cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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radeon_atpx_handler.c (15873B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (c) 2010 Red Hat Inc.
      4 * Author : Dave Airlie <airlied@redhat.com>
      5 *
      6 * ATPX support for both Intel/ATI
      7 */
      8#include <linux/vga_switcheroo.h>
      9#include <linux/slab.h>
     10#include <linux/acpi.h>
     11#include <linux/pci.h>
     12#include <linux/delay.h>
     13
     14#include "radeon_acpi.h"
     15
     16struct radeon_atpx_functions {
     17	bool px_params;
     18	bool power_cntl;
     19	bool disp_mux_cntl;
     20	bool i2c_mux_cntl;
     21	bool switch_start;
     22	bool switch_end;
     23	bool disp_connectors_mapping;
     24	bool disp_detetion_ports;
     25};
     26
     27struct radeon_atpx {
     28	acpi_handle handle;
     29	struct radeon_atpx_functions functions;
     30	bool is_hybrid;
     31	bool dgpu_req_power_for_displays;
     32};
     33
     34static struct radeon_atpx_priv {
     35	bool atpx_detected;
     36	bool bridge_pm_usable;
     37	/* handle for device - and atpx */
     38	acpi_handle dhandle;
     39	struct radeon_atpx atpx;
     40} radeon_atpx_priv;
     41
     42struct atpx_verify_interface {
     43	u16 size;		/* structure size in bytes (includes size field) */
     44	u16 version;		/* version */
     45	u32 function_bits;	/* supported functions bit vector */
     46} __packed;
     47
     48struct atpx_px_params {
     49	u16 size;		/* structure size in bytes (includes size field) */
     50	u32 valid_flags;	/* which flags are valid */
     51	u32 flags;		/* flags */
     52} __packed;
     53
     54struct atpx_power_control {
     55	u16 size;
     56	u8 dgpu_state;
     57} __packed;
     58
     59struct atpx_mux {
     60	u16 size;
     61	u16 mux;
     62} __packed;
     63
     64bool radeon_has_atpx(void) {
     65	return radeon_atpx_priv.atpx_detected;
     66}
     67
     68bool radeon_has_atpx_dgpu_power_cntl(void) {
     69	return radeon_atpx_priv.atpx.functions.power_cntl;
     70}
     71
     72bool radeon_is_atpx_hybrid(void) {
     73	return radeon_atpx_priv.atpx.is_hybrid;
     74}
     75
     76bool radeon_atpx_dgpu_req_power_for_displays(void) {
     77	return radeon_atpx_priv.atpx.dgpu_req_power_for_displays;
     78}
     79
     80/**
     81 * radeon_atpx_call - call an ATPX method
     82 *
     83 * @handle: acpi handle
     84 * @function: the ATPX function to execute
     85 * @params: ATPX function params
     86 *
     87 * Executes the requested ATPX function (all asics).
     88 * Returns a pointer to the acpi output buffer.
     89 */
     90static union acpi_object *radeon_atpx_call(acpi_handle handle, int function,
     91					   struct acpi_buffer *params)
     92{
     93	acpi_status status;
     94	union acpi_object atpx_arg_elements[2];
     95	struct acpi_object_list atpx_arg;
     96	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
     97
     98	atpx_arg.count = 2;
     99	atpx_arg.pointer = &atpx_arg_elements[0];
    100
    101	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
    102	atpx_arg_elements[0].integer.value = function;
    103
    104	if (params) {
    105		atpx_arg_elements[1].type = ACPI_TYPE_BUFFER;
    106		atpx_arg_elements[1].buffer.length = params->length;
    107		atpx_arg_elements[1].buffer.pointer = params->pointer;
    108	} else {
    109		/* We need a second fake parameter */
    110		atpx_arg_elements[1].type = ACPI_TYPE_INTEGER;
    111		atpx_arg_elements[1].integer.value = 0;
    112	}
    113
    114	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
    115
    116	/* Fail only if calling the method fails and ATPX is supported */
    117	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
    118		printk("failed to evaluate ATPX got %s\n",
    119		       acpi_format_exception(status));
    120		kfree(buffer.pointer);
    121		return NULL;
    122	}
    123
    124	return buffer.pointer;
    125}
    126
    127/**
    128 * radeon_atpx_parse_functions - parse supported functions
    129 *
    130 * @f: supported functions struct
    131 * @mask: supported functions mask from ATPX
    132 *
    133 * Use the supported functions mask from ATPX function
    134 * ATPX_FUNCTION_VERIFY_INTERFACE to determine what functions
    135 * are supported (all asics).
