xref: /openbmc/u-boot/arch/arm/cpu/armv8/sec_firmware.c (revision 04ab29ab257598b0e33785c075c9163ea090e6b7)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2016 NXP Semiconductor, Inc.
4  */
5 
6 #include <common.h>
7 #include <errno.h>
8 #include <linux/kernel.h>
9 #include <asm/io.h>
10 #include <asm/system.h>
11 #include <asm/types.h>
12 #include <asm/macro.h>
13 #include <asm/armv8/sec_firmware.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 extern void c_runtime_cpu_setup(void);
17 
18 #define SEC_FIRMWARE_LOADED	0x1
19 #define SEC_FIRMWARE_RUNNING	0x2
20 #define SEC_FIRMWARE_ADDR_MASK	(~0x3)
21 /*
22  * Secure firmware load addr
23  * Flags used: 0x1 secure firmware has been loaded to secure memory
24  *             0x2 secure firmware is running
25  */
26 phys_addr_t sec_firmware_addr;
27 
28 #ifndef SEC_FIRMWARE_FIT_IMAGE
29 #define SEC_FIRMWARE_FIT_IMAGE		"firmware"
30 #endif
31 #ifndef SEC_FIRMEWARE_FIT_CNF_NAME
32 #define SEC_FIRMEWARE_FIT_CNF_NAME	"config-1"
33 #endif
34 #ifndef SEC_FIRMWARE_TARGET_EL
35 #define SEC_FIRMWARE_TARGET_EL		2
36 #endif
37 
38 static int sec_firmware_get_data(const void *sec_firmware_img,
39 				const void **data, size_t *size)
40 {
41 	int conf_node_off, fw_node_off;
42 	char *conf_node_name = NULL;
43 	char *desc;
44 	int ret;
45 
46 	conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
47 
48 	conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
49 	if (conf_node_off < 0) {
50 		printf("SEC Firmware: %s: no such config\n", conf_node_name);
51 		return -ENOENT;
52 	}
53 
54 	fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
55 			SEC_FIRMWARE_FIT_IMAGE);
56 	if (fw_node_off < 0) {
57 		printf("SEC Firmware: No '%s' in config\n",
58 		       SEC_FIRMWARE_FIT_IMAGE);
59 		return -ENOLINK;
60 	}
61 
62 	/* Verify secure firmware image */
63 	if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
64 		printf("SEC Firmware: Bad firmware image (bad CRC)\n");
65 		return -EINVAL;
66 	}
67 
68 	if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
69 		printf("SEC Firmware: Can't get %s subimage data/size",
70 		       SEC_FIRMWARE_FIT_IMAGE);
71 		return -ENOENT;
72 	}
73 
74 	ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
75 	if (ret)
76 		printf("SEC Firmware: Can't get description\n");
77 	else
78 		printf("%s\n", desc);
79 
80 	return ret;
81 }
82 
83 /*
84  * SEC Firmware FIT image parser checks if the image is in FIT
85  * format, verifies integrity of the image and calculates raw
86  * image address and size values.
87  *
88  * Returns 0 on success and a negative errno on error task fail.
89  */
90 static int sec_firmware_parse_image(const void *sec_firmware_img,
91 					const void **raw_image_addr,
92 					size_t *raw_image_size)
93 {
94 	int ret;
95 
96 	ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
97 					raw_image_size);
98 	if (ret)
99 		return ret;
100 
101 	debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
102 	      *raw_image_addr, *raw_image_size);
103 
104 	return 0;
105 }
106 
107 /*
108  * SEC Firmware FIT image parser to check if any loadable is
109  * present. If present, verify integrity of the loadable and
110  * copy loadable to address provided in (loadable_h, loadable_l).
111  *
112  * Returns 0 on success and a negative errno on error task fail.
