cregit-Linux how code gets into the kernel

Release 4.14 drivers/gpu/vga/vga_switcheroo.c

Directory: drivers/gpu/vga
/*
 * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs
 *
 * Copyright (c) 2010 Red Hat Inc.
 * Author : Dave Airlie <airlied@redhat.com>
 *
 * Copyright (c) 2015 Lukas Wunner <lukas@wunner.de>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS
 * IN THE SOFTWARE.
 *
 */


#define pr_fmt(fmt) "vga_switcheroo: " fmt

#include <linux/apple-gmux.h>
#include <linux/console.h>
#include <linux/debugfs.h>
#include <linux/fb.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/vgaarb.h>
#include <linux/vga_switcheroo.h>

/**
 * DOC: Overview
 *
 * vga_switcheroo is the Linux subsystem for laptop hybrid graphics.
 * These come in two flavors:
 *
 * * muxed: Dual GPUs with a multiplexer chip to switch outputs between GPUs.
 * * muxless: Dual GPUs but only one of them is connected to outputs.
 *   The other one is merely used to offload rendering, its results
 *   are copied over PCIe into the framebuffer. On Linux this is
 *   supported with DRI PRIME.
 *
 * Hybrid graphics started to appear in the late Naughties and were initially
 * all muxed. Newer laptops moved to a muxless architecture for cost reasons.
 * A notable exception is the MacBook Pro which continues to use a mux.
 * Muxes come with varying capabilities: Some switch only the panel, others
 * can also switch external displays. Some switch all display pins at once
 * while others can switch just the DDC lines. (To allow EDID probing
 * for the inactive GPU.) Also, muxes are often used to cut power to the
 * discrete GPU while it is not used.
 *
 * DRM drivers register GPUs with vga_switcheroo, these are henceforth called
 * clients. The mux is called the handler. Muxless machines also register a
 * handler to control the power state of the discrete GPU, its ->switchto
 * callback is a no-op for obvious reasons. The discrete GPU is often equipped
 * with an HDA controller for the HDMI/DP audio signal, this will also
 * register as a client so that vga_switcheroo can take care of the correct
 * suspend/resume order when changing the discrete GPU's power state. In total
 * there can thus be up to three clients: Two vga clients (GPUs) and one audio
 * client (on the discrete GPU). The code is mostly prepared to support
 * machines with more than two GPUs should they become available.
 *
 * The GPU to which the outputs are currently switched is called the
 * active client in vga_switcheroo parlance. The GPU not in use is the
 * inactive client. When the inactive client's DRM driver is loaded,
 * it will be unable to probe the panel's EDID and hence depends on
 * VBIOS to provide its display modes. If the VBIOS modes are bogus or
 * if there is no VBIOS at all (which is common on the MacBook Pro),
 * a client may alternatively request that the DDC lines are temporarily
 * switched to it, provided that the handler supports this. Switching
 * only the DDC lines and not the entire output avoids unnecessary
 * flickering.
 */

/**
 * struct vga_switcheroo_client - registered client
 * @pdev: client pci device
 * @fb_info: framebuffer to which console is remapped on switching
 * @pwr_state: current power state
 * @ops: client callbacks
 * @id: client identifier. Determining the id requires the handler,
 *      so gpus are initially assigned VGA_SWITCHEROO_UNKNOWN_ID
 *      and later given their true id in vga_switcheroo_enable()
 * @active: whether the outputs are currently switched to this client
 * @driver_power_control: whether power state is controlled by the driver's
 *      runtime pm. If true, writing ON and OFF to the vga_switcheroo debugfs
 *      interface is a no-op so as not to interfere with runtime pm
 * @list: client list
 *
 * Registered client. A client can be either a GPU or an audio device on a GPU.
 * For audio clients, the @fb_info, @active and @driver_power_control members
 * are bogus.
 */

struct vga_switcheroo_client {
	
struct pci_dev *pdev;
	
struct fb_info *fb_info;
	
enum vga_switcheroo_state pwr_state;
	
const struct vga_switcheroo_client_ops *ops;
	
enum vga_switcheroo_client_id id;
	
bool active;
	
bool driver_power_control;
	
struct list_head list;
};

