1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * io-unit.c: IO-UNIT specific routines for memory management.
4 *
5 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6 */
7
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/bitops.h>
14 #include <linux/dma-map-ops.h>
15 #include <linux/of.h>
16 #include <linux/of_platform.h>
17 #include <linux/platform_device.h>
18
19 #include <asm/io.h>
20 #include <asm/io-unit.h>
21 #include <asm/mxcc.h>
22 #include <asm/cacheflush.h>
23 #include <asm/tlbflush.h>
24 #include <asm/dma.h>
25 #include <asm/oplib.h>
26
27 #include "mm_32.h"
28
29 /* #define IOUNIT_DEBUG */
30 #ifdef IOUNIT_DEBUG
31 #define IOD(x) printk(x)
32 #else
33 #define IOD(x) do { } while (0)
34 #endif
35
36 #define IOPERM (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID)
37 #define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM)
38
39 static const struct dma_map_ops iounit_dma_ops;
40
iounit_iommu_init(struct platform_device * op)41 static void __init iounit_iommu_init(struct platform_device *op)
42 {
43 struct iounit_struct *iounit;
44 iopte_t __iomem *xpt;
45 iopte_t __iomem *xptend;
46
47 iounit = kzalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
48 if (!iounit) {
49 prom_printf("SUN4D: Cannot alloc iounit, halting.\n");
50 prom_halt();
51 }
52
53 iounit->limit[0] = IOUNIT_BMAP1_START;
54 iounit->limit[1] = IOUNIT_BMAP2_START;
55 iounit->limit[2] = IOUNIT_BMAPM_START;
56 iounit->limit[3] = IOUNIT_BMAPM_END;
57 iounit->rotor[1] = IOUNIT_BMAP2_START;
58 iounit->rotor[2] = IOUNIT_BMAPM_START;
59
60 xpt = of_ioremap(&op->resource[2], 0, PAGE_SIZE * 16, "XPT");
61 if (!xpt) {
62 prom_printf("SUN4D: Cannot map External Page Table.");
63 prom_halt();
64 }
65
66 op->dev.archdata.iommu = iounit;
67 iounit->page_table = xpt;
68 spin_lock_init(&iounit->lock);
69
70 xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
71 for (; xpt < xptend; xpt++)
72 sbus_writel(0, xpt);
73
74 op->dev.dma_ops = &iounit_dma_ops;
75 }
76
iounit_init(void)77 static int __init iounit_init(void)
78 {
79 extern void sun4d_init_sbi_irq(void);
80 struct device_node *dp;
81
82 for_each_node_by_name(dp, "sbi") {
83 struct platform_device *op = of_find_device_by_node(dp);
84
85 iounit_iommu_init(op);
86 of_propagate_archdata(op);
87 }
88
89 sun4d_init_sbi_irq();
90
91 return 0;
92 }
93
94 subsys_initcall(iounit_init);
95
96 /* One has to hold iounit->lock to call this */
iounit_get_area(struct iounit_struct * iounit,phys_addr_t phys,int size)97 static dma_addr_t iounit_get_area(struct iounit_struct *iounit,
98 phys_addr_t phys, int size)
99 {
100 int i, j, k, npages;
101 unsigned long rotor, scan, limit;
102 iopte_t iopte;
103
104 npages = (offset_in_page(phys) + size + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
105
106 /* A tiny bit of magic ingredience :) */
107 switch (npages) {
108 case 1: i = 0x0231; break;
109 case 2: i = 0x0132; break;
110 default: i = 0x0213; break;
111 }
112
113 IOD(("%s(%pa,%d[%d])=", __func__, &phys, size, npages));
114
115 next: j = (i & 15);
116 rotor = iounit->rotor[j - 1];
117 limit = iounit->limit[j];
118 scan = rotor;
119 nexti: scan = find_next_zero_bit(iounit->bmap, limit, scan);
120 if (scan + npages > limit) {
121 if (limit != rotor) {
122 limit = rotor;
123 scan = iounit->limit[j - 1];
124 goto nexti;
125 }
126 i >>= 4;
127 if (!(i & 15))
128 panic("iounit_get_area: Couldn't find free iopte slots for (%pa,%d)\n",
129 &phys, size);
130 goto next;
131 }
132 for (k = 1, scan++; k < npages; k++)
133 if (test_bit(scan++, iounit->bmap))
134 goto nexti;
135 iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
136 scan -= npages;
137 iopte = MKIOPTE(phys & PAGE_MASK);
138 phys = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + offset_in_page(phys);
139 for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
140 set_bit(scan, iounit->bmap);
141 sbus_writel(iopte_val(iopte), &iounit->page_table[scan]);
142 }
143 IOD(("%pa\n", &phys));
144 return phys;
145 }
146
iounit_map_phys(struct device * dev,phys_addr_t phys,size_t len,enum dma_data_direction dir,unsigned long attrs)147 static dma_addr_t iounit_map_phys(struct device *dev, phys_addr_t phys,
148 size_t len, enum dma_data_direction dir, unsigned long attrs)
149 {
150 struct iounit_struct *iounit = dev->archdata.iommu;
151 unsigned long flags;
152 dma_addr_t ret;
153
154 /* XXX So what is maxphys for us and how do drivers know it? */
155 if (!len || len > 256 * 1024)
156 return DMA_MAPPING_ERROR;
157
