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io-unit.c

/* $Id: io-unit.c,v 1.24 2001/12/17 07:05:09 davem Exp $
 * io-unit.c:  IO-UNIT specific routines for memory management.
 *
 * Copyright (C) 1997,1998 Jakub Jelinek    (jj@sunsite.mff.cuni.cz)
 */
 
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/highmem.h>    /* pte_offset_map => kmap_atomic */
#include <linux/bitops.h>
#include <linux/scatterlist.h>

#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/sbus.h>
#include <asm/io.h>
#include <asm/io-unit.h>
#include <asm/mxcc.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/dma.h>
#include <asm/oplib.h>

/* #define IOUNIT_DEBUG */
#ifdef IOUNIT_DEBUG
#define IOD(x) printk(x)
#else
#define IOD(x) do { } while (0)
#endif

#define IOPERM        (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID)
#define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM)

void __init
iounit_init(int sbi_node, int io_node, struct sbus_bus *sbus)
{
      iopte_t *xpt, *xptend;
      struct iounit_struct *iounit;
      struct linux_prom_registers iommu_promregs[PROMREG_MAX];
      struct resource r;

      iounit = kzalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
      if (!iounit) {
            prom_printf("SUN4D: Cannot alloc iounit, halting.\n");
            prom_halt();
      }

      iounit->limit[0] = IOUNIT_BMAP1_START;
      iounit->limit[1] = IOUNIT_BMAP2_START;
      iounit->limit[2] = IOUNIT_BMAPM_START;
      iounit->limit[3] = IOUNIT_BMAPM_END;
      iounit->rotor[1] = IOUNIT_BMAP2_START;
      iounit->rotor[2] = IOUNIT_BMAPM_START;

      xpt = NULL;
      if(prom_getproperty(sbi_node, "reg", (void *) iommu_promregs,
                      sizeof(iommu_promregs)) != -1) {
            prom_apply_generic_ranges(io_node, 0, iommu_promregs, 3);
            memset(&r, 0, sizeof(r));
            r.flags = iommu_promregs[2].which_io;
            r.start = iommu_promregs[2].phys_addr;
            xpt = (iopte_t *) sbus_ioremap(&r, 0, PAGE_SIZE * 16, "XPT");
      }
      if(!xpt) panic("Cannot map External Page Table.");
      
      sbus->ofdev.dev.archdata.iommu = iounit;
      iounit->page_table = xpt;
      spin_lock_init(&iounit->lock);
      
      for (xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
           xpt < xptend;)
            iopte_val(*xpt++) = 0;
}

/* One has to hold iounit->lock to call this */
static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size)
{
      int i, j, k, npages;
      unsigned long rotor, scan, limit;
      iopte_t iopte;

        npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT;

      /* A tiny bit of magic ingredience :) */
      switch (npages) {
      case 1: i = 0x0231; break;
      case 2: i = 0x0132; break;
      default: i = 0x0213; break;
      }
      
      IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages));
      
next: j = (i & 15);
      rotor = iounit->rotor[j - 1];
      limit = iounit->limit[j];
      scan = rotor;
nexti:      scan = find_next_zero_bit(iounit->bmap, limit, scan);
      if (scan + npages > limit) {
            if (limit != rotor) {
                  limit = rotor;
                  scan = iounit->limit[j - 1];
                  goto nexti;
            }
            i >>= 4;
            if (!(i & 15))
                  panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size);
            goto next;
      }
      for (k = 1, scan++; k < npages; k++)
            if (test_bit(scan++, iounit->bmap))
                  goto nexti;
      iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
      scan -= npages;
      iopte = MKIOPTE(__pa(vaddr & PAGE_MASK));
      vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK);
      for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
            set_bit(scan, iounit->bmap);
            iounit->page_table[scan] = iopte;
      }
      IOD(("%08lx\n", vaddr));
      return vaddr;
}

static __u32 iounit_get_scsi_one(char *vaddr, unsigned long len, struct sbus_bus *sbus)
{
      unsigned long ret, flags;
      struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;
      
      spin_lock_irqsave(&iounit->lock, flags);
      ret = iounit_get_area(iounit, (unsigned long)vaddr, len);
      spin_unlock_irqrestore(&iounit->lock, flags);
      return ret;
}

static void iounit_get_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
{
      unsigned long flags;
      struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;

      /* FIXME: Cache some resolved pages - often several sg entries are to the same page */
      spin_lock_irqsave(&iounit->lock, flags);
      while (sz != 0) {
            --sz;
            sg->dvma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length);
            sg->dvma_length = sg->length;
            sg = sg_next(sg);
      }
      spin_unlock_irqrestore(&iounit->lock, flags);
}

static void iounit_release_scsi_one(__u32 vaddr, unsigned long len, struct sbus_bus *sbus)
{
      unsigned long flags;
      struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;
      
      spin_lock_irqsave(&iounit->lock, flags);
      len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT;
      vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
      IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
      for (len += vaddr; vaddr < len; vaddr++)
            clear_bit(vaddr, iounit->bmap);
      spin_unlock_irqrestore(&iounit->lock, flags);
}

static void iounit_release_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
{
      unsigned long flags;
      unsigned long vaddr, len;
      struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;

      spin_lock_irqsave(&iounit->lock, flags);
      while (sz != 0) {
            --sz;
            len = ((sg->dvma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
            vaddr = (sg->dvma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
            IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
            for (len += vaddr; vaddr < len; vaddr++)
                  clear_bit(vaddr, iounit->bmap);
            sg = sg_next(sg);
      }
      spin_unlock_irqrestore(&iounit->lock, flags);
}