113  */
114 static int sec_firmware_check_copy_loadable(const void *sec_firmware_img,
115 					    u32 *loadable_l, u32 *loadable_h)
116 {
117 	phys_addr_t sec_firmware_loadable_addr = 0;
118 	int conf_node_off, ld_node_off;
119 	char *conf_node_name = NULL;
120 	const void *data;
121 	size_t size;
122 	ulong load;
123 
124 	conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
125 
126 	conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
127 	if (conf_node_off < 0) {
128 		printf("SEC Firmware: %s: no such config\n", conf_node_name);
129 	return -ENOENT;
130 	}
131 
132 	ld_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
133 					     FIT_LOADABLE_PROP);
134 	if (ld_node_off >= 0) {
135 		printf("SEC Firmware: '%s' present in config\n",
136 		       FIT_LOADABLE_PROP);
137 
138 		/* Verify secure firmware image */
139 		if (!(fit_image_verify(sec_firmware_img, ld_node_off))) {
140 			printf("SEC Loadable: Bad loadable image (bad CRC)\n");
141 			return -EINVAL;
142 		}
143 
144 		if (fit_image_get_data(sec_firmware_img, ld_node_off,
145 				       &data, &size)) {
146 			printf("SEC Loadable: Can't get subimage data/size");
147 			return -ENOENT;
148 		}
149 
150 		/* Get load address, treated as load offset to secure memory */
151 		if (fit_image_get_load(sec_firmware_img, ld_node_off, &load)) {
152 			printf("SEC Loadable: Can't get subimage load");
153 			return -ENOENT;
154 		}
155 
156 		/* Compute load address for loadable in secure memory */
157 		sec_firmware_loadable_addr = (sec_firmware_addr -
158 						gd->arch.tlb_size) + load;
159 
160 		/* Copy loadable to secure memory and flush dcache */
161 		debug("%s copied to address 0x%p\n",
162 		      FIT_LOADABLE_PROP, (void *)sec_firmware_loadable_addr);
163 		memcpy((void *)sec_firmware_loadable_addr, data, size);
164 		flush_dcache_range(sec_firmware_loadable_addr,
165 				   sec_firmware_loadable_addr + size);
166 	}
167 
168 	/* Populate address ptrs for loadable image with loadbale addr */
169 	out_le32(loadable_l, (sec_firmware_loadable_addr & WORD_MASK));
170 	out_le32(loadable_h, (sec_firmware_loadable_addr >> WORD_SHIFT));
171 
172 	return 0;
173 }
174 
175 static int sec_firmware_copy_image(const char *title,
176 			 u64 image_addr, u32 image_size, u64 sec_firmware)
177 {
178 	debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
179 	memcpy((void *)sec_firmware, (void *)image_addr, image_size);
180 	flush_dcache_range(sec_firmware, sec_firmware + image_size);
181 
182 	return 0;
183 }
184 
185 /*
186  * This function will parse the SEC Firmware image, and then load it
187  * to secure memory. Also load any loadable if present along with SEC
188  * Firmware image.
189  */
190 static int sec_firmware_load_image(const void *sec_firmware_img,
191 				   u32 *loadable_l, u32 *loadable_h)
192 {
193 	const void *raw_image_addr;
194 	size_t raw_image_size = 0;
195 	int ret;
196 
197 	/*
198 	 * The Excetpion Level must be EL3 to load and initialize
199 	 * the SEC Firmware.
200 	 */
201 	if (current_el() != 3) {
202 		ret = -EACCES;
203 		goto out;
204 	}
205 
206 #ifdef CONFIG_SYS_MEM_RESERVE_SECURE
207 	/*
208 	 * The SEC Firmware must be stored in secure memory.
209 	 * Append SEC Firmware to secure mmu table.
210 	 */
211 	if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
212 		ret = -ENXIO;
213 		goto out;
214 	}
215 
216 	sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
217 			gd->arch.tlb_size;
218 #else
219 #error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
220 #endif
221 
222 	/* Align SEC Firmware base address to 4K */
223 	sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
224 	debug("SEC Firmware: Load address: 0x%llx\n",
225 	      sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
226 
227 	ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
228 			&raw_image_size);
229 	if (ret)
230 		goto out;
231 
232 	/* TODO:
233 	 * Check if the end addr of SEC Firmware has been extend the secure
234 	 * memory.
235 	 */
236 
237 	/* Copy the secure firmware to secure memory */
238 	ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
239 			raw_image_size, sec_firmware_addr &
240 			SEC_FIRMWARE_ADDR_MASK);
241 	if (ret)
242 		goto out;
243 
244 	/*
245 	 * Check if any loadable are present along with firmware image, if
246 	 * present load them.
247 	 */
248 	ret = sec_firmware_check_copy_loadable(sec_firmware_img, loadable_l,
249 					       loadable_h);
250 	if (ret)
251 		goto out;
252 
253 	sec_firmware_addr |= SEC_FIRMWARE_LOADED;
254 	debug("SEC Firmware: Entry point: 0x%llx\n",
255 	      sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
256 
257 	return 0;
258 
259 out:
260 	printf("SEC Firmware: error (%d)\n", ret);
261 	sec_firmware_addr = 0;
262 
263 	return ret;
264 }
265 
266 static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
267 {
268 	const void *entry = (void *)(sec_firmware_addr &
269 				SEC_FIRMWARE_ADDR_MASK);
270 
271 	return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
272 }
273 
274 /* Check the secure firmware FIT image */
275 __weak bool sec_firmware_is_valid(const void *sec_firmware_img)
276 {
277 	if (fdt_check_header(sec_firmware_img)) {
278 		printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
279 		return false;
280 	}
281 
282 	if (!fit_check_format(sec_firmware_img)) {
283 		printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
284 		return false;
285 	}
286 
287 	return true;
288 }
289 
290 #ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
291 /*
292  * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
293  * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
294  * number will be returned according to SMC Calling Conventions. But
295  * when getting the NOT_SUPPORTED error number, we cannot ensure if
296  * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
297  * won't be supported by this framework.
