xref: /rk3399_ARM-atf/plat/nvidia/tegra/common/tegra_fiq_glue.c (revision 82cb2c1ad9897473743f08437d0a3995bed561b9)
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 <gic_v2.h>
16 #include <interrupt_mgmt.h>
17 #include <platform.h>
18 #include <tegra_def.h>
19 #include <tegra_private.h>
20 
21 DEFINE_BAKERY_LOCK(tegra_fiq_lock);
22 
23 /*******************************************************************************
24  * Static variables
25  ******************************************************************************/
26 static uint64_t ns_fiq_handler_addr;
27 static unsigned int fiq_handler_active;
28 static pcpu_fiq_state_t fiq_state[PLATFORM_CORE_COUNT];
29 
30 /*******************************************************************************
31  * Handler for FIQ interrupts
32  ******************************************************************************/
33 static uint64_t tegra_fiq_interrupt_handler(uint32_t id,
34 					  uint32_t flags,
35 					  void *handle,
36 					  void *cookie)
37 {
38 	cpu_context_t *ctx = cm_get_context(NON_SECURE);
39 	el3_state_t *el3state_ctx = get_el3state_ctx(ctx);
40 	int cpu = plat_my_core_pos();
41 	uint32_t irq;
42 
43 	bakery_lock_get(&tegra_fiq_lock);
44 
45 	/*
46 	 * The FIQ was generated when the execution was in the non-secure
47 	 * world. Save the context registers to start with.
48 	 */
49 	cm_el1_sysregs_context_save(NON_SECURE);
50 
51 	/*
52 	 * Save elr_el3 and spsr_el3 from the saved context, and overwrite
53 	 * the context with the NS fiq_handler_addr and SPSR value.
54 	 */
55 	fiq_state[cpu].elr_el3 = read_ctx_reg(el3state_ctx, CTX_ELR_EL3);
56 	fiq_state[cpu].spsr_el3 = read_ctx_reg(el3state_ctx, CTX_SPSR_EL3);
57 
58 	/*
59 	 * Set the new ELR to continue execution in the NS world using the
60 	 * FIQ handler registered earlier.
61 	 */
62 	assert(ns_fiq_handler_addr);
63 	write_ctx_reg(el3state_ctx, CTX_ELR_EL3, ns_fiq_handler_addr);
64 
65 	/*
66 	 * Mark this interrupt as complete to avoid a FIQ storm.
67 	 */
68 	irq = plat_ic_acknowledge_interrupt();
69 	if (irq < 1022)
70 		plat_ic_end_of_interrupt(irq);
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 	uint64_t flags;
83 	int rc;
84 
85 	/* return if already registered */
86 	if (fiq_handler_active)
87 		return;
88 
89 	/*
90 	 * Register an interrupt handler for FIQ interrupts generated for
91 	 * NS interrupt sources
92 	 */
93 	flags = 0;
94 	set_interrupt_rm_flag(flags, NON_SECURE);
95 	rc = register_interrupt_type_handler(INTR_TYPE_EL3,
96 				tegra_fiq_interrupt_handler,
97 				flags);
98 	if (rc)
99 		panic();
100 
101 	/* handler is now active */
102 	fiq_handler_active = 1;
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 int 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 	el1_sys_regs_t *el1state_ctx = get_sysregs_ctx(ctx);
121 	int 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, CTX_GPREG_X0, fiq_state[cpu].elr_el3);
129 	write_ctx_reg(gpregs_ctx, CTX_GPREG_X1, fiq_state[cpu].spsr_el3);
130 
131 	val = read_ctx_reg(gpregs_ctx, CTX_GPREG_SP_EL0);
132 	write_ctx_reg(gpregs_ctx, CTX_GPREG_X2, val);
133 
134 	val = read_ctx_reg(el1state_ctx, CTX_SP_EL1);
135 	write_ctx_reg(gpregs_ctx, CTX_GPREG_X3, val);
136 
137 	return 0;
138 }
139