xref: /openbmc/linux/arch/arm/mach-omap2/sram.c (revision f71a261a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * OMAP SRAM detection and management
5  *
6  * Copyright (C) 2005 Nokia Corporation
7  * Written by Tony Lindgren <tony@atomide.com>
8  *
9  * Copyright (C) 2009-2012 Texas Instruments
10  * Added OMAP4/5 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
11  */
12 
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/io.h>
17 
18 #include <asm/fncpy.h>
19 #include <asm/tlb.h>
20 #include <asm/cacheflush.h>
21 #include <asm/set_memory.h>
22 
23 #include <asm/mach/map.h>
24 
25 #include "soc.h"
26 #include "iomap.h"
27 #include "prm2xxx_3xxx.h"
28 #include "sdrc.h"
29 #include "sram.h"
30 
31 #define OMAP2_SRAM_PUB_PA	(OMAP2_SRAM_PA + 0xf800)
32 #define OMAP3_SRAM_PUB_PA       (OMAP3_SRAM_PA + 0x8000)
33 
34 #define SRAM_BOOTLOADER_SZ	0x00
35 
36 #define OMAP24XX_VA_REQINFOPERM0	OMAP2_L3_IO_ADDRESS(0x68005048)
37 #define OMAP24XX_VA_READPERM0		OMAP2_L3_IO_ADDRESS(0x68005050)
38 #define OMAP24XX_VA_WRITEPERM0		OMAP2_L3_IO_ADDRESS(0x68005058)
39 
40 #define OMAP34XX_VA_REQINFOPERM0	OMAP2_L3_IO_ADDRESS(0x68012848)
41 #define OMAP34XX_VA_READPERM0		OMAP2_L3_IO_ADDRESS(0x68012850)
42 #define OMAP34XX_VA_WRITEPERM0		OMAP2_L3_IO_ADDRESS(0x68012858)
43 #define OMAP34XX_VA_ADDR_MATCH2		OMAP2_L3_IO_ADDRESS(0x68012880)
44 #define OMAP34XX_VA_SMS_RG_ATT0		OMAP2_L3_IO_ADDRESS(0x6C000048)
45 
46 #define GP_DEVICE		0x300
47 
48 #define ROUND_DOWN(value,boundary)	((value) & (~((boundary)-1)))
49 
50 static unsigned long omap_sram_start;
51 static unsigned long omap_sram_size;
52 static void __iomem *omap_sram_base;
53 static unsigned long omap_sram_skip;
54 static void __iomem *omap_sram_ceil;
55 
56 /*
57  * Memory allocator for SRAM: calculates the new ceiling address
58  * for pushing a function using the fncpy API.
59  *
60  * Note that fncpy requires the returned address to be aligned
61  * to an 8-byte boundary.
62  */
63 static void *omap_sram_push_address(unsigned long size)
64 {
65 	unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;
66 
67 	available = omap_sram_ceil - (omap_sram_base + omap_sram_skip);
68 
69 	if (size > available) {
70 		pr_err("Not enough space in SRAM\n");
71 		return NULL;
72 	}
73 
74 	new_ceil -= size;
75 	new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN);
76 	omap_sram_ceil = IOMEM(new_ceil);
77 
78 	return (void __force *)omap_sram_ceil;
79 }
80 
81 void *omap_sram_push(void *funcp, unsigned long size)
82 {
83 	void *sram;
84 	unsigned long base;
85 	int pages;
86 	void *dst = NULL;
87 
88 	sram = omap_sram_push_address(size);
89 	if (!sram)
90 		return NULL;
91 
92 	base = (unsigned long)sram & PAGE_MASK;
93 	pages = PAGE_ALIGN(size) / PAGE_SIZE;
94 
95 	set_memory_rw(base, pages);
96 
97 	dst = fncpy(sram, funcp, size);
98 
99 	set_memory_ro(base, pages);
100 	set_memory_x(base, pages);
101 
102 	return dst;
103 }
104 
105 /*
106  * The SRAM context is lost during off-idle and stack
107  * needs to be reset.
108  */
109 static void omap_sram_reset(void)
110 {
111 	omap_sram_ceil = omap_sram_base + omap_sram_size;
112 }
113 
114 /*
115  * Depending on the target RAMFS firewall setup, the public usable amount of
116  * SRAM varies.  The default accessible size for all device types is 2k. A GP
117  * device allows ARM11 but not other initiators for full size. This
118  * functionality seems ok until some nice security API happens.
