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    SubjectRe: [PATCH v2 00/11] Fix typos, comments and copyright
    On Wed, Aug 09, 2023 at 06:34:01AM +0800, Sui Jingfeng wrote:
    > From: Sui Jingfeng <suijingfeng@loongson.cn>
    >
    > v1:
    > * Various improve.
    > v2:
    > * More fixes, optimizations and improvements.
    >
    > Sui Jingfeng (11):
    > PCI/VGA: Use unsigned type for the io_state variable

    > PCI: Add the pci_get_class_masked() helper
    > PCI/VGA: Deal with VGA class devices

    I dropped these two patches, at least for now. There's no other use
    of pci_get_class_masked(), and the VGA use seems to be mostly
    optimization and possibly some behavior change that isn't 100% clear
    yet. If it's important, we can look at it again later.

    > PCI/VGA: Drop the inline in the vga_update_device_decodes() function.
    > PCI/VGA: Move the new_state assignment out of the loop
    > PCI/VGA: Fix two typos in the comments of pci_notify()
    > PCI/VGA: vga_client_register() return -ENODEV on failure, not -1
    > PCI/VGA: Fix a typo to the comment of vga_default
    > PCI/VGA: Fix a typo to the comments in vga_str_to_iostate() function
    > PCI/VGA: Tidy up the code and comment format
    > PCI/VGA: Replace full MIT license text with SPDX identifier
    >
    > drivers/pci/search.c | 30 ++++++
    > drivers/pci/vgaarb.c | 233 +++++++++++++++++++++++++----------------
    > include/linux/pci.h | 7 ++
    > include/linux/vgaarb.h | 27 +----
    > 4 files changed, 185 insertions(+), 112 deletions(-)

    I applied the rest of the patches on pci/vga for v6.5.

    I updated the commit logs and tweaked some of the patches.

    I squashed all the typo fixes together and added several more that I
    had done previously but not posted. The diff between your original v2
    posting and the current pci/vga branch is attached. Most of it is
    additional typo fixes, but if you look closely you'll see:

    - The omission of the pci_get_class_masked() patches (in
    vga_arbiter_add_pci_device(), pci_notify(), vga_arb_device_init())

    - The tweaks I did to:

    vga_update_device_decodes()
    vga_client_register()
    vga_arbiter_notify_clients()

    I dropped the Reviewed-bys from the typo fixes because I didn't want
    to extend them to everything that got squashed together. Happy to add
    them back if anybody wants to look again.

    The branch is at https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/log/?h=vga

    Bjorn

    diff --git a/drivers/pci/search.c b/drivers/pci/search.c
    index f1c15aea868b..b4c138a6ec02 100644
    --- a/drivers/pci/search.c
    +++ b/drivers/pci/search.c
    @@ -334,36 +334,6 @@ struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
    }
    EXPORT_SYMBOL(pci_get_device);

