1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ARM APMT table support. 4 * Design document number: ARM DEN0117. 5 * 6 * Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. 7 * 8 */ 9 10 #define pr_fmt(fmt) "ACPI: APMT: " fmt 11 12 #include <linux/acpi.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/platform_device.h> 16 #include "init.h" 17 18 #define DEV_NAME "arm-cs-arch-pmu" 19 20 /* There can be up to 3 resources: page 0 and 1 address, and interrupt. */ 21 #define DEV_MAX_RESOURCE_COUNT 3 22 23 /* Root pointer to the mapped APMT table */ 24 static struct acpi_table_header *apmt_table; 25 26 static int __init apmt_init_resources(struct resource *res, 27 struct acpi_apmt_node *node) 28 { 29 int irq, trigger; 30 int num_res = 0; 31 32 res[num_res].start = node->base_address0; 33 res[num_res].end = node->base_address0 + SZ_4K - 1; 34 res[num_res].flags = IORESOURCE_MEM; 35 36 num_res++; 37 38 if (node->flags & ACPI_APMT_FLAGS_DUAL_PAGE) { 39 res[num_res].start = node->base_address1; 40 res[num_res].end = node->base_address1 + SZ_4K - 1; 41 res[num_res].flags = IORESOURCE_MEM; 42 43 num_res++; 44 } 45 46 if (node->ovflw_irq != 0) { 47 trigger = (node->ovflw_irq_flags & ACPI_APMT_OVFLW_IRQ_FLAGS_MODE); 48 trigger = (trigger == ACPI_APMT_OVFLW_IRQ_FLAGS_MODE_LEVEL) ? 49 ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE; 50 irq = acpi_register_gsi(NULL, node->ovflw_irq, trigger, 51 ACPI_ACTIVE_HIGH); 52 53 if (irq <= 0) { 54 pr_warn("APMT could not register gsi hwirq %d\n", irq); 55 return num_res; 56 } 57 58 res[num_res].start = irq; 59 res[num_res].end = irq; 60 res[num_res].flags = IORESOURCE_IRQ; 61 62 num_res++; 63 } 64 65 return num_res; 66 } 67 68 /** 69 * apmt_add_platform_device() - Allocate a platform device for APMT node 70 * @node: Pointer to device ACPI APMT node 71 * @fwnode: fwnode associated with the APMT node 72 * 73 * Returns: 0 on success, <0 failure 74 */ 75 static int __init apmt_add_platform_device(struct acpi_apmt_node *node, 76 struct fwnode_handle *fwnode) 77 { 78 struct platform_device *pdev; 79 int ret, count; 80 struct resource res[DEV_MAX_RESOURCE_COUNT]; 81 82 pdev = platform_device_alloc(DEV_NAME, PLATFORM_DEVID_AUTO); 83 if (!pdev) 84 return -ENOMEM; 85 86 memset(res, 0, sizeof(res)); 87 88 count = apmt_init_resources(res, node); 89 90 ret = platform_device_add_resources(pdev, res, count); 91 if (ret) 92 goto dev_put; 93 94 /* 95 * Add a copy of APMT node pointer to platform_data to be used to 96 * retrieve APMT data information. 97 */ 98 ret = platform_device_add_data(pdev, &node, sizeof(node)); 99 if (ret) 100 goto dev_put; 101 102 pdev->dev.fwnode = fwnode; 103 104 ret = platform_device_add(pdev); 105 106 if (ret) 107 goto dev_put; 108 109 return 0; 110 111 dev_put: 112 platform_device_put(pdev); 113 114 return ret; 115 } 116 117 static int __init apmt_init_platform_devices(void) 118 { 119 struct acpi_apmt_node *apmt_node; 120 struct acpi_table_apmt *apmt; 121 struct fwnode_handle *fwnode; 122 u64 offset, end; 123 int ret; 124 125 /* 126 * apmt_table and apmt both point to the start of APMT table, but 127 * have different struct types 128 */ 129 apmt = (struct acpi_table_apmt *)apmt_table; 130 offset = sizeof(*apmt); 131 end = apmt->header.length; 132 133 while (offset < end) { 134 apmt_node = ACPI_ADD_PTR(struct acpi_apmt_node, apmt, 135 offset); 136 137 fwnode = acpi_alloc_fwnode_static(); 138 if (!fwnode) 139 return -ENOMEM; 140 141 ret = apmt_add_platform_device(apmt_node, fwnode); 142 if (ret) { 143 acpi_free_fwnode_static(fwnode); 144 return ret; 145 } 146 147 offset += apmt_node->length; 148 } 149 150 return 0; 151 } 152 153 void __init acpi_apmt_init(void) 154 { 155 acpi_status status; 156 int ret; 157 158 /** 159 * APMT table nodes will be used at runtime after the apmt init, 160 * so we don't need to call acpi_put_table() to release 161 * the APMT table mapping. 162 */ 163 status = acpi_get_table(ACPI_SIG_APMT, 0, &apmt_table); 164 165 if (ACPI_FAILURE(status)) { 166 if (status != AE_NOT_FOUND) { 167 const char *msg = acpi_format_exception(status); 168 169 pr_err("Failed to get APMT table, %s\n", msg); 170 } 171 172 return; 173 } 174 175 ret = apmt_init_platform_devices(); 176 if (ret) { 177 pr_err("Failed to initialize APMT platform devices, ret: %d\n", ret); 178 acpi_put_table(apmt_table); 179 } 180 } 181