1 /*
2 * Copyright (c) 2016-2020, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 /*
8 * Contains generic routines to fix up the device tree blob passed on to
9 * payloads like BL32 and BL33 (and further down the boot chain).
10 * This allows to easily add PSCI nodes, when the original DT does not have
11 * it or advertises another method.
12 * Also it supports to add reserved memory nodes to describe memory that
13 * is used by the secure world, so that non-secure software avoids using
14 * that.
15 */
16
17 #include <errno.h>
18 #include <stdio.h>
19 #include <string.h>
20
21 #include <libfdt.h>
22
23 #include <arch.h>
24 #include <common/debug.h>
25 #include <common/fdt_fixup.h>
26 #include <common/fdt_wrappers.h>
27 #include <drivers/console.h>
28 #include <lib/psci/psci.h>
29 #include <plat/common/platform.h>
30
31
append_psci_compatible(void * fdt,int offs,const char * str)32 static int append_psci_compatible(void *fdt, int offs, const char *str)
33 {
34 return fdt_appendprop(fdt, offs, "compatible", str, strlen(str) + 1);
35 }
36
37 /*
38 * Those defines are for PSCI v0.1 legacy clients, which we expect to use
39 * the same execution state (AArch32/AArch64) as TF-A.
40 * Kernels running in AArch32 on an AArch64 TF-A should use PSCI v0.2.
41 */
42 #ifdef __aarch64__
43 #define PSCI_CPU_SUSPEND_FNID PSCI_CPU_SUSPEND_AARCH64
44 #define PSCI_CPU_ON_FNID PSCI_CPU_ON_AARCH64
45 #else
46 #define PSCI_CPU_SUSPEND_FNID PSCI_CPU_SUSPEND_AARCH32
47 #define PSCI_CPU_ON_FNID PSCI_CPU_ON_AARCH32
48 #endif
49
50 /*******************************************************************************
51 * dt_add_psci_node() - Add a PSCI node into an existing device tree
52 * @fdt: pointer to the device tree blob in memory
53 *
54 * Add a device tree node describing PSCI into the root level of an existing
55 * device tree blob in memory.
56 * This will add v0.1, v0.2 and v1.0 compatible strings and the standard
57 * function IDs for v0.1 compatibility.
58 * An existing PSCI node will not be touched, the function will return success
59 * in this case. This function will not touch the /cpus enable methods, use
60 * dt_add_psci_cpu_enable_methods() for that.
61 *
62 * Return: 0 on success, -1 otherwise.
63 ******************************************************************************/
dt_add_psci_node(void * fdt)64 int dt_add_psci_node(void *fdt)
65 {
66 int offs;
67
68 if (fdt_path_offset(fdt, "/psci") >= 0) {
69 WARN("PSCI Device Tree node already exists!\n");
70 return 0;
71 }
72
73 offs = fdt_path_offset(fdt, "/");
74 if (offs < 0)
75 return -1;
76 offs = fdt_add_subnode(fdt, offs, "psci");
77 if (offs < 0)
78 return -1;
79 if (append_psci_compatible(fdt, offs, "arm,psci-1.0"))
80 return -1;
81 if (append_psci_compatible(fdt, offs, "arm,psci-0.2"))
82 return -1;
83 if (append_psci_compatible(fdt, offs, "arm,psci"))
84 return -1;
85 if (fdt_setprop_string(fdt, offs, "method", "smc"))
86 return -1;
87 if (fdt_setprop_u32(fdt, offs, "cpu_suspend", PSCI_CPU_SUSPEND_FNID))
88 return -1;
89 if (fdt_setprop_u32(fdt, offs, "cpu_off", PSCI_CPU_OFF))
90 return -1;
91 if (fdt_setprop_u32(fdt, offs, "cpu_on", PSCI_CPU_ON_FNID))
92 return -1;
93 return 0;
94 }
95
96 /*
97 * Find the first subnode that has a "device_type" property with the value
98 * "cpu" and which's enable-method is not "psci" (yet).
99 * Returns 0 if no such subnode is found, so all have already been patched
100 * or none have to be patched in the first place.
101 * Returns 1 if *one* such subnode has been found and successfully changed
102 * to "psci".
103 * Returns negative values on error.
104 *
105 * Call in a loop until it returns 0. Recalculate the node offset after
106 * it has returned 1.