#ifdef CONFIG_SBUS
static int iounit_map_dma_area(dma_addr_t *pba, unsigned long va, __u32 addr, int len)
{
      unsigned long page, end;
      pgprot_t dvma_prot;
      iopte_t *iopte;
      struct sbus_bus *sbus;

      *pba = addr;

      dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
      end = PAGE_ALIGN((addr + len));
      while(addr < end) {
            page = va;
            {
                  pgd_t *pgdp;
                  pmd_t *pmdp;
                  pte_t *ptep;
                  long i;

                  pgdp = pgd_offset(&init_mm, addr);
                  pmdp = pmd_offset(pgdp, addr);
                  ptep = pte_offset_map(pmdp, addr);

                  set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
                  
                  i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);

                  for_each_sbus(sbus) {
                        struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;

                        iopte = (iopte_t *)(iounit->page_table + i);
                        *iopte = MKIOPTE(__pa(page));
                  }
            }
            addr += PAGE_SIZE;
            va += PAGE_SIZE;
      }
      flush_cache_all();
      flush_tlb_all();

      return 0;
}

static void iounit_unmap_dma_area(unsigned long addr, int len)
{
      /* XXX Somebody please fill this in */
}

/* XXX We do not pass sbus device here, bad. */
static struct page *iounit_translate_dvma(unsigned long addr)
{
      struct sbus_bus *sbus = sbus_root;  /* They are all the same */
      struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;
      int i;
      iopte_t *iopte;

      i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
      iopte = (iopte_t *)(iounit->page_table + i);
      return pfn_to_page(iopte_val(*iopte) >> (PAGE_SHIFT-4)); /* XXX sun4d guru, help */
}
#endif

static char *iounit_lockarea(char *vaddr, unsigned long len)
{
/* FIXME: Write this */
      return vaddr;
}

static void iounit_unlockarea(char *vaddr, unsigned long len)
{
/* FIXME: Write this */
}

void __init ld_mmu_iounit(void)
{
      BTFIXUPSET_CALL(mmu_lockarea, iounit_lockarea, BTFIXUPCALL_RETO0);
      BTFIXUPSET_CALL(mmu_unlockarea, iounit_unlockarea, BTFIXUPCALL_NOP);

      BTFIXUPSET_CALL(mmu_get_scsi_one, iounit_get_scsi_one, BTFIXUPCALL_NORM);
      BTFIXUPSET_CALL(mmu_get_scsi_sgl, iounit_get_scsi_sgl, BTFIXUPCALL_NORM);
      BTFIXUPSET_CALL(mmu_release_scsi_one, iounit_release_scsi_one, BTFIXUPCALL_NORM);
      BTFIXUPSET_CALL(mmu_release_scsi_sgl, iounit_release_scsi_sgl, BTFIXUPCALL_NORM);

#ifdef CONFIG_SBUS
      BTFIXUPSET_CALL(mmu_map_dma_area, iounit_map_dma_area, BTFIXUPCALL_NORM);
      BTFIXUPSET_CALL(mmu_unmap_dma_area, iounit_unmap_dma_area, BTFIXUPCALL_NORM);
      BTFIXUPSET_CALL(mmu_translate_dvma, iounit_translate_dvma, BTFIXUPCALL_NORM);
#endif
}

__u32 iounit_map_dma_init(struct sbus_bus *sbus, int size)
{
      int i, j, k, npages;
      unsigned long rotor, scan, limit;
      unsigned long flags;
      __u32 ret;
      struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;

        npages = (size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
      i = 0x0213;
      spin_lock_irqsave(&iounit->lock, flags);
next: j = (i & 15);
      rotor = iounit->rotor[j - 1];
      limit = iounit->limit[j];
      scan = rotor;
nexti:      scan = find_next_zero_bit(iounit->bmap, limit, scan);
      if (scan + npages > limit) {
            if (limit != rotor) {
                  limit = rotor;
                  scan = iounit->limit[j - 1];
                  goto nexti;
            }
            i >>= 4;
            if (!(i & 15))
                  panic("iounit_map_dma_init: Couldn't find free iopte slots for %d bytes\n", size);
            goto next;
      }
      for (k = 1, scan++; k < npages; k++)
            if (test_bit(scan++, iounit->bmap))
                  goto nexti;
      iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
      scan -= npages;
      ret = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT);
      for (k = 0; k < npages; k++, scan++)
            set_bit(scan, iounit->bmap);
      spin_unlock_irqrestore(&iounit->lock, flags);
      return ret;
}

__u32 iounit_map_dma_page(__u32 vaddr, void *addr, struct sbus_bus *sbus)
{
      int scan = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
      struct iounit_struct *iounit = sbus->ofdev.dev.archdata.iommu;
      
      iounit->page_table[scan] = MKIOPTE(__pa(((unsigned long)addr) & PAGE_MASK));
      return vaddr + (((unsigned long)addr) & ~PAGE_MASK);
}

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