xref: /openbmc/linux/arch/sparc/mm/io-unit.c (revision 1da177e4)
1 /* $Id: io-unit.c,v 1.24 2001/12/17 07:05:09 davem Exp $
2  * io-unit.c:  IO-UNIT specific routines for memory management.
3  *
4  * Copyright (C) 1997,1998 Jakub Jelinek    (jj@sunsite.mff.cuni.cz)
5  */
6 
7 #include <linux/config.h>
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/slab.h>
11 #include <linux/spinlock.h>
12 #include <linux/mm.h>
13 #include <linux/highmem.h>	/* pte_offset_map => kmap_atomic */
14 #include <linux/bitops.h>
15 
16 #include <asm/scatterlist.h>
17 #include <asm/pgalloc.h>
18 #include <asm/pgtable.h>
19 #include <asm/sbus.h>
20 #include <asm/io.h>
21 #include <asm/io-unit.h>
22 #include <asm/mxcc.h>
23 #include <asm/cacheflush.h>
24 #include <asm/tlbflush.h>
25 #include <asm/dma.h>
26 
27 /* #define IOUNIT_DEBUG */
28 #ifdef IOUNIT_DEBUG
29 #define IOD(x) printk(x)
30 #else
31 #define IOD(x) do { } while (0)
32 #endif
33 
34 #define IOPERM        (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID)
35 #define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM)
36 
37 void __init
38 iounit_init(int sbi_node, int io_node, struct sbus_bus *sbus)
39 {
40 	iopte_t *xpt, *xptend;
41 	struct iounit_struct *iounit;
42 	struct linux_prom_registers iommu_promregs[PROMREG_MAX];
43 	struct resource r;
44 
45 	iounit = kmalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
46 
47 	memset(iounit, 0, sizeof(*iounit));
48 	iounit->limit[0] = IOUNIT_BMAP1_START;
49 	iounit->limit[1] = IOUNIT_BMAP2_START;
50 	iounit->limit[2] = IOUNIT_BMAPM_START;
51 	iounit->limit[3] = IOUNIT_BMAPM_END;
52 	iounit->rotor[1] = IOUNIT_BMAP2_START;
53 	iounit->rotor[2] = IOUNIT_BMAPM_START;
54 
55 	xpt = NULL;
56 	if(prom_getproperty(sbi_node, "reg", (void *) iommu_promregs,
57 			    sizeof(iommu_promregs)) != -1) {
58 		prom_apply_generic_ranges(io_node, 0, iommu_promregs, 3);
59 		memset(&r, 0, sizeof(r));
60 		r.flags = iommu_promregs[2].which_io;
61 		r.start = iommu_promregs[2].phys_addr;
62 		xpt = (iopte_t *) sbus_ioremap(&r, 0, PAGE_SIZE * 16, "XPT");
63 	}
64 	if(!xpt) panic("Cannot map External Page Table.");
65 
66 	sbus->iommu = (struct iommu_struct *)iounit;
67 	iounit->page_table = xpt;
68 
69 	for (xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
70 	     xpt < xptend;)
71 	     	iopte_val(*xpt++) = 0;
72 }
73 
74 /* One has to hold iounit->lock to call this */
75 static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size)
76 {
77 	int i, j, k, npages;
78 	unsigned long rotor, scan, limit;
79 	iopte_t iopte;
80 
81         npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
82 
83 	/* A tiny bit of magic ingredience :) */
84 	switch (npages) {
85 	case 1: i = 0x0231; break;
86 	case 2: i = 0x0132; break;
87 	default: i = 0x0213; break;
88 	}
89 
90 	IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages));
91 
92 next:	j = (i & 15);
93 	rotor = iounit->rotor[j - 1];
94 	limit = iounit->limit[j];
95 	scan = rotor;
96 nexti:	scan = find_next_zero_bit(iounit->bmap, limit, scan);
97 	if (scan + npages > limit) {
98 		if (limit != rotor) {
99 			limit = rotor;
100 			scan = iounit->limit[j - 1];
101 			goto nexti;
102 		}
103 		i >>= 4;
104 		if (!(i & 15))
105 			panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size);
106 		goto next;
107 	}
108 	for (k = 1, scan++; k < npages; k++)
109 		if (test_bit(scan++, iounit->bmap))
110 			goto nexti;
111 	iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
112 	scan -= npages;
113 	iopte = MKIOPTE(__pa(vaddr & PAGE_MASK));
