1/*
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/kernel.h>
8#include <linux/init.h>
9#include <linux/slab.h>
10#include <linux/spinlock.h>
11#include <linux/mm.h>
12#include <linux/highmem.h>	/* pte_offset_map => kmap_atomic */
13#include <linux/bitops.h>
14#include <linux/scatterlist.h>
15#include <linux/of.h>
16#include <linux/of_device.h>
17
18#include <asm/pgalloc.h>
19#include <asm/pgtable.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#include <asm/oplib.h>
27
28#include "mm_32.h"
29
30/* #define IOUNIT_DEBUG */
31#ifdef IOUNIT_DEBUG
32#define IOD(x) printk(x)
33#else
34#define IOD(x) do { } while (0)
35#endif
36
37#define IOPERM        (IOUPTE_CACHE | IOUPTE_WRITE | IOUPTE_VALID)
38#define MKIOPTE(phys) __iopte((((phys)>>4) & IOUPTE_PAGE) | IOPERM)
39
40static void __init iounit_iommu_init(struct platform_device *op)
41{
42	struct iounit_struct *iounit;
43	iopte_t __iomem *xpt;
44	iopte_t __iomem *xptend;
45
46	iounit = kzalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
47	if (!iounit) {
48		prom_printf("SUN4D: Cannot alloc iounit, halting.\n");
49		prom_halt();
50	}
51
52	iounit->limit[0] = IOUNIT_BMAP1_START;
53	iounit->limit[1] = IOUNIT_BMAP2_START;
54	iounit->limit[2] = IOUNIT_BMAPM_START;
55	iounit->limit[3] = IOUNIT_BMAPM_END;
56	iounit->rotor[1] = IOUNIT_BMAP2_START;
57	iounit->rotor[2] = IOUNIT_BMAPM_START;
58
59	xpt = of_ioremap(&op->resource[2], 0, PAGE_SIZE * 16, "XPT");
60	if (!xpt) {
61		prom_printf("SUN4D: Cannot map External Page Table.");
62		prom_halt();
63	}
64
65	op->dev.archdata.iommu = iounit;
66	iounit->page_table = xpt;
67	spin_lock_init(&iounit->lock);
68
69	xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
70	for (; xpt < xptend; xpt++)
71		sbus_writel(0, xpt);
72}
73
74static int __init iounit_init(void)
75{
76	extern void sun4d_init_sbi_irq(void);
77	struct device_node *dp;
78
79	for_each_node_by_name(dp, "sbi") {
80		struct platform_device *op = of_find_device_by_node(dp);
81
82		iounit_iommu_init(op);
83		of_propagate_archdata(op);
84	}
85
86	sun4d_init_sbi_irq();
87
88	return 0;
89}
90
91subsys_initcall(iounit_init);
92
93/* One has to hold iounit->lock to call this */
94static unsigned long iounit_get_area(struct iounit_struct *iounit, unsigned long vaddr, int size)
95{
96	int i, j, k, npages;
97	unsigned long rotor, scan, limit;
98	iopte_t iopte;
99
100        npages = ((vaddr & ~PAGE_MASK) + size + (PAGE_SIZE-1)) >> PAGE_SHIFT;
101
102	/* A tiny bit of magic ingredience :) */
103	switch (npages) {
104	case 1: i = 0x0231; break;
105	case 2: i = 0x0132; break;
106	default: i = 0x0213; break;
107	}
108
109	IOD(("iounit_get_area(%08lx,%d[%d])=", vaddr, size, npages));
110
111next:	j = (i & 15);
112	rotor = iounit->rotor[j - 1];
113	limit = iounit->limit[j];
114	scan = rotor;
115nexti:	scan = find_next_zero_bit(iounit->bmap, limit, scan);
116	if (scan + npages > limit) {
117		if (limit != rotor) {
118			limit = rotor;
119			scan = iounit->limit[j - 1];
120			goto nexti;
121		}
122		i >>= 4;
123		if (!(i & 15))
124			panic("iounit_get_area: Couldn't find free iopte slots for (%08lx,%d)\n", vaddr, size);
125		goto next;
126	}
127	for (k = 1, scan++; k < npages; k++)
128		if (test_bit(scan++, iounit->bmap))
129			goto nexti;
130	iounit->rotor[j - 1] = (scan < limit) ? scan : iounit->limit[j - 1];
131	scan -= npages;
132	iopte = MKIOPTE(__pa(vaddr & PAGE_MASK));
133	vaddr = IOUNIT_DMA_BASE + (scan << PAGE_SHIFT) + (vaddr & ~PAGE_MASK);
134	for (k = 0; k < npages; k++, iopte = __iopte(iopte_val(iopte) + 0x100), scan++) {
135		set_bit(scan, iounit->bmap);
136		sbus_writel(iopte, &iounit->page_table[scan]);
137	}
138	IOD(("%08lx\n", vaddr));
139	return vaddr;
140}
141