    -/**
    - * pci_get_class_masked - begin or continue searching for a PCI device by class and mask
    - * @class: search for a PCI device with this class designation
    - * @from: Previous PCI device found in search, or %NULL for new search.
    - *
    - * Iterates through the list of known PCI devices. If a PCI device is
    - * found with a matching @class, the reference count to the device is
    - * incremented and a pointer to its device structure is returned.
    - * Otherwise, %NULL is returned.
    - * A new search is initiated by passing %NULL as the @from argument.
    - * Otherwise if @from is not %NULL, searches continue from next device
    - * on the global list. The reference count for @from is always decremented
    - * if it is not %NULL.
    - */
    -struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int mask,
    - struct pci_dev *from)
    -{
    - struct pci_device_id id = {
    - .vendor = PCI_ANY_ID,
    - .device = PCI_ANY_ID,
    - .subvendor = PCI_ANY_ID,
    - .subdevice = PCI_ANY_ID,
    - .class_mask = mask,
    - .class = class,
    - };
    -
    - return pci_get_dev_by_id(&id, from);
    -}
    -EXPORT_SYMBOL(pci_get_class_masked);
    -
    /**
    * pci_get_class - begin or continue searching for a PCI device by class
    * @class: search for a PCI device with this class designation
    diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
    index a2f6e0e6b634..5e6b1eb54c64 100644
    --- a/drivers/pci/vgaarb.c
    +++ b/drivers/pci/vgaarb.c
    @@ -1,6 +1,6 @@
    // SPDX-License-Identifier: MIT
    /*
    - * vgaarb.c: Implements the VGA arbitration. For details refer to
    + * vgaarb.c: Implements VGA arbitration. For details refer to
    * Documentation/gpu/vgaarbiter.rst
    *
    * (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
    @@ -42,9 +42,9 @@ static void vga_arbiter_notify_clients(void);
    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 decodes; /* what it decodes */
    + unsigned int owns; /* what it owns */
    + unsigned int locks; /* what 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 */
    @@ -116,20 +116,18 @@ static struct vga_device *vgadev_find(struct pci_dev *pdev)
    /**
    * vga_default_device - return the default VGA device, for vgacon
    *
    - * This can be defined by the platform. The default implementation
    - * is rather dumb and will probably only work properly on single
    - * vga card setups and/or x86 platforms.
    + * This can be defined by the platform. The default implementation is
    + * rather dumb and will probably only work properly on single VGA card
    + * setups and/or x86 platforms.
    *
    - * If your VGA default device is not PCI, you'll have to return
    - * NULL here. In this case, I assume it will not conflict with
    - * any PCI card. If this is not true, I'll have to define two archs
    - * hooks for enabling/disabling the VGA default device if that is
    - * possible. This may be a problem with real _ISA_ VGA cards, in
    - * addition to a PCI one. I don't know at this point how to deal
    - * with that card. Can theirs IOs be disabled at all ? If not, then
    - * I suppose it's a matter of having the proper arch hook telling
    - * us about it, so we basically never allow anybody to succeed a
    - * vga_get()...
    + * If your VGA default device is not PCI, you'll have to return NULL here.
    + * In this case, I assume it will not conflict with any PCI card. If this
    + * is not true, I'll have to define two arch hooks for enabling/disabling
    + * the VGA default device if that is possible. This may be a problem with
    + * real _ISA_ VGA cards, in addition to a PCI one. I don't know at this
    + * point how to deal with that card. Can their IOs be disabled at all? If
    + * not, then I suppose it's a matter of having the proper arch hook telling
    + * us about it, so we basically never allow anybody to succeed a vga_get().
    */
    struct pci_dev *vga_default_device(void)
    {
    @@ -147,14 +145,13 @@ void vga_set_default_device(struct pci_dev *pdev)
    }

    /**
    - * vga_remove_vgacon - deactivete vga console
    + * vga_remove_vgacon - deactivate VGA console
    *
    - * Unbind and unregister vgacon in case pdev is the default vga
    - * device. Can be called by gpu drivers on initialization to make
    - * sure vga register access done by vgacon will not disturb the
    - * device.
    + * Unbind and unregister vgacon in case pdev is the default VGA device.
    + * Can be called by GPU drivers on initialization to make sure VGA register
    + * access done by vgacon will not disturb the device.
    *
    - * @pdev: pci device.
    + * @pdev: PCI device.
    */
    #if !defined(CONFIG_VGA_CONSOLE)
    int vga_remove_vgacon(struct pci_dev *pdev)
    @@ -194,14 +191,15 @@ int vga_remove_vgacon(struct pci_dev *pdev)
    EXPORT_SYMBOL(vga_remove_vgacon);

    /*
    - * If we don't ever use vgaarb, we should avoid turning off anything anywhere.
    - * Due to old X servers getting confused about the boot device not being VGA.
    + * If we don't ever use VGA arbitration, 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
    - * vgaarb has occurred and to try and disable resources if they can
    + * Inform all GPUs in the system that VGA arbitration has occurred
    + * so they can disable resources if possible.
    */
    if (!vga_arbiter_used) {
    vga_arbiter_used = true;
    @@ -241,13 +239,13 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,

    /*
    * We don't need to request a legacy resource, we just enable
    - * appropriate decoding and go
    + * 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 */
    + /* Ok, we don't, let's find out who we need to kick off */
    list_for_each_entry(conflict, &vga_list, list) {
    unsigned int lwants = legacy_wants;
    unsigned int change_bridge = 0;
    @@ -257,11 +255,11 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,
    continue;

    /*
    - * We have a possible conflict. before we go further, we must
    + * 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
    + * 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
    + * VGA forwarding on P2P bridges.
    */
    if (vgadev->pdev->bus != conflict->pdev->bus) {
    change_bridge = 1;
    @@ -270,14 +268,14 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,

    /*
    * Check if the guy has a lock on the resource. If he does,
    - * return the conflicting entry
    + * 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
    + * lock resources that are not decoded; therefore a device
    * can own resources it doesn't decode.
    */
    match = lwants & conflict->owns;
    @@ -285,8 +283,8 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,
    continue;

