1 /*
2  * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <inttypes.h>
9 #include <stdint.h>
10 
11 #include <libfdt.h>
12 
13 #include <platform_def.h>
14 #include <arch_helpers.h>
15 #include <common/bl_common.h>
16 #include <lib/mmio.h>
17 #include <lib/xlat_tables/xlat_mmu_helpers.h>
18 #include <lib/xlat_tables/xlat_tables_defs.h>
19 #include <lib/xlat_tables/xlat_tables_v2.h>
20 #include <plat/common/platform.h>
21 #include <common/fdt_fixup.h>
22 #include <common/fdt_wrappers.h>
23 #include <libfdt.h>
24 
25 #include <drivers/arm/gicv2.h>
26 
27 #include <rpi_shared.h>
28 
29 /*
30  * Fields at the beginning of armstub8.bin.
31  * While building the BL31 image, we put the stub magic into the binary.
32  * The GPU firmware detects this at boot time, clears that field as a
33  * confirmation and puts the kernel and DT address in the following words.
34  */
35 extern uint32_t stub_magic;
36 extern uint32_t dtb_ptr32;
37 extern uint32_t kernel_entry32;
38 
39 static const gicv2_driver_data_t rpi4_gic_data = {
40 	.gicd_base = RPI4_GIC_GICD_BASE,
41 	.gicc_base = RPI4_GIC_GICC_BASE,
42 };
43 
44 /*
45  * To be filled by the code below. At the moment BL32 is not supported.
46  * In the future these might be passed down from BL2.
47  */
48 static entry_point_info_t bl32_image_ep_info;
49 static entry_point_info_t bl33_image_ep_info;
50 
51 /*******************************************************************************
52  * Return a pointer to the 'entry_point_info' structure of the next image for
53  * the security state specified. BL33 corresponds to the non-secure image type
54  * while BL32 corresponds to the secure image type. A NULL pointer is returned
55  * if the image does not exist.
56  ******************************************************************************/
bl31_plat_get_next_image_ep_info(uint32_t type)57 entry_point_info_t *bl31_plat_get_next_image_ep_info(uint32_t type)
58 {
59 	entry_point_info_t *next_image_info;
60 
61 	assert(sec_state_is_valid(type) != 0);
62 
63 	next_image_info = (type == NON_SECURE)
64 			? &bl33_image_ep_info : &bl32_image_ep_info;
65 
66 	/* None of the images can have 0x0 as the entrypoint. */
67 	if (next_image_info->pc) {
68 		return next_image_info;
69 	} else {
70 		return NULL;
71 	}
72 }
73 
plat_get_ns_image_entrypoint(void)74 uintptr_t plat_get_ns_image_entrypoint(void)
75 {
76 #ifdef PRELOADED_BL33_BASE
77 	return PRELOADED_BL33_BASE;
78 #else
79 	/* Cleared by the GPU if kernel address is valid. */
80 	if (stub_magic == 0)
81 		return kernel_entry32;
82 
83 	WARN("Stub magic failure, using default kernel address 0x80000\n");
84 	return 0x80000;
85 #endif
86 }
87 
rpi4_get_dtb_address(void)88 static uintptr_t rpi4_get_dtb_address(void)
89 {
90 #ifdef RPI3_PRELOADED_DTB_BASE
91 	return RPI3_PRELOADED_DTB_BASE;
92 #else
93 	/* Cleared by the GPU if DTB address is valid. */
94 	if (stub_magic == 0)
95 		return dtb_ptr32;
96 
97 	WARN("Stub magic failure, DTB address unknown\n");
98 	return 0;
99 #endif
100 }
101 
ldelay(register_t delay)102 static void ldelay(register_t delay)
103 {
104 	__asm__ volatile (
105 		"1:\tcbz %0, 2f\n\t"
106 		"sub %0, %0, #1\n\t"
107 		"b 1b\n"
108 		"2:"
109 		: "=&r" (delay) : "0" (delay)
110 	);
111 }
112 
113 /*******************************************************************************
114  * Perform any BL31 early platform setup. Here is an opportunity to copy
115  * parameters passed by the calling EL (S-EL1 in BL2 & EL3 in BL1) before
116  * they are lost (potentially). This needs to be done before the MMU is
117  * initialized so that the memory layout can be used while creating page
118  * tables. BL2 has flushed this information to memory, so we are guaranteed
119  * to pick up good data.
