1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright © 2020 - 2021 Intel Corporation 4 */ 5 6 /** 7 * DOC: MEI_PXP Client Driver 8 * 9 * The mei_pxp driver acts as a translation layer between PXP 10 * protocol implementer (I915) and ME FW by translating PXP 11 * negotiation messages to ME FW command payloads and vice versa. 12 */ 13 14 #include <linux/module.h> 15 #include <linux/slab.h> 16 #include <linux/mei.h> 17 #include <linux/mei_cl_bus.h> 18 #include <linux/component.h> 19 #include <drm/drm_connector.h> 20 #include <drm/i915_component.h> 21 #include <drm/i915_pxp_tee_interface.h> 22 23 #include "mei_pxp.h" 24 25 /** 26 * mei_pxp_send_message() - Sends a PXP message to ME FW. 27 * @dev: device corresponding to the mei_cl_device 28 * @message: a message buffer to send 29 * @size: size of the message 30 * Return: 0 on Success, <0 on Failure 31 */ 32 static int 33 mei_pxp_send_message(struct device *dev, const void *message, size_t size) 34 { 35 struct mei_cl_device *cldev; 36 ssize_t byte; 37 38 if (!dev || !message) 39 return -EINVAL; 40 41 cldev = to_mei_cl_device(dev); 42 43 byte = mei_cldev_send(cldev, message, size); 44 if (byte < 0) { 45 dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte); 46 return byte; 47 } 48 49 return 0; 50 } 51 52 /** 53 * mei_pxp_receive_message() - Receives a PXP message from ME FW. 54 * @dev: device corresponding to the mei_cl_device 55 * @buffer: a message buffer to contain the received message 56 * @size: size of the buffer 57 * Return: bytes sent on Success, <0 on Failure 58 */ 59 static int 60 mei_pxp_receive_message(struct device *dev, void *buffer, size_t size) 61 { 62 struct mei_cl_device *cldev; 63 ssize_t byte; 64 65 if (!dev || !buffer) 66 return -EINVAL; 67 68 cldev = to_mei_cl_device(dev); 69 70 byte = mei_cldev_recv(cldev, buffer, size); 71 if (byte < 0) { 72 dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte); 73 return byte; 74 } 75 76 return byte; 77 } 78 79 /** 80 * mei_pxp_gsc_command() - sends a gsc command, by sending 81 * a sgl mei message to gsc and receiving reply from gsc 82 * 83 * @dev: device corresponding to the mei_cl_device 84 * @client_id: client id to send the command to 85 * @fence_id: fence id to send the command to 86 * @sg_in: scatter gather list containing addresses for rx message buffer 87 * @total_in_len: total length of data in 'in' sg, can be less than the sum of buffers sizes 88 * @sg_out: scatter gather list containing addresses for tx message buffer 89 * 90 * Return: bytes sent on Success, <0 on Failure 91 */ 92 static ssize_t mei_pxp_gsc_command(struct device *dev, u8 client_id, u32 fence_id, 93 struct scatterlist *sg_in, size_t total_in_len, 94 struct scatterlist *sg_out) 95 { 96 struct mei_cl_device *cldev; 97 98 cldev = to_mei_cl_device(dev); 99 100 return mei_cldev_send_gsc_command(cldev, client_id, fence_id, sg_in, total_in_len, sg_out); 101 } 102 103 static const struct i915_pxp_component_ops mei_pxp_ops = { 104 .owner = THIS_MODULE, 105 .send = mei_pxp_send_message, 106 .recv = mei_pxp_receive_message, 107 .gsc_command = mei_pxp_gsc_command, 108 }; 109 110 static int mei_component_master_bind(struct device *dev) 111 { 112 struct mei_cl_device *cldev = to_mei_cl_device(dev); 113 struct i915_pxp_component *comp_master = mei_cldev_get_drvdata(cldev); 114 int ret; 115 116 comp_master->ops = &mei_pxp_ops; 117 comp_master->tee_dev = dev; 118 ret = component_bind_all(dev, comp_master); 119 if (ret < 0) 120 return ret; 121 122 return 0; 123 } 124 125 static void mei_component_master_unbind(struct device *dev) 126 { 127 struct mei_cl_device *cldev = to_mei_cl_device(dev); 128 struct i915_pxp_component *comp_master = mei_cldev_get_drvdata(cldev); 129 130 component_unbind_all(dev, comp_master); 131 } 132 133 static const struct component_master_ops mei_component_master_ops = { 134 .bind = mei_component_master_bind, 135 .unbind = mei_component_master_unbind, 136 }; 137 138 /** 139 * mei_pxp_component_match - compare function for matching mei pxp. 140 * 141 * The function checks if the driver is i915, the subcomponent is PXP 142 * and the grand parent of pxp and the parent of i915 are the same 143 * PCH device. 144 * 145 * @dev: master device 146 * @subcomponent: subcomponent to match (I915_COMPONENT_PXP) 147 * @data: compare data (mei pxp device) 148 * 149 * Return: 150 * * 1 - if components match 151 * * 0 - otherwise 152 */ 153 static int mei_pxp_component_match(struct device *dev, int subcomponent, 154 void *data) 155 { 156 struct device *base = data; 157 158 if (!dev) 159 return 0; 160 161 if (!dev->driver || strcmp(dev->driver->name, "i915") || 162 subcomponent != I915_COMPONENT_PXP) 163 return 0; 164 165 base = base->parent; 166 if (!base) /* mei device */ 167 return 0; 168 169 base = base->parent; /* pci device */ 170 /* for dgfx */ 171 if (base && dev == base) 172 return 1; 173 174 /* for pch */ 175 dev = dev->parent; 176 return (base && dev && dev == base); 177 } 178 179 static int mei_pxp_probe(struct mei_cl_device *cldev, 180 const struct mei_cl_device_id *id) 181 { 182 struct i915_pxp_component *comp_master; 183 struct component_match *master_match; 184 int ret; 185 186 ret = mei_cldev_enable(cldev); 187 if (ret < 0) { 188 dev_err(&cldev->dev, "mei_cldev_enable Failed. %d\n", ret); 189 goto enable_err_exit; 190 } 191 192 comp_master = kzalloc(sizeof(*comp_master), GFP_KERNEL); 193 if (!comp_master) { 194 ret = -ENOMEM; 195 goto err_exit; 196 } 197 198 master_match = NULL; 199 component_match_add_typed(&cldev->dev, &master_match, 200 mei_pxp_component_match, &cldev->dev); 201 if (IS_ERR_OR_NULL(master_match)) { 202 ret = -ENOMEM; 203 goto err_exit; 204 } 205 206 mei_cldev_set_drvdata(cldev, comp_master); 207 ret = component_master_add_with_match(&cldev->dev, 208 &mei_component_master_ops, 209 master_match); 210 if (ret < 0) { 211 dev_err(&cldev->dev, "Master comp add failed %d\n", ret); 212 goto err_exit; 213 } 214 215 return 0; 216 217 err_exit: 218 mei_cldev_set_drvdata(cldev, NULL); 219 kfree(comp_master); 220 mei_cldev_disable(cldev); 221 enable_err_exit: 222 return ret; 223 } 224 225 static void mei_pxp_remove(struct mei_cl_device *cldev) 226 { 227 struct i915_pxp_component *comp_master = mei_cldev_get_drvdata(cldev); 228 int ret; 229 230 component_master_del(&cldev->dev, &mei_component_master_ops); 231 kfree(comp_master); 232 mei_cldev_set_drvdata(cldev, NULL); 233 234 ret = mei_cldev_disable(cldev); 235 if (ret) 236 dev_warn(&cldev->dev, "mei_cldev_disable() failed\n"); 237 } 238 239 /* fbf6fcf1-96cf-4e2e-a6a6-1bab8cbe36b1 : PAVP GUID*/ 240 #define MEI_GUID_PXP UUID_LE(0xfbf6fcf1, 0x96cf, 0x4e2e, 0xA6, \ 241 0xa6, 0x1b, 0xab, 0x8c, 0xbe, 0x36, 0xb1) 242 243 static struct mei_cl_device_id mei_pxp_tbl[] = { 244 { .uuid = MEI_GUID_PXP, .version = MEI_CL_VERSION_ANY }, 245 { } 246 }; 247 MODULE_DEVICE_TABLE(mei, mei_pxp_tbl); 248 249 static struct mei_cl_driver mei_pxp_driver = { 250 .id_table = mei_pxp_tbl, 251 .name = KBUILD_MODNAME, 252 .probe = mei_pxp_probe, 253 .remove = mei_pxp_remove, 254 }; 255 256 module_mei_cl_driver(mei_pxp_driver); 257 258 MODULE_AUTHOR("Intel Corporation"); 259 MODULE_LICENSE("GPL"); 260 MODULE_DESCRIPTION("MEI PXP"); 261