xref: /openbmc/linux/arch/sparc/mm/leon_mm.c (revision aac28965)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/arch/sparc/mm/leon_m.c
4  *
5  * Copyright (C) 2004 Konrad Eisele (eiselekd@web.de, konrad@gaisler.com) Gaisler Research
6  * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
7  * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
8  *
9  * do srmmu probe in software
10  *
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <asm/asi.h>
16 #include <asm/leon.h>
17 #include <asm/tlbflush.h>
18 
19 #include "mm_32.h"
20 
21 int leon_flush_during_switch = 1;
22 static int srmmu_swprobe_trace;
23 
24 static inline unsigned long leon_get_ctable_ptr(void)
25 {
26 	unsigned int retval;
27 
28 	__asm__ __volatile__("lda [%1] %2, %0\n\t" :
29 			     "=r" (retval) :
30 			     "r" (SRMMU_CTXTBL_PTR),
31 			     "i" (ASI_LEON_MMUREGS));
32 	return (retval & SRMMU_CTX_PMASK) << 4;
33 }
34 
35 
36 unsigned long leon_swprobe(unsigned long vaddr, unsigned long *paddr)
37 {
38 
39 	unsigned int ctxtbl;
40 	unsigned int pgd, pmd, ped;
41 	unsigned int ptr;
42 	unsigned int lvl, pte, paddrbase;
43 	unsigned int ctx;
44 	unsigned int paddr_calc;
45 
46 	paddrbase = 0;
47 
48 	if (srmmu_swprobe_trace)
49 		printk(KERN_INFO "swprobe: trace on\n");
50 
51 	ctxtbl = leon_get_ctable_ptr();
52 	if (!(ctxtbl)) {
53 		if (srmmu_swprobe_trace)
54 			printk(KERN_INFO "swprobe: leon_get_ctable_ptr returned 0=>0\n");
55 		return 0;
56 	}
57 	if (!_pfn_valid(PFN(ctxtbl))) {
58 		if (srmmu_swprobe_trace)
59 			printk(KERN_INFO
60 			       "swprobe: !_pfn_valid(%x)=>0\n",
61 			       PFN(ctxtbl));
62 		return 0;
63 	}
64 
65 	ctx = srmmu_get_context();
66 	if (srmmu_swprobe_trace)
67 		printk(KERN_INFO "swprobe:  --- ctx (%x) ---\n", ctx);
68 
69 	pgd = LEON_BYPASS_LOAD_PA(ctxtbl + (ctx * 4));
70 
71 	if (((pgd & SRMMU_ET_MASK) == SRMMU_ET_PTE)) {
72 		if (srmmu_swprobe_trace)
73 			printk(KERN_INFO "swprobe: pgd is entry level 3\n");
74 		lvl = 3;
75 		pte = pgd;
76 		paddrbase = pgd & _SRMMU_PTE_PMASK_LEON;
77 		goto ready;
78 	}
79 	if (((pgd & SRMMU_ET_MASK) != SRMMU_ET_PTD)) {
80 		if (srmmu_swprobe_trace)
81 			printk(KERN_INFO "swprobe: pgd is invalid => 0\n");
82 		return 0;
83 	}
84 
85 	if (srmmu_swprobe_trace)
86 		printk(KERN_INFO "swprobe:  --- pgd (%x) ---\n", pgd);
87 
88 	ptr = (pgd & SRMMU_PTD_PMASK) << 4;
89 	ptr += ((((vaddr) >> LEON_PGD_SH) & LEON_PGD_M) * 4);
90 	if (!_pfn_valid(PFN(ptr)))
91 		return 0;
92 
93 	pmd = LEON_BYPASS_LOAD_PA(ptr);
94 	if (((pmd & SRMMU_ET_MASK) == SRMMU_ET_PTE)) {
95 		if (srmmu_swprobe_trace)
96 			printk(KERN_INFO "swprobe: pmd is entry level 2\n");
97 		lvl = 2;
98 		pte = pmd;
99 		paddrbase = pmd & _SRMMU_PTE_PMASK_LEON;
100 		goto ready;
101 	}
102 	if (((pmd & SRMMU_ET_MASK) != SRMMU_ET_PTD)) {
103 		if (srmmu_swprobe_trace)
104 			printk(KERN_INFO "swprobe: pmd is invalid => 0\n");
105 		return 0;
106 	}
107 
108 	if (srmmu_swprobe_trace)
109 		printk(KERN_INFO "swprobe:  --- pmd (%x) ---\n", pmd);
110 
111 	ptr = (pmd & SRMMU_PTD_PMASK) << 4;
112 	ptr += (((vaddr >> LEON_PMD_SH) & LEON_PMD_M) * 4);
113 	if (!_pfn_valid(PFN(ptr))) {
114 		if (srmmu_swprobe_trace)
115 			printk(KERN_INFO "swprobe: !_pfn_valid(%x)=>0\n",
116 			       PFN(ptr));
117 		return 0;
118 	}
119 
120 	ped = LEON_BYPASS_LOAD_PA(ptr);