119  */
120 static int is_sram_locked(void)
121 {
122 	if (OMAP2_DEVICE_TYPE_GP == omap_type()) {
123 		/* RAMFW: R/W access to all initiators for all qualifier sets */
124 		if (cpu_is_omap242x()) {
125 			writel_relaxed(0xFF, OMAP24XX_VA_REQINFOPERM0); /* all q-vects */
126 			writel_relaxed(0xCFDE, OMAP24XX_VA_READPERM0);  /* all i-read */
127 			writel_relaxed(0xCFDE, OMAP24XX_VA_WRITEPERM0); /* all i-write */
128 		}
129 		if (cpu_is_omap34xx()) {
130 			writel_relaxed(0xFFFF, OMAP34XX_VA_REQINFOPERM0); /* all q-vects */
131 			writel_relaxed(0xFFFF, OMAP34XX_VA_READPERM0);  /* all i-read */
132 			writel_relaxed(0xFFFF, OMAP34XX_VA_WRITEPERM0); /* all i-write */
133 			writel_relaxed(0x0, OMAP34XX_VA_ADDR_MATCH2);
134 			writel_relaxed(0xFFFFFFFF, OMAP34XX_VA_SMS_RG_ATT0);
135 		}
136 		return 0;
137 	} else
138 		return 1; /* assume locked with no PPA or security driver */
139 }
140 
141 /*
142  * The amount of SRAM depends on the core type.
143  * Note that we cannot try to test for SRAM here because writes
144  * to secure SRAM will hang the system. Also the SRAM is not
145  * yet mapped at this point.
146  */
147 static void __init omap_detect_sram(void)
148 {
149 	omap_sram_skip = SRAM_BOOTLOADER_SZ;
150 	if (is_sram_locked()) {
151 		if (cpu_is_omap34xx()) {
152 			omap_sram_start = OMAP3_SRAM_PUB_PA;
153 			if ((omap_type() == OMAP2_DEVICE_TYPE_EMU) ||
154 			    (omap_type() == OMAP2_DEVICE_TYPE_SEC)) {
155 				omap_sram_size = 0x7000; /* 28K */
156 				omap_sram_skip += SZ_16K;
157 			} else {
158 				omap_sram_size = 0x8000; /* 32K */
159 			}
160 		} else {
161 			omap_sram_start = OMAP2_SRAM_PUB_PA;
162 			omap_sram_size = 0x800; /* 2K */
163 		}
164 	} else {
165 		if (cpu_is_omap34xx()) {
166 			omap_sram_start = OMAP3_SRAM_PA;
167 			omap_sram_size = 0x10000; /* 64K */
168 		} else {
169 			omap_sram_start = OMAP2_SRAM_PA;
170 			if (cpu_is_omap242x())
171 				omap_sram_size = 0xa0000; /* 640K */
172 			else if (cpu_is_omap243x())
173 				omap_sram_size = 0x10000; /* 64K */
174 		}
175 	}
176 }
177 
178 /*
179  * Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
180  */
181 static void __init omap2_map_sram(void)
182 {
183 	unsigned long base;
184 	int pages;
185 	int cached = 1;
186 
187 	if (cpu_is_omap34xx()) {
188 		/*
189 		 * SRAM must be marked as non-cached on OMAP3 since the
190 		 * CORE DPLL M2 divider change code (in SRAM) runs with the
191 		 * SDRAM controller disabled, and if it is marked cached,
192 		 * the ARM may attempt to write cache lines back to SDRAM
193 		 * which will cause the system to hang.
194 		 */
195 		cached = 0;
196 	}
197 
198 	if (omap_sram_size == 0)
199 		return;
200 
201 	omap_sram_start = ROUND_DOWN(omap_sram_start, PAGE_SIZE);
202 	omap_sram_base = __arm_ioremap_exec(omap_sram_start, omap_sram_size, cached);
203 	if (!omap_sram_base) {
204 		pr_err("SRAM: Could not map\n");
205 		return;
206 	}
207 
208 	omap_sram_reset();
209 
210 	/*
211 	 * Looks like we need to preserve some bootloader code at the
212 	 * beginning of SRAM for jumping to flash for reboot to work...