158 spin_lock_irqsave(&iounit->lock, flags);
159 ret = iounit_get_area(iounit, phys, len);
160 spin_unlock_irqrestore(&iounit->lock, flags);
161 return ret;
162 }
163
iounit_map_sg(struct device * dev,struct scatterlist * sgl,int nents,enum dma_data_direction dir,unsigned long attrs)164 static int iounit_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
165 enum dma_data_direction dir, unsigned long attrs)
166 {
167 struct iounit_struct *iounit = dev->archdata.iommu;
168 struct scatterlist *sg;
169 unsigned long flags;
170 int i;
171
172 /* FIXME: Cache some resolved pages - often several sg entries are to the same page */
173 spin_lock_irqsave(&iounit->lock, flags);
174 for_each_sg(sgl, sg, nents, i) {
175 sg->dma_address =
176 iounit_get_area(iounit, sg_phys(sg), sg->length);
177 sg->dma_length = sg->length;
178 }
179 spin_unlock_irqrestore(&iounit->lock, flags);
180 return nents;
181 }
182
iounit_unmap_phys(struct device * dev,dma_addr_t vaddr,size_t len,enum dma_data_direction dir,unsigned long attrs)183 static void iounit_unmap_phys(struct device *dev, dma_addr_t vaddr, size_t len,
184 enum dma_data_direction dir, unsigned long attrs)
185 {
186 struct iounit_struct *iounit = dev->archdata.iommu;
187 unsigned long flags;
188
189 spin_lock_irqsave(&iounit->lock, flags);
190 len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT;
191 vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
192 IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
193 for (len += vaddr; vaddr < len; vaddr++)
194 clear_bit(vaddr, iounit->bmap);
195 spin_unlock_irqrestore(&iounit->lock, flags);
196 }
197
iounit_unmap_sg(struct device * dev,struct scatterlist * sgl,int nents,enum dma_data_direction dir,unsigned long attrs)198 static void iounit_unmap_sg(struct device *dev, struct scatterlist *sgl,
199 int nents, enum dma_data_direction dir, unsigned long attrs)
200 {
201 struct iounit_struct *iounit = dev->archdata.iommu;
202 unsigned long flags, vaddr, len;
203 struct scatterlist *sg;
204 int i;
205
206 spin_lock_irqsave(&iounit->lock, flags);
207 for_each_sg(sgl, sg, nents, i) {
208 len = ((sg->dma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
209 vaddr = (sg->dma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
210 IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
211 for (len += vaddr; vaddr < len; vaddr++)
212 clear_bit(vaddr, iounit->bmap);
213 }
214 spin_unlock_irqrestore(&iounit->lock, flags);
215 }
216
217 #ifdef CONFIG_SBUS
iounit_alloc(struct device * dev,size_t len,dma_addr_t * dma_handle,gfp_t gfp,unsigned long attrs)218 static void *iounit_alloc(struct device *dev, size_t len,
219 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
220 {
221 struct iounit_struct *iounit = dev->archdata.iommu;
222 unsigned long va, addr, page, end, ret;
223 pgprot_t dvma_prot;
224 iopte_t __iomem *iopte;
225
226 /* XXX So what is maxphys for us and how do drivers know it? */
227 if (!len || len > 256 * 1024)
228 return NULL;
229
230 len = PAGE_ALIGN(len);
231 va = __get_free_pages(gfp | __GFP_ZERO, get_order(len));
232 if (!va)
233 return NULL;
234
235 addr = ret = sparc_dma_alloc_resource(dev, len);
236 if (!addr)
237 goto out_free_pages;
238 *dma_handle = addr;
239
240 dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
241 end = PAGE_ALIGN((addr + len));
242 while(addr < end) {
243 page = va;
244 {
245 pmd_t *pmdp;
246 pte_t *ptep;
247 long i;
248
249 pmdp = pmd_off_k(addr);
250 ptep = pte_offset_kernel(pmdp, addr);
251
252 set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
253
254 i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
255
256 iopte = iounit->page_table + i;
257 sbus_writel(iopte_val(MKIOPTE(__pa(page))), iopte);
258 }
259 addr += PAGE_SIZE;
260 va += PAGE_SIZE;
261 }
262 flush_cache_all();
263 flush_tlb_all();
264
265 return (void *)ret;
266
267 out_free_pages:
268 free_pages(va, get_order(len));
269 return NULL;
270 }
271
iounit_free(struct device * dev,size_t size,void * cpu_addr,dma_addr_t dma_addr,unsigned long attrs)272 static void iounit_free(struct device *dev, size_t size, void *cpu_addr,
273 dma_addr_t dma_addr, unsigned long attrs)
274 {
275 /* XXX Somebody please fill this in */
276 }
277 #endif
278
279 static const struct dma_map_ops iounit_dma_ops = {
280 #ifdef CONFIG_SBUS
281 .alloc = iounit_alloc,
282 .free = iounit_free,
283 #endif
284 .map_phys = iounit_map_phys,
285 .unmap_phys = iounit_unmap_phys,
286 .map_sg = iounit_map_sg,
287 .unmap_sg = iounit_unmap_sg,
288 };
289