/*
 * protects access to struct vgasr_priv
 */
static DEFINE_MUTEX(vgasr_mutex);

/**
 * struct vgasr_priv - vga_switcheroo private data
 * @active: whether vga_switcheroo is enabled.
 *      Prerequisite is the registration of two GPUs and a handler
 * @delayed_switch_active: whether a delayed switch is pending
 * @delayed_client_id: client to which a delayed switch is pending
 * @debugfs_root: directory for vga_switcheroo debugfs interface
 * @switch_file: file for vga_switcheroo debugfs interface
 * @registered_clients: number of registered GPUs
 *      (counting only vga clients, not audio clients)
 * @clients: list of registered clients
 * @handler: registered handler
 * @handler_flags: flags of registered handler
 * @mux_hw_lock: protects mux state
 *      (in particular while DDC lines are temporarily switched)
 * @old_ddc_owner: client to which DDC lines will be switched back on unlock
 *
 * vga_switcheroo private data. Currently only one vga_switcheroo instance
 * per system is supported.
 */

struct vgasr_priv {
	
bool active;
	
bool delayed_switch_active;
	
enum vga_switcheroo_client_id delayed_client_id;

	
struct dentry *debugfs_root;
	
struct dentry *switch_file;

	
int registered_clients;
	
struct list_head clients;

	
const struct vga_switcheroo_handler *handler;
	
enum vga_switcheroo_handler_flags_t handler_flags;
	
struct mutex mux_hw_lock;
	
int old_ddc_owner;
};


#define ID_BIT_AUDIO		0x100

#define client_is_audio(c)	((c)->id & ID_BIT_AUDIO)

#define client_is_vga(c)	((c)->id == VGA_SWITCHEROO_UNKNOWN_ID || \
                                 !client_is_audio(c))

#define client_id(c)		((c)->id & ~ID_BIT_AUDIO)

static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv);

/* only one switcheroo per system */

static struct vgasr_priv vgasr_priv = {
	.clients = LIST_HEAD_INIT(vgasr_priv.clients),
	.mux_hw_lock = __MUTEX_INITIALIZER(vgasr_priv.mux_hw_lock),
};


static bool vga_switcheroo_ready(void) { /* we're ready if we get two clients + handler */ return !vgasr_priv.active && vgasr_priv.registered_clients == 2 && vgasr_priv.handler; }

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static void vga_switcheroo_enable(void) { int ret; struct vga_switcheroo_client *client; /* call the handler to init */ if (vgasr_priv.handler->init) vgasr_priv.handler->init(); list_for_each_entry(client, &vgasr_priv.clients, list) { if (client->id != VGA_SWITCHEROO_UNKNOWN_ID) continue; ret = vgasr_priv.handler->get_client_id(client->pdev); if (ret < 0) return; client->id = ret; } vga_switcheroo_debugfs_init(&vgasr_priv); vgasr_priv.active = true; }

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/** * vga_switcheroo_register_handler() - register handler * @handler: handler callbacks * @handler_flags: handler flags * * Register handler. Enable vga_switcheroo if two vga clients have already * registered. * * Return: 0 on success, -EINVAL if a handler was already registered. */
int vga_switcheroo_register_handler( const struct vga_switcheroo_handler *handler, enum vga_switcheroo_handler_flags_t handler_flags) { mutex_lock(&vgasr_mutex); if (vgasr_priv.handler) { mutex_unlock(&vgasr_mutex); return -EINVAL; } vgasr_priv.handler = handler; vgasr_priv.handler_flags = handler_flags; if (vga_switcheroo_ready()) { pr_info("enabled\n"); vga_switcheroo_enable(); } mutex_unlock(&vgasr_mutex); return 0; }