    /*
    - * Looks like he doesn't have a lock, we can steal
    - * them from him
    + * Looks like he doesn't have a lock, we can steal them
    + * from him.
    */

    flags = 0;
    @@ -321,7 +319,7 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,

    enable_them:
    /*
    - * Ok dude, we got it, everybody conflicting has been disabled, let's
    + * Ok, 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".
    @@ -364,8 +362,8 @@ static void __vga_put(struct vga_device *vgadev, unsigned int rsrc)
    vgaarb_dbg(dev, "%s\n", __func__);

    /*
    - * Update our counters, and account for equivalent legacy resources
    - * if we decode them
    + * 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--;
    @@ -384,7 +382,7 @@ static void __vga_put(struct vga_device *vgadev, unsigned int rsrc)

    /*
    * Just clear lock bits, we do lazy operations so we don't really
    - * have to bother about anything else at this point
    + * have to bother about anything else at this point.
    */
    if (vgadev->io_lock_cnt == 0)
    vgadev->locks &= ~VGA_RSRC_LEGACY_IO;
    @@ -393,23 +391,23 @@ static void __vga_put(struct vga_device *vgadev, unsigned int rsrc)

    /*
    * Kick the wait queue in case somebody was waiting if we actually
    - * released something
    + * released something.
    */
    if (old_locks != vgadev->locks)
    wake_up_all(&vga_wait_queue);
    }

    /**
    - * vga_get - acquire & locks VGA resources
    - * @pdev: pci device of the VGA card or NULL for the system default
    + * vga_get - acquire & lock VGA resources
    + * @pdev: PCI device of the VGA card or NULL for the system default
    * @rsrc: bit mask of resources to acquire and lock
    * @interruptible: blocking should be interruptible by signals ?
    *
    - * This function acquires VGA resources for the given card and mark those
    - * resources locked. If the resource requested are "normal" (and not legacy)
    + * Acquire VGA resources for the given card and mark those resources
    + * locked. If the resources requested are "normal" (and not legacy)
    * resources, the arbiter will first check whether the card is doing legacy
    - * decoding for that type of resource. If yes, the lock is "converted" into a
    - * legacy resource lock.
    + * decoding for that type of resource. If yes, the lock is "converted" into
    + * a legacy resource lock.
    *
    * The arbiter will first look for all VGA cards that might conflict and disable
    * their IOs and/or Memory access, including VGA forwarding on P2P bridges if
    @@ -441,7 +439,7 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
    int rc = 0;

    vga_check_first_use();
    - /* The one who calls us should check for this, but lets be sure... */
    + /* The caller should check for this, but let's be sure */
    if (pdev == NULL)
    pdev = vga_default_device();
    if (pdev == NULL)
    @@ -461,11 +459,11 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
    break;

    /*
    - * We have a conflict, we wait until somebody kicks the
    + * 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
    + * 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);
    @@ -487,12 +485,12 @@ EXPORT_SYMBOL(vga_get);

    /**
    * vga_tryget - try to acquire & lock legacy VGA resources
    - * @pdev: pci devivce of VGA card or NULL for system default
    + * @pdev: PCI device of VGA card or NULL for system default
    * @rsrc: bit mask of resources to acquire and lock
    *
    - * This function performs the same operation as vga_get(), but will return an
    - * error (-EBUSY) instead of blocking if the resources are already locked by
    - * another card. It can be called in any context
    + * Perform the same operation as vga_get(), but return an error (-EBUSY)
    + * instead of blocking if the resources are already locked by another card.
    + * Can be called in any context.
    *
    * On success, release the VGA resource again with vga_put().
    *
    @@ -508,7 +506,7 @@ static int vga_tryget(struct pci_dev *pdev, unsigned int rsrc)

    vga_check_first_use();

    - /* The one who calls us should check for this, but lets be sure... */
    + /* The caller should check for this, but let's be sure */
    if (pdev == NULL)
    pdev = vga_default_device();
    if (pdev == NULL)
    @@ -528,20 +526,20 @@ static int vga_tryget(struct pci_dev *pdev, unsigned int rsrc)

