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