xref: /openbmc/u-boot/arch/arm/cpu/armv8/sec_firmware.c (revision 85231c08)
1 /*
2  * Copyright 2016 NXP Semiconductor, Inc.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <errno.h>
9 #include <linux/kernel.h>
10 #include <asm/io.h>
11 #include <asm/system.h>
12 #include <asm/types.h>
13 #include <asm/macro.h>
14 #include <asm/armv8/sec_firmware.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 extern void c_runtime_cpu_setup(void);
18 
19 #define SEC_FIRMWARE_LOADED	0x1
20 #define SEC_FIRMWARE_RUNNING	0x2
21 #define SEC_FIRMWARE_ADDR_MASK	(~0x3)
22 /*
23  * Secure firmware load addr
24  * Flags used: 0x1 secure firmware has been loaded to secure memory
25  *             0x2 secure firmware is running
26  */
27 phys_addr_t sec_firmware_addr;
28 
29 #ifndef SEC_FIRMWARE_FIT_IMAGE
30 #define SEC_FIRMWARE_FIT_IMAGE		"firmware"
31 #endif
32 #ifndef SEC_FIRMEWARE_FIT_CNF_NAME
33 #define SEC_FIRMEWARE_FIT_CNF_NAME	"config-1"
34 #endif
35 #ifndef SEC_FIRMWARE_TARGET_EL
36 #define SEC_FIRMWARE_TARGET_EL		2
37 #endif
38 
39 static int sec_firmware_get_data(const void *sec_firmware_img,
40 				const void **data, size_t *size)
41 {
42 	int conf_node_off, fw_node_off;
43 	char *conf_node_name = NULL;
44 	char *desc;
45 	int ret;
46 
47 	conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
48 
49 	conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
50 	if (conf_node_off < 0) {
51 		printf("SEC Firmware: %s: no such config\n", conf_node_name);
52 		return -ENOENT;
53 	}
54 
55 	fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
56 			SEC_FIRMWARE_FIT_IMAGE);
57 	if (fw_node_off < 0) {
58 		printf("SEC Firmware: No '%s' in config\n",
59 		       SEC_FIRMWARE_FIT_IMAGE);
60 		return -ENOLINK;
61 	}
62 
63 	/* Verify secure firmware image */
64 	if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
65 		printf("SEC Firmware: Bad firmware image (bad CRC)\n");
66 		return -EINVAL;
67 	}
68 
69 	if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
70 		printf("SEC Firmware: Can't get %s subimage data/size",
71 		       SEC_FIRMWARE_FIT_IMAGE);
72 		return -ENOENT;
73 	}
74 
75 	ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
76 	if (ret)
77 		printf("SEC Firmware: Can't get description\n");
78 	else
79 		printf("%s\n", desc);
80 
81 	return ret;
82 }
83 
84 /*
85  * SEC Firmware FIT image parser checks if the image is in FIT
86  * format, verifies integrity of the image and calculates raw
87  * image address and size values.
88  *
89  * Returns 0 on success and a negative errno on error task fail.
90  */
91 static int sec_firmware_parse_image(const void *sec_firmware_img,
92 					const void **raw_image_addr,
93 					size_t *raw_image_size)
94 {
95 	int ret;
96 
97 	ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
98 					raw_image_size);
99 	if (ret)
100 		return ret;
101 
102 	debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
103 	      *raw_image_addr, *raw_image_size);
104 
105 	return 0;
106 }
107 
108 /*
109  * SEC Firmware FIT image parser to check if any loadable is
110  * present. If present, verify integrity of the loadable and
111  * copy loadable to address provided in (loadable_h, loadable_l).
112  *
113  * Returns 0 on success and a negative errno on error task fail.
