diff options
Diffstat (limited to 'arch/m68k/sun3x/dvma.c')
| -rw-r--r-- | arch/m68k/sun3x/dvma.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/arch/m68k/sun3x/dvma.c b/arch/m68k/sun3x/dvma.c new file mode 100644 index 000000000..08bb92113 --- /dev/null +++ b/arch/m68k/sun3x/dvma.c @@ -0,0 +1,201 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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/memblock.h> +#include <linux/vmalloc.h> + +#include <asm/sun3x.h> +#include <asm/dvma.h> +#include <asm/io.h> +#include <asm/page.h> +#include <asm/tlbflush.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))) + +#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; + + pr_info("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; + p4d_t *p4d; + pud_t *pud; + unsigned long end; + int ret = 0; + + kaddr &= PAGE_MASK; + vaddr &= PAGE_MASK; + + end = PAGE_ALIGN(vaddr + len); + + pr_debug("dvma: mapping kern %08lx to virt %08lx\n", kaddr, vaddr); + pgd = pgd_offset_k(vaddr); + p4d = p4d_offset(pgd, vaddr); + pud = pud_offset(p4d, vaddr); + + do { + pmd_t *pmd; + unsigned long end2; + + if((pmd = pmd_alloc(&init_mm, pud, 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 { + pr_debug("mapping %08lx phys to %08lx\n", + __pa(kaddr), vaddr); + 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(); +// pr_info("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++) { + pr_debug("freeing bus mapping %08x\n", + index << DVMA_PAGE_SHIFT); +#if 0 + if(!dvma_entry_use(index)) + pr_info("dvma_unmap freeing unused entry %04x\n", + index); + else + dvma_entry_dec(index); +#endif + dvma_entry_clr(index); + } + +} |