/*
* 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);
}
}
