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