    136 */
    137static void radeon_atpx_parse_functions(struct radeon_atpx_functions *f, u32 mask)
    138{
    139	f->px_params = mask & ATPX_GET_PX_PARAMETERS_SUPPORTED;
    140	f->power_cntl = mask & ATPX_POWER_CONTROL_SUPPORTED;
    141	f->disp_mux_cntl = mask & ATPX_DISPLAY_MUX_CONTROL_SUPPORTED;
    142	f->i2c_mux_cntl = mask & ATPX_I2C_MUX_CONTROL_SUPPORTED;
    143	f->switch_start = mask & ATPX_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION_SUPPORTED;
    144	f->switch_end = mask & ATPX_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION_SUPPORTED;
    145	f->disp_connectors_mapping = mask & ATPX_GET_DISPLAY_CONNECTORS_MAPPING_SUPPORTED;
    146	f->disp_detetion_ports = mask & ATPX_GET_DISPLAY_DETECTION_PORTS_SUPPORTED;
    147}
    148
    149/**
    150 * radeon_atpx_validate_functions - validate ATPX functions
    151 *
    152 * @atpx: radeon atpx struct
    153 *
    154 * Validate that required functions are enabled (all asics).
    155 * returns 0 on success, error on failure.
    156 */
    157static int radeon_atpx_validate(struct radeon_atpx *atpx)
    158{
    159	u32 valid_bits = 0;
    160
    161	if (atpx->functions.px_params) {
    162		union acpi_object *info;
    163		struct atpx_px_params output;
    164		size_t size;
    165
    166		info = radeon_atpx_call(atpx->handle, ATPX_FUNCTION_GET_PX_PARAMETERS, NULL);
    167		if (!info)
    168			return -EIO;
    169
    170		memset(&output, 0, sizeof(output));
    171
    172		size = *(u16 *) info->buffer.pointer;
    173		if (size < 10) {
    174			printk("ATPX buffer is too small: %zu\n", size);
    175			kfree(info);
    176			return -EINVAL;
    177		}
    178		size = min(sizeof(output), size);
    179
    180		memcpy(&output, info->buffer.pointer, size);
    181
    182		valid_bits = output.flags & output.valid_flags;
    183
    184		kfree(info);
    185	}
    186
    187	/* if separate mux flag is set, mux controls are required */
    188	if (valid_bits & ATPX_SEPARATE_MUX_FOR_I2C) {
    189		atpx->functions.i2c_mux_cntl = true;
    190		atpx->functions.disp_mux_cntl = true;
    191	}
    192	/* if any outputs are muxed, mux controls are required */
    193	if (valid_bits & (ATPX_CRT1_RGB_SIGNAL_MUXED |
    194			  ATPX_TV_SIGNAL_MUXED |
    195			  ATPX_DFP_SIGNAL_MUXED))
    196		atpx->functions.disp_mux_cntl = true;
    197
    198	/* some bioses set these bits rather than flagging power_cntl as supported */
    199	if (valid_bits & (ATPX_DYNAMIC_PX_SUPPORTED |
    200			  ATPX_DYNAMIC_DGPU_POWER_OFF_SUPPORTED))
    201		atpx->functions.power_cntl = true;
    202
    203	atpx->is_hybrid = false;
    204	if (valid_bits & ATPX_MS_HYBRID_GFX_SUPPORTED) {
    205		printk("ATPX Hybrid Graphics\n");
    206		/*
    207		 * Disable legacy PM methods only when pcie port PM is usable,
    208		 * otherwise the device might fail to power off or power on.
    209		 */
    210		atpx->functions.power_cntl = !radeon_atpx_priv.bridge_pm_usable;
    211		atpx->is_hybrid = true;
    212	}
    213
    214	return 0;
    215}
    216
    217/**
    218 * radeon_atpx_verify_interface - verify ATPX
    219 *
    220 * @atpx: radeon atpx struct
    221 *
    222 * Execute the ATPX_FUNCTION_VERIFY_INTERFACE ATPX function
    223 * to initialize ATPX and determine what features are supported
    224 * (all asics).
    225 * returns 0 on success, error on failure.
