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