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EXPORT_SYMBOL(vga_switcheroo_register_handler); /** * vga_switcheroo_unregister_handler() - unregister handler * * Unregister handler. Disable vga_switcheroo. */
void vga_switcheroo_unregister_handler(void) { mutex_lock(&vgasr_mutex); mutex_lock(&vgasr_priv.mux_hw_lock); vgasr_priv.handler_flags = 0; vgasr_priv.handler = NULL; if (vgasr_priv.active) { pr_info("disabled\n"); vga_switcheroo_debugfs_fini(&vgasr_priv); vgasr_priv.active = false; } mutex_unlock(&vgasr_priv.mux_hw_lock); mutex_unlock(&vgasr_mutex); }

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EXPORT_SYMBOL(vga_switcheroo_unregister_handler); /** * vga_switcheroo_handler_flags() - obtain handler flags * * Helper for clients to obtain the handler flags bitmask. * * Return: Handler flags. A value of 0 means that no handler is registered * or that the handler has no special capabilities. */
enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void) { return vgasr_priv.handler_flags; }

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EXPORT_SYMBOL(vga_switcheroo_handler_flags);
static int register_client(struct pci_dev *pdev, const struct vga_switcheroo_client_ops *ops, enum vga_switcheroo_client_id id, bool active, bool driver_power_control) { struct vga_switcheroo_client *client; client = kzalloc(sizeof(*client), GFP_KERNEL); if (!client) return -ENOMEM; client->pwr_state = VGA_SWITCHEROO_ON; client->pdev = pdev; client->ops = ops; client->id = id; client->active = active; client->driver_power_control = driver_power_control; mutex_lock(&vgasr_mutex); list_add_tail(&client->list, &vgasr_priv.clients); if (client_is_vga(client)) vgasr_priv.registered_clients++; if (vga_switcheroo_ready()) { pr_info("enabled\n"); vga_switcheroo_enable(); } mutex_unlock(&vgasr_mutex); return 0; }

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/** * vga_switcheroo_register_client - register vga client * @pdev: client pci device * @ops: client callbacks * @driver_power_control: whether power state is controlled by the driver's * runtime pm * * Register vga client (GPU). Enable vga_switcheroo if another GPU and a * handler have already registered. The power state of the client is assumed * to be ON. Beforehand, vga_switcheroo_client_probe_defer() shall be called * to ensure that all prerequisites are met. * * Return: 0 on success, -ENOMEM on memory allocation error. */
int vga_switcheroo_register_client(struct pci_dev *pdev, const struct vga_switcheroo_client_ops *ops, bool driver_power_control) { return register_client(pdev, ops, VGA_SWITCHEROO_UNKNOWN_ID, pdev == vga_default_device(), driver_power_control); }

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EXPORT_SYMBOL(vga_switcheroo_register_client); /** * vga_switcheroo_register_audio_client - register audio client * @pdev: client pci device * @ops: client callbacks * @id: client identifier * * Register audio client (audio device on a GPU). The power state of the * client is assumed to be ON. Beforehand, vga_switcheroo_client_probe_defer() * shall be called to ensure that all prerequisites are met. * * Return: 0 on success, -ENOMEM on memory allocation error. */
int vga_switcheroo_register_audio_client(struct pci_dev *pdev, const struct vga_switcheroo_client_ops *ops, enum vga_switcheroo_client_id id) { return register_client(pdev, ops, id | ID_BIT_AUDIO, false, false); }

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EXPORT_SYMBOL(vga_switcheroo_register_audio_client);
static struct vga_switcheroo_client * find_client_from_pci(struct list_head *head, struct pci_dev *pdev) { struct vga_switcheroo_client *client; list_for_each_entry(client, head, list) if (client->pdev == pdev) return client; return NULL; }

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static struct vga_switcheroo_client * find_client_from_id(struct list_head *head, enum vga_switcheroo_client_id client_id) { struct vga_switcheroo_client *client; list_for_each_entry(client, head, list) if (client->id == client_id) return client; return NULL; }

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static struct vga_switcheroo_client * find_active_client(struct list_head *head) { struct vga_switcheroo_client *client; list_for_each_entry(client, head, list) if (client->active) return client; return NULL; }

