diff options
Diffstat (limited to 'drivers/gpu/vga/vga_switcheroo.c')
| -rw-r--r-- | drivers/gpu/vga/vga_switcheroo.c | 706 |
1 files changed, 608 insertions, 98 deletions
diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c index cf787e1d9322..68e45a26e85f 100644 --- a/drivers/gpu/vga/vga_switcheroo.c +++ b/drivers/gpu/vga/vga_switcheroo.c @@ -1,73 +1,179 @@ /* + * 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> * - * Licensed under GPLv2 + * 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. * - * vga_switcheroo.c - Support for laptop with dual GPU using one set of outputs - - Switcher interface - methods require for ATPX and DCM - - switchto - this throws the output MUX switch - - discrete_set_power - sets the power state for the discrete card - - GPU driver interface - - set_gpu_state - this should do the equiv of s/r for the card - - this should *not* set the discrete power state - - switch_check - check if the device is in a position to switch now */ -#include <linux/module.h> -#include <linux/seq_file.h> -#include <linux/uaccess.h> -#include <linux/fs.h> +#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/fbcon.h> +#include <linux/module.h> #include <linux/pci.h> -#include <linux/console.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> -#include <linux/vgaarb.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 if manual power control is used. + * For driver power control, call vga_switcheroo_pwr_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 + * @vga_dev: pci device, indicate which GPU is bound to current audio client + * + * Registered client. A client can be either a GPU or an audio device on a GPU. + * For audio clients, the @fb_info and @active members are bogus. For GPU + * clients, the @vga_dev is bogus. + */ struct vga_switcheroo_client { struct pci_dev *pdev; struct fb_info *fb_info; - int pwr_state; + enum vga_switcheroo_state pwr_state; const struct vga_switcheroo_client_ops *ops; - int id; + enum vga_switcheroo_client_id id; bool active; + bool driver_power_control; struct list_head list; + struct pci_dev *vga_dev; }; +/* + * 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 + * @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; - struct vga_switcheroo_handler *handler; + 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 == -1 || !client_is_audio(c)) +#define client_is_audio(c) ((c)->id & ID_BIT_AUDIO) +#define client_is_vga(c) (!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_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) @@ -87,19 +193,48 @@ static void vga_switcheroo_enable(void) vgasr_priv.handler->init(); list_for_each_entry(client, &vgasr_priv.clients, list) { - if (client->id != -1) + if (!client_is_vga(client) || + client_id(client) != VGA_SWITCHEROO_UNKNOWN_ID) continue; + ret = vgasr_priv.handler->get_client_id(client->pdev); if (ret < 0) return; client->id = ret; } + + list_for_each_entry(client, &vgasr_priv.clients, list) { + if (!client_is_audio(client) || + client_id(client) != VGA_SWITCHEROO_UNKNOWN_ID) + continue; + + ret = vgasr_priv.handler->get_client_id(client->vga_dev); + if (ret < 0) + return; + + client->id = ret | ID_BIT_AUDIO; + if (client->ops->gpu_bound) + client->ops->gpu_bound(client->pdev, ret); + } + vga_switcheroo_debugfs_init(&vgasr_priv); vgasr_priv.active = true; } -int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler) +/** + * 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) { @@ -108,8 +243,9 @@ int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler) } vgasr_priv.handler = handler; + vgasr_priv.handler_flags = handler_flags; if (vga_switcheroo_ready()) { - printk(KERN_INFO "vga_switcheroo: enabled\n"); + pr_info("enabled\n"); vga_switcheroo_enable(); } mutex_unlock(&vgasr_mutex); @@ -117,22 +253,47 @@ int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler) } 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("vga_switcheroo: disabled\n"); + 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); } 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; +} +EXPORT_SYMBOL(vga_switcheroo_handler_flags); + static int register_client(struct pci_dev *pdev, const struct vga_switcheroo_client_ops *ops, - int id, bool active) + enum vga_switcheroo_client_id id, + struct pci_dev *vga_dev, + bool active, + bool