114 	vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK);
115 	for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
116 		set_bit(scan, iounit->bmap);
117 		iounit->page_table[scan] = iopte;
118 	}
119 	IOD(("%08lx\n", vaddr));
120 	return vaddr;
121 }
122 
123 static __u32 iounit_get_scsi_one(char *vaddr, unsigned long len, struct sbus_bus *sbus)
124 {
125 	unsigned long ret, flags;
126 	struct iounit_struct *iounit = (struct iounit_struct *)sbus->iommu;
127 
128 	spin_lock_irqsave(&iounit->lock, flags);
129 	ret = iounit_get_area(iounit, (unsigned long)vaddr, len);
130 	spin_unlock_irqrestore(&iounit->lock, flags);
131 	return ret;
132 }
133 
134 static void iounit_get_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
135 {
136 	unsigned long flags;
137 	struct iounit_struct *iounit = (struct iounit_struct *)sbus->iommu;
138 
139 	/* FIXME: Cache some resolved pages - often several sg entries are to the same page */
140 	spin_lock_irqsave(&iounit->lock, flags);
141 	while (sz != 0) {
142 		--sz;
143 		sg[sz].dvma_address = iounit_get_area(iounit, (unsigned long)page_address(sg[sz].page) + sg[sz].offset, sg[sz].length);
144 		sg[sz].dvma_length = sg[sz].length;
145 	}
146 	spin_unlock_irqrestore(&iounit->lock, flags);
147 }
148 
149 static void iounit_release_scsi_one(__u32 vaddr, unsigned long len, struct sbus_bus *sbus)
150 {
151 	unsigned long flags;
152 	struct iounit_struct *iounit = (struct iounit_struct *)sbus->iommu;
153 
154 	spin_lock_irqsave(&iounit->lock, flags);
155 	len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT;
156 	vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
157 	IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
158 	for (len += vaddr; vaddr < len; vaddr++)
159 		clear_bit(vaddr, iounit->bmap);
160 	spin_unlock_irqrestore(&iounit->lock, flags);
161 }
162 
163 static void iounit_release_scsi_sgl(struct scatterlist *sg, int sz, struct sbus_bus *sbus)
164 {
165 	unsigned long flags;
166 	unsigned long vaddr, len;
167 	struct iounit_struct *iounit = (struct iounit_struct *)sbus->iommu;
168 
169 	spin_lock_irqsave(&iounit->lock, flags);
170 	while (sz != 0) {
171 		--sz;
172 		len = ((sg[sz].dvma_address & ~PAGE_MASK) + sg[sz].length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
173 		vaddr = (sg[sz].dvma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
174 		IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
175 		for (len += vaddr; vaddr < len; vaddr++)
176 			clear_bit(vaddr, iounit->bmap);
177 	}
178 	spin_unlock_irqrestore(&iounit->lock, flags);
179 }
180 
181 #ifdef CONFIG_SBUS
182 static int iounit_map_dma_area(dma_addr_t *pba, unsigned long va, __u32 addr, int len)
183 {
184 	unsigned long page, end;
185 	pgprot_t dvma_prot;
186 	iopte_t *iopte;
187 	struct sbus_bus *sbus;
188 
189 	*pba = addr;
190 
191 	dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
192 	end = PAGE_ALIGN((addr + len));
193 	while(addr < end) {
194 		page = va;
195 		{
196 			pgd_t *pgdp;
197 			pmd_t *pmdp;
198 			pte_t *ptep;
199 			long i;
200 
201 			pgdp = pgd_offset(&init_mm, addr);
202 			pmdp = pmd_offset(pgdp, addr);
203 			ptep = pte_offset_map(pmdp, addr);
204 
205 			set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
206 
207 			i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
208 
209 			for_each_sbus(sbus) {
210 				struct iounit_struct *iounit = (struct iounit_struct *)sbus->iommu;
211 
212 				iopte = (iopte_t *)(iounit->page_table + i);
213 				*iopte = MKIOPTE(__pa(page));
