From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/gpu/vga/Kconfig | 30 + kernel/drivers/gpu/vga/Makefile | 2 + kernel/drivers/gpu/vga/vga_switcheroo.c | 711 ++++++++++++++++ kernel/drivers/gpu/vga/vgaarb.c | 1357 +++++++++++++++++++++++++++++++ 4 files changed, 2100 insertions(+) create mode 100644 kernel/drivers/gpu/vga/Kconfig create mode 100644 kernel/drivers/gpu/vga/Makefile create mode 100644 kernel/drivers/gpu/vga/vga_switcheroo.c create mode 100644 kernel/drivers/gpu/vga/vgaarb.c (limited to 'kernel/drivers/gpu/vga') diff --git a/kernel/drivers/gpu/vga/Kconfig b/kernel/drivers/gpu/vga/Kconfig new file mode 100644 index 000000000..29437eabe --- /dev/null +++ b/kernel/drivers/gpu/vga/Kconfig @@ -0,0 +1,30 @@ +config VGA_ARB + bool "VGA Arbitration" if EXPERT + default y + depends on (PCI && !S390) + help + Some "legacy" VGA devices implemented on PCI typically have the same + hard-decoded addresses as they did on ISA. When multiple PCI devices + are accessed at same time they need some kind of coordination. Please + see Documentation/vgaarbiter.txt for more details. Select this to + enable VGA arbiter. + +config VGA_ARB_MAX_GPUS + int "Maximum number of GPUs" + default 16 + depends on VGA_ARB + help + Reserves space in the kernel to maintain resource locking for + multiple GPUS. The overhead for each GPU is very small. + +config VGA_SWITCHEROO + bool "Laptop Hybrid Graphics - GPU switching support" + depends on X86 + depends on ACPI + select VGA_ARB + help + Many laptops released in 2008/9/10 have two GPUs with a multiplexer + to switch between them. This adds support for dynamic switching when + X isn't running and delayed switching until the next logoff. This + feature is called hybrid graphics, ATI PowerXpress, and Nvidia + HybridPower. diff --git a/kernel/drivers/gpu/vga/Makefile b/kernel/drivers/gpu/vga/Makefile new file mode 100644 index 000000000..14ca30b75 --- /dev/null +++ b/kernel/drivers/gpu/vga/Makefile @@ -0,0 +1,2 @@ +obj-$(CONFIG_VGA_ARB) += vgaarb.o +obj-$(CONFIG_VGA_SWITCHEROO) += vga_switcheroo.o diff --git a/kernel/drivers/gpu/vga/vga_switcheroo.c b/kernel/drivers/gpu/vga/vga_switcheroo.c new file mode 100644 index 000000000..37ac7b5db --- /dev/null +++ b/kernel/drivers/gpu/vga/vga_switcheroo.c @@ -0,0 +1,711 @@ +/* + * Copyright (c) 2010 Red Hat Inc. + * Author : Dave Airlie + * + * + * Licensed under GPLv2 + * + * 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 +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include + +struct vga_switcheroo_client { + struct pci_dev *pdev; + struct fb_info *fb_info; + int pwr_state; + const struct vga_switcheroo_client_ops *ops; + int id; + bool active; + bool driver_power_control; + struct list_head list; +}; + +static DEFINE_MUTEX(vgasr_mutex); + +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; +}; + +#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_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), +}; + +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; +} + +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 != -1) + 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; +} + +int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler) +{ + mutex_lock(&vgasr_mutex); + if (vgasr_priv.handler) { + mutex_unlock(&vgasr_mutex); + return -EINVAL; + } + + vgasr_priv.handler = handler; + if (vga_switcheroo_ready()) { + printk(KERN_INFO "vga_switcheroo: enabled\n"); + vga_switcheroo_enable(); + } + mutex_unlock(&vgasr_mutex); + return 0; +} +EXPORT_SYMBOL(vga_switcheroo_register_handler); + +void vga_switcheroo_unregister_handler(void) +{ + mutex_lock(&vgasr_mutex); + vgasr_priv.handler = NULL; + if (vgasr_priv.active) { + pr_info("vga_switcheroo: disabled\n"); + vga_switcheroo_debugfs_fini(&vgasr_priv); + vgasr_priv.active = false; + } + mutex_unlock(&vgasr_mutex); +} +EXPORT_SYMBOL(vga_switcheroo_unregister_handler); + +static int register_client(struct pci_dev *pdev, + const struct vga_switcheroo_client_ops *ops, + int 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()) { + printk(KERN_INFO "vga_switcheroo: enabled\n"); + vga_switcheroo_enable(); + } + mutex_unlock(&vgasr_mutex); + return 0; +} + +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, -1, + pdev == vga_default_device(), driver_power_control); +} +EXPORT_SYMBOL(vga_switcheroo_register_client); + +int vga_switcheroo_register_audio_client(struct pci_dev *pdev, + const struct vga_switcheroo_client_ops *ops, + int id, bool active) +{ + return register_client(pdev, ops, id | ID_BIT_AUDIO, active, false); +} +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; +} + +static struct vga_switcheroo_client * +find_client_from_id(struct list_head *head, int client_id) +{ + struct vga_switcheroo_client *client; + list_for_each_entry(client, head, list) + if (client->id == client_id) + return client; + return NULL; +} + +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)) + return client; + return NULL; +} + +int vga_switcheroo_get_client_state(struct pci_dev *pdev) +{ + struct vga_switcheroo_client *client; + + 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; +} +EXPORT_SYMBOL(vga_switcheroo_get_client_state); + +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) { + printk(KERN_INFO "vga_switcheroo: disabled\n"); + vga_switcheroo_debugfs_fini(&vgasr_priv); + vgasr_priv.active = false; + } + mutex_unlock(&vgasr_mutex); +} +EXPORT_SYMBOL(vga_switcheroo_unregister_client); + +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); +} +EXPORT_SYMBOL(vga_switcheroo_client_fb_set); + +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; +} + +static int vga_switcheroo_debugfs_open(struct inode *inode, struct