xref: /openbmc/linux/arch/m68k/sun3/dvma.c (revision feac8c8b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/arch/m68k/sun3/dvma.c
4  *
5  * Written by Sam Creasey
6  *
7  * Sun3 IOMMU routines used for dvma accesses.
8  *
9  */
10 
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/bootmem.h>
15 #include <linux/list.h>
16 #include <asm/page.h>
17 #include <asm/pgtable.h>
18 #include <asm/sun3mmu.h>
19 #include <asm/dvma.h>
20 
21 
22 static unsigned long ptelist[120];
23 
24 static unsigned long dvma_page(unsigned long kaddr, unsigned long vaddr)
25 {
26 	unsigned long pte;
27 	unsigned long j;
28 	pte_t ptep;
29 
30 	j = *(volatile unsigned long *)kaddr;
31 	*(volatile unsigned long *)kaddr = j;
32 
33 	ptep = pfn_pte(virt_to_pfn(kaddr), PAGE_KERNEL);
34 	pte = pte_val(ptep);
35 //	pr_info("dvma_remap: addr %lx -> %lx pte %08lx\n", kaddr, vaddr, pte);
36 	if(ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] != pte) {
37 		sun3_put_pte(vaddr, pte);
38 		ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] = pte;
39 	}
40 
41 	return (vaddr + (kaddr & ~PAGE_MASK));
42 
43 }
44 
45 int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
46 			      int len)
47 {
48 
49 	unsigned long end;
50 	unsigned long vaddr;
51 
52 	vaddr = dvma_btov(baddr);
53 
54 	end = vaddr + len;
55 
56 	while(vaddr < end) {
57 		dvma_page(kaddr, vaddr);
58 		kaddr += PAGE_SIZE;
59 		vaddr += PAGE_SIZE;
60 	}
61 
62 	return 0;
63 
64 }
65 
66 void __init sun3_dvma_init(void)
67 {
68 	memset(ptelist, 0, sizeof(ptelist));
69 }
70