/* * 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); } }