file *file) +{ + return single_open(file, vga_switcheroo_show, NULL); +} + +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; +} + +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; +} + +static void set_audio_state(int id, int 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; + } +} + +/* 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; +} + +/* 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(); + } + + ret = vgasr_priv.handler->switchto(new_client->id); + 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; +} + +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)) { + printk(KERN_ERR "vga_switcheroo: client %x refused switch\n", client->id); + return false; + } + } + return true; +} + +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; + int client_id = -1; + 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 == -1) + 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) { + ret = vgasr_priv.handler->switchto(client_id); + 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) + printk(KERN_ERR "vga_switcheroo: 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); + + } else { + printk(KERN_INFO "vga_switcheroo: 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); + } + +out: + mutex_unlock(&vgasr_mutex); + return cnt; +} + +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) +{ + 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; + } +} + +static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv) +{ + /* already initialised */ + if (priv->debugfs_root) + return 0; + priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL); + + if (!priv->debugfs_root) { + printk(KERN_ERR "vga_switcheroo: Cannot create /sys/kernel/debug/vgaswitcheroo\n"); + goto fail; + } + + 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; +} + +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; + + printk(KERN_INFO "vga_switcheroo: 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) + printk(KERN_ERR "vga_switcheroo: delayed switching failed stage 2 %d\n", ret); + + vgasr_priv.delayed_switch_active = false; + err = 0; +err: + mutex_unlock(&vgasr_mutex); + return err; +} +EXPORT_SYMBOL(vga_switcheroo_process_delayed_switch); + +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); +} + +/* force a PCI device to a certain state - mainly to turn off audio clients */ + +void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic) +{ + struct vga_switcheroo_client *client; + + client = find_client_from_pci(&vgasr_priv.clients, pdev); + if (!client) + return; + + if (!client->driver_power_control) + return; + + client->pwr_state = dynamic; + set_audio_state(client->id, dynamic); +} +EXPORT_SYMBOL(vga_switcheroo_set_dynamic_switch); + +/* 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; + if (vgasr_priv.handler->switchto) + vgasr_priv.handler->switchto(VGA_SWITCHEROO_IGD); + vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_OFF); + return 0; +} + +static int vga_switcheroo_runtime_resume(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + int ret; + + vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_ON); + ret = dev->bus->pm->runtime_resume(dev); + if (ret) + return ret; + + return 0; +} + +/* this version is for the case 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 = domain; + return 0; + } + dev->pm_domain = NULL; + return -EINVAL; +} +EXPORT_SYMBOL(vga_switcheroo_init_domain_pm_ops); + +void vga_switcheroo_fini_domain_pm_ops(struct device *dev) +{ + dev->pm_domain = NULL; +} +EXPORT_SYMBOL(vga_switcheroo_fini_domain_pm_ops); + +static int vga_switcheroo_runtime_resume_hdmi_audio(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + int ret; + struct vga_switcheroo_client *client, *found = NULL; + + /* we need to check if we have to switch back on the video + device so the audio device can come back */ + list_for_each_entry(client, &vgasr_priv.clients, list) { + if (PCI_SLOT(client->pdev->devfn) == PCI_SLOT(pdev->devfn) && client_is_vga(client)) { + found = client; + ret = pm_runtime_get_sync(&client->pdev->dev); + if (ret) { + if (ret != 1) + return ret; + } + break; + } + } + ret = dev->bus->pm->runtime_resume(dev); + + /* put the reference for the gpu */ + if (found) { + pm_runtime_mark_last_busy(&found->pdev->dev); + pm_runtime_put_autosuspend(&found->pdev->dev); + } + return ret; +} + +int vga_switcheroo_init_domain_pm_optimus_hdmi_audio(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_resume = vga_switcheroo_runtime_resume_hdmi_audio; + + dev->pm_domain = domain; + return 0; + } + dev->pm_domain = NULL; + return -EINVAL; +} +EXPORT_SYMBOL(vga_switcheroo_init_domain_pm_optimus_hdmi_audio); diff --git a/kernel/drivers/gpu/vga/vgaarb.c b/kernel/drivers/gpu/vga/vgaarb.c new file mode 100644 index 000000000..7bcbf8636 --- /dev/null +++ b/kernel/drivers/gpu/vga/vgaarb.c @@ -0,0 +1,1357 @@ +/* + * vgaarb.c: Implements the VGA arbitration. For details refer to + * Documentation/vgaarbiter.txt + * + * + * (C) Copyright 2005 Benjamin Herrenschmidt + * (C) Copyright 2007 Paulo R. Zanoni + * (C) Copyright 2007, 2009 Tiago Vignatti + * + * 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. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include + +static void vga_arbiter_notify_clients(void); +/* + * We keep a list of all vga devices in the system to speed + * up the various operations of the arbiter + */ +struct vga_device { + struct list_head list; + struct pci_dev *pdev; + unsigned int decodes; /* what does it decodes */ + unsigned int owns; /* what does it owns */ + unsigned int locks; /* what does it locks */ + unsigned int io_lock_cnt; /* legacy IO lock count */ + unsigned int mem_lock_cnt; /* legacy MEM lock count */ + unsigned int io_norm_cnt; /* normal IO count */ + unsigned int mem_norm_cnt; /* normal MEM count */ + bool bridge_has_one_vga; + /* allow IRQ enable/disable hook */ + void *cookie; + void (*irq_set_state)(void *cookie, bool enable); + unsigned int (*set_vga_decode)(void *cookie, bool decode); +}; + +static LIST_HEAD(vga_list); +static int vga_count, vga_decode_count; +static bool vga_arbiter_used; +static DEFINE_SPINLOCK(vga_lock); +static DECLARE_WAIT_QUEUE_HEAD(vga_wait_queue); + + +static const char *vga_iostate_to_str(unsigned int iostate) +{ + /* Ignore VGA_RSRC_IO and VGA_RSRC_MEM */ + iostate &= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; + switch (iostate) { + case VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM: + return "io+mem"; + case VGA_RSRC_LEGACY_IO: + return "io"; + case VGA_RSRC_LEGACY_MEM: + return "mem"; + } + return "none"; +} + +static int vga_str_to_iostate(char *buf, int str_size, int *io_state) +{ + /* we could in theory hand out locks on IO and mem + * separately to userspace but it can cause deadlocks */ + if (strncmp(buf, "none", 4) == 0) { + *io_state = VGA_RSRC_NONE; + return 1; + } + + /* XXX We're not chekcing the str_size! */ + if (strncmp(buf, "io+mem", 6) == 0) + goto both; + else if (strncmp(buf, "io", 2) == 0) + goto both; + else if (strncmp(buf, "mem", 3) == 0) + goto both; + return 0; +both: + *io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; + return 1; +} + +/* this is only used a cookie - it should not be dereferenced */ +static struct pci_dev *vga_default; + +static void vga_arb_device_card_gone(struct pci_dev *pdev); + +/* Find somebody in our list */ +static struct vga_device *vgadev_find(struct pci_dev *pdev) +{ + struct vga_device *vgadev; + + list_for_each_entry(vgadev, &vga_list, list) + if (pdev == vgadev->pdev) + return vgadev; + return NULL; +} + +/* Returns the default VGA device (vgacon's babe) */ +struct pci_dev *vga_default_device(void) +{ + return vga_default; +} + +EXPORT_SYMBOL_GPL(vga_default_device); + +void vga_set_default_device(struct pci_dev *pdev) +{ + if (vga_default == pdev) + return; + + pci_dev_put(vga_default); + vga_default = pci_dev_get(pdev); +} + +static inline void vga_irq_set_state(struct vga_device *vgadev, bool state) +{ + if (vgadev->irq_set_state) + vgadev->irq_set_state(vgadev->cookie, state); +} + + +/* If we don't ever use VGA arb we should avoid + turning off anything anywhere due to old X servers getting + confused about the boot device not being VGA */ +static void vga_check_first_use(void) +{ + /* we should inform all GPUs in the system that + * VGA arb has occurred and to try and disable resources + * if they can */ + if (!vga_arbiter_used) { + vga_arbiter_used = true; + vga_arbiter_notify_clients(); + } +} + +static struct vga_device *__vga_tryget(struct vga_device *vgadev, + unsigned int rsrc) +{ + unsigned int wants, legacy_wants, match; + struct vga_device *conflict; + unsigned int pci_bits; + u32 flags = 0; + + /* Account for "normal" resources to lock. If we decode the legacy, + * counterpart, we need to request it as well + */ + if ((rsrc & VGA_RSRC_NORMAL_IO) && + (vgadev->decodes & VGA_RSRC_LEGACY_IO)) + rsrc |= VGA_RSRC_LEGACY_IO; + if ((rsrc & VGA_RSRC_NORMAL_MEM) && + (vgadev->decodes & VGA_RSRC_LEGACY_MEM)) + rsrc |= VGA_RSRC_LEGACY_MEM; + + pr_debug("%s: %d\n", __func__, rsrc); + pr_debug("%s: owns: %d\n", __func__, vgadev->owns); + + /* Check what resources we need to acquire */ + wants = rsrc & ~vgadev->owns; + + /* We already own everything, just mark locked & bye bye */ + if (wants == 0) + goto lock_them; + + /* We don't need to request a legacy resource, we just enable + * appropriate decoding and go + */ + legacy_wants = wants & VGA_RSRC_LEGACY_MASK; + if (legacy_wants == 0) + goto enable_them; + + /* Ok, we don't, let's find out how we need to kick off */ + list_for_each_entry(conflict, &vga_list, list) { + unsigned int lwants = legacy_wants; + unsigned int change_bridge = 0; + + /* Don't conflict with myself */ + if (vgadev == conflict) + continue; + + /* Check if the architecture allows a conflict between those + * 2 devices or if they are on separate domains + */ + if (!vga_conflicts(vgadev->pdev, conflict->pdev)) + continue; + + /* We have a possible conflict. before we go further, we must + * check if we sit on the same bus as the conflicting device. + * if we don't, then we must tie both IO and MEM resources + * together since there is only a single bit controlling + * VGA forwarding on P2P bridges + */ + if (vgadev->pdev->bus != conflict->pdev->bus) { + change_bridge = 1; + lwants = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; + } + + /* Check if the guy has a lock on the resource. If he does, + * return the conflicting entry + */ + if (conflict->locks & lwants) + return conflict; + + /* Ok, now check if it owns the resource we want. We can + * lock resources that are not decoded, therefore a device + * can own resources it doesn't decode. + */ + match = lwants & conflict->owns; + if (!match) + continue; + + /* looks like he doesn't have a lock, we can steal + * them from him + */ + + flags = 0; + pci_bits = 0; + + /* If we can't control legacy resources via the bridge, we + * also need to disable normal decoding. + */ + if (!conflict->bridge_has_one_vga) { + if ((match & conflict->decodes) & VGA_RSRC_LEGACY_MEM) + pci_bits |= PCI_COMMAND_MEMORY; + if ((match & conflict->decodes) & VGA_RSRC_LEGACY_IO) + pci_bits |= PCI_COMMAND_IO; + + if (pci_bits) { + vga_irq_set_state(conflict, false); + flags |= PCI_VGA_STATE_CHANGE_DECODES; + } + } + + if (change_bridge) + flags |= PCI_VGA_STATE_CHANGE_BRIDGE; + + pci_set_vga_state(conflict->pdev, false, pci_bits, flags); + conflict->owns &= ~match; + + /* If we disabled normal decoding, reflect it in owns */ + if (pci_bits & PCI_COMMAND_MEMORY) + conflict->owns &= ~VGA_RSRC_NORMAL_MEM; + if (pci_bits & PCI_COMMAND_IO) + conflict->owns &= ~VGA_RSRC_NORMAL_IO; + } + +enable_them: + /* ok dude, we got it, everybody conflicting has been disabled, let's + * enable us. Mark any bits in "owns" regardless of whether we + * decoded them. We can lock resources we don't decode, therefore + * we must track them via "owns". + */ + flags = 0; + pci_bits = 0; + + if (!vgadev->bridge_has_one_vga) { + flags |= PCI_VGA_STATE_CHANGE_DECODES; + if (wants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM)) + pci_bits |= PCI_COMMAND_MEMORY; + if (wants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO)) + pci_bits |= PCI_COMMAND_IO; + } + if (wants & VGA_RSRC_LEGACY_MASK) + flags |= PCI_VGA_STATE_CHANGE_BRIDGE; + + pci_set_vga_state(vgadev->pdev, true, pci_bits, flags); + + if (!vgadev->bridge_has_one_vga) { + vga_irq_set_state(vgadev, true); + } + vgadev->owns |= wants; +lock_them: + vgadev->locks |= (rsrc & VGA_RSRC_LEGACY_MASK); + if (rsrc & VGA_RSRC_LEGACY_IO) + vgadev->io_lock_cnt++; + if (rsrc & VGA_RSRC_LEGACY_MEM) + vgadev->mem_lock_cnt++; + if (rsrc & VGA_RSRC_NORMAL_IO) + vgadev->io_norm_cnt++; + if (rsrc & VGA_RSRC_NORMAL_MEM) + vgadev->mem_norm_cnt++; + + return NULL; +} + +static void __vga_put(struct vga_device *vgadev, unsigned int rsrc) +{ + unsigned int old_locks = vgadev->locks; + + pr_debug("%s\n", __func__); + + /* Update our counters, and account for equivalent legacy resources + * if we decode them + */ + if ((rsrc & VGA_RSRC_NORMAL_IO) && vgadev->io_norm_cnt > 0) { + vgadev->io_norm_cnt--; + if (vgadev->decodes & VGA_RSRC_LEGACY_IO) + rsrc |= VGA_RSRC_LEGACY_IO; + } + if ((rsrc & VGA_RSRC_NORMAL_MEM) && vgadev->mem_norm_cnt > 0) { + vgadev->mem_norm_cnt--; + if (vgadev->decodes & VGA_RSRC_LEGACY_MEM) + rsrc |= VGA_RSRC_LEGACY_MEM; + } + if ((rsrc & VGA_RSRC_LEGACY_IO) && vgadev->io_lock_cnt > 0) + vgadev->io_lock_cnt--; + if ((rsrc & VGA_RSRC_LEGACY_MEM) && vgadev->mem_lock_cnt > 0) + vgadev->mem_lock_cnt--; + + /* Just clear lock bits, we do lazy operations so we don't really + * have to bother about anything else at this point + */ + if (vgadev->io_lock_cnt == 0) + vgadev->locks &= ~VGA_RSRC_LEGACY_IO; + if (vgadev->mem_lock_cnt == 0) + vgadev->locks &= ~VGA_RSRC_LEGACY_MEM; + + /* Kick the wait queue in case somebody was waiting if we actually + * released something + */ + if (old_locks != vgadev->locks) + wake_up_all(&vga_wait_queue); +} + +int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) +{ + struct vga_device *vgadev, *conflict; + unsigned long flags; + wait_queue_t wait; + int rc = 0; + + vga_check_first_use(); + /* The one who calls us should check for this, but lets be sure... */ + if (pdev == NULL) + pdev = vga_default_device(); + if (pdev == NULL) + return 0; + + for (;;) { + spin_lock_irqsave(&vga_lock, flags); + vgadev = vgadev_find(pdev); + if (vgadev == NULL) { + spin_unlock_irqrestore(&vga_lock, flags); + rc = -ENODEV; + break; + } + conflict = __vga_tryget(vgadev, rsrc); + spin_unlock_irqrestore(&vga_lock, flags); + if (conflict == NULL) + break; + + + /* We have a conflict, we wait until somebody kicks the + * work queue. Currently we have one work queue that we + * kick each time some resources are released, but it would + * be fairly easy to have a per device one so that we only + * need to attach to the conflicting device + */ + init_waitqueue_entry(&wait, current); + add_wait_queue(&vga_wait_queue, &wait); + set_current_state(interruptible ? + TASK_INTERRUPTIBLE : + TASK_UNINTERRUPTIBLE); + if (signal_pending(current)) { + rc = -EINTR; + break; + } + schedule(); + remove_wait_queue(&vga_wait_queue, &wait); + } + return rc; +} +EXPORT_SYMBOL(vga_get); + +int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) +{ + struct vga_device *vgadev; + unsigned long flags; + int rc = 0; + + vga_check_first_use(); + + /* The one who calls us should check for this, but lets be sure... */ + if (pdev == NULL) + pdev = vga_default_device(); + if (pdev == NULL) + return 0; + spin_lock_irqsave(&vga_lock, flags); + vgadev = vgadev_find(pdev); + if (vgadev == NULL) { + rc = -ENODEV; + goto bail; + } + if (__vga_tryget(vgadev, rsrc)) + rc = -EBUSY; +bail: + spin_unlock_irqrestore(&vga_lock, flags); + return rc; +} +EXPORT_SYMBOL(vga_tryget); + +void vga_put(struct pci_dev *pdev, unsigned int rsrc) +{ + struct vga_device *vgadev; + unsigned long flags; + + /* The one who calls us should check for this, but lets be sure... */ + if (pdev == NULL) + pdev = vga_default_device(); + if (pdev == NULL) + return; + spin_lock_irqsave(&vga_lock, flags); + vgadev = vgadev_find(pdev); + if (vgadev == NULL) + goto bail; + __vga_put(vgadev, rsrc); +bail: + spin_unlock_irqrestore(&vga_lock, flags); +} +EXPORT_SYMBOL(vga_put); + +/* Rules for using a bridge to control a VGA descendant decoding: + if a bridge has only one VGA descendant then it can be used + to control the VGA routing for that device. + It should always use the bridge closest to the device to control it. + If a bridge has a direct VGA descendant, but also have a sub-bridge + VGA descendant then we cannot use that bridge to control the direct VGA descendant. + So for every device we register, we need to iterate all its parent bridges + so we can invalidate any devices using them properly. +*/ +static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev) +{ + struct vga_device *same_bridge_vgadev; + struct pci_bus *new_bus, *bus; + struct pci_dev *new_bridge, *bridge; + + vgadev->bridge_has_one_vga = true; + + if (list_empty(&vga_list)) + return; + + /* okay iterate the new devices bridge hierarachy */ + new_bus = vgadev->pdev->bus; + while (new_bus) { + new_bridge = new_bus->self; + + /* go through list of devices already registered */ + list_for_each_entry(same_bridge_vgadev, &vga_list, list) { + bus = same_bridge_vgadev->pdev->bus; + bridge = bus->self; + + /* see if the share a bridge with this device */ + if (new_bridge == bridge) { + /* if their direct parent bridge is the same + as any bridge of this device then it can't be used + for that device */ + same_bridge_vgadev->bridge_has_one_vga = false; + } + + /* now iterate the previous devices bridge hierarchy */ + /* if the new devices parent bridge is in the other devices + hierarchy then we can't use it to control this device */ + while (bus) { + bridge = bus->self; + if (bridge) { + if (bridge == vgadev->pdev->bus->self) + vgadev->bridge_has_one_vga = false; + } + bus = bus->parent; + } + } + new_bus = new_bus->parent; + } +} + +/* + * Currently, we assume that the "initial" setup of the system is + * not sane, that is we come up with conflicting devices and let + * the arbiter's client decides if devices decodes or not legacy + * things. + */ +static bool vga_arbiter_add_pci_device(struct pci_dev *pdev) +{ + struct vga_device *vgadev; + unsigned long flags; + struct pci_bus *bus; + struct pci_dev *bridge; + u16 cmd; + + /* Only deal with VGA class devices */ + if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA) + return false; + + /* Allocate structure */ + vgadev = kmalloc(sizeof(struct vga_device), GFP_KERNEL); + if (vgadev == NULL) { + pr_err("vgaarb: failed to allocate pci device\n"); + /* What to do on allocation failure ? For now, let's + * just do nothing, I'm not sure there is anything saner + * to be done + */ + return false; + } + + memset(vgadev, 0, sizeof(*vgadev)); + + /* Take lock & check for duplicates */ + spin_lock_irqsave(&vga_lock, flags); + if (vgadev_find(pdev) != NULL) { + BUG_ON(1); + goto fail; + } + vgadev->pdev = pdev; + + /* By default, assume we decode everything */ + vgadev->decodes = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM | + VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM; + + /* by default mark it as decoding */ + vga_decode_count++; + /* Mark that we "own" resources based on our enables, we will + * clear that below if the bridge isn't forwarding + */ + pci_read_config_word(pdev, PCI_COMMAND, &cmd); + if (cmd & PCI_COMMAND_IO) + vgadev->owns |= VGA_RSRC_LEGACY_IO; + if (cmd & PCI_COMMAND_MEMORY) + vgadev->owns |= VGA_RSRC_LEGACY_MEM; + + /* Check if VGA cycles can get down to us */ + bus = pdev->bus; + while (bus) { + bridge = bus->self; + if (bridge) { + u16 l; + pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, + &l); + if (!(l & PCI_BRIDGE_CTL_VGA)) { + vgadev->owns = 0; + break; + } + } + bus = bus->parent; + } + + /* Deal with VGA default device. Use first enabled one + * by default if arch doesn't have it's own hook + */ + if (vga_default == NULL && + ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { + pr_info("vgaarb: setting as boot device: PCI:%s\n", + pci_name(pdev)); + vga_set_default_device(pdev); + } + + vga_arbiter_check_bridge_sharing(vgadev); + + /* Add to the list */ + list_add(&vgadev->list, &vga_list); + vga_count++; + pr_info("vgaarb: device added: PCI:%s,decodes=%s,owns=%s,locks=%s\n", + pci_name(pdev), + vga_iostate_to_str(vgadev->decodes), + vga_iostate_to_str(vgadev->owns), + vga_iostate_to_str(vgadev->locks)); + + spin_unlock_irqrestore(&vga_lock, flags); + return true; +fail: + spin_unlock_irqrestore(&vga_lock, flags); + kfree(vgadev); + return false; +} + +static bool vga_arbiter_del_pci_device(struct pci_dev *pdev) +{ + struct vga_device *vgadev; + unsigned long flags; + bool ret = true; + + spin_lock_irqsave(&vga_lock, flags); + vgadev = vgadev_find(pdev); + if (vgadev == NULL) { + ret = false; + goto bail; + } + + if (vga_default == pdev) + vga_set_default_device(NULL); + + if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)) + vga_decode_count--; + + /* Remove entry from list */ + list_del(&vgadev->list); + vga_count--; + /* Notify userland driver that the device is gone so it discards + * it's copies of the pci_dev pointer + */ + vga_arb_device_card_gone(pdev); + + /* Wake up all possible waiters */ + wake_up_all(&vga_wait_queue); +bail: + spin_unlock_irqrestore(&vga_lock, flags); + kfree(vgadev); + return ret; +} + +/* this is called with the lock */ +static inline void vga_update_device_decodes(struct vga_device *vgadev, + int new_decodes) +{ + int old_decodes, decodes_removed, decodes_unlocked; + + old_decodes = vgadev->decodes; + decodes_removed = ~new_decodes & old_decodes; + decodes_unlocked = vgadev->locks & decodes_removed; + vgadev->decodes = new_decodes; + + pr_info("vgaarb: device changed decodes: PCI:%s,olddecodes=%s,decodes=%s:owns=%s\n", + pci_name(vgadev->pdev), + vga_iostate_to_str(old_decodes), + vga_iostate_to_str(vgadev->decodes), + vga_iostate_to_str(vgadev->owns)); + + /* if we removed locked decodes, lock count goes to zero, and release */ + if (decodes_unlocked) { + if (decodes_unlocked & VGA_RSRC_LEGACY_IO) + vgadev->io_lock_cnt = 0; + if (decodes_unlocked & VGA_RSRC_LEGACY_MEM) + vgadev->mem_lock_cnt = 0; + __vga_put(vgadev, decodes_unlocked); + } + + /* change decodes counter */ + if (old_decodes & VGA_RSRC_LEGACY_MASK && + !(new_decodes & VGA_RSRC_LEGACY_MASK)) + vga_decode_count--; + if (!