107 */
dt_update_one_cpu_node(void * fdt,int offset)108 static int dt_update_one_cpu_node(void *fdt, int offset)
109 {
110 int offs;
111
112 /* Iterate over all subnodes to find those with device_type = "cpu". */
113 for (offs = fdt_first_subnode(fdt, offset); offs >= 0;
114 offs = fdt_next_subnode(fdt, offs)) {
115 const char *prop;
116 int len;
117 int ret;
118
119 prop = fdt_getprop(fdt, offs, "device_type", &len);
120 if (prop == NULL)
121 continue;
122 if ((strcmp(prop, "cpu") != 0) || (len != 4))
123 continue;
124
125 /* Ignore any nodes which already use "psci". */
126 prop = fdt_getprop(fdt, offs, "enable-method", &len);
127 if ((prop != NULL) &&
128 (strcmp(prop, "psci") == 0) && (len == 5))
129 continue;
130
131 ret = fdt_setprop_string(fdt, offs, "enable-method", "psci");
132 if (ret < 0)
133 return ret;
134 /*
135 * Subnode found and patched.
136 * Restart to accommodate potentially changed offsets.
137 */
138 return 1;
139 }
140
141 if (offs == -FDT_ERR_NOTFOUND)
142 return 0;
143
144 return offs;
145 }
146
147 /*******************************************************************************
148 * dt_add_psci_cpu_enable_methods() - switch CPU nodes in DT to use PSCI
149 * @fdt: pointer to the device tree blob in memory
150 *
151 * Iterate over all CPU device tree nodes (/cpus/cpu@x) in memory to change
152 * the enable-method to PSCI. This will add the enable-method properties, if
153 * required, or will change existing properties to read "psci".
154 *
155 * Return: 0 on success, or a negative error value otherwise.
156 ******************************************************************************/
157
dt_add_psci_cpu_enable_methods(void * fdt)158 int dt_add_psci_cpu_enable_methods(void *fdt)
159 {
160 int offs, ret;
161
162 do {
163 offs = fdt_path_offset(fdt, "/cpus");
164 if (offs < 0)
165 return offs;
166
167 ret = dt_update_one_cpu_node(fdt, offs);
168 } while (ret > 0);
169
170 return ret;
171 }
172
173 #define HIGH_BITS(x) ((sizeof(x) > 4) ? ((x) >> 32) : (typeof(x))0)
174
175 /*******************************************************************************
176 * fdt_add_reserved_memory() - reserve (secure) memory regions in DT
177 * @dtb: pointer to the device tree blob in memory
178 * @node_name: name of the subnode to be used
179 * @base: physical base address of the reserved region
180 * @size: size of the reserved region
181 *
182 * Add a region of memory to the /reserved-memory node in a device tree in
183 * memory, creating that node if required. Each region goes into a subnode
184 * of that node and has a @node_name, a @base address and a @size.
185 * This will prevent any device tree consumer from using that memory. It
186 * can be used to announce secure memory regions, as it adds the "no-map"
187 * property to prevent mapping and speculative operations on that region.
188 *
189 * See reserved-memory/reserved-memory.txt in the (Linux kernel) DT binding
190 * documentation for details.
191 * According to this binding, the address-cells and size-cells must match
192 * those of the root node.
193 *
194 * Return: 0 on success, a negative error value otherwise.
195 ******************************************************************************/
fdt_add_reserved_memory(void * dtb,const char * node_name,uintptr_t base,size_t size)196 int fdt_add_reserved_memory(void *dtb, const char *node_name,
197 uintptr_t base, size_t size)
198 {
199 int offs = fdt_path_offset(dtb, "/reserved-memory");
200 uint32_t addresses[4];
201 int ac, sc;
202 unsigned int idx = 0;
203
204 ac = fdt_address_cells(dtb, 0);
205 sc = fdt_size_cells(dtb, 0);
206 if (offs < 0) { /* create if not existing yet */
207 offs = fdt_add_subnode(dtb, 0, "reserved-memory");
208 if (offs < 0) {
209 return offs;
210 }
211 fdt_setprop_u32(dtb, offs, "#address-cells", ac);
212 fdt_setprop_u32(dtb, offs, "#size-cells", sc);
213 fdt_setprop(dtb, offs, "ranges", NULL, 0);
214 }
215
216 if (ac > 1) {
217 addresses[idx] = cpu_to_fdt32(HIGH_BITS(base));
218 idx++;
219 }
220 addresses[idx] = cpu_to_fdt32(base & 0xffffffff);
221 idx++;
222 if (sc > 1) {
223 addresses[idx] = cpu_to_fdt32(HIGH_BITS(size));
224 idx++;
225 }
226 addresses[idx] = cpu_to_fdt32(size & 0xffffffff);
227 idx++;
228 offs = fdt_add_subnode(dtb, offs, node_name);
229 fdt_setprop(dtb, offs, "no-map", NULL, 0);
230 fdt_setprop(dtb, offs, "reg", addresses, idx * sizeof(uint32_t));
231
232 return 0;
233 }
234
235 /*******************************************************************************
236 * fdt_add_cpu() Add a new CPU node to the DT
237 * @dtb: Pointer to the device tree blob in memory
238 * @parent: Offset of the parent node
239 * @mpidr: MPIDR for the current CPU
240 *
241 * Create and add a new cpu node to a DTB.
