arch/sparc/mm/io-unit.c

   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_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 };