1 // SPDX-License-Identifier: GPL-2.0
3 * Virtual DMA allocation
5 * (C) 1999 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
7 * 11/26/2000 -- disabled the existing code because it didn't work for
8 * me in 2.4. Replaced with a significantly more primitive version
9 * similar to the sun3 code. the old functionality was probably more
10 * desirable, but.... -- Sam Creasey (sammy@oh.verio.com)
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/bitops.h>
18 #include <linux/bootmem.h>
19 #include <linux/vmalloc.h>
21 #include <asm/sun3x.h>
25 #include <asm/pgtable.h>
26 #include <asm/pgalloc.h>
30 #define IOMMU_ADDR_MASK 0x03ffe000
31 #define IOMMU_CACHE_INHIBIT 0x00000040
32 #define IOMMU_FULL_BLOCK 0x00000020
33 #define IOMMU_MODIFIED 0x00000010
34 #define IOMMU_USED 0x00000008
35 #define IOMMU_WRITE_PROTECT 0x00000004
36 #define IOMMU_DT_MASK 0x00000003
37 #define IOMMU_DT_INVALID 0x00000000
38 #define IOMMU_DT_VALID 0x00000001
39 #define IOMMU_DT_BAD 0x00000002
42 static volatile unsigned long *iommu_pte = (unsigned long *)SUN3X_IOMMU;
45 #define dvma_entry_paddr(index) (iommu_pte[index] & IOMMU_ADDR_MASK)
46 #define dvma_entry_vaddr(index,paddr) ((index << DVMA_PAGE_SHIFT) | \
47 (paddr & (DVMA_PAGE_SIZE-1)))
49 #define dvma_entry_set(index,addr) (iommu_pte[index] = \
50 (addr & IOMMU_ADDR_MASK) | \
51 IOMMU_DT_VALID | IOMMU_CACHE_INHIBIT)
53 #define dvma_entry_set(index,addr) (iommu_pte[index] = \
54 (addr & IOMMU_ADDR_MASK) | \
57 #define dvma_entry_clr(index) (iommu_pte[index] = IOMMU_DT_INVALID)
58 #define dvma_entry_hash(addr) ((addr >> DVMA_PAGE_SHIFT) ^ \
59 ((addr & 0x03c00000) >> \
63 /* code to print out a dvma mapping for debugging purposes */
64 void dvma_print (unsigned long dvma_addr)
69 index = dvma_addr >> DVMA_PAGE_SHIFT;
71 pr_info("idx %lx dvma_addr %08lx paddr %08lx\n", index, dvma_addr,
72 dvma_entry_paddr(index));
77 /* create a virtual mapping for a page assigned within the IOMMU
78 so that the cpu can reach it easily */
79 inline int dvma_map_cpu(unsigned long kaddr,
80 unsigned long vaddr, int len)
89 end = PAGE_ALIGN(vaddr + len);
91 pr_debug("dvma: mapping kern %08lx to virt %08lx\n", kaddr, vaddr);
92 pgd = pgd_offset_k(vaddr);
98 if((pmd = pmd_alloc(&init_mm, pgd, vaddr)) == NULL) {
103 if((end & PGDIR_MASK) > (vaddr & PGDIR_MASK))
104 end2 = (vaddr + (PGDIR_SIZE-1)) & PGDIR_MASK;
112 if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) {
117 if((end2 & PMD_MASK) > (vaddr & PMD_MASK))
118 end3 = (vaddr + (PMD_SIZE-1)) & PMD_MASK;
123 pr_debug("mapping %08lx phys to %08lx\n",
125 set_pte(pte, pfn_pte(virt_to_pfn(kaddr),
130 } while(vaddr < end3);
132 } while(vaddr < end2);
134 } while(vaddr < end);
143 inline int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
146 unsigned long end, index;
148 index = baddr >> DVMA_PAGE_SHIFT;
149 end = ((baddr+len) >> DVMA_PAGE_SHIFT);
151 if(len & ~DVMA_PAGE_MASK)
154 for(; index < end ; index++) {
155 // if(dvma_entry_use(index))
157 // pr_info("mapping pa %lx to ba %lx\n", __pa(kaddr),
158 // index << DVMA_PAGE_SHIFT);
160 dvma_entry_set(index, __pa(kaddr));
162 iommu_pte[index] |= IOMMU_FULL_BLOCK;
163 // dvma_entry_inc(index);
165 kaddr += DVMA_PAGE_SIZE;
169 for(index = (baddr >> DVMA_PAGE_SHIFT); index < end; index++)
170 dvma_print(index << DVMA_PAGE_SHIFT);
176 void dvma_unmap_iommu(unsigned long baddr, int len)
182 index = baddr >> DVMA_PAGE_SHIFT;
183 end = (DVMA_PAGE_ALIGN(baddr+len) >> DVMA_PAGE_SHIFT);
185 for(; index < end ; index++) {
186 pr_debug("freeing bus mapping %08x\n",
187 index << DVMA_PAGE_SHIFT);
189 if(!dvma_entry_use(index))
190 pr_info("dvma_unmap freeing unused entry %04x\n",
193 dvma_entry_dec(index);
195 dvma_entry_clr(index);