xref: /openbmc/u-boot/arch/arm/cpu/armv7/virt-v7.c (revision 067716ba)
1 /*
2  * (C) Copyright 2013
3  * Andre Przywara, Linaro <andre.przywara@linaro.org>
4  *
5  * Routines to transition ARMv7 processors from secure into non-secure state
6  * and from non-secure SVC into HYP mode
7  * needed to enable ARMv7 virtualization for current hypervisors
8  *
9  * SPDX-License-Identifier:	GPL-2.0+
10  */
11 
12 #include <common.h>
13 #include <asm/armv7.h>
14 #include <asm/gic.h>
15 #include <asm/io.h>
16 #include <asm/secure.h>
17 
18 static unsigned int read_id_pfr1(void)
19 {
20 	unsigned int reg;
21 
22 	asm("mrc p15, 0, %0, c0, c1, 1\n" : "=r"(reg));
23 	return reg;
24 }
25 
26 static unsigned long get_gicd_base_address(void)
27 {
28 #ifdef CONFIG_ARM_GIC_BASE_ADDRESS
29 	return CONFIG_ARM_GIC_BASE_ADDRESS + GIC_DIST_OFFSET;
30 #else
31 	unsigned periphbase;
32 
33 	/* get the GIC base address from the CBAR register */
34 	asm("mrc p15, 4, %0, c15, c0, 0\n" : "=r" (periphbase));
35 
36 	/* the PERIPHBASE can be mapped above 4 GB (lower 8 bits used to
37 	 * encode this). Bail out here since we cannot access this without
38 	 * enabling paging.
39 	 */
40 	if ((periphbase & 0xff) != 0) {
41 		printf("nonsec: PERIPHBASE is above 4 GB, no access.\n");
42 		return -1;
43 	}
44 
45 	return (periphbase & CBAR_MASK) + GIC_DIST_OFFSET;
46 #endif
47 }
48 
49 /* Define a specific version of this function to enable any available
50  * hardware protections for the reserved region */
51 void __weak protect_secure_section(void) {}
52 
53 static void relocate_secure_section(void)
54 {
55 #ifdef CONFIG_ARMV7_SECURE_BASE
56 	size_t sz = __secure_end - __secure_start;
57 	unsigned long szflush = ALIGN(sz + 1, CONFIG_SYS_CACHELINE_SIZE);
58 
59 	memcpy((void *)CONFIG_ARMV7_SECURE_BASE, __secure_start, sz);
60 
61 	flush_dcache_range(CONFIG_ARMV7_SECURE_BASE,
62 			   CONFIG_ARMV7_SECURE_BASE + szflush);
63 	protect_secure_section();
64 	invalidate_icache_all();
65 #endif
66 }
67 
68 static void kick_secondary_cpus_gic(unsigned long gicdaddr)
69 {
70 	/* kick all CPUs (except this one) by writing to GICD_SGIR */
71 	writel(1U << 24, gicdaddr + GICD_SGIR);
72 }
73 
74 void __weak smp_kick_all_cpus(void)
75 {
76 	unsigned long gic_dist_addr;
77 
78 	gic_dist_addr = get_gicd_base_address();
79 	if (gic_dist_addr == -1)
80 		return;
81 
82 	kick_secondary_cpus_gic(gic_dist_addr);
83 }
84 
85 __weak void psci_board_init(void)
86 {
87 }
88 
89 int armv7_init_nonsec(void)
90 {
91 	unsigned int reg;
92 	unsigned itlinesnr, i;
93 	unsigned long gic_dist_addr;
94 
95 	/* check whether the CPU supports the security extensions */
96 	reg = read_id_pfr1();
97 	if ((reg & 0xF0) == 0) {
98 		printf("nonsec: Security extensions not implemented.\n");
99 		return -1;
100 	}
101 
102 	/* the SCR register will be set directly in the monitor mode handler,
103 	 * according to the spec one should not tinker with it in secure state
104 	 * in SVC mode. Do not try to read it once in non-secure state,
105 	 * any access to it will trap.
106 	 */
107 
108 	gic_dist_addr = get_gicd_base_address();
109 	if (gic_dist_addr == -1)
110 		return -1;
111 
112 	/* enable the GIC distributor */
113 	writel(readl(gic_dist_addr + GICD_CTLR) | 0x03,
114 	       gic_dist_addr + GICD_CTLR);
115 
116 	/* TYPER[4:0] contains an encoded number of available interrupts */
117 	itlinesnr = readl(gic_dist_addr + GICD_TYPER) & 0x1f;
118 
119 	/* set all bits in the GIC group registers to one to allow access
120 	 * from non-secure state. The first 32 interrupts are private per
121 	 * CPU and will be set later when enabling the GIC for each core
122 	 */
123 	for (i = 1; i <= itlinesnr; i++)
124 		writel((unsigned)-1, gic_dist_addr + GICD_IGROUPRn + 4 * i);
125 
126 	psci_board_init();
127 
128 	/*
129 	 * Relocate secure section before any cpu runs in secure ram.
130 	 * smp_kick_all_cpus may enable other cores and runs into secure
131 	 * ram, so need to relocate secure section before enabling other
132 	 * cores.
133 	 */
134 	relocate_secure_section();
135 
136 #ifndef CONFIG_ARMV7_PSCI
137 	smp_set_core_boot_addr((unsigned long)secure_ram_addr(_smp_pen), -1);
138 	smp_kick_all_cpus();
139 #endif
140 
141 	/* call the non-sec switching code on this CPU also */
142 	secure_ram_addr(_nonsec_init)();
143 	return 0;
144 }
145