114  */
115 static int sec_firmware_check_copy_loadable(const void *sec_firmware_img,
116 					    u32 *loadable_l, u32 *loadable_h)
117 {
118 	phys_addr_t sec_firmware_loadable_addr = 0;
119 	int conf_node_off, ld_node_off;
120 	char *conf_node_name = NULL;
121 	const void *data;
122 	size_t size;
123 	ulong load;
124 
125 	conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
126 
127 	conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
128 	if (conf_node_off < 0) {
129 		printf("SEC Firmware: %s: no such config\n", conf_node_name);
130 	return -ENOENT;
131 	}
132 
133 	ld_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
134 					     FIT_LOADABLE_PROP);
135 	if (ld_node_off >= 0) {
136 		printf("SEC Firmware: '%s' present in config\n",
137 		       FIT_LOADABLE_PROP);
138 
139 		/* Verify secure firmware image */
140 		if (!(fit_image_verify(sec_firmware_img, ld_node_off))) {
141 			printf("SEC Loadable: Bad loadable image (bad CRC)\n");
142 			return -EINVAL;
143 		}
144 
145 		if (fit_image_get_data(sec_firmware_img, ld_node_off,
146 				       &data, &size)) {
147 			printf("SEC Loadable: Can't get subimage data/size");
148 			return -ENOENT;
149 		}
150 
151 		/* Get load address, treated as load offset to secure memory */
152 		if (fit_image_get_load(sec_firmware_img, ld_node_off, &load)) {
153 			printf("SEC Loadable: Can't get subimage load");
154 			return -ENOENT;
155 		}
156 
157 		/* Compute load address for loadable in secure memory */
158 		sec_firmware_loadable_addr = (sec_firmware_addr -
159 						gd->arch.tlb_size) + load;
160 
161 		/* Copy loadable to secure memory and flush dcache */
162 		debug("%s copied to address 0x%p\n",
163 		      FIT_LOADABLE_PROP, (void *)sec_firmware_loadable_addr);
164 		memcpy((void *)sec_firmware_loadable_addr, data, size);
165 		flush_dcache_range(sec_firmware_loadable_addr,
166 				   sec_firmware_loadable_addr + size);
167 	}
168 
169 	/* Populate address ptrs for loadable image with loadbale addr */
170 	out_le32(loadable_l, (sec_firmware_loadable_addr & WORD_MASK));
171 	out_le32(loadable_h, (sec_firmware_loadable_addr >> WORD_SHIFT));
172 
173 	return 0;
174 }
175 
176 static int sec_firmware_copy_image(const char *title,
177 			 u64 image_addr, u32 image_size, u64 sec_firmware)
178 {
179 	debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
180 	memcpy((void *)sec_firmware, (void *)image_addr, image_size);
181 	flush_dcache_range(sec_firmware, sec_firmware + image_size);
182 
183 	return 0;
184 }
185 
186 /*
187  * This function will parse the SEC Firmware image, and then load it
188  * to secure memory. Also load any loadable if present along with SEC
189  * Firmware image.
190  */
191 static int sec_firmware_load_image(const void *sec_firmware_img,
192 				   u32 *loadable_l, u32 *loadable_h)
193 {
194 	const void *raw_image_addr;
195 	size_t raw_image_size = 0;
196 	int ret;
197 
198 	/*
199 	 * The Excetpion Level must be EL3 to load and initialize
200 	 * the SEC Firmware.
201 	 */
202 	if (current_el() != 3) {
203 		ret = -EACCES;
204 		goto out;
205 	}
206 
207 #ifdef CONFIG_SYS_MEM_RESERVE_SECURE
208 	/*
209 	 * The SEC Firmware must be stored in secure memory.
210 	 * Append SEC Firmware to secure mmu table.
211 	 */
212 	if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
213 		ret = -ENXIO;
214 		goto out;
215 	}
216 
217 	sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
218 			gd->arch.tlb_size;
219 #else
220 #error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
221 #endif
222 
223 	/* Align SEC Firmware base address to 4K */
224 	sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
225 	debug("SEC Firmware: Load address: 0x%llx\n",
226 	      sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
227 
228 	ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
229 			&raw_image_size);
230 	if (ret)
231 		goto out;
232 
233 	/* TODO:
234 	 * Check if the end addr of SEC Firmware has been extend the secure
235 	 * memory.
236 	 */
237 
238 	/* Copy the secure firmware to secure memory */
239 	ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
240 			raw_image_size, sec_firmware_addr &
241 			SEC_FIRMWARE_ADDR_MASK);
242 	if (ret)
243 		goto out;
244 
245 	/*
246 	 * Check if any loadable are present along with firmware image, if
247 	 * present load them.
248 	 */
249 	ret = sec_firmware_check_copy_loadable(sec_firmware_img, loadable_l,
250 					       loadable_h);
251 	if (ret)
252 		goto out;
253 
254 	sec_firmware_addr |= SEC_FIRMWARE_LOADED;
255 	debug("SEC Firmware: Entry point: 0x%llx\n",
256 	      sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
257 
258 	return 0;
259 
260 out:
261 	printf("SEC Firmware: error (%d)\n", ret);
262 	sec_firmware_addr = 0;
263 
264 	return ret;
265 }
266 
267 static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
268 {
269 	const void *entry = (void *)(sec_firmware_addr &
270 				SEC_FIRMWARE_ADDR_MASK);
271 
272 	return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
273 }
274 
275 /* Check the secure firmware FIT image */
276 __weak bool sec_firmware_is_valid(const void *sec_firmware_img)
277 {
278 	if (fdt_check_header(sec_firmware_img)) {
279 		printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
280 		return false;
281 	}
282 
283 	if (!fit_check_format(sec_firmware_img)) {
284 		printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
285 		return false;
286 	}
287 
288 	return true;
289 }
290 
291 #ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
292 /*
293  * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
294  * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
295  * number will be returned according to SMC Calling Conventions. But
296  * when getting the NOT_SUPPORTED error number, we cannot ensure if
297  * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
298  * won't be supported by this framework.