120  ******************************************************************************/
bl31_early_platform_setup2(u_register_t arg0,u_register_t arg1,u_register_t arg2,u_register_t arg3)121 void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
122 				u_register_t arg2, u_register_t arg3)
123 
124 {
125 	/*
126 	 * LOCAL_CONTROL:
127 	 * Bit 9 clear: Increment by 1 (vs. 2).
128 	 * Bit 8 clear: Timer source is 19.2MHz crystal (vs. APB).
129 	 */
130 	mmio_write_32(RPI4_LOCAL_CONTROL_BASE_ADDRESS, 0);
131 
132 	/* LOCAL_PRESCALER; divide-by (0x80000000 / register_val) == 1 */
133 	mmio_write_32(RPI4_LOCAL_CONTROL_PRESCALER, 0x80000000);
134 
135 	/* Early GPU firmware revisions need a little break here. */
136 	ldelay(100000);
137 
138 	/* Initialize the console to provide early debug support. */
139 	rpi3_console_init();
140 
141 	bl33_image_ep_info.pc = plat_get_ns_image_entrypoint();
142 	bl33_image_ep_info.spsr = rpi3_get_spsr_for_bl33_entry();
143 	SET_SECURITY_STATE(bl33_image_ep_info.h.attr, NON_SECURE);
144 
145 #if RPI3_DIRECT_LINUX_BOOT
146 # if RPI3_BL33_IN_AARCH32
147 	/*
148 	 * According to the file ``Documentation/arm/Booting`` of the Linux
149 	 * kernel tree, Linux expects:
150 	 * r0 = 0
151 	 * r1 = machine type number, optional in DT-only platforms (~0 if so)
152 	 * r2 = Physical address of the device tree blob
153 	 */
154 	VERBOSE("rpi4: Preparing to boot 32-bit Linux kernel\n");
155 	bl33_image_ep_info.args.arg0 = 0U;
156 	bl33_image_ep_info.args.arg1 = ~0U;
157 	bl33_image_ep_info.args.arg2 = rpi4_get_dtb_address();
158 # else
159 	/*
160 	 * According to the file ``Documentation/arm64/booting.txt`` of the
161 	 * Linux kernel tree, Linux expects the physical address of the device
162 	 * tree blob (DTB) in x0, while x1-x3 are reserved for future use and
163 	 * must be 0.
164 	 */
165 	VERBOSE("rpi4: Preparing to boot 64-bit Linux kernel\n");
166 	bl33_image_ep_info.args.arg0 = rpi4_get_dtb_address();
167 	bl33_image_ep_info.args.arg1 = 0ULL;
168 	bl33_image_ep_info.args.arg2 = 0ULL;
169 	bl33_image_ep_info.args.arg3 = 0ULL;
170 # endif /* RPI3_BL33_IN_AARCH32 */
171 #endif /* RPI3_DIRECT_LINUX_BOOT */
172 }
173 
bl31_plat_arch_setup(void)174 void bl31_plat_arch_setup(void)
175 {
176 	/*
177 	 * Is the dtb_ptr32 pointer valid? If yes, map the DTB region.
178 	 * We map the 2MB region the DTB start address lives in, plus
179 	 * the next 2MB, to have enough room for expansion.
180 	 */
181 	if (stub_magic == 0) {
182 		unsigned long long dtb_region = dtb_ptr32;
183 
184 		dtb_region &= ~0x1fffff;	/* Align to 2 MB. */
185 		mmap_add_region(dtb_region, dtb_region, 4U << 20,
186 				MT_MEMORY | MT_RW | MT_NS);
187 	}
188 	/*
189 	 * Add the first page of memory, which holds the stub magic,
190 	 * the kernel and the DT address.
191 	 * This also holds the secondary CPU's entrypoints and mailboxes.
