/* * vgaarb.c * * (C) Copyright 2005 Benjamin Herrenschmidt * (C) Copyright 2007 Paulo R. Zanoni * (C) Copyright 2007, 2009 Tiago Vignatti * * Implements the VGA arbitration. For details refer to * Documentation/vgaarbiter.txt */ #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 */ /* 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; } #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE /* this is only used a cookie - it should not be dereferenced */ static struct pci_dev *vga_default; #endif 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) */ #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE struct pci_dev *vga_default_device(void) { return vga_default; } #endif 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 occured 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; /* 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 he owns the resource we want. We don't need * to check "decodes" since it should be impossible to own * own legacy resources you don't decode unless I have a bug * in this code... */ WARN_ON(conflict->owns & ~conflict->decodes); match = lwants & conflict->owns; if (!match) continue; /* looks like he doesn't have a lock, we can steal * them from him */ vga_irq_set_state(conflict, false); pci_bits = 0; if (lwants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM)) pci_bits |= PCI_COMMAND_MEMORY; if (lwants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO)) pci_bits |= PCI_COMMAND_IO; pci_set_vga_state(conflict->pdev, false, pci_bits, change_bridge); conflict->owns &= ~lwants; /* If he also owned non-legacy, that is no longer the case */ if (lwants & VGA_RSRC_LEGACY_MEM) conflict->owns &= ~VGA_RSRC_NORMAL_MEM; if (lwants & VGA_RSRC_LEGACY_IO) conflict->owns &= ~VGA_RSRC_NORMAL_IO; } enable_them: /* ok dude, we got it, everybody conflicting has been disabled, let's * enable us. Make sure we don't mark a bit in "owns" that we don't * also have in "decodes". We can lock resources we don't decode but * not own them. */ pci_bits = 0; 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; pci_set_vga_state(vgadev->pdev, true, pci_bits, !!(wants & VGA_RSRC_LEGACY_MASK)); vga_irq_set_state(vgadev, true); vgadev->owns |= (wants & vgadev->decodes); 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); set_current_state(TASK_RUNNING); } 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); /* * 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 */ #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE if (vga_default == NULL && ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) vga_default = pci_dev_get(pdev); #endif /* 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) { pci_dev_put(vga_default); vga_default = 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; struct vga_device *new_vgadev, *conflict; old_decodes = vgadev->decodes; 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 own the decodes we should move them along to another card */ if ((vgadev->owns & old_decodes) && (vga_count > 1)) { /* set us to own nothing */ vgadev->owns &= ~old_decodes; list_for_each_entry(new_vgadev, &vga_list, list) { if ((new_vgadev != vgadev) && (new_vgadev->decodes & VGA_RSRC_LEGACY_MASK)) { pr_info("vgaarb: transferring owner from PCI:%s to PCI:%s\n", pci_name(vgadev->pdev), pci_name(new_vgadev->pdev)); conflict = __vga_tryget(new_vgadev, VGA_RSRC_LEGACY_MASK); if (!conflict) __vga_put(new_vgadev, VGA_RSRC_LEGACY_MASK); break; } } } /* change decodes counter */ if (old_decodes != new_decodes) { if (new_decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)) vga_decode_count++; else vga_decode_count--; } pr_debug("vgaarb: decoding count now is: %d\n", vga_decode_count); } 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 = -1; 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 targetting 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) return -EINVAL; if (io_state & VGA_RSRC_LEGACY_IO && uc->io_cnt == 0) return -EINVAL; if (io_state & VGA_RSRC_LEGACY_MEM && uc->mem_cnt == 0) return -EINVAL; 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) { struct pci_bus *pbus; 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)); pbus = pci_find_bus(domain, bus); pr_debug("vgaarb: pbus %p\n", pbus); if (pbus == NULL) { pr_err("vgaarb: invalid PCI domain and/or bus address %x:%x\n", domain, bus); ret_val = -ENODEV; goto done; } pdev = pci_get_slot(pbus, devfn); pr_debug("vgaarb: pdev %p\n", pdev); if (!pdev) { pr_err("vgaarb: invalid PCI address %x:%x\n", 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 = kmalloc(sizeof(struct vga_arb_private), GFP_KERNEL); if (priv == NULL) return -ENOMEM; memset(priv, 0, sizeof(*priv)); 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, }; 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; 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"); return rc; } subsys_initcall(vga_arb_device_init);