242 *
243 * Return the offset of the new node or a negative value in case of error
244 ******************************************************************************/
245
fdt_add_cpu(void * dtb,int parent,u_register_t mpidr)246 static int fdt_add_cpu(void *dtb, int parent, u_register_t mpidr)
247 {
248 int cpu_offs;
249 int err;
250 char snode_name[15];
251 uint64_t reg_prop;
252
253 reg_prop = mpidr & MPID_MASK & ~MPIDR_MT_MASK;
254
255 snprintf(snode_name, sizeof(snode_name), "cpu@%x",
256 (unsigned int)reg_prop);
257
258 cpu_offs = fdt_add_subnode(dtb, parent, snode_name);
259 if (cpu_offs < 0) {
260 ERROR ("FDT: add subnode \"%s\" failed: %i\n",
261 snode_name, cpu_offs);
262 return cpu_offs;
263 }
264
265 err = fdt_setprop_string(dtb, cpu_offs, "compatible", "arm,armv8");
266 if (err < 0) {
267 ERROR ("FDT: write to \"%s\" property of node at offset %i failed\n",
268 "compatible", cpu_offs);
269 return err;
270 }
271
272 err = fdt_setprop_u64(dtb, cpu_offs, "reg", reg_prop);
273 if (err < 0) {
274 ERROR ("FDT: write to \"%s\" property of node at offset %i failed\n",
275 "reg", cpu_offs);
276 return err;
277 }
278
279 err = fdt_setprop_string(dtb, cpu_offs, "device_type", "cpu");
280 if (err < 0) {
281 ERROR ("FDT: write to \"%s\" property of node at offset %i failed\n",
282 "device_type", cpu_offs);
283 return err;
284 }
285
286 err = fdt_setprop_string(dtb, cpu_offs, "enable-method", "psci");
287 if (err < 0) {
288 ERROR ("FDT: write to \"%s\" property of node at offset %i failed\n",
289 "enable-method", cpu_offs);
290 return err;
291 }
292
293 return cpu_offs;
294 }
295
296 /******************************************************************************
297 * fdt_add_cpus_node() - Add the cpus node to the DTB
298 * @dtb: pointer to the device tree blob in memory
299 * @afflv0: Maximum number of threads per core (affinity level 0).
300 * @afflv1: Maximum number of CPUs per cluster (affinity level 1).
301 * @afflv2: Maximum number of clusters (affinity level 2).
302 *
303 * Iterate over all the possible MPIDs given the maximum affinity levels and
304 * add a cpus node to the DTB with all the valid CPUs on the system.
305 * If there is already a /cpus node, exit gracefully
306 *
307 * A system with two CPUs would generate a node equivalent or similar to:
308 *
309 * cpus {
310 * #address-cells = <2>;
311 * #size-cells = <0>;
312 *
313 * cpu0: cpu@0 {
314 * compatible = "arm,armv8";
315 * reg = <0x0 0x0>;
316 * device_type = "cpu";
317 * enable-method = "psci";
318 * };
319 * cpu1: cpu@10000 {
320 * compatible = "arm,armv8";
321 * reg = <0x0 0x100>;
322 * device_type = "cpu";
323 * enable-method = "psci";
324 * };
325 * };
326 *
327 * Full documentation about the CPU bindings can be found at:
328 * https://www.kernel.org/doc/Documentation/devicetree/bindings/arm/cpus.txt
329 *
330 * Return the offset of the node or a negative value on error.