    226 */
    227static int radeon_atpx_verify_interface(struct radeon_atpx *atpx)
    228{
    229	union acpi_object *info;
    230	struct atpx_verify_interface output;
    231	size_t size;
    232	int err = 0;
    233
    234	info = radeon_atpx_call(atpx->handle, ATPX_FUNCTION_VERIFY_INTERFACE, NULL);
    235	if (!info)
    236		return -EIO;
    237
    238	memset(&output, 0, sizeof(output));
    239
    240	size = *(u16 *) info->buffer.pointer;
    241	if (size < 8) {
    242		printk("ATPX buffer is too small: %zu\n", size);
    243		err = -EINVAL;
    244		goto out;
    245	}
    246	size = min(sizeof(output), size);
    247
    248	memcpy(&output, info->buffer.pointer, size);
    249
    250	/* TODO: check version? */
    251	printk("ATPX version %u, functions 0x%08x\n",
    252	       output.version, output.function_bits);
    253
    254	radeon_atpx_parse_functions(&atpx->functions, output.function_bits);
    255
    256out:
    257	kfree(info);
    258	return err;
    259}
    260
    261/**
    262 * radeon_atpx_set_discrete_state - power up/down discrete GPU
    263 *
    264 * @atpx: atpx info struct
    265 * @state: discrete GPU state (0 = power down, 1 = power up)
    266 *
    267 * Execute the ATPX_FUNCTION_POWER_CONTROL ATPX function to
    268 * power down/up the discrete GPU (all asics).
    269 * Returns 0 on success, error on failure.
    270 */
    271static int radeon_atpx_set_discrete_state(struct radeon_atpx *atpx, u8 state)
    272{
    273	struct acpi_buffer params;
    274	union acpi_object *info;
    275	struct atpx_power_control input;
    276
    277	if (atpx->functions.power_cntl) {
    278		input.size = 3;
    279		input.dgpu_state = state;
    280		params.length = input.size;
    281		params.pointer = &input;
    282		info = radeon_atpx_call(atpx->handle,
    283					ATPX_FUNCTION_POWER_CONTROL,
    284					&params);
    285		if (!info)
    286			return -EIO;
    287		kfree(info);
    288
    289		/* 200ms delay is required after off */
    290		if (state == 0)
    291			msleep(200);
    292	}
    293	return 0;
    294}
    295
    296/**
    297 * radeon_atpx_switch_disp_mux - switch display mux
    298 *
    299 * @atpx: atpx info struct
    300 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
    301 *
    302 * Execute the ATPX_FUNCTION_DISPLAY_MUX_CONTROL ATPX function to
    303 * switch the display mux between the discrete GPU and integrated GPU
    304 * (all asics).
    305 * Returns 0 on success, error on failure.
    306 */
    307static int radeon_atpx_switch_disp_mux(struct radeon_atpx *atpx, u16 mux_id)
    308{
    309	struct acpi_buffer params;
    310	union acpi_object *info;
    311	struct atpx_mux input;
    312
    313	if (atpx->functions.disp_mux_cntl) {
    314		input.size = 4;
    315		input.mux = mux_id;
    316		params.length = input.size;
    317		params.pointer = &input;
    318		info = radeon_atpx_call(atpx->handle,
    319					ATPX_FUNCTION_DISPLAY_MUX_CONTROL,
    320					&params);
    321		if (!info)
    322			return -EIO;
    323		kfree(info);
    324	}
    325	return 0;
    326}
    327
    328/**
    329 * radeon_atpx_switch_i2c_mux - switch i2c/hpd mux
    330 *
    331 * @atpx: atpx info struct
    332 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
    333 *
    334 * Execute the ATPX_FUNCTION_I2C_MUX_CONTROL ATPX function to
    335 * switch the i2c/hpd mux between the discrete GPU and integrated GPU
    336 * (all asics).
    337 * Returns 0 on success, error on failure.
    338 */
    339static int radeon_atpx_switch_i2c_mux(struct radeon_atpx *atpx, u16 mux_id)
    340{
    341	struct acpi_buffer params;
    342	union acpi_object *info;
    343	struct atpx_mux input;
    344
    345	if (atpx->functions.i2c_mux_cntl) {
    346		input.size = 4;
    347		input.mux = mux_id;
    348		params.length = input.size;
    349		params.pointer = &input;
    350		info = radeon_atpx_call(atpx->handle,
    351					ATPX_FUNCTION_I2C_MUX_CONTROL,
    352					&params);
    353		if (!info)
    354			return -EIO;
    355		kfree(info);
    356	}
    357	return 0;
    358}
    359
    360/**
    361 * radeon_atpx_switch_start - notify the sbios of a GPU switch
    362 *
    363 * @atpx: atpx info struct
    364 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
    365 *
    366 * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION ATPX
    367 * function to notify the sbios that a switch between the discrete GPU and
    368 * integrated GPU has begun (all asics).