192 	 */
193 	mmap_add_region(0, 0, 4096, MT_NON_CACHEABLE | MT_RW | MT_SECURE);
194 
195 	rpi3_setup_page_tables(BL31_BASE, BL31_END - BL31_BASE,
196 			       BL_CODE_BASE, BL_CODE_END,
197 			       BL_RO_DATA_BASE, BL_RO_DATA_END
198 #if USE_COHERENT_MEM
199 			       , BL_COHERENT_RAM_BASE, BL_COHERENT_RAM_END
200 #endif
201 			      );
202 
203 	enable_mmu_el3(0);
204 }
205 
206 /*
207  * Remove the FDT /memreserve/ entry that covers the region at the very
208  * beginning of memory (if that exists). This is where the secondaries
209  * originally spin, but we pull them out there.
210  * Having overlapping /reserved-memory and /memreserve/ regions confuses
211  * the Linux kernel, so we need to get rid of this one.
212  */
remove_spintable_memreserve(void * dtb)213 static void remove_spintable_memreserve(void *dtb)
214 {
215 	uint64_t addr, size;
216 	int regions = fdt_num_mem_rsv(dtb);
217 	int i;
218 
219 	for (i = 0; i < regions; i++) {
220 		if (fdt_get_mem_rsv(dtb, i, &addr, &size) != 0) {
221 			return;
222 		}
223 		if (size == 0U) {
224 			return;
225 		}
226 		/* We only look for the region at the beginning of DRAM. */
227 		if (addr != 0U) {
228 			continue;
229 		}
230 		/*
231 		 * Currently the region in the existing DTs is exactly 4K
232 		 * in size. Should this value ever change, there is probably
233 		 * a reason for that, so inform the user about this.
234 		 */
235 		if (size == 4096U) {
236 			fdt_del_mem_rsv(dtb, i);
237 			return;
238 		}
239 		WARN("Keeping unknown /memreserve/ region at 0, size: %" PRId64 "\n",
240 		     size);
241 	}
242 }
243 
rpi4_prepare_dtb(void)244 static void rpi4_prepare_dtb(void)
245 {
246 	void *dtb = (void *)rpi4_get_dtb_address();
247 	uint32_t gic_int_prop[3];
248 	int ret, offs;
249 
250 	/* Return if no device tree is detected */
251 	if (fdt_check_header(dtb) != 0)
252 		return;
253 
254 	ret = fdt_open_into(dtb, dtb, 0x100000);
255 	if (ret < 0) {
256 		ERROR("Invalid Device Tree at %p: error %d\n", dtb, ret);
257 		return;
258 	}
259 
260 	if (dt_add_psci_node(dtb)) {
261 		ERROR("Failed to add PSCI Device Tree node\n");
262 		return;
263 	}
264 
265 	if (dt_add_psci_cpu_enable_methods(dtb)) {
266 		ERROR("Failed to add PSCI cpu enable methods in Device Tree\n");
267 		return;
268 	}
269 
270 	/*
271 	 * Remove the original reserved region (used for the spintable), and
272 	 * replace it with a region describing the whole of Trusted Firmware.
273 	 */
274 	remove_spintable_memreserve(dtb);
275 	if (fdt_add_reserved_memory(dtb, "atf@0", 0, 0x80000))
276 		WARN("Failed to add reserved memory nodes to DT.\n");
277 
278 	offs = fdt_node_offset_by_compatible(dtb, 0, "arm,gic-400");
279 	gic_int_prop[0] = cpu_to_fdt32(1);		// PPI
280 	gic_int_prop[1] = cpu_to_fdt32(9);		// PPI #9
281 	gic_int_prop[2] = cpu_to_fdt32(0x0f04);		// all cores, level high
282 	fdt_setprop(dtb, offs, "interrupts", gic_int_prop, 12);
283 
284 	offs = fdt_path_offset(dtb, "/chosen");
285 	fdt_setprop_string(dtb, offs, "stdout-path", "serial0");
286 
287 	ret = fdt_pack(dtb);
288 	if (ret < 0)
289 		ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret);
290 
291 	clean_dcache_range((uintptr_t)dtb, fdt_blob_size(dtb));
292 	INFO("Changed device tree to advertise PSCI.\n");
293 }
294 
bl31_platform_setup(void)295 void bl31_platform_setup(void)
296 {
297 	rpi4_prepare_dtb();
298 
299 	/* Configure the interrupt controller */
300 	gicv2_driver_init(&rpi4_gic_data);
301 	gicv2_distif_init();
302 	gicv2_pcpu_distif_init();
303 	gicv2_cpuif_enable();
304 }
305