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-map-ops.h> 15 #include <linux/of.h> 16 #include <linux/of_platform.h> 17 #include <linux/platform_device.h> 18 19 #include <asm/io.h> 20 #include <asm/io-unit.h> 21 #include <asm/mxcc.h> 22 #include <asm/cacheflush.h> 23 #include <asm/tlbflush.h> 24 #include <asm/dma.h> 25 #include <asm/oplib.h> 26 27 #include "mm_32.h" 28 29 /* #define IOUNIT_DEBUG */ 30 #ifdef IOUNIT_DEBUG 31 #define IOD(x) printk(x) 32 #else 33 #define IOD(x) do { } while (0) 34 #endif 35 36 #define IOPERM (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID) 37 #define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM) 38 39 static const struct dma_map_ops iounit_dma_ops; 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 op->dev.dma_ops = &iounit_dma_ops; 75 } 76 77 static int __init iounit_init(void) 78 { 79 extern void sun4d_init_sbi_irq(void); 80 struct device_node *dp; 81 82 for_each_node_by_name(dp, "sbi") { 83 struct platform_device *op = of_find_device_by_node(dp); 84 85 iounit_iommu_init(op); 86 of_propagate_archdata(op); 87 } 88 89 sun4d_init_sbi_irq(); 90 91 return 0; 92 } 93 94 subsys_initcall(iounit_init); 95 96 /* One has to hold iounit->lock to call this */ 97 static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size) 98 { 99 int i, j, k, npages; 100 unsigned long rotor, scan, limit; 101 iopte_t iopte; 102 103 npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT; 104 105 /* A tiny bit of magic ingredience :) */ 106 switch (npages) { 107 case 1: i = 0x0231; break; 108 case 2: i = 0x0132; break; 109 default: i = 0x0213; break; 110 } 111 112 IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages)); 113 114 next: j = (i & 15); 115 rotor = iounit->rotor[j - 1]; 116 limit = iounit->limit[j]; 117 scan = rotor; 118 nexti: scan = find_next_zero_bit(iounit->bmap, limit, scan); 119 if (scan + npages > limit) { 120 if (limit != rotor) { 121 limit = rotor; 122 scan = iounit->limit[j - 1]; 123 goto nexti; 124 } 125 i >>= 4; 126 if (!(i & 15)) 127 panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size); 128 goto next; 129 } 130 for (k = 1, scan++; k < npages; k++) 131 if (test_bit(scan++, iounit->bmap)) 132 goto nexti; 133 iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1]; 134 scan -= npages; 135 iopte = MKIOPTE(__pa(vaddr & PAGE_MASK)); 136 vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK); 137 for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) { 138 set_bit(scan, iounit->bmap); 139 sbus_writel(iopte_val(iopte), &iounit->page_table[scan]); 140 } 141 IOD(("%08lx\n", vaddr)); 142 return vaddr; 143 } 144 145 static dma_addr_t iounit_map_page(struct device *dev, struct page *page, 146 unsigned long offset, size_t len, enum dma_data_direction dir, 147 unsigned long attrs) 148 { 149 void *vaddr = page_address(page) + offset; 150 struct iounit_struct *iounit = dev->archdata.iommu; 151 unsigned long ret, flags; 152 153 /* XXX So what is maxphys for us and how do drivers know it? */ 154 if (!len || len > 256 * 1024) 155 return DMA_MAPPING_ERROR; 156 157 spin_lock_irqsave(&iounit->lock, flags); 158 ret = iounit_get_area(iounit, (unsigned long)vaddr, len); 159 spin_unlock_irqrestore(&iounit->lock, flags); 160 return ret; 161 } 162 163 static int iounit_map_sg(struct device *dev, struct scatterlist *sgl, int nents, 164 enum dma_data_direction dir, unsigned long attrs) 165 { 166 struct iounit_struct *iounit = dev->archdata.iommu; 167 struct scatterlist *sg; 168 unsigned long flags; 169 int i; 170 171 /* FIXME: Cache some resolved pages - often several sg entries are to the same page */ 172 spin_lock_irqsave(&iounit->lock, flags); 173 for_each_sg(sgl, sg, nents, i) { 174 sg->dma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length); 175 sg->dma_length = sg->length; 176 } 177 spin_unlock_irqrestore(&iounit->lock, flags); 178 return nents; 179 } 180 181 static void iounit_unmap_page(struct device *dev, dma_addr_t vaddr, size_t len, 182 enum dma_data_direction dir, unsigned long attrs) 183 { 184 struct iounit_struct *iounit = dev->archdata.iommu; 185 unsigned long flags; 186 187 spin_lock_irqsave(&iounit->lock, flags); 188 len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT; 189 vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT; 190 IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr)); 191 for (len += vaddr; vaddr < len; vaddr++) 192 clear_bit(vaddr, iounit->bmap); 193 spin_unlock_irqrestore(&iounit->lock, flags); 194 } 195 196 static void iounit_unmap_sg(struct device *dev, struct scatterlist *sgl, 197 int nents, enum dma_data_direction dir, unsigned long attrs) 198 { 199 struct iounit_struct *iounit = dev->archdata.iommu; 200 unsigned long flags, vaddr, len; 201 struct scatterlist *sg; 202 int i; 203 204 spin_lock_irqsave(&iounit->lock, flags); 205 for_each_sg(sgl, sg, nents, i) { 206 len = ((sg->dma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT; 207 vaddr = (sg->dma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT; 208 IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr)); 209 for (len += vaddr; vaddr < len; vaddr++) 210 clear_bit(vaddr, iounit->bmap); 211 } 212 spin_unlock_irqrestore(&iounit->lock, flags); 213 } 214 215 #ifdef CONFIG_SBUS 216 static void *iounit_alloc(struct device *dev, size_t len, 217 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) 218 { 219 struct iounit_struct *iounit = dev->archdata.iommu; 220 unsigned long va, addr, page, end, ret; 221 pgprot_t dvma_prot; 222 iopte_t __iomem *iopte; 223 224 /* XXX So what is maxphys for us and how do drivers know it? */ 225 if (!len || len > 256 * 1024) 226 return NULL; 227 228 len = PAGE_ALIGN(len); 229 va = __get_free_pages(gfp | __GFP_ZERO, get_order(len)); 230 if (!va) 231 return NULL; 232 233 addr = ret = sparc_dma_alloc_resource(dev, len); 234 if (!addr) 235 goto out_free_pages; 236 *dma_handle = addr; 237 238 dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV); 239 end = PAGE_ALIGN((addr + len)); 240 while(addr < end) { 241 page = va; 242 { 243 pmd_t *pmdp; 244 pte_t *ptep; 245 long i; 246 247 pmdp = pmd_off_k(addr); 248 ptep = pte_offset_kernel(pmdp, addr); 249 250 set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot)); 251 252 i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT); 253 254 iopte = iounit->page_table + i; 255 sbus_writel(iopte_val(MKIOPTE(__pa(page))), iopte); 256 } 257 addr += PAGE_SIZE; 258 va += PAGE_SIZE; 259 } 260 flush_cache_all(); 261 flush_tlb_all(); 262 263 return (void *)ret; 264 265 out_free_pages: 266 free_pages(va, get_order(len)); 267 return NULL; 268 } 269 270 static void iounit_free(struct device *dev, size_t size, void *cpu_addr, 271 dma_addr_t dma_addr, unsigned long attrs) 272 { 273 /* XXX Somebody please fill this in */ 274 } 275 #endif 276 277 static const struct dma_map_ops iounit_dma_ops = { 278 #ifdef CONFIG_SBUS 279 .alloc = iounit_alloc, 280 .free = iounit_free, 281 #endif 282 .map_page = iounit_map_page, 283 .unmap_page = iounit_unmap_page, 284 .map_sg = iounit_map_sg, 285 .unmap_sg = iounit_unmap_sg, 286 }; 287