xref: /openbmc/u-boot/arch/arm/cpu/armv7/virt-v7.c (revision f510aeae689925a660bff14683eef4147785d271)
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 unsigned long gic_dist_addr;
19 
20 static unsigned int read_id_pfr1(void)
21 {
22 	unsigned int reg;
23 
24 	asm("mrc p15, 0, %0, c0, c1, 1\n" : "=r"(reg));
25 	return reg;
26 }
27 
28 static unsigned long get_gicd_base_address(void)
29 {
30 #ifdef CONFIG_ARM_GIC_BASE_ADDRESS
31 	return CONFIG_ARM_GIC_BASE_ADDRESS + GIC_DIST_OFFSET;
32 #else
33 	unsigned midr;
34 	unsigned periphbase;
35 
36 	/* check whether we are an Cortex-A15 or A7.
37 	 * The actual HYP switch should work with all CPUs supporting
38 	 * the virtualization extension, but we need the GIC address,
39 	 * which we know only for sure for those two CPUs.
40 	 */
41 	asm("mrc p15, 0, %0, c0, c0, 0\n" : "=r"(midr));
42 	switch (midr & MIDR_PRIMARY_PART_MASK) {
43 	case MIDR_CORTEX_A9_R0P1:
44 	case MIDR_CORTEX_A15_R0P0:
45 	case MIDR_CORTEX_A7_R0P0:
46 		break;
47 	default:
48 		printf("nonsec: could not determine GIC address.\n");
49 		return -1;
50 	}
51 
52 	/* get the GIC base address from the CBAR register */
53 	asm("mrc p15, 4, %0, c15, c0, 0\n" : "=r" (periphbase));
54 
55 	/* the PERIPHBASE can be mapped above 4 GB (lower 8 bits used to
56 	 * encode this). Bail out here since we cannot access this without
57 	 * enabling paging.
58 	 */
59 	if ((periphbase & 0xff) != 0) {
60 		printf("nonsec: PERIPHBASE is above 4 GB, no access.\n");
61 		return -1;
62 	}
63 
64 	return (periphbase & CBAR_MASK) + GIC_DIST_OFFSET;
65 #endif
66 }
67 
68 static void relocate_secure_section(void)
69 {
70 #ifdef CONFIG_ARMV7_SECURE_BASE
71 	size_t sz = __secure_end - __secure_start;
72 
73 	memcpy((void *)CONFIG_ARMV7_SECURE_BASE, __secure_start, sz);
74 	flush_dcache_range(CONFIG_ARMV7_SECURE_BASE,
75 			   CONFIG_ARMV7_SECURE_BASE + sz + 1);
76 	invalidate_icache_all();
77 #endif
78 }
79 
80 static void kick_secondary_cpus_gic(unsigned long gicdaddr)
81 {
82 	/* kick all CPUs (except this one) by writing to GICD_SGIR */
83 	writel(1U << 24, gicdaddr + GICD_SGIR);
84 }
85 
86 void __weak smp_kick_all_cpus(void)
87 {
88 	kick_secondary_cpus_gic(gic_dist_addr);
89 }
90 
91 int armv7_init_nonsec(void)
92 {
93 	unsigned int reg;
94 	unsigned itlinesnr, i;
95 
96 	/* check whether the CPU supports the security extensions */
97 	reg = read_id_pfr1();
98 	if ((reg & 0xF0) == 0) {
99 		printf("nonsec: Security extensions not implemented.\n");
100 		return -1;
101 	}
102 
103 	/* the SCR register will be set directly in the monitor mode handler,
104 	 * according to the spec one should not tinker with it in secure state
105 	 * in SVC mode. Do not try to read it once in non-secure state,
106 	 * any access to it will trap.
107 	 */
108 
109 	gic_dist_addr = get_gicd_base_address();
110 	if (gic_dist_addr == -1)
111 		return -1;
112 
113 	/* enable the GIC distributor */
114 	writel(readl(gic_dist_addr + GICD_CTLR) | 0x03,
115 	       gic_dist_addr + GICD_CTLR);
116 
117 	/* TYPER[4:0] contains an encoded number of available interrupts */
118 	itlinesnr = readl(gic_dist_addr + GICD_TYPER) & 0x1f;
119 
120 	/* set all bits in the GIC group registers to one to allow access
121 	 * from non-secure state. The first 32 interrupts are private per
122 	 * CPU and will be set later when enabling the GIC for each core
123 	 */
124 	for (i = 1; i <= itlinesnr; i++)
125 		writel((unsigned)-1, gic_dist_addr + GICD_IGROUPRn + 4 * i);
126 
127 #ifndef CONFIG_ARMV7_PSCI
128 	smp_set_core_boot_addr((unsigned long)secure_ram_addr(_smp_pen), -1);
129 	smp_kick_all_cpus();
130 #endif
131 
132 	/* call the non-sec switching code on this CPU also */
133 	relocate_secure_section();
134 	secure_ram_addr(_nonsec_init)();
135 	return 0;
136 }
137