    369 * Returns 0 on success, error on failure.
    370 */
    371static int radeon_atpx_switch_start(struct radeon_atpx *atpx, u16 mux_id)
    372{
    373	struct acpi_buffer params;
    374	union acpi_object *info;
    375	struct atpx_mux input;
    376
    377	if (atpx->functions.switch_start) {
    378		input.size = 4;
    379		input.mux = mux_id;
    380		params.length = input.size;
    381		params.pointer = &input;
    382		info = radeon_atpx_call(atpx->handle,
    383					ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION,
    384					&params);
    385		if (!info)
    386			return -EIO;
    387		kfree(info);
    388	}
    389	return 0;
    390}
    391
    392/**
    393 * radeon_atpx_switch_end - notify the sbios of a GPU switch
    394 *
    395 * @atpx: atpx info struct
    396 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
    397 *
    398 * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION ATPX
    399 * function to notify the sbios that a switch between the discrete GPU and
    400 * integrated GPU has ended (all asics).
    401 * Returns 0 on success, error on failure.
    402 */
    403static int radeon_atpx_switch_end(struct radeon_atpx *atpx, u16 mux_id)
    404{
    405	struct acpi_buffer params;
    406	union acpi_object *info;
    407	struct atpx_mux input;
    408
    409	if (atpx->functions.switch_end) {
    410		input.size = 4;
    411		input.mux = mux_id;
    412		params.length = input.size;
    413		params.pointer = &input;
    414		info = radeon_atpx_call(atpx->handle,
    415					ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION,
    416					&params);
    417		if (!info)
    418			return -EIO;
    419		kfree(info);
    420	}
    421	return 0;
    422}
    423
    424/**
    425 * radeon_atpx_switchto - switch to the requested GPU
    426 *
    427 * @id: GPU to switch to
    428 *
    429 * Execute the necessary ATPX functions to switch between the discrete GPU and
    430 * integrated GPU (all asics).
    431 * Returns 0 on success, error on failure.
    432 */
    433static int radeon_atpx_switchto(enum vga_switcheroo_client_id id)
    434{
    435	u16 gpu_id;
    436
    437	if (id == VGA_SWITCHEROO_IGD)
    438		gpu_id = ATPX_INTEGRATED_GPU;
    439	else
    440		gpu_id = ATPX_DISCRETE_GPU;
    441
    442	radeon_atpx_switch_start(&radeon_atpx_priv.atpx, gpu_id);
    443	radeon_atpx_switch_disp_mux(&radeon_atpx_priv.atpx, gpu_id);
    444	radeon_atpx_switch_i2c_mux(&radeon_atpx_priv.atpx, gpu_id);
    445	radeon_atpx_switch_end(&radeon_atpx_priv.atpx, gpu_id);
    446
    447	return 0;
    448}
    449
    450/**
    451 * radeon_atpx_power_state - power down/up the requested GPU
    452 *
    453 * @id: GPU to power down/up
    454 * @state: requested power state (0 = off, 1 = on)
    455 *
    456 * Execute the necessary ATPX function to power down/up the discrete GPU
    457 * (all asics).
    458 * Returns 0 on success, error on failure.
    459 */
    460static int radeon_atpx_power_state(enum vga_switcheroo_client_id id,
    461				   enum vga_switcheroo_state state)
    462{
    463	/* on w500 ACPI can't change intel gpu state */
    464	if (id == VGA_SWITCHEROO_IGD)
    465		return 0;
    466
    467	radeon_atpx_set_discrete_state(&radeon_atpx_priv.atpx, state);
    468	return 0;
    469}
    470
    471/**
    472 * radeon_atpx_pci_probe_handle - look up the ATPX handle
    473 *
    474 * @pdev: pci device
    475 *
    476 * Look up the ATPX handles (all asics).
    477 * Returns true if the handles are found, false if not.
