arch/sparc/mm/io-unit.c

   1 /*
   2  * io-unit.c:  IO-UNIT specific routines for memory management.
   3  *
   4  * Copyright (C) 1997,1998 Jakub Jelinek    (jj@sunsite.mff.cuni.cz)
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/init.h>
   9 #include <linux/slab.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/mm.h>
  12 #include <linux/highmem.h>      /* pte_offset_map => kmap_atomic */
  13 #include <linux/bitops.h>
  14 #include <linux/scatterlist.h>
  15 #include <linux/of.h>
  16 #include <linux/of_device.h>
  17
  18 #include <asm/pgalloc.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/io.h>
  21 #include <asm/io-unit.h>
  22 #include <asm/mxcc.h>
  23 #include <asm/cacheflush.h>
  24 #include <asm/tlbflush.h>
  25 #include <asm/dma.h>
  26 #include <asm/oplib.h>
  27
  28 #include "mm_32.h"
  29
  30 /* #define IOUNIT_DEBUG */
  31 #ifdef IOUNIT_DEBUG
  32 #define IOD(x) printk(x)
  33 #else
  34 #define IOD(x) do { } while (0)
  35 #endif
  36
  37 #define IOPERM        (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID)
  38 #define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM)
  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
  74 static int __init iounit_init(void)
  75 {
  76         extern void sun4d_init_sbi_irq(void);
  77         struct device_node *dp;
  78
  79         for_each_node_by_name(dp, "sbi") {
  80                 struct platform_device *op = of_find_device_by_node(dp);
  81
  82                 iounit_iommu_init(op);
  83                 of_propagate_archdata(op);
  84         }
  85
  86         sun4d_init_sbi_irq();
  87
  88         return 0;
  89 }
  90
  91 subsys_initcall(iounit_init);
  92
  93 /* One has to hold iounit->lock to call this */
  94 static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size)
  95 {
  96         int i, j, k, npages;
  97         unsigned long rotor, scan, limit;
  98         iopte_t iopte;
  99
 100         npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
 101
 102         /* A tiny bit of magic ingredience :) */
 103         switch (npages) {
 104         case 1: i = 0x0231; break;
 105         case 2: i = 0x0132; break;
 106         default: i = 0x0213; break;
 107         }
 108
 109         IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages));
 110
 111 next:   j = (i & 15);
 112         rotor = iounit->rotor[j - 1];
 113         limit = iounit->limit[j];
 114         scan = rotor;
 115 nexti:  scan = find_next_zero_bit(iounit->bmap, limit, scan);
 116         if (scan + npages > limit) {
 117                 if (limit != rotor) {
 118                         limit = rotor;
 119                         scan = iounit->limit[j - 1];
 120                         goto nexti;
 121                 }
 122                 i >>= 4;
 123                 if (!(i & 15))
 124                         panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size);
 125                 goto next;
 126         }
 127         for (k = 1, scan++; k < npages; k++)
 128                 if (test_bit(scan++, iounit->bmap))
 129                         goto nexti;
 130         iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
 131         scan -= npages;
 132         iopte = MKIOPTE(__pa(vaddr & PAGE_MASK));
 133         vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK);
 134         for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
 135                 set_bit(scan, iounit->bmap);
 136                 sbus_writel(iopte, &iounit->page_table[scan]);
 137         }
 138         IOD(("%08lx\n", vaddr));
 139         return vaddr;
 140 }
 141
 142 static __u32 iounit_get_scsi_one(struct device *dev, char *vaddr, unsigned long len)
 143 {
 144         struct iounit_struct *iounit = dev->archdata.iommu;
 145         unsigned long ret, flags;
 146
 147         spin_lock_irqsave(&iounit->lock, flags);
 148         ret = iounit_get_area(iounit, (unsigned long)vaddr, len);
 149         spin_unlock_irqrestore(&iounit->lock, flags);
 150         return ret;
 151 }
 152
 153 static void iounit_get_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
 154 {
 155         struct iounit_struct *iounit = dev->archdata.iommu;