121 
122 	if (((ped & SRMMU_ET_MASK) == SRMMU_ET_PTE)) {
123 		if (srmmu_swprobe_trace)
124 			printk(KERN_INFO "swprobe: ped is entry level 1\n");
125 		lvl = 1;
126 		pte = ped;
127 		paddrbase = ped & _SRMMU_PTE_PMASK_LEON;
128 		goto ready;
129 	}
130 	if (((ped & SRMMU_ET_MASK) != SRMMU_ET_PTD)) {
131 		if (srmmu_swprobe_trace)
132 			printk(KERN_INFO "swprobe: ped is invalid => 0\n");
133 		return 0;
134 	}
135 
136 	if (srmmu_swprobe_trace)
137 		printk(KERN_INFO "swprobe:  --- ped (%x) ---\n", ped);
138 
139 	ptr = (ped & SRMMU_PTD_PMASK) << 4;
140 	ptr += (((vaddr >> LEON_PTE_SH) & LEON_PTE_M) * 4);
141 	if (!_pfn_valid(PFN(ptr)))
142 		return 0;
143 
144 	ptr = LEON_BYPASS_LOAD_PA(ptr);
145 	if (((ptr & SRMMU_ET_MASK) == SRMMU_ET_PTE)) {
146 		if (srmmu_swprobe_trace)
147 			printk(KERN_INFO "swprobe: ptr is entry level 0\n");
148 		lvl = 0;
149 		pte = ptr;
150 		paddrbase = ptr & _SRMMU_PTE_PMASK_LEON;
151 		goto ready;
152 	}
153 	if (srmmu_swprobe_trace)
154 		printk(KERN_INFO "swprobe: ptr is invalid => 0\n");
155 	return 0;
156 
157 ready:
158 	switch (lvl) {
159 	case 0:
160 		paddr_calc =
161 		    (vaddr & ~(-1 << LEON_PTE_SH)) | ((pte & ~0xff) << 4);
162 		break;
163 	case 1:
164 		paddr_calc =
165 		    (vaddr & ~(-1 << LEON_PMD_SH)) | ((pte & ~0xff) << 4);
166 		break;
167 	case 2:
168 		paddr_calc =
169 		    (vaddr & ~(-1 << LEON_PGD_SH)) | ((pte & ~0xff) << 4);
170 		break;
171 	default:
172 	case 3:
173 		paddr_calc = vaddr;
174 		break;
175 	}
176 	if (srmmu_swprobe_trace)
177 		printk(KERN_INFO "swprobe: padde %x\n", paddr_calc);
178 	if (paddr)
179 		*paddr = paddr_calc;
180 	return pte;
181 }
182 
183 void leon_flush_icache_all(void)
184 {
185 	__asm__ __volatile__(" flush ");	/*iflush*/
186 }
187 
188 void leon_flush_dcache_all(void)
189 {
190 	__asm__ __volatile__("sta %%g0, [%%g0] %0\n\t" : :
191 			     "i"(ASI_LEON_DFLUSH) : "memory");
192 }
193 
194 void leon_flush_pcache_all(struct vm_area_struct *vma, unsigned long page)
195 {
196 	if (vma->vm_flags & VM_EXEC)
197 		leon_flush_icache_all();
198 	leon_flush_dcache_all();
199 }
200 
201 void leon_flush_cache_all(void)
202 {
203 	__asm__ __volatile__(" flush ");	/*iflush*/
204 	__asm__ __volatile__("sta %%g0, [%%g0] %0\n\t" : :
205 			     "i"(ASI_LEON_DFLUSH) : "memory");
206 }
207 
208 void leon_flush_tlb_all(void)
209 {
210 	leon_flush_cache_all();
211 	__asm__ __volatile__("sta %%g0, [%0] %1\n\t" : : "r"(0x400),
212 			     "i"(ASI_LEON_MMUFLUSH) : "memory");
213 }
214 
215 /* get all cache regs */
216 void leon3_getCacheRegs(struct leon3_cacheregs *regs)
217 {
218 	unsigned long ccr, iccr, dccr;
219 
220 	if (!regs)
221 		return;
222 	/* Get Cache regs from "Cache ASI" address 0x0, 0x8 and 0xC */
223 	__asm__ __volatile__("lda [%%g0] %3, %0\n\t"
224 			     "mov 0x08, %%g1\n\t"
225 			     "lda [%%g1] %3, %1\n\t"
226 			     "mov 0x0c, %%g1\n\t"
227 			     "lda [%%g1] %3, %2\n\t"
228 			     : "=r"(ccr), "=r"(iccr), "=r"(dccr)
229 			       /* output */
230 			     : "i"(ASI_LEON_CACHEREGS)	/* input */
231 			     : "g1"	/* clobber list */
232 	    );
233 	regs->ccr = ccr;
234 	regs->iccr = iccr;
235 	regs->dccr = dccr;
236 }
237 
238 /* Due to virtual cache we need to check cache configuration if
239  * it is possible to skip flushing in some cases.
