);
289 bit_map_clear(&iommu->usemap, ioptex, npages);
292 static void iommu_release_scsi_one(__u32 vaddr, unsigned long len, struct sbus_bus *sbus)
297 off = vaddr & ~PAGE_MASK;
298 npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
299 iommu_release_one(vaddr & PAGE_MASK, npages, sbus);
302 static void iommu_release_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
309 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
310 iommu_release_one(sg->dvma_address & PAGE_MASK, n, sbus);
311 sg->dvma_address = 0x21212121;
317 static int iommu_map_dma_area(dma_addr_t *pba, unsigned long va,
318 unsigned long addr, int len)
320 unsigned long page, end;
321 struct iommu_struct *iommu = sbus_root->iommu;
322 iopte_t *iopte = iommu->page_table;
326 if ((va & ~PAGE_MASK) != 0) BUG();
327 if ((addr & ~PAGE_MASK) != 0) BUG();
328 if ((len & ~PAGE_MASK) != 0) BUG();
330 ioptex = bit_map_string_get(&iommu->usemap, len >> PAGE_SHIFT, 1);
344 if (viking_mxcc_present)
345 viking_mxcc_flush_page(page);
346 else if (viking_flush)
347 viking_flush_page(page);
349 __flush_page_to_ram(page);
351 pgdp = pgd_offset(&init_mm, addr);
352 pmdp = pmd_offset(pgdp, addr);
353 ptep = pte_offset_map(pmdp, addr);
355 set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
357 iopte_val(*iopte++) =
358 MKIOPTE(page_to_pfn(virt_to_page(page)), ioperm_noc);
362 /* P3: why do we need this?
364 * DAVEM: Because there are several aspects, none of which
365 * are handled by a single interface. Some cpus are
366 * completely not I/O DMA coherent, and some have
367 * virtually indexed caches. The driver DMA flushing
368 * methods handle the former case, but here during
369 * IOMMU page table modifications, and usage of non-cacheable
370 * cpu mappings of pages potentially in the cpu caches, we have
371 * to handle the latter case as well.
374 iommu_viking_flush_iotlb(first, len >> PAGE_SHIFT);
376 iommu_invalidate(iommu->regs);
378 *pba = iommu->start + (ioptex << PAGE_SHIFT);
382 static void iommu_unmap_dma_area(unsigned long busa, int len)
384 struct iommu_struct *iommu = sbus_root->iommu;
385 iopte_t *iopte = iommu->page_table;
387 int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
389 if ((busa & ~PAGE_MASK) != 0) BUG();
390 if ((len & ~PAGE_MASK) != 0) BUG();
395 iopte_val(*iopte++) = 0;
399 iommu_invalidate(iommu->regs);
400 bit_map_clear(&iommu->usemap, ioptex, len >> PAGE_SHIFT);
403 static struct page *iommu_translate_dvma(unsigned long busa)
405 struct iommu_struct *iommu = sbus_root->iommu;
406 iopte_t *iopte = iommu->page_table;
408 iopte += ((busa - iommu->start) >> PAGE_SHIFT);
409 return pfn_to_page((iopte_val(*iopte) & IOPTE_PAGE) >> (PAGE_SHIFT-4));
413 static char *iommu_lockarea(char *vaddr, unsigned long len)
418 static void iommu_unlockarea(char *vaddr, unsigned long len)
422 void __init ld_mmu_iommu(void)
424 viking_flush = (BTFIXUPVAL_CALL(flush_page_for_dma) == (unsigned long)viking_flush_page);
425 BTFIXUPSET_CALL(mmu_lockarea, iommu_lockarea, BTFIXUPCALL_RETO0);
426 BTFIXUPSET_CALL(mmu_unlockarea, iommu_unlockarea, BTFIXUPCALL_NOP);
428 if (!BTFIXUPVAL_CALL(flush_page_for_dma)) {
429 /* IO coherent chip */
430 BTFIXUPSET_CALL(mmu_get_scsi_one, iommu_get_scsi_one_noflush, BTFIXUPCALL_RETO0);
431 BTFIXUPSET_CALL(mmu_get_scsi_sgl, iommu_get_scsi_sgl_noflush, BTFIXUPCALL_NORM);
432 } else if (flush_page_for_dma_global) {
433 /* flush_page_for_dma flushes everything, no matter of what page is it */
434 BTFIXUPSET_CALL(mmu_get_scsi_one, iommu_get_scsi_one_gflush, BTFIXUPCALL_NORM);
435 BTFIXUPSET_CALL(mmu_get_scsi_sgl, iommu_get_scsi_sgl_gflush, BTFIXUPCALL_NORM);
437 BTFIXUPSET_CALL(mmu_get_scsi_one, iommu_get_scsi_one_pflush, BTFIXUPCALL_NORM);
438 BTFIXUPSET_CALL(mmu_get_scsi_sgl, iommu_get_scsi_sgl_pflush, BTFIXUPCALL_NORM);
440 BTFIXUPSET_CALL(mmu_release_scsi_one, iommu_release_scsi_one, BTFIXUPCALL_NORM);
441 BTFIXUPSET_CALL(mmu_release_scsi_sgl, iommu_release_scsi_sgl, BTFIXUPCALL_NORM);
444 BTFIXUPSET_CALL(mmu_map_dma_area, iommu_map_dma_area, BTFIXUPCALL_NORM);
445 BTFIXUPSET_CALL(mmu_unmap_dma_area, iommu_unmap_dma_area, BTFIXUPCALL_NORM);
446 BTFIXUPSET_CALL(mmu_translate_dvma, iommu_translate_dvma, BTFIXUPCALL_NORM);
449 if (viking_mxcc_present || srmmu_modtype == HyperSparc) {
450 dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
451 ioperm_noc = IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID;
453 dvma_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV);
454 ioperm_noc = IOPTE_WRITE | IOPTE_VALID;