298  * And if the secure firmware isn't running, return NOT_SUPPORTED.
299  *
300  * The return value on success is PSCI version in format
301  * major[31:16]:minor[15:0].
302  */
303 unsigned int sec_firmware_support_psci_version(void)
304 {
305 	if (current_el() == SEC_FIRMWARE_TARGET_EL)
306 		return _sec_firmware_support_psci_version();
307 
308 	return PSCI_INVALID_VER;
309 }
310 #endif
311 
312 /*
313  * Check with sec_firmware if it supports random number generation
314  * via HW RNG
315  *
316  * The return value will be true if it is supported
317  */
318 bool sec_firmware_support_hwrng(void)
319 {
320 	uint8_t rand[8];
321 	if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
322 		if (!sec_firmware_get_random(rand, 8))
323 			return true;
324 	}
325 
326 	return false;
327 }
328 
329 /*
330  * sec_firmware_get_random - Get a random number from SEC Firmware
331  * @rand:		random number buffer to be filled
332  * @bytes:		Number of bytes of random number to be supported
333  * @eret:		-1 in case of error, 0 for success
334  */
335 int sec_firmware_get_random(uint8_t *rand, int bytes)
336 {
337 	unsigned long long num;
338 	struct pt_regs regs;
339 	int param1;
340 
341 	if (!bytes || bytes > 8) {
342 		printf("Max Random bytes genration supported is 8\n");
343 		return -1;
344 	}
345 #define SIP_RNG_64 0xC200FF11
346 	regs.regs[0] = SIP_RNG_64;
347 
348 	if (bytes <= 4)
349 		param1 = 0;
350 	else
351 		param1 = 1;
352 	regs.regs[1] = param1;
353 
354 	smc_call(&regs);
355 
356 	if (regs.regs[0])
357 		return -1;
358 
359 	num = regs.regs[1];
360 	memcpy(rand, &num, bytes);
361 
362 	return 0;
363 }
364 
365 /*
366  * sec_firmware_init - Initialize the SEC Firmware
367  * @sec_firmware_img:	the SEC Firmware image address
368  * @eret_hold_l:	the address to hold exception return address low
369  * @eret_hold_h:	the address to hold exception return address high
370  * @loadable_l:		the address to hold loadable address low
371  * @loadable_h:		the address to hold loadable address high
372  */
373 int sec_firmware_init(const void *sec_firmware_img,
374 			u32 *eret_hold_l,
375 			u32 *eret_hold_h,
376 			u32 *loadable_l,
377 			u32 *loadable_h)
378 {
379 	int ret;
380 
381 	if (!sec_firmware_is_valid(sec_firmware_img))
382 		return -EINVAL;
383 
384 	ret = sec_firmware_load_image(sec_firmware_img, loadable_l,
385 				      loadable_h);
386 	if (ret) {
387 		printf("SEC Firmware: Failed to load image\n");
388 		return ret;
389 	} else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
390 		ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
391 		if (ret) {
392 			printf("SEC Firmware: Failed to initialize\n");
393 			return ret;
394 		}
395 	}
396 
397 	debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
398 	      current_el());
399 
400 	/*
401 	 * The PE will be turned into target EL when returned from
402 	 * SEC Firmware.
403 	 */
404 	if (current_el() != SEC_FIRMWARE_TARGET_EL)
405 		return -EACCES;
406 
407 	sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
408 
409 	/* Set exception table and enable caches if it isn't EL3 */
410 	if (current_el() != 3) {
411 		c_runtime_cpu_setup();
412 		enable_caches();
413 	}
414 
415 	return 0;
416 }
417 
418 /*
419  * fdt_fix_kaslr - Add kalsr-seed node in Device tree
420  * @fdt:		Device tree
421  * @eret:		0 in case of error, 1 for success
422  */
423 int fdt_fixup_kaslr(void *fdt)
424 {
425 	int nodeoffset;
426 	int err, ret = 0;
427 	u8 rand[8];
428 
429 #if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
430 	/* Check if random seed generation is  supported */
431 	if (sec_firmware_support_hwrng() == false)
432 		return 0;
433 
434 	ret = sec_firmware_get_random(rand, 8);
435 	if (ret < 0) {
436 		printf("WARNING: No random number to set kaslr-seed\n");
437 		return 0;
438 	}
439 
440 	err = fdt_check_header(fdt);
441 	if (err < 0) {
442 		printf("fdt_chosen: %s\n", fdt_strerror(err));
443 		return 0;
444 	}
445 
446 	/* find or create "/chosen" node. */
447 	nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
448 	if (nodeoffset < 0)
449 		return 0;
450 
451 	err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
452 				  sizeof(rand));
453 	if (err < 0) {
454 		printf("WARNING: can't set kaslr-seed %s.\n",
455 		       fdt_strerror(err));
456 		return 0;
457 	}
458 	ret = 1;
459 #endif
460 
461 	return ret;
462 }
463