240  *
241  * Leon2 and Leon3 differ in their way of telling cache information
242  *
243  */
244 int __init leon_flush_needed(void)
245 {
246 	int flush_needed = -1;
247 	unsigned int ssize, sets;
248 	char *setStr[4] =
249 	    { "direct mapped", "2-way associative", "3-way associative",
250 		"4-way associative"
251 	};
252 	/* leon 3 */
253 	struct leon3_cacheregs cregs;
254 	leon3_getCacheRegs(&cregs);
255 	sets = (cregs.dccr & LEON3_XCCR_SETS_MASK) >> 24;
256 	/* (ssize=>realsize) 0=>1k, 1=>2k, 2=>4k, 3=>8k ... */
257 	ssize = 1 << ((cregs.dccr & LEON3_XCCR_SSIZE_MASK) >> 20);
258 
259 	printk(KERN_INFO "CACHE: %s cache, set size %dk\n",
260 	       sets > 3 ? "unknown" : setStr[sets], ssize);
261 	if ((ssize <= (PAGE_SIZE / 1024)) && (sets == 0)) {
262 		/* Set Size <= Page size  ==>
263 		   flush on every context switch not needed. */
264 		flush_needed = 0;
265 		printk(KERN_INFO "CACHE: not flushing on every context switch\n");
266 	}
267 	return flush_needed;
268 }
269 
270 void leon_switch_mm(void)
271 {
272 	flush_tlb_mm((void *)0);
273 	if (leon_flush_during_switch)
274 		leon_flush_cache_all();
275 }
276 
277 static void leon_flush_cache_mm(struct mm_struct *mm)
278 {
279 	leon_flush_cache_all();
280 }
281 
282 static void leon_flush_cache_page(struct vm_area_struct *vma, unsigned long page)
283 {
284 	leon_flush_pcache_all(vma, page);
285 }
286 
287 static void leon_flush_cache_range(struct vm_area_struct *vma,
288 				   unsigned long start,
289 				   unsigned long end)
290 {
291 	leon_flush_cache_all();
292 }
293 
294 static void leon_flush_tlb_mm(struct mm_struct *mm)
295 {
296 	leon_flush_tlb_all();
297 }
298 
299 static void leon_flush_tlb_page(struct vm_area_struct *vma,
300 				unsigned long page)
301 {
302 	leon_flush_tlb_all();
303 }
304 
305 static void leon_flush_tlb_range(struct vm_area_struct *vma,
306 				 unsigned long start,
307 				 unsigned long end)
308 {
309 	leon_flush_tlb_all();
310 }
311 
312 static void leon_flush_page_to_ram(unsigned long page)
313 {
314 	leon_flush_cache_all();
315 }
316 
317 static void leon_flush_sig_insns(struct mm_struct *mm, unsigned long page)
318 {
319 	leon_flush_cache_all();
320 }
321 
322 static void leon_flush_page_for_dma(unsigned long page)
323 {
324 	leon_flush_dcache_all();
325 }
326 
327 void __init poke_leonsparc(void)
328 {
329 }
330 
331 static const struct sparc32_cachetlb_ops leon_ops = {
332 	.cache_all	= leon_flush_cache_all,
333 	.cache_mm	= leon_flush_cache_mm,
334 	.cache_page	= leon_flush_cache_page,
335 	.cache_range	= leon_flush_cache_range,
336 	.tlb_all	= leon_flush_tlb_all,
337 	.tlb_mm		= leon_flush_tlb_mm,
338 	.tlb_page	= leon_flush_tlb_page,
339 	.tlb_range	= leon_flush_tlb_range,
340 	.page_to_ram	= leon_flush_page_to_ram,
341 	.sig_insns	= leon_flush_sig_insns,
342 	.page_for_dma	= leon_flush_page_for_dma,
343 };
344 
345 void __init init_leon(void)
346 {
347 	srmmu_name = "LEON";
348 	sparc32_cachetlb_ops = &leon_ops;
349 	poke_srmmu = poke_leonsparc;
350 
351 	leon_flush_during_switch = leon_flush_needed();
352 }
353