[PATCH 1/2] vga_switcheroo: Refactor using linked list

Refactor the code base a bit for the further work to adapt more clients.

Signed-off-by: Takashi Iwai tiwai@suse.de --- drivers/gpu/vga/vga_switcheroo.c | 209 ++++++++++++++++++++------------------ 1 file changed, 110 insertions(+), 99 deletions(-)

diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c index 58434e8..c91573f 100644 --- a/drivers/gpu/vga/vga_switcheroo.c +++ b/drivers/gpu/vga/vga_switcheroo.c @@ -37,6 +37,7 @@ struct vga_switcheroo_client { bool (*can_switch)(struct pci_dev *pdev); int id; bool active; + struct list_head list; };

static DEFINE_MUTEX(vgasr_mutex); @@ -51,7 +52,7 @@ struct vgasr_priv { struct dentry *switch_file;

int registered_clients; - struct vga_switcheroo_client clients[VGA_SWITCHEROO_MAX_CLIENTS]; + struct list_head clients;

struct vga_switcheroo_handler *handler; }; @@ -60,7 +61,9 @@ 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; +static struct vgasr_priv vgasr_priv = { + .clients = LIST_HEAD_INIT(vgasr_priv.clients), +};

int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler) { @@ -86,17 +89,18 @@ EXPORT_SYMBOL(vga_switcheroo_unregister_handler);

static void vga_switcheroo_enable(void) { - int i; int ret; + struct vga_switcheroo_client *client; + /* call the handler to init */ vgasr_priv.handler->init();

- for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - ret = vgasr_priv.handler->get_client_id(vgasr_priv.clients[i].pdev); + list_for_each_entry(client, &vgasr_priv.clients, list) { + ret = vgasr_priv.handler->get_client_id(client->pdev); if (ret < 0) return;

- vgasr_priv.clients[i].id = ret; + client->id = ret; } vga_switcheroo_debugfs_init(&vgasr_priv); vgasr_priv.active = true; @@ -107,28 +111,27 @@ int vga_switcheroo_register_client(struct pci_dev *pdev, void (*reprobe)(struct pci_dev *pdev), bool (*can_switch)(struct pci_dev *pdev)) { - int index; + struct vga_switcheroo_client *client;

- mutex_lock(&vgasr_mutex); - /* don't do IGD vs DIS here */ - if (vgasr_priv.registered_clients & 1) - index = 1; - else - index = 0; - - vgasr_priv.clients[index].pwr_state = VGA_SWITCHEROO_ON; - vgasr_priv.clients[index].pdev = pdev; - vgasr_priv.clients[index].set_gpu_state = set_gpu_state; - vgasr_priv.clients[index].reprobe = reprobe; - vgasr_priv.clients[index].can_switch = can_switch; - vgasr_priv.clients[index].id = -1; + client = kzalloc(sizeof(*client), GFP_KERNEL); + if (!client) + return -ENOMEM; + + client->pwr_state = VGA_SWITCHEROO_ON; + client->pdev = pdev; + client->set_gpu_state = set_gpu_state; + client->reprobe = reprobe; + client->can_switch = can_switch; + client->id = -1; if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW) - vgasr_priv.clients[index].active = true; + client->active = true;

- vgasr_priv.registered_clients |= (1 << index); + mutex_lock(&vgasr_mutex); + list_add_tail(&client->list, &vgasr_priv.clients); + vgasr_priv.registered_clients++;

/* if we get two clients + handler */ - if (vgasr_priv.registered_clients == 0x3 && vgasr_priv.handler) { + if (vgasr_priv.registered_clients == 2 && vgasr_priv.handler) { printk(KERN_INFO "vga_switcheroo: enabled\n"); vga_switcheroo_enable(); } @@ -137,18 +140,47 @@ int vga_switcheroo_register_client(struct pci_dev *pdev, } EXPORT_SYMBOL(vga_switcheroo_register_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 == true) + return client; + return NULL; +} + void vga_switcheroo_unregister_client(struct pci_dev *pdev) { - int i; + struct vga_switcheroo_client *client;

mutex_lock(&vgasr_mutex); - for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - if (vgasr_priv.clients[i].pdev == pdev) { - vgasr_priv.registered_clients &= ~(1 << i); - break; - } + client = find_client_from_pci(&vgasr_priv.clients, pdev); + if (client) { + list_del(&client->list); + kfree(client); + vgasr_priv.registered_clients--; } - printk(KERN_INFO "vga_switcheroo: disabled\n"); vga_switcheroo_debugfs_fini(&vgasr_priv); vgasr_priv.active = false; @@ -159,29 +191,28 @@ EXPORT_SYMBOL(vga_switcheroo_unregister_client); void vga_switcheroo_client_fb_set(struct pci_dev *pdev, struct fb_info *info) { - int i; + struct vga_switcheroo_client *client;