    /**
    * vga_put - release lock on legacy VGA resources
    - * @pdev: pci device of VGA card or NULL for system default
    - * @rsrc: but mask of resource to release
    + * @pdev: PCI device of VGA card or NULL for system default
    + * @rsrc: bit mask of resource to release
    *
    - * This fuction releases resources previously locked by vga_get() or
    - * vga_tryget(). The resources aren't disabled right away, so that a subsequence
    - * vga_get() on the same card will succeed immediately. Resources have a
    - * counter, so locks are only released if the counter reaches 0.
    + * Release resources previously locked by vga_get() or vga_tryget(). The
    + * resources aren't disabled right away, so that a subsequent vga_get() on
    + * the same card will succeed immediately. Resources have a counter, so
    + * locks are only released if the counter reaches 0.
    */
    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... */
    + /* The caller should check for this, but let's be sure */
    if (pdev == NULL)
    pdev = vga_default_device();
    if (pdev == NULL)
    @@ -709,20 +707,20 @@ static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev)
    return;
    }

    - /* okay iterate the new devices bridge hierarachy */
    + /* Iterate the new device's bridge hierarchy */
    new_bus = vgadev->pdev->bus;
    while (new_bus) {
    new_bridge = new_bus->self;

    - /* go through list of devices already registered */
    + /* 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 */
    + /* See if it shares a bridge with this device */
    if (new_bridge == bridge) {
    /*
    - * If their direct parent bridge is the same
    + * If its direct parent bridge is the same
    * as any bridge of this device then it can't
    * be used for that device.
    */
    @@ -730,10 +728,10 @@ static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev)
    }

    /*
    - * 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
    + * Now iterate the previous device's bridge hierarchy.
    + * If the new device's parent bridge is in the other
    + * device's hierarchy, we can't use it to control this
    + * device.
    */
    while (bus) {
    bridge = bus->self;
    @@ -754,10 +752,9 @@ static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev)
    }

    /*
    - * 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.
    + * 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 decide if devices decodes legacy things or not.
    */
    static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
    {
    @@ -767,12 +764,16 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
    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 = kzalloc(sizeof(struct vga_device), GFP_KERNEL);
    if (vgadev == NULL) {
    vgaarb_err(&pdev->dev, "failed to allocate VGA arbiter data\n");
    /*
    - * What to do on allocation failure ? For now, let's just do
    + * 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;
    @@ -792,9 +793,10 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)

    /* 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
    + * clear that below if the bridge isn't forwarding.
    */
    pci_read_config_word(pdev, PCI_COMMAND, &cmd);
    if (cmd & PCI_COMMAND_IO)
    @@ -874,7 +876,7 @@ static bool vga_arbiter_del_pci_device(struct pci_dev *pdev)
    return ret;
    }

    -/* This is called with the lock */
    +/* Called with the lock */
    static void vga_update_device_decodes(struct vga_device *vgadev,
    unsigned int new_decodes)
    {
    @@ -885,8 +887,7 @@ static void vga_update_device_decodes(struct vga_device *vgadev,

    vgadev->decodes = new_decodes;

    - vgaarb_info(dev,
    - "VGA decodes changed: olddecodes=%s,decodes=%s:owns=%s\n",
    + vgaarb_info(dev, "VGA decodes changed: olddecodes=%s,decodes=%s:owns=%s\n",
    vga_iostate_to_str(old_decodes),
    vga_iostate_to_str(vgadev->decodes),
    vga_iostate_to_str(vgadev->owns));
    @@ -932,9 +933,9 @@ static void __vga_set_legacy_decoding(struct pci_dev *pdev,
    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 ...
    + * XXX If somebody is going from "doesn't decode" to "decodes"
    + * state here, additional care must be taken as we may have pending
    + * ownership of non-legacy region.
    */
    bail:
    spin_unlock_irqrestore(&vga_lock, flags);
    @@ -942,10 +943,10 @@ static void __vga_set_legacy_decoding(struct pci_dev *pdev,

    /**
    * vga_set_legacy_decoding
    - * @pdev: pci device of the VGA card
    + * @pdev: PCI device of the VGA card
    * @decodes: bit mask of what legacy regions the card decodes
    *
    - * Indicates to the arbiter if the card decodes legacy VGA IOs, legacy VGA
    + * Indicate to the arbiter if the card decodes legacy VGA IOs, legacy VGA
    * Memory, both, or none. All cards default to both, the card driver (fbdev for
    * example) should tell the arbiter if it has disabled legacy decoding, so the
    * card can be left out of the arbitration process (and can be safe to take
    @@ -959,44 +960,42 @@ EXPORT_SYMBOL(vga_set_legacy_decoding);