142static __u32 iounit_get_scsi_one(struct device *dev, char *vaddr, unsigned long len)
143{
144	struct iounit_struct *iounit = dev->archdata.iommu;
145	unsigned long ret, flags;
146
147	spin_lock_irqsave(&iounit->lock, flags);
148	ret = iounit_get_area(iounit, (unsigned long)vaddr, len);
149	spin_unlock_irqrestore(&iounit->lock, flags);
150	return ret;
151}
152
153static void iounit_get_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
154{
155	struct iounit_struct *iounit = dev->archdata.iommu;
156	unsigned long flags;
157
158	/* FIXME: Cache some resolved pages - often several sg entries are to the same page */
159	spin_lock_irqsave(&iounit->lock, flags);
160	while (sz != 0) {
161		--sz;
162		sg->dma_address = iounit_get_area(iounit, (unsigned long) sg_virt(sg), sg->length);
163		sg->dma_length = sg->length;
164		sg = sg_next(sg);
165	}
166	spin_unlock_irqrestore(&iounit->lock, flags);
167}
168
169static void iounit_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
170{
171	struct iounit_struct *iounit = dev->archdata.iommu;
172	unsigned long flags;
173
174	spin_lock_irqsave(&iounit->lock, flags);
175	len = ((vaddr & ~PAGE_MASK) + len + (PAGE_SIZE-1)) >> PAGE_SHIFT;
176	vaddr = (vaddr - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
177	IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
178	for (len += vaddr; vaddr < len; vaddr++)
179		clear_bit(vaddr, iounit->bmap);
180	spin_unlock_irqrestore(&iounit->lock, flags);
181}
182
183static void iounit_release_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
184{
185	struct iounit_struct *iounit = dev->archdata.iommu;
186	unsigned long flags;
187	unsigned long vaddr, len;
188
189	spin_lock_irqsave(&iounit->lock, flags);
190	while (sz != 0) {
191		--sz;
192		len = ((sg->dma_address & ~PAGE_MASK) + sg->length + (PAGE_SIZE-1)) >> PAGE_SHIFT;
193		vaddr = (sg->dma_address - IOUNIT_DMA_BASE) >> PAGE_SHIFT;
194		IOD(("iounit_release %08lx-%08lx\n", (long)vaddr, (long)len+vaddr));
195		for (len += vaddr; vaddr < len; vaddr++)
196			clear_bit(vaddr, iounit->bmap);
197		sg = sg_next(sg);
198	}
199	spin_unlock_irqrestore(&iounit->lock, flags);
200}
201
202#ifdef CONFIG_SBUS
203static int iounit_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned long va, unsigned long addr, int len)
204{
205	struct iounit_struct *iounit = dev->archdata.iommu;
206	unsigned long page, end;
207	pgprot_t dvma_prot;
208	iopte_t __iomem *iopte;
209
210	*pba = addr;
211
212	dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
213	end = PAGE_ALIGN((addr + len));
214	while(addr < end) {
215		page = va;
216		{
217			pgd_t *pgdp;
218			pmd_t *pmdp;
219			pte_t *ptep;
220			long i;
221
222			pgdp = pgd_offset(&init_mm, addr);
223			pmdp = pmd_offset(pgdp, addr);
224			ptep = pte_offset_map(pmdp, addr);
225
226			set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
227
228			i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
229
230			iopte = iounit->page_table + i;
231			sbus_writel(MKIOPTE(__pa(page)), iopte);
232		}
233		addr += PAGE_SIZE;
234		va += PAGE_SIZE;
235	}
236	flush_cache_all();
237	flush_tlb_all();
238
239	return 0;
240}
241
242static void iounit_unmap_dma_area(struct device *dev, unsigned long addr, int len)
243{
244	/* XXX Somebody please fill this in */
245}
246#endif
247
248static const struct sparc32_dma_ops iounit_dma_ops = {
249	.get_scsi_one		= iounit_get_scsi_one,
250	.get_scsi_sgl		= iounit_get_scsi_sgl,
251	.release_scsi_one	= iounit_release_scsi_one,
252	.release_scsi_sgl	= iounit_release_scsi_sgl,
253#ifdef CONFIG_SBUS
254	.map_dma_area		= iounit_map_dma_area,
255	.unmap_dma_area		= iounit_unmap_dma_area,
256#endif
257};
258
259void __init ld_mmu_iounit(void)
260{
261	sparc32_dma_ops = &iounit_dma_ops;
262}
263