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/** * vga_switcheroo_client_probe_defer() - whether to defer probing a given client * @pdev: client pci device * * Determine whether any prerequisites are not fulfilled to probe a given * client. Drivers shall invoke this early on in their ->probe callback * and return %-EPROBE_DEFER if it evaluates to %true. Thou shalt not * register the client ere thou hast called this. * * Return: %true if probing should be deferred, otherwise %false. */
bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev) { if ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY) { /* * apple-gmux is needed on pre-retina MacBook Pro * to probe the panel if pdev is the inactive GPU. */ if (apple_gmux_present() && pdev != vga_default_device() && !vgasr_priv.handler_flags) return true; } return false; }

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EXPORT_SYMBOL(vga_switcheroo_client_probe_defer); /** * vga_switcheroo_get_client_state() - obtain power state of a given client * @pdev: client pci device * * Obtain power state of a given client as seen from vga_switcheroo. * The function is only called from hda_intel.c. * * Return: Power state. */
enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *pdev) { struct vga_switcheroo_client *client; enum vga_switcheroo_state ret; mutex_lock(&vgasr_mutex); client = find_client_from_pci(&vgasr_priv.clients, pdev); if (!client) ret = VGA_SWITCHEROO_NOT_FOUND; else ret = client->pwr_state; mutex_unlock(&vgasr_mutex); return ret; }

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EXPORT_SYMBOL(vga_switcheroo_get_client_state); /** * vga_switcheroo_unregister_client() - unregister client * @pdev: client pci device * * Unregister client. Disable vga_switcheroo if this is a vga client (GPU). */
void vga_switcheroo_unregister_client(struct pci_dev *pdev) { struct vga_switcheroo_client *client; mutex_lock(&vgasr_mutex); client = find_client_from_pci(&vgasr_priv.clients, pdev); if (client) { if (client_is_vga(client)) vgasr_priv.registered_clients--; list_del(&client->list); kfree(client); } if (vgasr_priv.active && vgasr_priv.registered_clients < 2) { pr_info("disabled\n"); vga_switcheroo_debugfs_fini(&vgasr_priv); vgasr_priv.active = false; } mutex_unlock(&vgasr_mutex); }

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EXPORT_SYMBOL(vga_switcheroo_unregister_client); /** * vga_switcheroo_client_fb_set() - set framebuffer of a given client * @pdev: client pci device * @info: framebuffer * * Set framebuffer of a given client. The console will be remapped to this * on switching. */
void vga_switcheroo_client_fb_set(struct pci_dev *pdev, struct fb_info *info) { struct vga_switcheroo_client *client; mutex_lock(&vgasr_mutex); client = find_client_from_pci(&vgasr_priv.clients, pdev); if (client) client->fb_info = info; mutex_unlock(&vgasr_mutex); }

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EXPORT_SYMBOL(vga_switcheroo_client_fb_set); /** * vga_switcheroo_lock_ddc() - temporarily switch DDC lines to a given client * @pdev: client pci device * * Temporarily switch DDC lines to the client identified by @pdev * (but leave the outputs otherwise switched to where they are). * This allows the inactive client to probe EDID. The DDC lines must * afterwards be switched back by calling vga_switcheroo_unlock_ddc(), * even if this function returns an error. * * Return: Previous DDC owner on success or a negative int on error. * Specifically, %-ENODEV if no handler has registered or if the handler * does not support switching the DDC lines. Also, a negative value * returned by the handler is propagated back to the caller. * The return value has merely an informational purpose for any caller * which might be interested in it. It is acceptable to ignore the return * value and simply rely on the result of the subsequent EDID probe, * which will be %NULL if DDC switching failed. */
int vga_switcheroo_lock_ddc(struct pci_dev *pdev) { enum vga_switcheroo_client_id id; mutex_lock(&vgasr_priv.mux_hw_lock); if (!vgasr_priv.handler || !vgasr_priv.handler->switch_ddc) { vgasr_priv.old_ddc_owner = -ENODEV; return -ENODEV; } id = vgasr_priv.handler->get_client_id(pdev); vgasr_priv.old_ddc_owner = vgasr_priv.handler->switch_ddc(id); return vgasr_priv.old_ddc_owner; }