    /**
    * vga_client_register - register or unregister a VGA arbitration client
    - * @pdev: pci device of the VGA client
    - * @set_decode: vga decode change callback
    + * @pdev: PCI device of the VGA client
    + * @set_decode: VGA decode change callback
    *
    * Clients have two callback mechanisms they can use.
    *
    * @set_decode callback: If a client can disable its GPU VGA resource, it
    * will get a callback from this to set the encode/decode state.
    *
    - * Rationale: we cannot disable VGA decode resources unconditionally, some
    - * single GPU laptops seem to require ACPI or BIOS access to the VGA registers
    - * to control things like backlights etc. Hopefully newer multi-GPU laptops do
    - * something saner, and desktops won't have any special ACPI for this. The
    - * driver will get a callback when VGA arbitration is first used by userspace
    - * since some older X servers have issues.
    + * Rationale: we cannot disable VGA decode resources unconditionally
    + * because some single GPU laptops seem to require ACPI or BIOS access to
    + * the VGA registers to control things like backlights etc. Hopefully newer
    + * multi-GPU laptops do something saner, and desktops won't have any
    + * special ACPI for this. The driver will get a callback when VGA
    + * arbitration is first used by userspace since some older X servers have
    + * issues.
    *
    - * This function does not check whether a client for @pdev has been registered
    - * already.
    + * Does not check whether a client for @pdev has been registered already.
    *
    - * To unregister just call vga_client_unregister().
    + * To unregister, call vga_client_unregister().
    *
    * Returns: 0 on success, -ENODEV on failure
    */
    int vga_client_register(struct pci_dev *pdev,
    unsigned int (*set_decode)(struct pci_dev *pdev, bool decode))
    {
    - int ret = -ENODEV;
    - struct vga_device *vgadev;
    unsigned long flags;
    + struct vga_device *vgadev;

    spin_lock_irqsave(&vga_lock, flags);
    vgadev = vgadev_find(pdev);
    - if (vgadev) {
    + if (vgadev)
    vgadev->set_decode = set_decode;
    - ret = 0;
    - }
    spin_unlock_irqrestore(&vga_lock, flags);
    -
    - return ret;
    + if (!vgadev)
    + return -ENODEV;
    + return 0;
    }
    EXPORT_SYMBOL(vga_client_register);

    @@ -1005,13 +1004,13 @@ EXPORT_SYMBOL(vga_client_register);
    *
    * Semantics is:
    *
    - * open : open user instance of the arbitrer. by default, it's
    + * open : Open user instance of the arbiter. By default, it's
    * attached to the default VGA device of the system.
    *
    - * close : close user instance, release locks
    + * 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},
    + * 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
    @@ -1025,7 +1024,7 @@ EXPORT_SYMBOL(vga_client_register);
    * write : write a command to the arbiter. List of commands is:
    *
    * target <card_ID> : switch target to card <card_ID> (see below)
    - * lock <io_state> : acquires locks on target ("none" is invalid io_state)
    + * lock <io_state> : acquire locks on target ("none" is invalid io_state)
    * trylock <io_state> : non-blocking acquire locks on target
    * unlock <io_state> : release locks on target
    * unlock all : release all locks on target held by this user
    @@ -1042,23 +1041,21 @@ EXPORT_SYMBOL(vga_client_register);
    * 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
    + * supports stacking, like the kernel one. This complicates 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
    + * it 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
    - */
    +/* 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;
    @@ -1077,9 +1074,8 @@ 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.
    + * Take a string in the format: "PCI:domain:bus:dev.fn" and return the
    + * respective values. If the string is not in this format, return 0.
    */
    static int vga_pci_str_to_vars(char *buf, int count, unsigned int *domain,
    unsigned int *bus, unsigned int *devfn)
    @@ -1111,7 +1107,7 @@ static ssize_t vga_arb_read(struct file *file, char __user *buf,
    if (lbuf == NULL)
    return -ENOMEM;

    - /* Protects vga_list */
    + /* Protect vga_list */
    spin_lock_irqsave(&vga_lock, flags);

    /* If we are targeting the default, use it */
    @@ -1126,15 +1122,15 @@ static ssize_t vga_arb_read(struct file *file, char __user *buf,
    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
    + * Wow, it's not in the list, that shouldn't happen, let's
    + * fix us up and return invalid card.
    */
    spin_unlock_irqrestore(&vga_lock, flags);
    len = sprintf(lbuf, "invalid");
    goto done;
    }

