Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 * 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);
	}
 
}