xref: /openbmc/linux/arch/m68k/sun3/dvma.c (revision 842ed298)
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/memblock.h>
15 #include <linux/list.h>
16 #include <asm/page.h>
17 #include <asm/sun3mmu.h>
18 #include <asm/dvma.h>
19 
20 
21 static unsigned long ptelist[120];
22 
23 static unsigned long dvma_page(unsigned long kaddr, unsigned long vaddr)
24 {
25 	unsigned long pte;
26 	unsigned long j;
27 	pte_t ptep;
28 
29 	j = *(volatile unsigned long *)kaddr;
30 	*(volatile unsigned long *)kaddr = j;
31 
32 	ptep = pfn_pte(virt_to_pfn(kaddr), PAGE_KERNEL);
33 	pte = pte_val(ptep);
34 //	pr_info("dvma_remap: addr %lx -> %lx pte %08lx\n", kaddr, vaddr, pte);
35 	if(ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] != pte) {
36 		sun3_put_pte(vaddr, pte);
37 		ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] = pte;
38 	}
39 
40 	return (vaddr + (kaddr & ~PAGE_MASK));
41 
42 }
43 
44 int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
45 			      int len)
46 {
47 
48 	unsigned long end;
49 	unsigned long vaddr;
50 
51 	vaddr = dvma_btov(baddr);
52 
53 	end = vaddr + len;
54 
55 	while(vaddr < end) {
56 		dvma_page(kaddr, vaddr);
57 		kaddr += PAGE_SIZE;
58 		vaddr += PAGE_SIZE;
59 	}
60 
61 	return 0;
62 
63 }
64 
65 void __init sun3_dvma_init(void)
66 {
67 	memset(ptelist, 0, sizeof(ptelist));
68 }
69