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EXPORT_SYMBOL(vga_switcheroo_lock_ddc); /** * vga_switcheroo_unlock_ddc() - switch DDC lines back to previous owner * @pdev: client pci device * * Switch DDC lines back to the previous owner after calling * vga_switcheroo_lock_ddc(). This must be called even if * vga_switcheroo_lock_ddc() returned an error. * * Return: Previous DDC owner on success (i.e. the client identifier of @pdev) * or a negative int on error. * Specifically, %-ENODEV if no handler has registered or if the handler * does not support switching the DDC lines. Also, a negative value * returned by the handler is propagated back to the caller. * Finally, invoking this function without calling vga_switcheroo_lock_ddc() * first is not allowed and will result in %-EINVAL. */
int vga_switcheroo_unlock_ddc(struct pci_dev *pdev) { enum vga_switcheroo_client_id id; int ret = vgasr_priv.old_ddc_owner; if (WARN_ON_ONCE(!mutex_is_locked(&vgasr_priv.mux_hw_lock))) return -EINVAL; if (vgasr_priv.old_ddc_owner >= 0) { id = vgasr_priv.handler->get_client_id(pdev); if (vgasr_priv.old_ddc_owner != id) ret = vgasr_priv.handler->switch_ddc( vgasr_priv.old_ddc_owner); } mutex_unlock(&vgasr_priv.mux_hw_lock); return ret; }

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EXPORT_SYMBOL(vga_switcheroo_unlock_ddc); /** * DOC: Manual switching and manual power control * * In this mode of use, the file /sys/kernel/debug/vgaswitcheroo/switch * can be read to retrieve the current vga_switcheroo state and commands * can be written to it to change the state. The file appears as soon as * two GPU drivers and one handler have registered with vga_switcheroo. * The following commands are understood: * * * OFF: Power off the device not in use. * * ON: Power on the device not in use. * * IGD: Switch to the integrated graphics device. * Power on the integrated GPU if necessary, power off the discrete GPU. * Prerequisite is that no user space processes (e.g. Xorg, alsactl) * have opened device files of the GPUs or the audio client. If the * switch fails, the user may invoke lsof(8) or fuser(1) on /dev/dri/ * and /dev/snd/controlC1 to identify processes blocking the switch. * * DIS: Switch to the discrete graphics device. * * DIGD: Delayed switch to the integrated graphics device. * This will perform the switch once the last user space process has * closed the device files of the GPUs and the audio client. * * DDIS: Delayed switch to the discrete graphics device. * * MIGD: Mux-only switch to the integrated graphics device. * Does not remap console or change the power state of either gpu. * If the integrated GPU is currently off, the screen will turn black. * If it is on, the screen will show whatever happens to be in VRAM. * Either way, the user has to blindly enter the command to switch back. * * MDIS: Mux-only switch to the discrete graphics device. * * For GPUs whose power state is controlled by the driver's runtime pm, * the ON and OFF commands are a no-op (see next section). * * For muxless machines, the IGD/DIS, DIGD/DDIS and MIGD/MDIS commands * should not be used. */
static int vga_switcheroo_show(struct seq_file *m, void *v) { struct vga_switcheroo_client *client; int i = 0; mutex_lock(&vgasr_mutex); list_for_each_entry(client, &vgasr_priv.clients, list) { seq_printf(m, "%d:%s%s:%c:%s%s:%s\n", i, client_id(client) == VGA_SWITCHEROO_DIS ? "DIS" : "IGD", client_is_vga(client) ? "" : "-Audio", client->active ? '+' : ' ', client->driver_power_control ? "Dyn" : "", client->pwr_state ? "Pwr" : "Off", pci_name(client->pdev)); i++; } mutex_unlock(&vgasr_mutex); return 0; }

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static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file) { return single_open(file, vga_switcheroo_show, NULL); }

