1 /* 2 * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved. 3 * Copyright (c) 2020, NVIDIA Corporation. All rights reserved. 4 * 5 * SPDX-License-Identifier: BSD-3-Clause 6 */ 7 8 /* 9 * Driver for GIC-500 and GIC-600 specific features. This driver only 10 * overrides APIs that are different to those generic ones in GICv3 11 * driver. 12 * 13 * GIC-600 supports independently power-gating redistributor interface. 14 */ 15 16 #include <assert.h> 17 18 #include <arch_helpers.h> 19 #include <drivers/arm/arm_gicv3_common.h> 20 #include <drivers/arm/gicv3.h> 21 22 #include "gicv3_private.h" 23 24 /* GIC-600 specific register offsets */ 25 #define GICR_PWRR 0x24U 26 27 /* GICR_PWRR fields */ 28 #define PWRR_RDPD_SHIFT 0 29 #define PWRR_RDAG_SHIFT 1 30 #define PWRR_RDGPD_SHIFT 2 31 #define PWRR_RDGPO_SHIFT 3 32 33 #define PWRR_RDPD (1U << PWRR_RDPD_SHIFT) 34 #define PWRR_RDAG (1U << PWRR_RDAG_SHIFT) 35 #define PWRR_RDGPD (1U << PWRR_RDGPD_SHIFT) 36 #define PWRR_RDGPO (1U << PWRR_RDGPO_SHIFT) 37 38 /* 39 * Values to write to GICR_PWRR register to power redistributor 40 * for operating through the core (GICR_PWRR.RDAG = 0) 41 */ 42 #define PWRR_ON (0U << PWRR_RDPD_SHIFT) 43 #define PWRR_OFF (1U << PWRR_RDPD_SHIFT) 44 45 #if GICV3_SUPPORT_GIC600 46 47 /* GIC-600/700 specific accessor functions */ 48 static void gicr_write_pwrr(uintptr_t base, unsigned int val) 49 { 50 mmio_write_32(base + GICR_PWRR, val); 51 } 52 53 static uint32_t gicr_read_pwrr(uintptr_t base) 54 { 55 return mmio_read_32(base + GICR_PWRR); 56 } 57 58 static void gicr_wait_group_not_in_transit(uintptr_t base) 59 { 60 uint32_t pwrr; 61 62 do { 63 pwrr = gicr_read_pwrr(base); 64 65 /* Check group not transitioning: RDGPD == RDGPO */ 66 } while (((pwrr & PWRR_RDGPD) >> PWRR_RDGPD_SHIFT) != 67 ((pwrr & PWRR_RDGPO) >> PWRR_RDGPO_SHIFT)); 68 } 69 70 static void gic600_pwr_on(uintptr_t base) 71 { 72 do { /* Wait until group not transitioning */ 73 gicr_wait_group_not_in_transit(base); 74 75 /* Power on redistributor */ 76 gicr_write_pwrr(base, PWRR_ON); 77 78 /* 79 * Wait until the power on state is reflected. 80 * If RDPD == 0 then powered on. 81 */ 82 } while ((gicr_read_pwrr(base) & PWRR_RDPD) != PWRR_ON); 83 } 84 85 static void gic600_pwr_off(uintptr_t base) 86 { 87 /* Wait until group not transitioning */ 88 gicr_wait_group_not_in_transit(base); 89 90 /* Power off redistributor */ 91 gicr_write_pwrr(base, PWRR_OFF); 92 93 /* 94 * If this is the last man, turning this redistributor frame off will 95 * result in the group itself being powered off and RDGPD = 1. 96 * In that case, wait as long as it's in transition, or has aborted 97 * the transition altogether for any reason. 98 */ 99 if ((gicr_read_pwrr(base) & PWRR_RDGPD) != 0U) { 100 /* Wait until group not transitioning */ 101 gicr_wait_group_not_in_transit(base); 102 } 103 } 104 105 static uintptr_t get_gicr_base(unsigned int proc_num) 106 { 107 uintptr_t gicr_base; 108 109 assert(gicv3_driver_data != NULL); 110 assert(proc_num < gicv3_driver_data->rdistif_num); 111 assert(gicv3_driver_data->rdistif_base_addrs != NULL); 112 113 gicr_base = gicv3_driver_data->rdistif_base_addrs[proc_num]; 114 assert(gicr_base != 0UL); 115 116 return gicr_base; 117 } 118 119 static bool gicv3_redists_need_power_mgmt(uintptr_t gicr_base) 120 { 121 uint32_t reg = mmio_read_32(gicr_base + GICR_IIDR); 122 123 /* 124 * The Arm GIC-600 and GIC-700 models have their redistributors 125 * powered down at reset. 126 */ 127 return (((reg & IIDR_MODEL_MASK) == IIDR_MODEL_ARM_GIC_600) || 128 ((reg & IIDR_MODEL_MASK) == IIDR_MODEL_ARM_GIC_600AE) || 129 ((reg & IIDR_MODEL_MASK) == IIDR_MODEL_ARM_GIC_700)); 130 } 131 132 #endif /* GICV3_SUPPORT_GIC600 */ 133 134 void gicv3_distif_pre_save(unsigned int proc_num) 135 { 136 arm_gicv3_distif_pre_save(proc_num); 137 } 138 139 void gicv3_distif_post_restore(unsigned int proc_num) 140 { 141 arm_gicv3_distif_post_restore(proc_num); 142 } 143 144 /* 145 * Power off GIC-600 redistributor (if configured and detected) 146 */ 147 void gicv3_rdistif_off(unsigned int proc_num) 148 { 149 #if GICV3_SUPPORT_GIC600 150 uintptr_t gicr_base = get_gicr_base(proc_num); 151 152 /* Attempt to power redistributor off */ 153 if (gicv3_redists_need_power_mgmt(gicr_base)) { 154 gic600_pwr_off(gicr_base); 155 } 156 #endif 157 } 158 159 /* 160 * Power on GIC-600 redistributor (if configured and detected) 161 */ 162 void gicv3_rdistif_on(unsigned int proc_num) 163 { 164 #if GICV3_SUPPORT_GIC600 165 uintptr_t gicr_base = get_gicr_base(proc_num); 166 167 /* Power redistributor on */ 168 if (gicv3_redists_need_power_mgmt(gicr_base)) { 169 gic600_pwr_on(gicr_base); 170 } 171 #endif 172 } 173