mutex_lock(&vgasr_mutex); - for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - if (vgasr_priv.clients[i].pdev == pdev) { - vgasr_priv.clients[i].fb_info = info; - break; - } - } + 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) { - int i; + struct vga_switcheroo_client *client; + int i = 0; mutex_lock(&vgasr_mutex); - for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { + list_for_each_entry(client, &vgasr_priv.clients, list) { seq_printf(m, "%d:%s:%c:%s:%s\n", i, - vgasr_priv.clients[i].id == VGA_SWITCHEROO_DIS ? "DIS" : "IGD", - vgasr_priv.clients[i].active ? '+' : ' ', - vgasr_priv.clients[i].pwr_state ? "Pwr" : "Off", - pci_name(vgasr_priv.clients[i].pdev)); + client->id == VGA_SWITCHEROO_DIS ? "DIS" : "IGD", + client->active ? '+' : ' ', + client->pwr_state ? "Pwr" : "Off", + pci_name(client->pdev)); + i++; } mutex_unlock(&vgasr_mutex); return 0; @@ -215,15 +246,9 @@ static int vga_switchoff(struct vga_switcheroo_client *client) /* stage one happens before delay */ static int vga_switchto_stage1(struct vga_switcheroo_client *new_client) { - int i; - struct vga_switcheroo_client *active = NULL; + struct vga_switcheroo_client *active;

- for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - if (vgasr_priv.clients[i].active == true) { - active = &vgasr_priv.clients[i]; - break; - } - } + active = find_active_client(&vgasr_priv.clients); if (!active) return 0;

@@ -240,15 +265,9 @@ static int vga_switchto_stage1(struct vga_switcheroo_client *new_client) static int vga_switchto_stage2(struct vga_switcheroo_client *new_client) { int ret; - int i; - struct vga_switcheroo_client *active = NULL; + struct vga_switcheroo_client *active;

- for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - if (vgasr_priv.clients[i].active == true) { - active = &vgasr_priv.clients[i]; - break; - } - } + active = find_active_client(&vgasr_priv.clients); if (!active) return 0;

@@ -274,13 +293,26 @@ static int vga_switchto_stage2(struct vga_switcheroo_client *new_client) return 0; }

+static bool check_can_switch(void) +{ + struct vga_switcheroo_client *client; + + list_for_each_entry(client, &vgasr_priv.clients, list) { + if (!client->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]; const char *pdev_name; - int i, ret; + int ret; bool delay = false, can_switch; bool just_mux = false; int client_id = -1; @@ -301,21 +333,21 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,

/* pwr off the device not in use */ if (strncmp(usercmd, "OFF", 3) == 0) { - for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - if (vgasr_priv.clients[i].active) + list_for_each_entry(client, &vgasr_priv.clients, list) { + if (client->active) continue; - if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_ON) - vga_switchoff(&vgasr_priv.clients[i]); + 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) { - for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - if (vgasr_priv.clients[i].active) + list_for_each_entry(client, &vgasr_priv.clients, list) { + if (client->active) continue; - if (vgasr_priv.clients[i].pwr_state == VGA_SWITCHEROO_OFF) - vga_switchon(&vgasr_priv.clients[i]); + if (client->pwr_state == VGA_SWITCHEROO_OFF) + vga_switchon(client); } goto out; } @@ -348,13 +380,9 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,

if (client_id == -1) goto out; - - for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - if (vgasr_priv.clients[i].id == client_id) { - client = &vgasr_priv.clients[i]; - break; - } - } + client = find_client_from_id(&vgasr_priv.clients, client_id); + if (!client) + goto out;

vgasr_priv.delayed_switch_active = false;

@@ -363,23 +391,16 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf, goto out; }

- if (client->active == true) + if (client->active) goto out;

/* okay we want a switch - test if devices are willing to switch */ - can_switch = true; - for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev); - if (can_switch == false) { - printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i); - break; - } - } + can_switch = check_can_switch();

if (can_switch == false && delay == false) goto out;

- if (can_switch == true) { + if (can_switch) { pdev_name = pci_name(client->pdev); ret = vga_switchto_stage1(client); if (ret) @@ -451,10 +472,8 @@ fail:

int vga_switcheroo_process_delayed_switch(void) { - struct vga_switcheroo_client *client = NULL; + struct vga_switcheroo_client *client; const char *pdev_name; - bool can_switch = true; - int i; int ret; int err = -EINVAL;

@@ -464,17 +483,9 @@ int vga_switcheroo_process_delayed_switch(void)

printk(KERN_INFO "vga_switcheroo: processing delayed switch to %d\n", vgasr_priv.delayed_client_id);

- for (i = 0; i < VGA_SWITCHEROO_MAX_CLIENTS; i++) { - if (vgasr_priv.clients[i].id == vgasr_priv.delayed_client_id) - client = &vgasr_priv.clients[i]; - can_switch = vgasr_priv.clients[i].can_switch(vgasr_priv.clients[i].pdev); - if (can_switch == false) { - printk(KERN_ERR "vga_switcheroo: client %d refused switch\n", i); - break; - } - } - - if (can_switch == false || client == NULL) + client = find_client_from_id(&vgasr_priv.clients, + vgasr_priv.delayed_client_id); + if (!client || !check_can_switch()) goto err;

pdev_name = pci_name(client->pdev);