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static int vga_switchon(struct vga_switcheroo_client *client) { if (client->driver_power_control) return 0; if (vgasr_priv.handler->power_state) vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_ON); /* call the driver callback to turn on device */ client->ops->set_gpu_state(client->pdev, VGA_SWITCHEROO_ON); client->pwr_state = VGA_SWITCHEROO_ON; return 0; }

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static int vga_switchoff(struct vga_switcheroo_client *client) { if (client->driver_power_control) return 0; /* call the driver callback to turn off device */ client->ops->set_gpu_state(client->pdev, VGA_SWITCHEROO_OFF); if (vgasr_priv.handler->power_state) vgasr_priv.handler->power_state(client->id, VGA_SWITCHEROO_OFF); client->pwr_state = VGA_SWITCHEROO_OFF; return 0; }

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Takashi Iwai23.12%125.00%
Total64100.00%4100.00%


static void set_audio_state(enum vga_switcheroo_client_id id, enum vga_switcheroo_state state) { struct vga_switcheroo_client *client; client = find_client_from_id(&vgasr_priv.clients, id | ID_BIT_AUDIO); if (client && client->pwr_state != state) { client->ops->set_gpu_state(client->pdev, state); client->pwr_state = state; } }

Contributors

PersonTokensPropCommitsCommitProp
Takashi Iwai6093.75%133.33%
Lukas Wunner46.25%266.67%
Total64100.00%3100.00%

/* stage one happens before delay */
static int vga_switchto_stage1(struct vga_switcheroo_client *new_client) { struct vga_switcheroo_client *active; active = find_active_client(&vgasr_priv.clients); if (!active) return 0; if (new_client->pwr_state == VGA_SWITCHEROO_OFF) vga_switchon(new_client); vga_set_default_device(new_client->pdev); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Dave Airlie5189.47%250.00%
Matthew Garrett35.26%125.00%
Takashi Iwai35.26%125.00%
Total57100.00%4100.00%

/* post delay */
static int vga_switchto_stage2(struct vga_switcheroo_client *new_client) { int ret; struct vga_switcheroo_client *active; active = find_active_client(&vgasr_priv.clients); if (!active) return 0; active->active = false; set_audio_state(active->id, VGA_SWITCHEROO_OFF); if (new_client->fb_info) { struct fb_event event; console_lock(); event.info = new_client->fb_info; fb_notifier_call_chain(FB_EVENT_REMAP_ALL_CONSOLE, &event); console_unlock(); } mutex_lock(&vgasr_priv.mux_hw_lock); ret = vgasr_priv.handler->switchto(new_client->id); mutex_unlock(&vgasr_priv.mux_hw_lock); if (ret) return ret; if (new_client->ops->reprobe) new_client->ops->reprobe(new_client->pdev); if (active->pwr_state == VGA_SWITCHEROO_ON) vga_switchoff(active); set_audio_state(new_client->id, VGA_SWITCHEROO_ON); new_client->active = true; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Dave Airlie12874.42%450.00%
Takashi Iwai2816.28%337.50%
Lukas Wunner169.30%112.50%
Total172100.00%8100.00%


static bool check_can_switch(void) { struct vga_switcheroo_client *client; list_for_each_entry(client, &vgasr_priv.clients, list) { if (!client->ops->can_switch(client->pdev)) { pr_err("client %x refused switch\n", client->id); return false; } } return true; }

Contributors

PersonTokensPropCommitsCommitProp
Takashi Iwai5092.59%240.00%
Thierry Reding23.70%240.00%
Dave Airlie23.70%120.00%
Total54100.00%5100.00%