331 ******************************************************************************/
332
fdt_add_cpus_node(void * dtb,unsigned int afflv0,unsigned int afflv1,unsigned int afflv2)333 int fdt_add_cpus_node(void *dtb, unsigned int afflv0,
334 unsigned int afflv1, unsigned int afflv2)
335 {
336 int offs;
337 int err;
338 unsigned int i, j, k;
339 u_register_t mpidr;
340 int cpuid;
341
342 if (fdt_path_offset(dtb, "/cpus") >= 0) {
343 return -EEXIST;
344 }
345
346 offs = fdt_add_subnode(dtb, 0, "cpus");
347 if (offs < 0) {
348 ERROR ("FDT: add subnode \"cpus\" node to parent node failed");
349 return offs;
350 }
351
352 err = fdt_setprop_u32(dtb, offs, "#address-cells", 2);
353 if (err < 0) {
354 ERROR ("FDT: write to \"%s\" property of node at offset %i failed\n",
355 "#address-cells", offs);
356 return err;
357 }
358
359 err = fdt_setprop_u32(dtb, offs, "#size-cells", 0);
360 if (err < 0) {
361 ERROR ("FDT: write to \"%s\" property of node at offset %i failed\n",
362 "#size-cells", offs);
363 return err;
364 }
365
366 /*
367 * Populate the node with the CPUs.
368 * As libfdt prepends subnodes within a node, reverse the index count
369 * so the CPU nodes would be better ordered.
370 */
371 for (i = afflv2; i > 0U; i--) {
372 for (j = afflv1; j > 0U; j--) {
373 for (k = afflv0; k > 0U; k--) {
374 mpidr = ((i - 1) << MPIDR_AFF2_SHIFT) |
375 ((j - 1) << MPIDR_AFF1_SHIFT) |
376 ((k - 1) << MPIDR_AFF0_SHIFT) |
377 (read_mpidr_el1() & MPIDR_MT_MASK);
378
379 cpuid = plat_core_pos_by_mpidr(mpidr);
380 if (cpuid >= 0) {
381 /* Valid MPID found */
382 err = fdt_add_cpu(dtb, offs, mpidr);
383 if (err < 0) {
384 ERROR ("FDT: %s 0x%08x\n",
385 "error adding CPU",
386 (uint32_t)mpidr);
387 return err;
388 }
389 }
390 }
391 }
392 }
393
394 return offs;
395 }
396
397 /**
398 * fdt_adjust_gic_redist() - Adjust GICv3 redistributor size
399 * @dtb: Pointer to the DT blob in memory
400 * @nr_cores: Number of CPU cores on this system.
401 * @gicr_frame_size: Size of the GICR frame per core
402 *
403 * On a GICv3 compatible interrupt controller, the redistributor provides
404 * a number of 64k pages per each supported core. So with a dynamic topology,
405 * this size cannot be known upfront and thus can't be hardcoded into the DTB.
406 *
407 * Find the DT node describing the GICv3 interrupt controller, and adjust
408 * the size of the redistributor to match the number of actual cores on
409 * this system.
410 * A GICv4 compatible redistributor uses four 64K pages per core, whereas GICs
411 * without support for direct injection of virtual interrupts use two 64K pages.
412 * The @gicr_frame_size parameter should be 262144 and 131072, respectively.
413 *
414 * Return: 0 on success, negative error value otherwise.
415 */
fdt_adjust_gic_redist(void * dtb,unsigned int nr_cores,unsigned int gicr_frame_size)416 int fdt_adjust_gic_redist(void *dtb, unsigned int nr_cores,
417 unsigned int gicr_frame_size)
418 {
419 int offset = fdt_node_offset_by_compatible(dtb, 0, "arm,gic-v3");
420 uint64_t redist_size_64;
421 uint32_t redist_size_32;
422 void *val;
423 int parent;
424 int ac, sc;
425
426 if (offset < 0) {
427 return offset;
428 }
429
430 parent = fdt_parent_offset(dtb, offset);
431 if (parent < 0) {
432 return parent;
433 }
434 ac = fdt_address_cells(dtb, parent);
435 sc = fdt_size_cells(dtb, parent);
436 if (ac < 0 || sc < 0) {
437 return -EINVAL;
438 }
439
440 if (sc == 1) {
441 redist_size_32 = cpu_to_fdt32(nr_cores * gicr_frame_size);
442 val = &redist_size_32;
443 } else {
444 redist_size_64 = cpu_to_fdt64(nr_cores *
445 (uint64_t)gicr_frame_size);
446 val = &redist_size_64;
447 }
448
449 /*
450 * The redistributor is described in the second "reg" entry.
451 * So we have to skip one address and one size cell, then another
452 * address cell to get to the second size cell.
453 */
454 return fdt_setprop_inplace_namelen_partial(dtb, offset, "reg", 3,
455 (ac + sc + ac) * 4,
456 val, sc * 4);
457 }
458