299  * And if the secure firmware isn't running, return NOT_SUPPORTED.
300  *
301  * The return value on success is PSCI version in format
302  * major[31:16]:minor[15:0].
303  */
304 unsigned int sec_firmware_support_psci_version(void)
305 {
306 	if (current_el() == SEC_FIRMWARE_TARGET_EL)
307 		return _sec_firmware_support_psci_version();
308 
309 	return PSCI_INVALID_VER;
310 }
311 #endif
312 
313 /*
314  * Check with sec_firmware if it supports random number generation
315  * via HW RNG
316  *
317  * The return value will be true if it is supported
318  */
319 bool sec_firmware_support_hwrng(void)
320 {
321 	uint8_t rand[8];
322 	if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
323 		if (!sec_firmware_get_random(rand, 8))
324 			return true;
325 	}
326 
327 	return false;
328 }
329 
330 /*
331  * sec_firmware_get_random - Get a random number from SEC Firmware
332  * @rand:		random number buffer to be filled
333  * @bytes:		Number of bytes of random number to be supported
334  * @eret:		-1 in case of error, 0 for success
335  */
336 int sec_firmware_get_random(uint8_t *rand, int bytes)
337 {
338 	unsigned long long num;
339 	struct pt_regs regs;
340 	int param1;
341 
342 	if (!bytes || bytes > 8) {
343 		printf("Max Random bytes genration supported is 8\n");
344 		return -1;
345 	}
346 #define SIP_RNG_64 0xC200FF11
347 	regs.regs[0] = SIP_RNG_64;
348 
349 	if (bytes <= 4)
350 		param1 = 0;
351 	else
352 		param1 = 1;
353 	regs.regs[1] = param1;
354 
355 	smc_call(&regs);
356 
357 	if (regs.regs[0])
358 		return -1;
359 
360 	num = regs.regs[1];
361 	memcpy(rand, &num, bytes);
362 
363 	return 0;
364 }
365 
366 /*
367  * sec_firmware_init - Initialize the SEC Firmware
368  * @sec_firmware_img:	the SEC Firmware image address
369  * @eret_hold_l:	the address to hold exception return address low
370  * @eret_hold_h:	the address to hold exception return address high
371  * @loadable_l:		the address to hold loadable address low
372  * @loadable_h:		the address to hold loadable address high
373  */
374 int sec_firmware_init(const void *sec_firmware_img,
375 			u32 *eret_hold_l,
376 			u32 *eret_hold_h,
377 			u32 *loadable_l,
378 			u32 *loadable_h)
379 {
380 	int ret;
381 
382 	if (!sec_firmware_is_valid(sec_firmware_img))
383 		return -EINVAL;
384 
385 	ret = sec_firmware_load_image(sec_firmware_img, loadable_l,
386 				      loadable_h);
387 	if (ret) {
388 		printf("SEC Firmware: Failed to load image\n");
389 		return ret;
390 	} else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
391 		ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
392 		if (ret) {
393 			printf("SEC Firmware: Failed to initialize\n");
394 			return ret;
395 		}
396 	}
397 
398 	debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
399 	      current_el());
400 
401 	/*
402 	 * The PE will be turned into target EL when returned from
403 	 * SEC Firmware.
404 	 */
405 	if (current_el() != SEC_FIRMWARE_TARGET_EL)
406 		return -EACCES;
407 
408 	sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
409 
410 	/* Set exception table and enable caches if it isn't EL3 */
411 	if (current_el() != 3) {
412 		c_runtime_cpu_setup();
413 		enable_caches();
414 	}
415 
416 	return 0;
417 }
418 
419 /*
420  * fdt_fix_kaslr - Add kalsr-seed node in Device tree
421  * @fdt:		Device tree
422  * @eret:		0 in case of error, 1 for success
423  */
424 int fdt_fixup_kaslr(void *fdt)
425 {
426 	int nodeoffset;
427 	int err, ret = 0;
428 	u8 rand[8];
429 
430 #if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
431 	/* Check if random seed generation is  supported */
432 	if (sec_firmware_support_hwrng() == false)
433 		return 0;
434 
435 	ret = sec_firmware_get_random(rand, 8);
436 	if (ret < 0) {
437 		printf("WARNING: No random number to set kaslr-seed\n");
438 		return 0;
439 	}
440 
441 	err = fdt_check_header(fdt);
442 	if (err < 0) {
443 		printf("fdt_chosen: %s\n", fdt_strerror(err));
444 		return 0;
445 	}
446 
447 	/* find or create "/chosen" node. */
448 	nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
449 	if (nodeoffset < 0)
450 		return 0;
451 
452 	err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
453 				  sizeof(rand));
454 	if (err < 0) {
455 		printf("WARNING: can't set kaslr-seed %s.\n",
456 		       fdt_strerror(err));
457 		return 0;
458 	}
459 	ret = 1;
460 #endif
461 
462 	return ret;
463 }
464