static ssize_t vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { char usercmd[64]; int ret; bool delay = false, can_switch; bool just_mux = false; enum vga_switcheroo_client_id client_id = VGA_SWITCHEROO_UNKNOWN_ID; struct vga_switcheroo_client *client = NULL; if (cnt > 63) cnt = 63; if (copy_from_user(usercmd, ubuf, cnt)) return -EFAULT; mutex_lock(&vgasr_mutex); if (!vgasr_priv.active) { cnt = -EINVAL; goto out; } /* pwr off the device not in use */ if (strncmp(usercmd, "OFF", 3) == 0) { list_for_each_entry(client, &vgasr_priv.clients, list) { if (client->active || client_is_audio(client)) continue; if (client->driver_power_control) continue; set_audio_state(client->id, VGA_SWITCHEROO_OFF); if (client->pwr_state == VGA_SWITCHEROO_ON) vga_switchoff(client); } goto out; } /* pwr on the device not in use */ if (strncmp(usercmd, "ON", 2) == 0) { list_for_each_entry(client, &vgasr_priv.clients, list) { if (client->active || client_is_audio(client)) continue; if (client->driver_power_control) continue; if (client->pwr_state == VGA_SWITCHEROO_OFF) vga_switchon(client); set_audio_state(client->id, VGA_SWITCHEROO_ON); } goto out; } /* request a delayed switch - test can we switch now */ if (strncmp(usercmd, "DIGD", 4) == 0) { client_id = VGA_SWITCHEROO_IGD; delay = true; } if (strncmp(usercmd, "DDIS", 4) == 0) { client_id = VGA_SWITCHEROO_DIS; delay = true; } if (strncmp(usercmd, "IGD", 3) == 0) client_id = VGA_SWITCHEROO_IGD; if (strncmp(usercmd, "DIS", 3) == 0) client_id = VGA_SWITCHEROO_DIS; if (strncmp(usercmd, "MIGD", 4) == 0) { just_mux = true; client_id = VGA_SWITCHEROO_IGD; } if (strncmp(usercmd, "MDIS", 4) == 0) { just_mux = true; client_id = VGA_SWITCHEROO_DIS; } if (client_id == VGA_SWITCHEROO_UNKNOWN_ID) goto out; client = find_client_from_id(&vgasr_priv.clients, client_id); if (!client) goto out; vgasr_priv.delayed_switch_active = false; if (just_mux) { mutex_lock(&vgasr_priv.mux_hw_lock); ret = vgasr_priv.handler->switchto(client_id); mutex_unlock(&vgasr_priv.mux_hw_lock); goto out; } if (client->active) goto out; /* okay we want a switch - test if devices are willing to switch */ can_switch = check_can_switch(); if (can_switch == false && delay == false) goto out; if (can_switch) { ret = vga_switchto_stage1(client); if (ret) pr_err("switching failed stage 1 %d\n", ret); ret = vga_switchto_stage2(client); if (ret) pr_err("switching failed stage 2 %d\n", ret); } else { pr_info("setting delayed switch to client %d\n", client->id); vgasr_priv.delayed_switch_active = true; vgasr_priv.delayed_client_id = client_id; ret = vga_switchto_stage1(client); if (ret) pr_err("delayed switching stage 1 failed %d\n", ret); } out: mutex_unlock(&vgasr_mutex); return cnt; }

Contributors

PersonTokensPropCommitsCommitProp
Dave Airlie45179.54%428.57%
Takashi Iwai6912.17%214.29%
Lukas Wunner203.53%321.43%
Florian Mickler91.59%17.14%
Jiri Slaby81.41%17.14%
Thierry Reding81.41%214.29%
Dan Carpenter20.35%17.14%
Total567100.00%14100.00%

static const struct file_operations vga_switcheroo_debugfs_fops = { .owner = THIS_MODULE, .open = vga_switcheroo_debugfs_open, .write = vga_switcheroo_debugfs_write, .read = seq_read, .llseek = seq_lseek, .release = single_release, };
static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv) { debugfs_remove(priv->switch_file); priv->switch_file = NULL; debugfs_remove(priv->debugfs_root); priv->debugfs_root = NULL; }

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PersonTokensPropCommitsCommitProp
Dave Airlie37100.00%1100.00%
Total37100.00%1100.00%


static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv) { static const char mp[] = "/sys/kernel/debug"; /* already initialised */ if (priv->debugfs_root) return 0; priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL); if (!priv->debugfs_root) { pr_err("Cannot create %s/vgaswitcheroo\n", mp); goto fail; } priv->switch_file = debugfs_create_file("switch", 0644, priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops); if (!priv->switch_file) { pr_err("cannot create %s/vgaswitcheroo/switch\n", mp); goto fail; } return 0; fail: vga_switcheroo_debugfs_fini(priv); return -1; }