 156         unsigned long flags;
 157
 158         /* FIXME: Cache some resolved pages - often several sg entries are to the same page */
 159         spin_lock_irqsave(&iounit->lock, flags);
 160         while (sz != 0) {
 161                 --sz;
 162                 sg->dma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length);
 163                 sg->dma_length = sg->length;
 164                 sg = sg_next(sg);
 165         }
 166         spin_unlock_irqrestore(&iounit->lock, flags);
 167 }
 168
 169 static void iounit_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
 170 {
 171         struct iounit_struct *iounit = dev->archdata.iommu;
 172         unsigned long flags;
 173
 174         spin_lock_irqsave(&iounit->lock, flags);
 175         len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT;
 176         vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
 177         IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
 178         for (len += vaddr; vaddr < len; vaddr++)
 179                 clear_bit(vaddr, iounit->bmap);
 180         spin_unlock_irqrestore(&iounit->lock, flags);
 181 }
 182
 183 static void iounit_release_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
 184 {
 185         struct iounit_struct *iounit = dev->archdata.iommu;
 186         unsigned long flags;
 187         unsigned long vaddr, len;
 188
 189         spin_lock_irqsave(&iounit->lock, flags);
 190         while (sz != 0) {
 191                 --sz;
 192                 len = ((sg->dma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
 193                 vaddr = (sg->dma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
 194                 IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
 195                 for (len += vaddr; vaddr < len; vaddr++)
 196                         clear_bit(vaddr, iounit->bmap);
 197                 sg = sg_next(sg);
 198         }
 199         spin_unlock_irqrestore(&iounit->lock, flags);
 200 }
 201
 202 #ifdef CONFIG_SBUS
 203 static int iounit_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned long va, unsigned long addr, int len)
 204 {
 205         struct iounit_struct *iounit = dev->archdata.iommu;
 206         unsigned long page, end;
 207         pgprot_t dvma_prot;
 208         iopte_t __iomem *iopte;
 209
 210         *pba = addr;
 211
 212         dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
 213         end = PAGE_ALIGN((addr + len));
 214         while(addr < end) {
 215                 page = va;
 216                 {
 217                         pgd_t *pgdp;
 218                         pmd_t *pmdp;
 219                         pte_t *ptep;
 220                         long i;
 221
 222                         pgdp = pgd_offset(&init_mm, addr);
 223                         pmdp = pmd_offset(pgdp, addr);
 224                         ptep = pte_offset_map(pmdp, addr);
 225
 226                         set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
 227
 228                         i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
 229
 230                         iopte = iounit->page_table + i;
 231                         sbus_writel(MKIOPTE(__pa(page)), iopte);
 232                 }
 233                 addr += PAGE_SIZE;
 234                 va += PAGE_SIZE;
 235         }
 236         flush_cache_all();
 237         flush_tlb_all();
 238
 239         return 0;
 240 }
 241
 242 static void iounit_unmap_dma_area(struct device *dev, unsigned long addr, int len)
 243 {
 244         /* XXX Somebody please fill this in */
 245 }
 246 #endif
 247
 248 static const struct sparc32_dma_ops iounit_dma_ops = {
 249         .get_scsi_one           = iounit_get_scsi_one,
 250         .get_scsi_sgl           = iounit_get_scsi_sgl,
 251         .release_scsi_one       = iounit_release_scsi_one,
 252         .release_scsi_sgl       = iounit_release_scsi_sgl,
 253 #ifdef CONFIG_SBUS
 254         .map_dma_area           = iounit_map_dma_area,
 255         .unmap_dma_area         = iounit_unmap_dma_area,
 256 #endif
 257 };
 258
 259 void __init ld_mmu_iounit(void)
 260 {
 261         sparc32_dma_ops = &iounit_dma_ops;
 262 }