xref: /rk3399_ARM-atf/plat/nvidia/tegra/common/tegra_fiq_glue.c (revision c3cf06f1a3a9b9ee8ac7a0ae505f95c45f7dca84)
1 /*
2  * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <arch_helpers.h>
8 #include <assert.h>
9 #include <bakery_lock.h>
10 #include <bl_common.h>
11 #include <context.h>
12 #include <context_mgmt.h>
13 #include <debug.h>
14 #include <denver.h>
15 #include <interrupt_mgmt.h>
16 #include <platform.h>
17 #include <tegra_def.h>
18 #include <tegra_private.h>
19 
20 static DEFINE_BAKERY_LOCK(tegra_fiq_lock);
21 
22 /*******************************************************************************
23  * Static variables
24  ******************************************************************************/
25 static uint64_t ns_fiq_handler_addr;
26 static uint32_t fiq_handler_active;
27 static pcpu_fiq_state_t fiq_state[PLATFORM_CORE_COUNT];
28 
29 /*******************************************************************************
30  * Handler for FIQ interrupts
31  ******************************************************************************/
32 static uint64_t tegra_fiq_interrupt_handler(uint32_t id,
33 					  uint32_t flags,
34 					  void *handle,
35 					  void *cookie)
36 {
37 	cpu_context_t *ctx = cm_get_context(NON_SECURE);
38 	el3_state_t *el3state_ctx = get_el3state_ctx(ctx);
39 	uint32_t cpu = plat_my_core_pos();
40 	uint32_t irq;
41 
42 	bakery_lock_get(&tegra_fiq_lock);
43 
44 	/*
45 	 * The FIQ was generated when the execution was in the non-secure
46 	 * world. Save the context registers to start with.
47 	 */
48 	cm_el1_sysregs_context_save(NON_SECURE);
49 
50 	/*
51 	 * Save elr_el3 and spsr_el3 from the saved context, and overwrite
52 	 * the context with the NS fiq_handler_addr and SPSR value.
53 	 */
54 	fiq_state[cpu].elr_el3 = read_ctx_reg((el3state_ctx), (uint32_t)(CTX_ELR_EL3));
55 	fiq_state[cpu].spsr_el3 = read_ctx_reg((el3state_ctx), (uint32_t)(CTX_SPSR_EL3));
56 
57 	/*
58 	 * Set the new ELR to continue execution in the NS world using the
59 	 * FIQ handler registered earlier.
60 	 */
61 	assert(ns_fiq_handler_addr);
62 	write_ctx_reg((el3state_ctx), (uint32_t)(CTX_ELR_EL3), (ns_fiq_handler_addr));
63 
64 	/*
65 	 * Mark this interrupt as complete to avoid a FIQ storm.
66 	 */
67 	irq = plat_ic_acknowledge_interrupt();
68 	if (irq < 1022U) {
69 		plat_ic_end_of_interrupt(irq);
70 	}
71 
72 	bakery_lock_release(&tegra_fiq_lock);
73 
74 	return 0;
75 }
76 
77 /*******************************************************************************
78  * Setup handler for FIQ interrupts
79  ******************************************************************************/
80 void tegra_fiq_handler_setup(void)
81 {
82 	uint32_t flags;
83 	int32_t rc;
84 
85 	/* return if already registered */
86 	if (fiq_handler_active == 0U) {
87 		/*
88 		 * Register an interrupt handler for FIQ interrupts generated for
89 		 * NS interrupt sources
90 		 */
91 		flags = 0U;
92 		set_interrupt_rm_flag((flags), (NON_SECURE));
93 		rc = register_interrupt_type_handler(INTR_TYPE_EL3,
94 					tegra_fiq_interrupt_handler,
95 					flags);
96 		if (rc != 0) {
97 			panic();
98 		}
99 
100 		/* handler is now active */
101 		fiq_handler_active = 1;
102 	}
103 }
104 
105 /*******************************************************************************
106  * Validate and store NS world's entrypoint for FIQ interrupts
107  ******************************************************************************/
108 void tegra_fiq_set_ns_entrypoint(uint64_t entrypoint)
109 {
110 	ns_fiq_handler_addr = entrypoint;
111 }
112 
113 /*******************************************************************************
114  * Handler to return the NS EL1/EL0 CPU context
115  ******************************************************************************/
116 int32_t tegra_fiq_get_intr_context(void)
117 {
118 	cpu_context_t *ctx = cm_get_context(NON_SECURE);
119 	gp_regs_t *gpregs_ctx = get_gpregs_ctx(ctx);
120 	const el1_sys_regs_t *el1state_ctx = get_sysregs_ctx(ctx);
121 	uint32_t cpu = plat_my_core_pos();
122 	uint64_t val;
123 
124 	/*
125 	 * We store the ELR_EL3, SPSR_EL3, SP_EL0 and SP_EL1 registers so
126 	 * that el3_exit() sends these values back to the NS world.
127 	 */
128 	write_ctx_reg((gpregs_ctx), (uint32_t)(CTX_GPREG_X0), (fiq_state[cpu].elr_el3));
129 	write_ctx_reg((gpregs_ctx), (uint32_t)(CTX_GPREG_X1), (fiq_state[cpu].spsr_el3));
130 
131 	val = read_ctx_reg((gpregs_ctx), (uint32_t)(CTX_GPREG_SP_EL0));
132 	write_ctx_reg((gpregs_ctx), (uint32_t)(CTX_GPREG_X2), (val));
133 
134 	val = read_ctx_reg((el1state_ctx), (uint32_t)(CTX_SP_EL1));
135 	write_ctx_reg((gpregs_ctx), (uint32_t)(CTX_GPREG_X3), (val));
136 
137 	return 0;
138 }
139