214 			}
215 		}
216 		addr += PAGE_SIZE;
217 		va += PAGE_SIZE;
218 	}
219 	flush_cache_all();
220 	flush_tlb_all();
221 
222 	return 0;
223 }
224 
225 static void iounit_unmap_dma_area(unsigned long addr, int len)
226 {
227 	/* XXX Somebody please fill this in */
228 }
229 
230 /* XXX We do not pass sbus device here, bad. */
231 static struct page *iounit_translate_dvma(unsigned long addr)
232 {
233 	struct sbus_bus *sbus = sbus_root;	/* They are all the same */
234 	struct iounit_struct *iounit = (struct iounit_struct *)sbus->iommu;
235 	int i;
236 	iopte_t *iopte;
237 
238 	i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
239 	iopte = (iopte_t *)(iounit->page_table + i);
240 	return pfn_to_page(iopte_val(*iopte) >> (PAGE_SHIFT-4)); /* XXX sun4d guru, help */
241 }
242 #endif
243 
244 static char *iounit_lockarea(char *vaddr, unsigned long len)
245 {
246 /* FIXME: Write this */
247 	return vaddr;
248 }
249 
250 static void iounit_unlockarea(char *vaddr, unsigned long len)
251 {
252 /* FIXME: Write this */
253 }
254 
255 void __init ld_mmu_iounit(void)
256 {
257 	BTFIXUPSET_CALL(mmu_lockarea, iounit_lockarea, BTFIXUPCALL_RETO0);
258 	BTFIXUPSET_CALL(mmu_unlockarea, iounit_unlockarea, BTFIXUPCALL_NOP);
259 
260 	BTFIXUPSET_CALL(mmu_get_scsi_one, iounit_get_scsi_one, BTFIXUPCALL_NORM);
261 	BTFIXUPSET_CALL(mmu_get_scsi_sgl, iounit_get_scsi_sgl, BTFIXUPCALL_NORM);
262 	BTFIXUPSET_CALL(mmu_release_scsi_one, iounit_release_scsi_one, BTFIXUPCALL_NORM);
263 	BTFIXUPSET_CALL(mmu_release_scsi_sgl, iounit_release_scsi_sgl, BTFIXUPCALL_NORM);
264 
265 #ifdef CONFIG_SBUS
266 	BTFIXUPSET_CALL(mmu_map_dma_area, iounit_map_dma_area, BTFIXUPCALL_NORM);
267 	BTFIXUPSET_CALL(mmu_unmap_dma_area, iounit_unmap_dma_area, BTFIXUPCALL_NORM);
268 	BTFIXUPSET_CALL(mmu_translate_dvma, iounit_translate_dvma, BTFIXUPCALL_NORM);
269 #endif
270 }
271 
272 __u32 iounit_map_dma_init(struct sbus_bus *sbus, int size)
273 {
274 	int i, j, k, npages;
275 	unsigned long rotor, scan, limit;
276 	unsigned long flags;
277 	__u32 ret;
278 	struct iounit_struct *iounit = (struct iounit_struct *)sbus->iommu;
279 
280         npages = (size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
281 	i = 0x0213;
282 	spin_lock_irqsave(&iounit->lock, flags);
283 next:	j = (i & 15);
284 	rotor = iounit->rotor[j - 1];
285 	limit = iounit->limit[j];
286 	scan = rotor;
287 nexti:	scan = find_next_zero_bit(iounit->bmap, limit, scan);
288 	if (scan + npages > limit) {
289 		if (limit != rotor) {
290 			limit = rotor;
291 			scan = iounit->limit[j - 1];
292 			goto nexti;
293 		}
294 		i >>= 4;
295 		if (!(i & 15))
296 			panic("iounit_map_dma_init: Couldn't find free iopte slots for %d bytes\n", size);
297 		goto next;
298 	}
299 	for (k = 1, scan++; k < npages; k++)
300 		if (test_bit(scan++, iounit->bmap))
301 			goto nexti;
302 	iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
303 	scan -= npages;
304 	ret = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT);
305 	for (k = 0; k < npages; k++, scan++)
306 		set_bit(scan, iounit->bmap);
307 	spin_unlock_irqrestore(&iounit->lock, flags);
308 	return ret;
309 }
310 
311 __u32 iounit_map_dma_page(__u32 vaddr, void *addr, struct sbus_bus *sbus)
312 {
313 	int scan = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
314 	struct iounit_struct *iounit = (struct iounit_struct *)sbus->iommu;
315 
316 	iounit->page_table[scan] = MKIOPTE(__pa(((unsigned long)addr) & PAGE_MASK));
317 	return vaddr + (((unsigned long)addr) & ~PAGE_MASK);
318 }
319