xref: /openbmc/u-boot/arch/arm/cpu/armv7/virt-v7.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2013
4  * Andre Przywara, Linaro <andre.przywara@linaro.org>
5  *
6  * Routines to transition ARMv7 processors from secure into non-secure state
7  * and from non-secure SVC into HYP mode
8  * needed to enable ARMv7 virtualization for current hypervisors
9  */
10 
11 #include <common.h>
12 #include <asm/armv7.h>
13 #include <asm/gic.h>
14 #include <asm/io.h>
15 #include <asm/secure.h>
16 
17 static unsigned int read_id_pfr1(void)
18 {
19 	unsigned int reg;
20 
21 	asm("mrc p15, 0, %0, c0, c1, 1\n" : "=r"(reg));
22 	return reg;
23 }
24 
25 static unsigned long get_gicd_base_address(void)
26 {
27 #ifdef CONFIG_ARM_GIC_BASE_ADDRESS
28 	return CONFIG_ARM_GIC_BASE_ADDRESS + GIC_DIST_OFFSET;
29 #else
30 	unsigned periphbase;
31 
32 	/* get the GIC base address from the CBAR register */
33 	asm("mrc p15, 4, %0, c15, c0, 0\n" : "=r" (periphbase));
34 
35 	/* the PERIPHBASE can be mapped above 4 GB (lower 8 bits used to
36 	 * encode this). Bail out here since we cannot access this without
37 	 * enabling paging.
38 	 */
39 	if ((periphbase & 0xff) != 0) {
40 		printf("nonsec: PERIPHBASE is above 4 GB, no access.\n");
41 		return -1;
42 	}
43 
44 	return (periphbase & CBAR_MASK) + GIC_DIST_OFFSET;
45 #endif
46 }
47 
48 /* Define a specific version of this function to enable any available
49  * hardware protections for the reserved region */
50 void __weak protect_secure_section(void) {}
51 
52 static void relocate_secure_section(void)
53 {
54 #ifdef CONFIG_ARMV7_SECURE_BASE
55 	size_t sz = __secure_end - __secure_start;
56 	unsigned long szflush = ALIGN(sz + 1, CONFIG_SYS_CACHELINE_SIZE);
57 
58 	memcpy((void *)CONFIG_ARMV7_SECURE_BASE, __secure_start, sz);
59 
60 	flush_dcache_range(CONFIG_ARMV7_SECURE_BASE,
61 			   CONFIG_ARMV7_SECURE_BASE + szflush);
62 	protect_secure_section();
63 	invalidate_icache_all();
64 #endif
65 }
66 
67 static void kick_secondary_cpus_gic(unsigned long gicdaddr)
68 {
69 	/* kick all CPUs (except this one) by writing to GICD_SGIR */
70 	writel(1U << 24, gicdaddr + GICD_SGIR);
71 }
72 
73 void __weak smp_kick_all_cpus(void)
74 {
75 	unsigned long gic_dist_addr;
76 
77 	gic_dist_addr = get_gicd_base_address();
78 	if (gic_dist_addr == -1)
79 		return;
80 
81 	kick_secondary_cpus_gic(gic_dist_addr);
82 }
83 
84 __weak void psci_board_init(void)
85 {
86 }
87 
88 int armv7_init_nonsec(void)
89 {
90 	unsigned int reg;
91 	unsigned itlinesnr, i;
92 	unsigned long gic_dist_addr;
93 
94 	/* check whether the CPU supports the security extensions */
95 	reg = read_id_pfr1();
96 	if ((reg & 0xF0) == 0) {
97 		printf("nonsec: Security extensions not implemented.\n");
98 		return -1;
99 	}
100 
101 	/* the SCR register will be set directly in the monitor mode handler,
102 	 * according to the spec one should not tinker with it in secure state
103 	 * in SVC mode. Do not try to read it once in non-secure state,
104 	 * any access to it will trap.
105 	 */
106 
107 	gic_dist_addr = get_gicd_base_address();
108 	if (gic_dist_addr == -1)
109 		return -1;
110 
111 	/* enable the GIC distributor */
112 	writel(readl(gic_dist_addr + GICD_CTLR) | 0x03,
113 	       gic_dist_addr + GICD_CTLR);
114 
115 	/* TYPER[4:0] contains an encoded number of available interrupts */
116 	itlinesnr = readl(gic_dist_addr + GICD_TYPER) & 0x1f;
117 
118 	/* set all bits in the GIC group registers to one to allow access
119 	 * from non-secure state. The first 32 interrupts are private per
120 	 * CPU and will be set later when enabling the GIC for each core
121 	 */
122 	for (i = 1; i <= itlinesnr; i++)
123 		writel((unsigned)-1, gic_dist_addr + GICD_IGROUPRn + 4 * i);
124 
125 	psci_board_init();
126 
127 	/*
128 	 * Relocate secure section before any cpu runs in secure ram.
129 	 * smp_kick_all_cpus may enable other cores and runs into secure
130 	 * ram, so need to relocate secure section before enabling other
131 	 * cores.
132 	 */
133 	relocate_secure_section();
134 
135 #ifndef CONFIG_ARMV7_PSCI
136 	smp_set_core_boot_addr((unsigned long)secure_ram_addr(_smp_pen), -1);
137 	smp_kick_all_cpus();
138 #endif
139 
140 	/* call the non-sec switching code on this CPU also */
141 	secure_ram_addr(_nonsec_init)();
142 	return 0;
143 }
144