1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * io-unit.c: IO-UNIT specific routines for memory management. 4 * 5 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/init.h> 10 #include <linux/slab.h> 11 #include <linux/spinlock.h> 12 #include <linux/mm.h> 13 #include <linux/highmem.h> /* pte_offset_map => kmap_atomic */ 14 #include <linux/bitops.h> 15 #include <linux/dma-mapping.h> 16 #include <linux/of.h> 17 #include <linux/of_device.h> 18 19 #include <asm/pgalloc.h> 20 #include <asm/pgtable.h> 21 #include <asm/io.h> 22 #include <asm/io-unit.h> 23 #include <asm/mxcc.h> 24 #include <asm/cacheflush.h> 25 #include <asm/tlbflush.h> 26 #include <asm/dma.h> 27 #include <asm/oplib.h> 28 29 #include "mm_32.h" 30 31 /* #define IOUNIT_DEBUG */ 32 #ifdef IOUNIT_DEBUG 33 #define IOD(x) printk(x) 34 #else 35 #define IOD(x) do { } while (0) 36 #endif 37 38 #define IOPERM (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID) 39 #define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM) 40 41 static void __init iounit_iommu_init(struct platform_device *op) 42 { 43 struct iounit_struct *iounit; 44 iopte_t __iomem *xpt; 45 iopte_t __iomem *xptend; 46 47 iounit = kzalloc(sizeof(struct iounit_struct), GFP_ATOMIC); 48 if (!iounit) { 49 prom_printf("SUN4D: Cannot alloc iounit, halting.\n"); 50 prom_halt(); 51 } 52 53 iounit->limit[0] = IOUNIT_BMAP1_START; 54 iounit->limit[1] = IOUNIT_BMAP2_START; 55 iounit->limit[2] = IOUNIT_BMAPM_START; 56 iounit->limit[3] = IOUNIT_BMAPM_END; 57 iounit->rotor[1] = IOUNIT_BMAP2_START; 58 iounit->rotor[2] = IOUNIT_BMAPM_START; 59 60 xpt = of_ioremap(&op->resource[2], 0, PAGE_SIZE * 16, "XPT"); 61 if (!xpt) { 62 prom_printf("SUN4D: Cannot map External Page Table."); 63 prom_halt(); 64 } 65 66 op->dev.archdata.iommu = iounit; 67 iounit->page_table = xpt; 68 spin_lock_init(&iounit->lock); 69 70 xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t); 71 for (; xpt < xptend; xpt++) 72 sbus_writel(0, xpt); 73 } 74 75 static int __init iounit_init(void) 76 { 77 extern void sun4d_init_sbi_irq(void); 78 struct device_node *dp; 79 80 for_each_node_by_name(dp, "sbi") { 81 struct platform_device *op = of_find_device_by_node(dp); 82 83 iounit_iommu_init(op); 84 of_propagate_archdata(op); 85 } 86 87 sun4d_init_sbi_irq(); 88 89 return 0; 90 } 91 92 subsys_initcall(iounit_init); 93 94 /* One has to hold iounit->lock to call this */ 95 static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size) 96 { 97 int i, j, k, npages; 98 unsigned long rotor, scan, limit; 99 iopte_t iopte; 100 101 npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT; 102 103 /* A tiny bit of magic ingredience :) */ 104 switch (npages) { 105 case 1: i = 0x0231; break; 106 case 2: i = 0x0132; break; 107 default: i = 0x0213; break; 108 } 109 110 IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages)); 111 112 next: j = (i & 15); 113 rotor = iounit->rotor[j - 1]; 114 limit = iounit->limit[j]; 115 scan = rotor; 116 nexti: scan = find_next_zero_bit(iounit->bmap, limit, scan); 117 if (scan + npages > limit) { 118 if (limit != rotor) { 119 limit = rotor; 120 scan = iounit->limit[j - 1]; 121 goto nexti; 122 } 123 i >>= 4; 124 if (!(i & 15)) 125 panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size); 126 goto next; 127 } 128 for (k = 1, scan++; k < npages; k++) 129 if (test_bit(scan++, iounit->bmap)) 130 goto nexti; 131 iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1]; 132 scan -= npages; 133 iopte = MKIOPTE(__pa(vaddr & PAGE_MASK)); 134 vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK); 135 for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) { 136 set_bit(scan, iounit->bmap); 137 sbus_writel(iopte_val(iopte), &iounit->page_table[scan]); 138 } 139 IOD(("%08lx\n", vaddr)); 140 return vaddr; 141 } 142 143 static dma_addr_t iounit_map_page(struct device *dev, struct page *page, 144 unsigned long offset, size_t len, enum dma_data_direction dir, 145 unsigned long attrs) 146 { 147 void *vaddr = page_address(page) + offset; 148 struct iounit_struct *iounit = dev->archdata.iommu; 149 unsigned long ret, flags; 150 151 /* XXX So what is maxphys for us and how do drivers know it? */ 152 if (!len || len > 256 * 1024) 153 return DMA_MAPPING_ERROR; 154 155 