xref: /openbmc/linux/arch/arm/mach-omap2/sram.c (revision a33ca174)
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 #include <linux/set_memory.h>
18 
19 #include <asm/fncpy.h>
20 #include <asm/tlb.h>
21 #include <asm/cacheflush.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_rox(base, pages);
100 
101 	return dst;
102 }
103 
104 /*
105  * The SRAM context is lost during off-idle and stack
106  * needs to be reset.
107  */
108 static void omap_sram_reset(void)
109 {
110 	omap_sram_ceil = omap_sram_base + omap_sram_size;
111 }
112 
113 /*
114  * Depending on the target RAMFS firewall setup, the public usable amount of
115  * SRAM varies.  The default accessible size for all device types is 2k. A GP
116  * device allows ARM11 but not other initiators for full size. This
117  * functionality seems ok until some nice security API happens.
118  */
119 static int is_sram_locked(void)
120 {
121 	if (OMAP2_DEVICE_TYPE_GP == omap_type()) {
122 		/* RAMFW: R/W access to all initiators for all qualifier sets */
123 		if (cpu_is_omap242x()) {
124 			writel_relaxed(0xFF, OMAP24XX_VA_REQINFOPERM0); /* all q-vects */
125 			writel_relaxed(0xCFDE, OMAP24XX_VA_READPERM0);  /* all i-read */
126 			writel_relaxed(0xCFDE, OMAP24XX_VA_WRITEPERM0); /* all i-write */
127 		}
128 		if (cpu_is_omap34xx()) {
129 			writel_relaxed(0xFFFF, OMAP34XX_VA_REQINFOPERM0); /* all q-vects */
130 			writel_relaxed(0xFFFF, OMAP34XX_VA_READPERM0);  /* all i-read */
131 			writel_relaxed(0xFFFF, OMAP34XX_VA_WRITEPERM0); /* all i-write */
132 			writel_relaxed(0x0, OMAP34XX_VA_ADDR_MATCH2);
133 			writel_relaxed(0xFFFFFFFF, OMAP34XX_VA_SMS_RG_ATT0);
134 		}
135 		return 0;
136 	} else
137 		return 1; /* assume locked with no PPA or security driver */
138 }
139 
140 /*
141  * The amount of SRAM depends on the core type.
142  * Note that we cannot try to test for SRAM here because writes
143  * to secure SRAM will hang the system. Also the SRAM is not
144  * yet mapped at this point.
145  */
146 static void __init omap_detect_sram(void)
147 {
148 	omap_sram_skip = SRAM_BOOTLOADER_SZ;
149 	if (is_sram_locked()) {
150 		if (cpu_is_omap34xx()) {
151 			omap_sram_start = OMAP3_SRAM_PUB_PA;
152 			if ((omap_type() == OMAP2_DEVICE_TYPE_EMU) ||
153 			    (omap_type() == OMAP2_DEVICE_TYPE_SEC)) {
154 				omap_sram_size = 0x7000; /* 28K */
155 				omap_sram_skip += SZ_16K;
156 			} else {
157 				omap_sram_size = 0x8000; /* 32K */
158 			}
159 		} else {
160 			omap_sram_start = OMAP2_SRAM_PUB_PA;
161 			omap_sram_size = 0x800; /* 2K */
162 		}
163 	} else {
164 		if (cpu_is_omap34xx()) {
165 			omap_sram_start = OMAP3_SRAM_PA;
166 			omap_sram_size = 0x10000; /* 64K */
167 		} else {
168 			omap_sram_start = OMAP2_SRAM_PA;
169 			if (cpu_is_omap242x())
170 				omap_sram_size = 0xa0000; /* 640K */
171 			else if (cpu_is_omap243x())
172 				omap_sram_size = 0x10000; /* 64K */
173 		}
174 	}
175 }
176 
177 /*
178  * Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
179  */
180 static void __init omap2_map_sram(void)
181 {
182 	unsigned long base;
183 	int pages;
184 	int cached = 1;
185 
186 	if (cpu_is_omap34xx()) {
187 		/*
188 		 * SRAM must be marked as non-cached on OMAP3 since the
189 		 * CORE DPLL M2 divider change code (in SRAM) runs with the
190 		 * SDRAM controller disabled, and if it is marked cached,
191 		 * the ARM may attempt to write cache lines back to SDRAM
192 		 * which will cause the system to hang.