213 	 */
214 	memset_io(omap_sram_base + omap_sram_skip, 0,
215 		  omap_sram_size - omap_sram_skip);
216 
217 	base = (unsigned long)omap_sram_base;
218 	pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE;
219 
220 	set_memory_ro(base, pages);
221 	set_memory_x(base, pages);
222 }
223 
224 static void (*_omap2_sram_ddr_init)(u32 *slow_dll_ctrl, u32 fast_dll_ctrl,
225 			      u32 base_cs, u32 force_unlock);
226 
227 void omap2_sram_ddr_init(u32 *slow_dll_ctrl, u32 fast_dll_ctrl,
228 		   u32 base_cs, u32 force_unlock)
229 {
230 	BUG_ON(!_omap2_sram_ddr_init);
231 	_omap2_sram_ddr_init(slow_dll_ctrl, fast_dll_ctrl,
232 			     base_cs, force_unlock);
233 }
234 
235 static void (*_omap2_sram_reprogram_sdrc)(u32 perf_level, u32 dll_val,
236 					  u32 mem_type);
237 
238 void omap2_sram_reprogram_sdrc(u32 perf_level, u32 dll_val, u32 mem_type)
239 {
240 	BUG_ON(!_omap2_sram_reprogram_sdrc);
241 	_omap2_sram_reprogram_sdrc(perf_level, dll_val, mem_type);
242 }
243 
244 static u32 (*_omap2_set_prcm)(u32 dpll_ctrl_val, u32 sdrc_rfr_val, int bypass);
245 
246 u32 omap2_set_prcm(u32 dpll_ctrl_val, u32 sdrc_rfr_val, int bypass)
247 {
248 	BUG_ON(!_omap2_set_prcm);
249 	return _omap2_set_prcm(dpll_ctrl_val, sdrc_rfr_val, bypass);
250 }
251 
252 #ifdef CONFIG_SOC_OMAP2420
253 static int __init omap242x_sram_init(void)
254 {
255 	_omap2_sram_ddr_init = omap_sram_push(omap242x_sram_ddr_init,
256 					omap242x_sram_ddr_init_sz);
257 
258 	_omap2_sram_reprogram_sdrc = omap_sram_push(omap242x_sram_reprogram_sdrc,
259 					    omap242x_sram_reprogram_sdrc_sz);
260 
261 	_omap2_set_prcm = omap_sram_push(omap242x_sram_set_prcm,
262 					 omap242x_sram_set_prcm_sz);
263 
264 	return 0;
265 }
266 #else
267 static inline int omap242x_sram_init(void)
268 {
269 	return 0;
270 }
271 #endif
272 
273 #ifdef CONFIG_SOC_OMAP2430
274 static int __init omap243x_sram_init(void)
275 {
276 	_omap2_sram_ddr_init = omap_sram_push(omap243x_sram_ddr_init,
277 					omap243x_sram_ddr_init_sz);
278 
279 	_omap2_sram_reprogram_sdrc = omap_sram_push(omap243x_sram_reprogram_sdrc,
280 					    omap243x_sram_reprogram_sdrc_sz);
281 
282 	_omap2_set_prcm = omap_sram_push(omap243x_sram_set_prcm,
283 					 omap243x_sram_set_prcm_sz);
284 
285 	return 0;
286 }
287 #else
288 static inline int omap243x_sram_init(void)
289 {
290 	return 0;
291 }
292 #endif
293 
294 #ifdef CONFIG_ARCH_OMAP3
295 
296 void omap3_sram_restore_context(void)
297 {
298 	omap_sram_reset();
299 
300 	omap_push_sram_idle();
301 }
302 
303 static inline int omap34xx_sram_init(void)
304 {
305 	omap3_sram_restore_context();
306 	return 0;
307 }
308 #else
309 static inline int omap34xx_sram_init(void)
310 {
311 	return 0;
312 }
313 #endif /* CONFIG_ARCH_OMAP3 */
314 
315 int __init omap_sram_init(void)
316 {
317 	omap_detect_sram();
318 	omap2_map_sram();
319 
320 	if (cpu_is_omap242x())
321 		omap242x_sram_init();
322 	else if (cpu_is_omap2430())
323 		omap243x_sram_init();
324 	else if (cpu_is_omap34xx())
325 		omap34xx_sram_init();
326 
327 	return 0;
328 }
329