(old_decodes & VGA_RSRC_LEGACY_MASK) && + new_decodes & VGA_RSRC_LEGACY_MASK) + vga_decode_count++; + pr_debug("vgaarb: decoding count now is: %d\n", vga_decode_count); +} + +static void __vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes, bool userspace) +{ + struct vga_device *vgadev; + unsigned long flags; + + decodes &= VGA_RSRC_LEGACY_MASK; + + spin_lock_irqsave(&vga_lock, flags); + vgadev = vgadev_find(pdev); + if (vgadev == NULL) + goto bail; + + /* don't let userspace futz with kernel driver decodes */ + if (userspace && vgadev->set_vga_decode) + goto bail; + + /* update the device decodes + counter */ + vga_update_device_decodes(vgadev, decodes); + + /* XXX if somebody is going from "doesn't decode" to "decodes" state + * here, additional care must be taken as we may have pending owner + * ship of non-legacy region ... + */ +bail: + spin_unlock_irqrestore(&vga_lock, flags); +} + +void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes) +{ + __vga_set_legacy_decoding(pdev, decodes, false); +} +EXPORT_SYMBOL(vga_set_legacy_decoding); + +/* call with NULL to unregister */ +int vga_client_register(struct pci_dev *pdev, void *cookie, + void (*irq_set_state)(void *cookie, bool state), + unsigned int (*set_vga_decode)(void *cookie, bool decode)) +{ + int ret = -ENODEV; + struct vga_device *vgadev; + unsigned long flags; + + spin_lock_irqsave(&vga_lock, flags); + vgadev = vgadev_find(pdev); + if (!vgadev) + goto bail; + + vgadev->irq_set_state = irq_set_state; + vgadev->set_vga_decode = set_vga_decode; + vgadev->cookie = cookie; + ret = 0; + +bail: + spin_unlock_irqrestore(&vga_lock, flags); + return ret; + +} +EXPORT_SYMBOL(vga_client_register); + +/* + * Char driver implementation + * + * Semantics is: + * + * open : open user instance of the arbitrer. by default, it's + * attached to the default VGA device of the system. + * + * close : close user instance, release locks + * + * read : return a string indicating the status of the target. + * an IO state string is of the form {io,mem,io+mem,none}, + * mc and ic are respectively mem and io lock counts (for + * debugging/diagnostic only). "decodes" indicate what the + * card currently decodes, "owns" indicates what is currently + * enabled on it, and "locks" indicates what is locked by this + * card. If the card is unplugged, we get "invalid" then for + * card_ID and an -ENODEV error is returned for any command + * until a new card is targeted + * + * ",decodes=,owns=,locks= (ic,mc)" + * + * write : write a command to the arbiter. List of commands is: + * + * target : switch target to card (see below) + * lock : acquires locks on target ("none" is invalid io_state) + * trylock : non-blocking acquire locks on target + * unlock : release locks on target + * unlock all : release all locks on target held by this user + * decodes : set the legacy decoding attributes for the card + * + * poll : event if something change on any card (not just the target) + * + * card_ID is of the form "PCI:domain:bus:dev.fn". It can be set to "default" + * to go back to the system default card (TODO: not implemented yet). + * Currently, only PCI is supported as a prefix, but the userland API may + * support other bus types in the future, even if the current kernel + * implementation doesn't. + * + * Note about locks: + * + * The driver keeps track of which user has what locks on which card. It + * supports stacking, like the kernel one. This complexifies the implementation + * a bit, but makes the arbiter more tolerant to userspace problems and able + * to properly cleanup in all cases when a process dies. + * Currently, a max of 16 cards simultaneously can have locks issued from + * userspace for a given user (file descriptor instance) of the arbiter. + * + * If the device is hot-unplugged, there is a hook inside the module to notify + * they being added/removed in the system and automatically added/removed in + * the arbiter. + */ + +#define MAX_USER_CARDS CONFIG_VGA_ARB_MAX_GPUS +#define PCI_INVALID_CARD ((struct pci_dev *)-1UL) + +/* + * Each user has an array of these, tracking which cards have locks + */ +struct vga_arb_user_card { + struct pci_dev *pdev; + unsigned int mem_cnt; + unsigned int io_cnt; +}; + +struct vga_arb_private { + struct list_head list; + struct pci_dev *target; + struct vga_arb_user_card cards[MAX_USER_CARDS]; + spinlock_t lock; +}; + +static LIST_HEAD(vga_user_list); +static DEFINE_SPINLOCK(vga_user_lock); + + +/* + * This function gets a string in the format: "PCI:domain:bus:dev.fn" and + * returns the respective values. If the string is not in this format, + * it returns 0. + */ +static int vga_pci_str_to_vars(char *buf, int count, unsigned int *domain, + unsigned int *bus, unsigned int *devfn) +{ + int n; + unsigned int slot, func; + + + n = sscanf(buf, "PCI:%x:%x:%x.%x", domain, bus, &slot, &func); + if (n != 4) + return 0; + + *devfn = PCI_DEVFN(slot, func); + + return 1; +} + +static ssize_t vga_arb_read(struct file *file, char __user * buf, + size_t count, loff_t *ppos) +{ + struct vga_arb_private *priv = file->private_data; + struct vga_device *vgadev; + struct pci_dev *pdev; + unsigned long flags; + size_t len; + int rc; + char *lbuf; + + lbuf = kmalloc(1024, GFP_KERNEL); + if (lbuf == NULL) + return -ENOMEM; + + /* Shields against vga_arb_device_card_gone (pci_dev going + * away), and allows access to vga list + */ + spin_lock_irqsave(&vga_lock, flags); + + /* If we are targeting the default, use it */ + pdev = priv->target; + if (pdev == NULL || pdev == PCI_INVALID_CARD) { + spin_unlock_irqrestore(&vga_lock, flags); + len = sprintf(lbuf, "invalid"); + goto done; + } + + /* Find card vgadev structure */ + vgadev = vgadev_find(pdev); + if (vgadev == NULL) { + /* Wow, it's not in the list, that shouldn't happen, + * let's fix us up and return invalid card + */ + if (pdev == priv->target) + vga_arb_device_card_gone(pdev); + spin_unlock_irqrestore(&vga_lock, flags); + len = sprintf(lbuf, "invalid"); + goto done; + } + + /* Fill the buffer with infos */ + len = snprintf(lbuf, 1024, + "count:%d,PCI:%s,decodes=%s,owns=%s,locks=%s(%d:%d)\n", + vga_decode_count, pci_name(pdev), + vga_iostate_to_str(vgadev->decodes), + vga_iostate_to_str(vgadev->owns), + vga_iostate_to_str(vgadev->locks), + vgadev->io_lock_cnt, vgadev->mem_lock_cnt); + + spin_unlock_irqrestore(&vga_lock, flags); +done: + + /* Copy that to user */ + if (len > count) + len = count; + rc = copy_to_user(buf, lbuf, len); + kfree(lbuf); + if (rc) + return -EFAULT; + return len; +} + +/* + * TODO: To avoid parsing inside kernel and to improve the speed we may + * consider use ioctl here + */ +static ssize_t vga_arb_write(struct file *file, const char __user * buf, + size_t count, loff_t *ppos) +{ + struct vga_arb_private *priv = file->private_data; + struct vga_arb_user_card *uc = NULL; + struct pci_dev *pdev; + + unsigned int io_state; + + char *kbuf, *curr_pos; + size_t remaining = count; + + int ret_val; + int i; + + + kbuf = kmalloc(count + 1, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + if (copy_from_user(kbuf, buf, count)) { + kfree(kbuf); + return -EFAULT; + } + curr_pos = kbuf; + kbuf[count] = '\0'; /* Just to make sure... */ + + if (strncmp(curr_pos, "lock ", 5) == 0) { + curr_pos += 5; + remaining -= 5; + + pr_debug("client 0x%p called 'lock'\n", priv); + + if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { + ret_val = -EPROTO; + goto done; + } + if (io_state == VGA_RSRC_NONE) { + ret_val = -EPROTO; + goto done; + } + + pdev = priv->target; + if (priv->target == NULL) { + ret_val = -ENODEV; + goto done; + } + + vga_get_uninterruptible(pdev, io_state); + + /* Update the client's locks lists... */ + for (i = 0; i < MAX_USER_CARDS; i++) { + if (priv->cards[i].pdev == pdev) { + if (io_state & VGA_RSRC_LEGACY_IO) + priv->cards[i].io_cnt++; + if (io_state & VGA_RSRC_LEGACY_MEM) + priv->cards[i].mem_cnt++; + break; + } + } + + ret_val = count; + goto done; + } else if (strncmp(curr_pos, "unlock ", 7) == 0) { + curr_pos += 7; + remaining -= 7; + + pr_debug("client 0x%p called 'unlock'\n", priv); + + if (strncmp(curr_pos, "all", 3) == 0) + io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; + else { + if (!vga_str_to_iostate + (curr_pos, remaining, &io_state)) { + ret_val = -EPROTO; + goto done; + } + /* TODO: Add this? + if (io_state == VGA_RSRC_NONE) { + ret_val = -EPROTO; + goto done; + } + */ + } + + pdev = priv->target; + if (priv->target == NULL) { + ret_val = -ENODEV; + goto done; + } + for (i = 0; i < MAX_USER_CARDS; i++) { + if (priv->cards[i].pdev == pdev) + uc = &priv->cards[i]; + } + + if (!uc) { + ret_val = -EINVAL; + goto done; + } + + if (io_state & VGA_RSRC_LEGACY_IO && uc->io_cnt == 0) { + ret_val = -EINVAL; + goto done; + } + + if (io_state & VGA_RSRC_LEGACY_MEM && uc->mem_cnt == 0) { + ret_val = -EINVAL; + goto done; + } + + vga_put(pdev, io_state); + + if (io_state & VGA_RSRC_LEGACY_IO) + uc->io_cnt--; + if (io_state & VGA_RSRC_LEGACY_MEM) + uc->mem_cnt--; + + ret_val = count; + goto done; + } else if (strncmp(curr_pos, "trylock ", 8) == 0) { + curr_pos += 8; + remaining -= 8; + + pr_debug("client 0x%p called 'trylock'\n", priv); + + if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { + ret_val = -EPROTO; + goto done; + } + /* TODO: Add this? + if (io_state == VGA_RSRC_NONE) { + ret_val = -EPROTO; + goto done; + } + */ + + pdev = priv->target; + if (priv->target == NULL) { + ret_val = -ENODEV; + goto done; + } + + if (vga_tryget(pdev, io_state)) { + /* Update the client's locks lists... */ + for (i = 0; i < MAX_USER_CARDS; i++) { + if (priv->cards[i].pdev == pdev) { + if (io_state & VGA_RSRC_LEGACY_IO) + priv->cards[i].io_cnt++; + if (io_state & VGA_RSRC_LEGACY_MEM) + priv->cards[i].mem_cnt++; + break; + } + } + ret_val = count; + goto done; + } else { + ret_val = -EBUSY; + goto done; + } + + } else if (strncmp(curr_pos, "target ", 7) == 0) { + unsigned int domain, bus, devfn; + struct vga_device *vgadev; + + curr_pos += 7; + remaining -= 7; + pr_debug("client 0x%p called 'target'\n", priv); + /* if target is default */ + if (!strncmp(curr_pos, "default", 7)) + pdev = pci_dev_get(vga_default_device()); + else { + if (!vga_pci_str_to_vars(curr_pos, remaining, + &domain, &bus, &devfn)) { + ret_val = -EPROTO; + goto done; + } + pr_debug("vgaarb: %s ==> %x:%x:%x.%x\n", curr_pos, + domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn)); + + pdev = pci_get_domain_bus_and_slot(domain, bus, devfn); + pr_debug("vgaarb: pdev %p\n", pdev); + if (!pdev) { + pr_err("vgaarb: invalid PCI address %x:%x:%x\n", + domain, bus, devfn); + ret_val = -ENODEV; + goto done; + } + } + + vgadev = vgadev_find(pdev); + pr_debug("vgaarb: vgadev %p\n", vgadev); + if (vgadev == NULL) { + pr_err("vgaarb: this pci device is not a vga device\n"); + pci_dev_put(pdev); + ret_val = -ENODEV; + goto done; + } + + priv->target = pdev; + for (i = 0; i < MAX_USER_CARDS; i++) { + if (priv->cards[i].pdev == pdev) + break; + if (priv->cards[i].pdev == NULL) { + priv->cards[i].pdev = pdev; + priv->cards[i].io_cnt = 0; + priv->cards[i].mem_cnt = 0; + break; + } + } + if (i == MAX_USER_CARDS) { + pr_err("vgaarb: maximum user cards (%d) number reached!