193 		 */
194 		cached = 0;
195 	}
196 
197 	if (omap_sram_size == 0)
198 		return;
199 
200 	omap_sram_start = ROUND_DOWN(omap_sram_start, PAGE_SIZE);
201 	omap_sram_base = __arm_ioremap_exec(omap_sram_start, omap_sram_size, cached);
202 	if (!omap_sram_base) {
203 		pr_err("SRAM: Could not map\n");
204 		return;
205 	}
206 
207 	omap_sram_reset();
208 
209 	/*
210 	 * Looks like we need to preserve some bootloader code at the
211 	 * beginning of SRAM for jumping to flash for reboot to work...
212 	 */
213 	memset_io(omap_sram_base + omap_sram_skip, 0,
214 		  omap_sram_size - omap_sram_skip);
215 
216 	base = (unsigned long)omap_sram_base;
217 	pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE;
218 
219 	set_memory_rox(base, pages);
220 }
221 
222 static void (*_omap2_sram_ddr_init)(u32 *slow_dll_ctrl, u32 fast_dll_ctrl,
223 			      u32 base_cs, u32 force_unlock);
224 
225 void omap2_sram_ddr_init(u32 *slow_dll_ctrl, u32 fast_dll_ctrl,
226 		   u32 base_cs, u32 force_unlock)
227 {
228 	BUG_ON(!_omap2_sram_ddr_init);
229 	_omap2_sram_ddr_init(slow_dll_ctrl, fast_dll_ctrl,
230 			     base_cs, force_unlock);
231 }
232 
233 static void (*_omap2_sram_reprogram_sdrc)(u32 perf_level, u32 dll_val,
234 					  u32 mem_type);
235 
236 void omap2_sram_reprogram_sdrc(u32 perf_level, u32 dll_val, u32 mem_type)
237 {
238 	BUG_ON(!_omap2_sram_reprogram_sdrc);
239 	_omap2_sram_reprogram_sdrc(perf_level, dll_val, mem_type);
240 }
241 
242 static u32 (*_omap2_set_prcm)(u32 dpll_ctrl_val, u32 sdrc_rfr_val, int bypass);
243 
244 u32 omap2_set_prcm(u32 dpll_ctrl_val, u32 sdrc_rfr_val, int bypass)
245 {
246 	BUG_ON(!_omap2_set_prcm);
247 	return _omap2_set_prcm(dpll_ctrl_val, sdrc_rfr_val, bypass);
248 }
249 
250 #ifdef CONFIG_SOC_OMAP2420
251 static int __init omap242x_sram_init(void)
252 {
253 	_omap2_sram_ddr_init = omap_sram_push(omap242x_sram_ddr_init,
254 					omap242x_sram_ddr_init_sz);
255 
256 	_omap2_sram_reprogram_sdrc = omap_sram_push(omap242x_sram_reprogram_sdrc,
257 					    omap242x_sram_reprogram_sdrc_sz);
258 
259 	_omap2_set_prcm = omap_sram_push(omap242x_sram_set_prcm,
260 					 omap242x_sram_set_prcm_sz);
261 
262 	return 0;
263 }
264 #else
265 static inline int omap242x_sram_init(void)
266 {
267 	return 0;
268 }
269 #endif
270 
271 #ifdef CONFIG_SOC_OMAP2430
272 static int __init omap243x_sram_init(void)
273 {
274 	_omap2_sram_ddr_init = omap_sram_push(omap243x_sram_ddr_init,
275 					omap243x_sram_ddr_init_sz);
276 
277 	_omap2_sram_reprogram_sdrc = omap_sram_push(omap243x_sram_reprogram_sdrc,
278 					    omap243x_sram_reprogram_sdrc_sz);
279 
280 	_omap2_set_prcm = omap_sram_push(omap243x_sram_set_prcm,
281 					 omap243x_sram_set_prcm_sz);
282 
283 	return 0;
284 }
285 #else
286 static inline int omap243x_sram_init(void)
287 {
288 	return 0;
289 }
290 #endif
291 
292 #ifdef CONFIG_ARCH_OMAP3
293 
294 void omap3_sram_restore_context(void)
295 {
296 	omap_sram_reset();
297 
298 	omap_push_sram_idle();
299 }
300 
301 static inline int omap34xx_sram_init(void)
302 {
303 	omap3_sram_restore_context();
304 	return 0;
305 }
306 #else
307 static inline int omap34xx_sram_init(void)
308 {
309 	return 0;
310 }
311 #endif /* CONFIG_ARCH_OMAP3 */
312 
313 int __init omap_sram_init(void)
314 {
315 	omap_detect_sram();
316 	omap2_map_sram();
317 
318 	if (cpu_is_omap242x())
319 		omap242x_sram_init();
320 	else if (cpu_is_omap2430())
321 		omap243x_sram_init();
322 	else if (cpu_is_omap34xx())
323 		omap34xx_sram_init();
324 
325 	return 0;
326 }
327