spin_lock_irqsave(&iounit->lock, flags); 156 ret = iounit_get_area(iounit, (unsigned long)vaddr, len); 157 spin_unlock_irqrestore(&iounit->lock, flags); 158 return ret; 159 } 160 161 static int iounit_map_sg(struct device *dev, struct scatterlist *sgl, int nents, 162 enum dma_data_direction dir, unsigned long attrs) 163 { 164 struct iounit_struct *iounit = dev->archdata.iommu; 165 struct scatterlist *sg; 166 unsigned long flags; 167 int i; 168 169 /* FIXME: Cache some resolved pages - often several sg entries are to the same page */ 170 spin_lock_irqsave(&iounit->lock, flags); 171 for_each_sg(sgl, sg, nents, i) { 172 sg->dma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length); 173 sg->dma_length = sg->length; 174 } 175 spin_unlock_irqrestore(&iounit->lock, flags); 176 return nents; 177 } 178 179 static void iounit_unmap_page(struct device *dev, dma_addr_t vaddr, size_t len, 180 enum dma_data_direction dir, unsigned long attrs) 181 { 182 struct iounit_struct *iounit = dev->archdata.iommu; 183 unsigned long flags; 184 185 spin_lock_irqsave(&iounit->lock, flags); 186 len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT; 187 vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT; 188 IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr)); 189 for (len += vaddr; vaddr < len; vaddr++) 190 clear_bit(vaddr, iounit->bmap); 191 spin_unlock_irqrestore(&iounit->lock, flags); 192 } 193 194 static void iounit_unmap_sg(struct device *dev, struct scatterlist *sgl, 195 int nents, enum dma_data_direction dir, unsigned long attrs) 196 { 197 struct iounit_struct *iounit = dev->archdata.iommu; 198 unsigned long flags, vaddr, len; 199 struct scatterlist *sg; 200 int i; 201 202 spin_lock_irqsave(&iounit->lock, flags); 203 for_each_sg(sgl, sg, nents, i) { 204 len = ((sg->dma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT; 205 vaddr = (sg->dma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT; 206 IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr)); 207 for (len += vaddr; vaddr < len; vaddr++) 208 clear_bit(vaddr, iounit->bmap); 209 } 210 spin_unlock_irqrestore(&iounit->lock, flags); 211 } 212 213 #ifdef CONFIG_SBUS 214 static void *iounit_alloc(struct device *dev, size_t len, 215 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) 216 { 217 struct iounit_struct *iounit = dev->archdata.iommu; 218 unsigned long va, addr, page, end, ret; 219 pgprot_t dvma_prot; 220 iopte_t __iomem *iopte; 221 222 /* XXX So what is maxphys for us and how do drivers know it? */ 223 if (!len || len > 256 * 1024) 224 return NULL; 225 226 len = PAGE_ALIGN(len); 227 va = __get_free_pages(gfp | __GFP_ZERO, get_order(len)); 228 if (!va) 229 return NULL; 230 231 addr = ret = sparc_dma_alloc_resource(dev, len); 232 if (!addr) 233 goto out_free_pages; 234 *dma_handle = addr; 235 236 dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV); 237 end = PAGE_ALIGN((addr + len)); 238 while(addr < end) { 239 page = va; 240 { 241 pgd_t *pgdp; 242 p4d_t *p4dp; 243 pud_t *pudp; 244 pmd_t *pmdp; 245 pte_t *ptep; 246 long i; 247 248 pgdp = pgd_offset(&init_mm, addr); 249 p4dp = p4d_offset(pgdp, addr); 250 pudp = pud_offset(p4dp, addr); 251 pmdp = pmd_offset(pudp, addr); 252 ptep = pte_offset_map(pmdp, addr); 253 254 set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot)); 255 256 i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT); 257 258 iopte = iounit->page_table + i; 259 sbus_writel(iopte_val(MKIOPTE(__pa(page))), iopte); 260 } 261 addr += PAGE_SIZE; 262 va += PAGE_SIZE; 263 } 264 flush_cache_all(); 265 flush_tlb_all(); 266 267 return (void *)ret; 268 269 out_free_pages: 270 free_pages(va, get_order(len)); 271 return NULL; 272 } 273 274 static void iounit_free(struct device *dev, size_t size, void *cpu_addr, 275 dma_addr_t dma_addr, unsigned long attrs) 276 { 277 /* XXX Somebody please fill this in */ 278 } 279 #endif 280 281 static const struct dma_map_ops iounit_dma_ops = { 282 #ifdef CONFIG_SBUS 283 .alloc = iounit_alloc, 284 .free = iounit_free, 285 #endif 286 .map_page = iounit_map_page, 287 .unmap_page = iounit_unmap_page, 288 .map_sg = iounit_map_sg, 289 .unmap_sg = iounit_unmap_sg, 290 }; 291 292 void __init ld_mmu_iounit(void) 293 { 294 dma_ops = &iounit_dma_ops; 295 } 296