\n", + MAX_USER_CARDS); + pci_dev_put(pdev); + /* XXX: which value to return? */ + ret_val = -ENOMEM; + goto done; + } + + ret_val = count; + pci_dev_put(pdev); + goto done; + + + } else if (strncmp(curr_pos, "decodes ", 8) == 0) { + curr_pos += 8; + remaining -= 8; + pr_debug("vgaarb: client 0x%p called 'decodes'\n", priv); + + if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { + ret_val = -EPROTO; + goto done; + } + pdev = priv->target; + if (priv->target == NULL) { + ret_val = -ENODEV; + goto done; + } + + __vga_set_legacy_decoding(pdev, io_state, true); + ret_val = count; + goto done; + } + /* If we got here, the message written is not part of the protocol! */ + kfree(kbuf); + return -EPROTO; + +done: + kfree(kbuf); + return ret_val; +} + +static unsigned int vga_arb_fpoll(struct file *file, poll_table * wait) +{ + struct vga_arb_private *priv = file->private_data; + + pr_debug("%s\n", __func__); + + if (priv == NULL) + return -ENODEV; + poll_wait(file, &vga_wait_queue, wait); + return POLLIN; +} + +static int vga_arb_open(struct inode *inode, struct file *file) +{ + struct vga_arb_private *priv; + unsigned long flags; + + pr_debug("%s\n", __func__); + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (priv == NULL) + return -ENOMEM; + spin_lock_init(&priv->lock); + file->private_data = priv; + + spin_lock_irqsave(&vga_user_lock, flags); + list_add(&priv->list, &vga_user_list); + spin_unlock_irqrestore(&vga_user_lock, flags); + + /* Set the client' lists of locks */ + priv->target = vga_default_device(); /* Maybe this is still null! */ + priv->cards[0].pdev = priv->target; + priv->cards[0].io_cnt = 0; + priv->cards[0].mem_cnt = 0; + + + return 0; +} + +static int vga_arb_release(struct inode *inode, struct file *file) +{ + struct vga_arb_private *priv = file->private_data; + struct vga_arb_user_card *uc; + unsigned long flags; + int i; + + pr_debug("%s\n", __func__); + + if (priv == NULL) + return -ENODEV; + + spin_lock_irqsave(&vga_user_lock, flags); + list_del(&priv->list); + for (i = 0; i < MAX_USER_CARDS; i++) { + uc = &priv->cards[i]; + if (uc->pdev == NULL) + continue; + pr_debug("uc->io_cnt == %d, uc->mem_cnt == %d\n", + uc->io_cnt, uc->mem_cnt); + while (uc->io_cnt--) + vga_put(uc->pdev, VGA_RSRC_LEGACY_IO); + while (uc->mem_cnt--) + vga_put(uc->pdev, VGA_RSRC_LEGACY_MEM); + } + spin_unlock_irqrestore(&vga_user_lock, flags); + + kfree(priv); + + return 0; +} + +static void vga_arb_device_card_gone(struct pci_dev *pdev) +{ +} + +/* + * callback any registered clients to let them know we have a + * change in VGA cards + */ +static void vga_arbiter_notify_clients(void) +{ + struct vga_device *vgadev; + unsigned long flags; + uint32_t new_decodes; + bool new_state; + + if (!vga_arbiter_used) + return; + + spin_lock_irqsave(&vga_lock, flags); + list_for_each_entry(vgadev, &vga_list, list) { + if (vga_count > 1) + new_state = false; + else + new_state = true; + if (vgadev->set_vga_decode) { + new_decodes = vgadev->set_vga_decode(vgadev->cookie, new_state); + vga_update_device_decodes(vgadev, new_decodes); + } + } + spin_unlock_irqrestore(&vga_lock, flags); +} + +static int pci_notify(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct device *dev = data; + struct pci_dev *pdev = to_pci_dev(dev); + bool notify = false; + + pr_debug("%s\n", __func__); + + /* For now we're only intereted in devices added and removed. I didn't + * test this thing here, so someone needs to double check for the + * cases of hotplugable vga cards. */ + if (action == BUS_NOTIFY_ADD_DEVICE) + notify = vga_arbiter_add_pci_device(pdev); + else if (action == BUS_NOTIFY_DEL_DEVICE) + notify = vga_arbiter_del_pci_device(pdev); + + if (notify) + vga_arbiter_notify_clients(); + return 0; +} + +static struct notifier_block pci_notifier = { + .notifier_call = pci_notify, +}; + +static const struct file_operations vga_arb_device_fops = { + .read = vga_arb_read, + .write = vga_arb_write, + .poll = vga_arb_fpoll, + .open = vga_arb_open, + .release = vga_arb_release, + .llseek = noop_llseek, +}; + +static struct miscdevice vga_arb_device = { + MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops +}; + +static int __init vga_arb_device_init(void) +{ + int rc; + struct pci_dev *pdev; + struct vga_device *vgadev; + + rc = misc_register(&vga_arb_device); + if (rc < 0) + pr_err("vgaarb: error %d registering device\n", rc); + + bus_register_notifier(&pci_bus_type, &pci_notifier); + + /* We add all pci devices satisfying vga class in the arbiter by + * default */ + pdev = NULL; + while ((pdev = + pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, + PCI_ANY_ID, pdev)) != NULL) + vga_arbiter_add_pci_device(pdev); + + pr_info("vgaarb: loaded\n"); + + list_for_each_entry(vgadev, &vga_list, list) { +#if defined(CONFIG_X86) || defined(CONFIG_IA64) + /* Override I/O based detection done by vga_arbiter_add_pci_device() + * as it may take the wrong device (e.g. on Apple system under EFI). + * + * Select the device owning the boot framebuffer if there is one. + */ + resource_size_t start, end; + int i; + + /* Does firmware framebuffer belong to us? */ + for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { + if (!(pci_resource_flags(vgadev->pdev, i) & IORESOURCE_MEM)) + continue; + + start = pci_resource_start(vgadev->pdev, i); + end = pci_resource_end(vgadev->pdev, i); + + if (!start || !end) + continue; + + if (screen_info.lfb_base < start || + (screen_info.lfb_base + screen_info.lfb_size) >= end) + continue; + if (!vga_default_device()) + pr_info("vgaarb: setting as boot device: PCI:%s\n", + pci_name(vgadev->pdev)); + else if (vgadev->pdev != vga_default_device()) + pr_info("vgaarb: overriding boot device: PCI:%s\n", + pci_name(vgadev->pdev)); + vga_set_default_device(vgadev->pdev); + } +#endif + if (vgadev->bridge_has_one_vga) + pr_info("vgaarb: bridge control possible %s\n", pci_name(vgadev->pdev)); + else + pr_info("vgaarb: no bridge control possible %s\n", pci_name(vgadev->pdev)); + } + return rc; +} +subsys_initcall(vga_arb_device_init); -- cgit 1.2.3-korg