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