    478 */
    479static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
    480{
    481	acpi_handle dhandle, atpx_handle;
    482	acpi_status status;
    483
    484	dhandle = ACPI_HANDLE(&pdev->dev);
    485	if (!dhandle)
    486		return false;
    487
    488	status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
    489	if (ACPI_FAILURE(status))
    490		return false;
    491
    492	radeon_atpx_priv.dhandle = dhandle;
    493	radeon_atpx_priv.atpx.handle = atpx_handle;
    494	return true;
    495}
    496
    497/**
    498 * radeon_atpx_init - verify the ATPX interface
    499 *
    500 * Verify the ATPX interface (all asics).
    501 * Returns 0 on success, error on failure.
    502 */
    503static int radeon_atpx_init(void)
    504{
    505	int r;
    506
    507	/* set up the ATPX handle */
    508	r = radeon_atpx_verify_interface(&radeon_atpx_priv.atpx);
    509	if (r)
    510		return r;
    511
    512	/* validate the atpx setup */
    513	r = radeon_atpx_validate(&radeon_atpx_priv.atpx);
    514	if (r)
    515		return r;
    516
    517	return 0;
    518}
    519
    520/**
    521 * radeon_atpx_get_client_id - get the client id
    522 *
    523 * @pdev: pci device
    524 *
    525 * look up whether we are the integrated or discrete GPU (all asics).
    526 * Returns the client id.
    527 */
    528static enum vga_switcheroo_client_id radeon_atpx_get_client_id(struct pci_dev *pdev)
    529{
    530	if (radeon_atpx_priv.dhandle == ACPI_HANDLE(&pdev->dev))
    531		return VGA_SWITCHEROO_IGD;
    532	else
    533		return VGA_SWITCHEROO_DIS;
    534}
    535
    536static const struct vga_switcheroo_handler radeon_atpx_handler = {
    537	.switchto = radeon_atpx_switchto,
    538	.power_state = radeon_atpx_power_state,
    539	.get_client_id = radeon_atpx_get_client_id,
    540};
    541
    542/**
    543 * radeon_atpx_detect - detect whether we have PX
    544 *
    545 * Check if we have a PX system (all asics).
    546 * Returns true if we have a PX system, false if not.
    547 */
    548static bool radeon_atpx_detect(void)
    549{
    550	char acpi_method_name[255] = { 0 };
    551	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
    552	struct pci_dev *pdev = NULL;
    553	bool has_atpx = false;
    554	int vga_count = 0;
    555	bool d3_supported = false;
    556	struct pci_dev *parent_pdev;
    557
    558	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
    559		vga_count++;
    560
    561		has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
    562
    563		parent_pdev = pci_upstream_bridge(pdev);
    564		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
    565	}
    566
    567	/* some newer PX laptops mark the dGPU as a non-VGA display device */
    568	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) {
    569		vga_count++;
    570
    571		has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
    572
    573		parent_pdev = pci_upstream_bridge(pdev);
    574		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
    575	}
    576
    577	if (has_atpx && vga_count == 2) {
    578		acpi_get_name(radeon_atpx_priv.atpx.handle, ACPI_FULL_PATHNAME, &buffer);
    579		pr_info("vga_switcheroo: detected switching method %s handle\n",
    580			acpi_method_name);
    581		radeon_atpx_priv.atpx_detected = true;
    582		radeon_atpx_priv.bridge_pm_usable = d3_supported;
    583		radeon_atpx_init();
    584		return true;
    585	}
    586	return false;
    587}
    588
    589/**
    590 * radeon_register_atpx_handler - register with vga_switcheroo
    591 *
    592 * Register the PX callbacks with vga_switcheroo (all asics).
    593 */
    594void radeon_register_atpx_handler(void)
    595{
    596	bool r;
    597	enum vga_switcheroo_handler_flags_t handler_flags = 0;
    598
    599	/* detect if we have any ATPX + 2 VGA in the system */
    600	r = radeon_atpx_detect();
    601	if (!r)
    602		return;
    603
    604	vga_switcheroo_register_handler(&radeon_atpx_handler, handler_flags);
    605}
    606
    607/**
    608 * radeon_unregister_atpx_handler - unregister with vga_switcheroo
    609 *
    610 * Unregister the PX callbacks with vga_switcheroo (all asics).
    611 */
    612void radeon_unregister_atpx_handler(void)
    613{
    614	vga_switcheroo_unregister_handler();
    615}