driver_power_control) { struct vga_switcheroo_client *client; @@ -145,6 +306,8 @@ static int register_client(struct pci_dev *pdev, client->ops = ops; client->id = id; client->active = active; + client->driver_power_control = driver_power_control; + client->vga_dev = vga_dev; mutex_lock(&vgasr_mutex); list_add_tail(&client->list, &vgasr_priv.clients); @@ -152,26 +315,78 @@ static int register_client(struct pci_dev *pdev, vgasr_priv.registered_clients++; if (vga_switcheroo_ready()) { - printk(KERN_INFO "vga_switcheroo: enabled\n"); + pr_info("enabled\n"); vga_switcheroo_enable(); } mutex_unlock(&vgasr_mutex); return 0; } +/** + * 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) + const struct vga_switcheroo_client_ops *ops, + bool driver_power_control) { - return register_client(pdev, ops, -1, - pdev == vga_default_device()); + return register_client(pdev, ops, VGA_SWITCHEROO_UNKNOWN_ID, NULL, + pdev == vga_default_device(), + driver_power_control); } EXPORT_SYMBOL(vga_switcheroo_register_client); +/** + * vga_switcheroo_register_audio_client - register audio client + * @pdev: client pci device + * @ops: client callbacks + * @vga_dev: pci device which is bound to current audio client + * + * Register audio client (audio device on a GPU). The client is assumed + * to use runtime PM. 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, -EINVAL on getting + * client id error. + */ int vga_switcheroo_register_audio_client(struct pci_dev *pdev, - const struct vga_switcheroo_client_ops *ops, - int id, bool active) + const struct vga_switcheroo_client_ops *ops, + struct pci_dev *vga_dev) { - return register_client(pdev, ops, id | ID_BIT_AUDIO, active); + enum vga_switcheroo_client_id id = VGA_SWITCHEROO_UNKNOWN_ID; + + /* + * if vga_switcheroo has enabled, that mean two GPU clients and also + * handler are registered. Get audio client id from bound GPU client + * id directly, otherwise, set it as VGA_SWITCHEROO_UNKNOWN_ID, + * it will set to correct id in later when vga_switcheroo_enable() + * is called. + */ + mutex_lock(&vgasr_mutex); + if (vgasr_priv.active) { + id = vgasr_priv.handler->get_client_id(vga_dev); + if (id < 0) { + mutex_unlock(&vgasr_mutex); + return -EINVAL; + } + /* notify if GPU has been already bound */ + if (ops->gpu_bound) + ops->gpu_bound(pdev, id); + } + mutex_unlock(&vgasr_mutex); + + return register_client(pdev, ops, id | ID_BIT_AUDIO, vga_dev, + false, true); } EXPORT_SYMBOL(vga_switcheroo_register_audio_client); @@ -179,6 +394,7 @@ 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; @@ -186,9 +402,11 @@ find_client_from_pci(struct list_head *head, struct pci_dev *pdev) } static struct vga_switcheroo_client * -find_client_from_id(struct list_head *head, int client_id) +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; @@ -199,25 +417,84 @@ 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 && client_is_vga(client)) + if (client->active) return client; return NULL; } -int vga_switcheroo_get_client_state(struct pci_dev *pdev) +/** + * 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 (pci_is_display(pdev)) { + /* + * 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; +} +EXPORT_SYMBOL(vga_switcheroo_client_probe_defer); + +static enum vga_switcheroo_state +vga_switcheroo_pwr_state(struct vga_switcheroo_client *client) +{ + if (client->driver_power_control) + if (pm_runtime_enabled(&client->pdev->dev) && + pm_runtime_active(&client->pdev->dev)) + return VGA_SWITCHEROO_ON; + else + return VGA_SWITCHEROO_OFF; + else + return client->pwr_state; +} + +/** + * 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) - return VGA_SWITCHEROO_NOT_FOUND; - if (!vgasr_priv.active) - return VGA_SWITCHEROO_INIT; - return client->pwr_state; + ret = VGA_SWITCHEROO_NOT_FOUND; + else + ret = vga_switcheroo_pwr_state(client); + mutex_unlock(&vgasr_mutex); + return ret; } 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; @@ -231,7 +508,7 @@ void vga_switcheroo_unregister_client(struct pci_dev *pdev) kfree(client); } if (vgasr_priv.active && vgasr_priv.registered_clients < 2) { - printk(KERN_INFO "vga_switcheroo: disabled\n"); + pr_info("disabled\n"); vga_switcheroo_debugfs_fini(&vgasr_priv); vgasr_priv.active = false; } @@ -239,6 +516,14 @@ void vga_switcheroo_unregister_client(struct pci_dev *pdev) } 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) { @@ -252,17 +537,126 @@ void vga_switcheroo_client_fb_set(struct pci_dev *pdev, } 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; +} +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; +} +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\n", i, - client_id(client) == VGA_SWITCHEROO_DIS ? "DIS" : "IGD", + 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->pwr_state ? "Pwr" : "Off", + client->driver_power_control ? "Dyn" : "", + vga_switcheroo_pwr_state(client) ? "Pwr" : "Off", pci_name(client->pdev)); i++; } @@ -277,6 +671,8 @@ static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file) 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 */ @@ -287,6 +683,8 @@ static int vga_switchon(struct vga_switcheroo_client *client) 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) @@ -295,15 +693,14 @@ static int vga_switchoff(struct vga_switcheroo_client *client) return 0; } -static void set_audio_state(int id, int state) +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) { + if (client) client->ops->set_gpu_state(client->pdev, state); - client->pwr_state = state; - } } /* stage one happens before delay */ @@ -315,7 +712,7 @@ static int vga_switchto_stage1(struct vga_switcheroo_client *new_client) if (!active) return 0; - if (new_client->pwr_state == VGA_SWITCHEROO_OFF) + if (vga_switcheroo_pwr_state(new_client) == VGA_SWITCHEROO_OFF) vga_switchon(new_client); vga_set_default_device(new_client->pdev); @@ -334,27 +731,28 @@ static int vga_switchto_stage2(struct vga_switcheroo_client *new_client) active->active = false; - set_audio_state(active->id, VGA_SWITCHEROO_OFF); + /* let HDA controller autosuspend if GPU uses driver power control */ + if (!active->driver_power_control) + 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(); - } + if (new_client->fb_info) + fbcon_remap_all(new_client->fb_info); + 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) + if (vga_switcheroo_pwr_state(active) == VGA_SWITCHEROO_ON) vga_switchoff(active); - set_audio_state(new_client->id, VGA_SWITCHEROO_ON); + /* let HDA controller autoresume if GPU uses driver power control */ + if (!new_client->driver_power_control) + set_audio_state(new_client->id, VGA_SWITCHEROO_ON); new_client->active = true; return 0; @@ -366,7 +764,7 @@ static bool check_can_switch(void) list_for_each_entry(client, &vgasr_priv.clients, list) { if (!client->ops->can_switch(client->pdev)) { - printk(KERN_ERR "vga_switcheroo: client %x refused switch\n", client->id); + pr_err("client %x refused switch\n", client->id); return false; } } @@ -381,7 +779,7 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf, int ret; bool delay = false, can_switch; bool just_mux = false; - int client_id = -1; + enum vga_switcheroo_client_id client_id = VGA_SWITCHEROO_UNKNOWN_ID; struct vga_switcheroo_client *client = NULL; if (cnt > 63) @@ -402,6 +800,8 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf, 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); @@ -413,6 +813,8 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf, 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); @@ -446,7 +848,7 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf, client_id = VGA_SWITCHEROO_DIS; } - if (client_id == -1) + if (client_id == VGA_SWITCHEROO_UNKNOWN_ID) goto out; client = find_client_from_id(&vgasr_priv.clients, client_id); if (!client) @@ -455,7 +857,9 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf, 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; } @@ -471,20 +875,20 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf, if (can_switch) { ret = vga_switchto_stage1(client); if (ret) - printk(KERN_ERR "vga_switcheroo: switching failed stage 1 %d\n", ret); + pr_err("switching failed stage 1 %d\n", ret); ret = vga_switchto_stage2(client); if (ret) - printk(KERN_ERR "vga_switcheroo: switching failed stage 2 %d\n", ret); + pr_err("switching failed stage 2 %d\n", ret); } else { - printk(KERN_INFO "vga_switcheroo: setting delayed switch to client %d\n", client->id); + 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) - printk(KERN_ERR "vga_switcheroo: delayed switching stage 1 failed %d\n", ret); + pr_err("delayed switching stage 1 failed %d\n", ret); } out: @@ -503,40 +907,31 @@ static const struct file_operations vga_switcheroo_debugfs_fops = { static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv) { - if (priv->switch_file) { - debugfs_remove(priv->switch_file); - priv->switch_file = NULL; - } - if (priv->debugfs_root) { - debugfs_remove(priv->debugfs_root); - priv->debugfs_root = NULL; - } + debugfs_remove_recursive(priv->debugfs_root); + priv->debugfs_root = NULL; } -static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv) +static void vga_switcheroo_debugfs_init(struct vgasr_priv *priv) { /* already initialised */ if (priv->debugfs_root) - return 0; - priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL); + return; - if (!priv->debugfs_root) { - printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n"); - goto fail; - } + priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL); - priv->switch_file = debugfs_create_file("switch", 0644, - priv->debugfs_root, NULL, &vga_switcheroo_debugfs_fops); - if (!priv->switch_file) { - printk(KERN_ERR "vga_switcheroo: cannot create /sys/kernel/debug/vgaswitcheroo/switch\n"); - goto fail; - } - return 0; -fail: - vga_switcheroo_debugfs_fini(priv); - return -1; + debugfs_create_file("switch", 0644, priv->debugfs_root, NULL, + &vga_switcheroo_debugfs_fops); } +/** + * vga_switcheroo_process_delayed_switch() - helper for delayed switching + * + * Process a delayed switch if one is pending. + * + * 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; @@ -547,7 +942,8 @@ int vga_switcheroo_process_delayed_switch(void) if (!vgasr_priv.delayed_switch_active) goto err; - printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id); + 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); @@ -556,7 +952,7 @@ int vga_switcheroo_process_delayed_switch(void) ret = vga_switchto_stage2(client); if (ret) - printk(KERN_ERR "vga_switcheroo: delayed switching failed stage 2 %d\n", ret); + pr_err("delayed switching failed stage 2 %d\n", ret); vgasr_priv.delayed_switch_active = false; err = 0; @@ -565,3 +961,117 @@ err: return err; } 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. + * + * 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 a PCI quirk which calls device_link_add() to declare a dependency on the + * GPU. That way, the GPU is kept awake whenever and as long as the audio + * device is in use. + * + * 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); +} + +/* switcheroo power domain */ +static int vga_switcheroo_runtime_suspend(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + int ret; + + ret = dev->bus->pm->runtime_suspend(dev); + if (ret) + return ret; + mutex_lock(&vgasr_mutex); + if (vgasr_priv.handler->switchto) { + mutex_lock(&vgasr_priv.mux_hw_lock); + vgasr_priv.handler->switchto(VGA_SWITCHEROO_IGD); + mutex_unlock(&vgasr_priv.mux_hw_lock); + } + pci_bus_set_current_state(pdev->bus, PCI_D3cold); + vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_OFF); + mutex_unlock(&vgasr_mutex); + return 0; +} + +static int vga_switcheroo_runtime_resume(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + + mutex_lock(&vgasr_mutex); + vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_ON); + mutex_unlock(&vgasr_mutex); + pci_resume_bus(pdev->bus); + return dev->bus->pm->runtime_resume(dev); +} + +/** + * vga_switcheroo_init_domain_pm_ops() - helper for driver power control + * @dev: vga client device + * @domain: power domain + * + * Helper for GPUs whose power state is controlled by the driver's runtime pm. + * 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. To this end, this helper augments the suspend/resume functions + * by the requisite calls to the handler. It needs only be called on platforms + * where the power switch is separate to the device being powered down. + */ +int vga_switcheroo_init_domain_pm_ops(struct device *dev, + struct dev_pm_domain *domain) +{ + /* copy over all the bus versions */ + if (dev->bus && dev->bus->pm) { + domain->ops = *dev->bus->pm; + domain->ops.runtime_suspend = vga_switcheroo_runtime_suspend; + domain->ops.runtime_resume = vga_switcheroo_runtime_resume; + + dev_pm_domain_set(dev, domain); + return 0; + } + dev_pm_domain_set(dev, NULL); + return -EINVAL; +} +EXPORT_SYMBOL(vga_switcheroo_init_domain_pm_ops); + +void vga_switcheroo_fini_domain_pm_ops(struct device *dev) +{ + dev_pm_domain_set(dev, NULL); +} +EXPORT_SYMBOL(vga_switcheroo_fini_domain_pm_ops); |