Logo Search packages:      
Sourcecode: linux version File versions  Download package

dvma.c

/*
 * Virtual DMA allocation
 *
 * (C) 1999 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
 *
 * 11/26/2000 -- disabled the existing code because it didn't work for
 * me in 2.4.  Replaced with a significantly more primitive version
 * similar to the sun3 code.  the old functionality was probably more
 * desirable, but....   -- Sam Creasey (sammy@oh.verio.com)
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

#include <asm/sun3x.h>
#include <asm/dvma.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>

/* IOMMU support */

#define IOMMU_ADDR_MASK            0x03ffe000
#define IOMMU_CACHE_INHIBIT        0x00000040
#define IOMMU_FULL_BLOCK           0x00000020
#define IOMMU_MODIFIED             0x00000010
#define IOMMU_USED                 0x00000008
#define IOMMU_WRITE_PROTECT        0x00000004
#define IOMMU_DT_MASK              0x00000003
#define IOMMU_DT_INVALID           0x00000000
#define IOMMU_DT_VALID             0x00000001
#define IOMMU_DT_BAD               0x00000002


static volatile unsigned long *iommu_pte = (unsigned long *)SUN3X_IOMMU;


#define dvma_entry_paddr(index)           (iommu_pte[index] & IOMMU_ADDR_MASK)
#define dvma_entry_vaddr(index,paddr)     ((index << DVMA_PAGE_SHIFT) |  \
                               (paddr & (DVMA_PAGE_SIZE-1)))
#if 0
#define dvma_entry_set(index,addr)  (iommu_pte[index] =            \
                                  (addr & IOMMU_ADDR_MASK) | \
                                     IOMMU_DT_VALID | IOMMU_CACHE_INHIBIT)
#else
#define dvma_entry_set(index,addr)  (iommu_pte[index] =            \
                                  (addr & IOMMU_ADDR_MASK) | \
                                     IOMMU_DT_VALID)
#endif
#define dvma_entry_clr(index)       (iommu_pte[index] = IOMMU_DT_INVALID)
#define dvma_entry_hash(addr)       ((addr >> DVMA_PAGE_SHIFT) ^ \
                               ((addr & 0x03c00000) >>     \
                                    (DVMA_PAGE_SHIFT+4)))

#undef DEBUG

#ifdef DEBUG
/* code to print out a dvma mapping for debugging purposes */
void dvma_print (unsigned long dvma_addr)
{

        unsigned long index;

        index = dvma_addr >> DVMA_PAGE_SHIFT;

        printk("idx %lx dvma_addr %08lx paddr %08lx\n", index, dvma_addr,
               dvma_entry_paddr(index));


}
#endif


/* create a virtual mapping for a page assigned within the IOMMU
   so that the cpu can reach it easily */
inline int dvma_map_cpu(unsigned long kaddr,
                         unsigned long vaddr, int len)
{
      pgd_t *pgd;
      unsigned long end;
      int ret = 0;

      kaddr &= PAGE_MASK;
      vaddr &= PAGE_MASK;

      end = PAGE_ALIGN(vaddr + len);

#ifdef DEBUG
      printk("dvma: mapping kern %08lx to virt %08lx\n",
             kaddr, vaddr);
#endif
      pgd = pgd_offset_k(vaddr);

      do {
            pmd_t *pmd;
            unsigned long end2;

            if((pmd = pmd_alloc(&init_mm, pgd, vaddr)) == NULL) {
                  ret = -ENOMEM;
                  goto out;
            }

            if((end & PGDIR_MASK) > (vaddr & PGDIR_MASK))
                  end2 = (vaddr + (PGDIR_SIZE-1)) & PGDIR_MASK;
            else
                  end2 = end;

            do {
                  pte_t *pte;
                  unsigned long end3;

                  if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) {
                        ret = -ENOMEM;
                        goto out;
                  }

                  if((end2 & PMD_MASK) > (vaddr & PMD_MASK))
                        end3 = (vaddr + (PMD_SIZE-1)) & PMD_MASK;
                  else
                        end3 = end2;

                  do {
#ifdef DEBUG
                        printk("mapping %08lx phys to %08lx\n",
                               __pa(kaddr), vaddr);
#endif
                        set_pte(pte, pfn_pte(virt_to_pfn(kaddr),
                                         PAGE_KERNEL));
                        pte++;
                        kaddr += PAGE_SIZE;
                        vaddr += PAGE_SIZE;
                  } while(vaddr < end3);

            } while(vaddr < end2);

      } while(vaddr < end);

      flush_tlb_all();

 out:
      return ret;
}


inline int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
                         int len)
{
      unsigned long end, index;

      index = baddr >> DVMA_PAGE_SHIFT;
      end = ((baddr+len) >> DVMA_PAGE_SHIFT);

      if(len & ~DVMA_PAGE_MASK)
            end++;

      for(; index < end ; index++) {
//          if(dvma_entry_use(index))
//                BUG();
//          printk("mapping pa %lx to ba %lx\n", __pa(kaddr), index << DVMA_PAGE_SHIFT);

            dvma_entry_set(index, __pa(kaddr));

            iommu_pte[index] |= IOMMU_FULL_BLOCK;
//          dvma_entry_inc(index);

            kaddr += DVMA_PAGE_SIZE;
      }

#ifdef DEBUG
      for(index = (baddr >> DVMA_PAGE_SHIFT); index < end; index++)
            dvma_print(index << DVMA_PAGE_SHIFT);
#endif
      return 0;

}

void dvma_unmap_iommu(unsigned long baddr, int len)
{

      int index, end;


      index = baddr >> DVMA_PAGE_SHIFT;
      end = (DVMA_PAGE_ALIGN(baddr+len) >> DVMA_PAGE_SHIFT);

      for(; index < end ; index++) {
#ifdef DEBUG
            printk("freeing bus mapping %08x\n", index << DVMA_PAGE_SHIFT);
#endif
#if 0
            if(!dvma_entry_use(index))
                  printk("dvma_unmap freeing unused entry %04x\n",
                         index);
            else
                  dvma_entry_dec(index);
#endif
            dvma_entry_clr(index);
      }

}


Generated by  Doxygen 1.6.0   Back to index