Contributors

PersonTokensPropCommitsCommitProp
Dave Airlie9685.71%133.33%
Thierry Reding1614.29%266.67%
Total112100.00%3100.00%

/** * vga_switcheroo_process_delayed_switch() - helper for delayed switching * * Process a delayed switch if one is pending. DRM drivers should call this * from their ->lastclose callback. * * Return: 0 on success. -EINVAL if no delayed switch is pending, if the client * has unregistered in the meantime or if there are other clients blocking the * switch. If the actual switch fails, an error is reported and 0 is returned. */
int vga_switcheroo_process_delayed_switch(void) { struct vga_switcheroo_client *client; int ret; int err = -EINVAL; mutex_lock(&vgasr_mutex); if (!vgasr_priv.delayed_switch_active) goto err; pr_info("processing delayed switch to %d\n", vgasr_priv.delayed_client_id); client = find_client_from_id(&vgasr_priv.clients, vgasr_priv.delayed_client_id); if (!client || !check_can_switch()) goto err; ret = vga_switchto_stage2(client); if (ret) pr_err("delayed switching failed stage 2 %d\n", ret); vgasr_priv.delayed_switch_active = false; err = 0; err: mutex_unlock(&vgasr_mutex); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Dave Airlie9888.29%240.00%
Takashi Iwai98.11%120.00%
Thierry Reding43.60%240.00%
Total111100.00%5100.00%

EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch); /** * DOC: Driver power control * * In this mode of use, the discrete GPU automatically powers up and down at * the discretion of the driver's runtime pm. On muxed machines, the user may * still influence the muxer state by way of the debugfs interface, however * the ON and OFF commands become a no-op for the discrete GPU. * * This mode is the default on Nvidia HybridPower/Optimus and ATI PowerXpress. * Specifying nouveau.runpm=0, radeon.runpm=0 or amdgpu.runpm=0 on the kernel * command line disables it. * * When the driver decides to power up or down, it notifies vga_switcheroo * thereof so that it can (a) power the audio device on the GPU up or down, * and (b) update its internal power state representation for the device. * This is achieved by vga_switcheroo_set_dynamic_switch(). * * After the GPU has been suspended, the handler needs to be called to cut * power to the GPU. Likewise it needs to reinstate power before the GPU * can resume. This is achieved by vga_switcheroo_init_domain_pm_ops(), * which augments the GPU's suspend/resume functions by the requisite * calls to the handler. * * When the audio device resumes, the GPU needs to be woken. This is achieved * by vga_switcheroo_init_domain_pm_optimus_hdmi_audio(), which augments the * audio device's resume function. * * On muxed machines, if the mux is initially switched to the discrete GPU, * the user ends up with a black screen when the GPU powers down after boot. * As a workaround, the mux is forced to the integrated GPU on runtime suspend, * cf. https://bugs.freedesktop.org/show_bug.cgi?id=75917 */
static void vga_switcheroo_power_switch(struct pci_dev *pdev, enum vga_switcheroo_state state) { struct vga_switcheroo_client *client; if (!vgasr_priv.handler->power_state) return; client = find_client_from_pci(&vgasr_priv.clients, pdev); if (!client) return; if (!client->driver_power_control) return; vgasr_priv.handler->power_state(client->id, state); }

Contributors

PersonTokensPropCommitsCommitProp
Dave Airlie69100.00%1100.00%
Total69100.00%1100.00%

/** * vga_switcheroo_set_dynamic_switch() - helper for driver power control * @pdev: client pci device * @dynamic: new power state * * Helper for GPUs whose power state is controlled by the driver's runtime pm. * When the driver decides to power up or down, it notifies vga_switcheroo * thereof using this helper so that it can (a) power the audio device on * the GPU up or down, and (b) update its internal power state representation * for the device. */
void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic) { struct vga_switcheroo_client *client