    - /* Fill the buffer with infos */
    + /* Fill the buffer with info */
    len = snprintf(lbuf, 1024,
    "count:%d,PCI:%s,decodes=%s,owns=%s,locks=%s(%u:%u)\n",
    vga_decode_count, pci_name(pdev),
    @@ -1180,7 +1176,7 @@ static ssize_t vga_arb_write(struct file *file, const char __user *buf,
    if (copy_from_user(kbuf, buf, count))
    return -EFAULT;
    curr_pos = kbuf;
    - kbuf[count] = '\0'; /* Just to make sure... */
    + kbuf[count] = '\0';

    if (strncmp(curr_pos, "lock ", 5) == 0) {
    curr_pos += 5;
    @@ -1205,7 +1201,7 @@ static ssize_t vga_arb_write(struct file *file, const char __user *buf,

    vga_get_uninterruptible(pdev, io_state);

    - /* Update the client's locks lists... */
    + /* 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)
    @@ -1372,7 +1368,7 @@ static ssize_t vga_arb_write(struct file *file, const char __user *buf,
    vgaarb_dbg(&pdev->dev, "maximum user cards (%d) number reached, ignoring this one!\n",
    MAX_USER_CARDS);
    pci_dev_put(pdev);
    - /* XXX: which value to return? */
    + /* XXX: Which value to return? */
    ret_val = -ENOMEM;
    goto done;
    }
    @@ -1433,7 +1429,7 @@ static int vga_arb_open(struct inode *inode, struct file *file)
    list_add(&priv->list, &vga_user_list);
    spin_unlock_irqrestore(&vga_user_lock, flags);

    - /* Set the client' lists of locks */
    + /* Set the client's 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;
    @@ -1472,68 +1468,32 @@ static int vga_arb_release(struct inode *inode, struct file *file)
    }

    /*
    - * Callback any registered clients to let them know we have a
    - * change in VGA cards
    + * 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;
    - bool state;
    + unsigned int new_decodes;
    + bool new_state;

    if (!vga_arbiter_used)
    return;

    - state = (vga_count > 1) ? false : true;
    + new_state = (vga_count > 1) ? false : true;

    spin_lock_irqsave(&vga_lock, flags);
    list_for_each_entry(vgadev, &vga_list, list) {
    if (vgadev->set_decode) {
    - unsigned int decodes;
    -
    - decodes = vgadev->set_decode(vgadev->pdev, state);
    - vga_update_device_decodes(vgadev, decodes);
    + new_decodes = vgadev->set_decode(vgadev->pdev,
    + new_state);
    + vga_update_device_decodes(vgadev, new_decodes);
    }
    }
    spin_unlock_irqrestore(&vga_lock, flags);
    }

    -/*
    - * The PCI Class Code spec implies that only VGA devices with programming
    - * interface 0x00 can depend on the legacy VGA address range. VGA devices
    - * with programming interface 0x01 are 8514-compatible controllers. Since
    - * VGA devices with programming interface 0x00 is VGA compatible, the 'vga'
    - * suffix here should refer to the VGA-compatible devices after a strict
    - * reading of that specification. But considering the fact that there
    - * probably don't has a 8514-compatible controller that could be used with
    - * upstream kernel anymore, we would like to just ignore the programming
    - * interface byte.
    - *
    - * Besides, there do exist non VGA-compatible display controllers in the
    - * world and hardware vendors may abandon the old VGA standard someday.
    - * The meaning of 'vga' suffix here may change to evolve with time.
    - *
    - * A strict understanding of 'vga' certainly should be VGA-compatible, While
    - * a relaxed understanding of 'vga' would be PCI devices that are able to
    - * display. Currently, we just keep aligned to the previous behavior.
    - * Deal with VGA class devices.
    - */
    -static bool pci_dev_is_vga(struct pci_dev *pdev)
    -{
    - if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
    - return true;
    -
    - /*
    - * The PCI_CLASS_NOT_DEFINED_VGA is defined to provide backward
    - * compatibility for devices that were built before the class code
    - * field was defined.
    - */
    - if ((pdev->class >> 8) == PCI_CLASS_NOT_DEFINED_VGA)
    - return true;
    -
    - return false;
    -}
    -
    static int pci_notify(struct notifier_block *nb, unsigned long action,
    void *data)
    {
    @@ -1543,9 +1503,6 @@ static int pci_notify(struct notifier_block *nb, unsigned long action,

    vgaarb_dbg(dev, "%s\n", __func__);

    - if (!pci_dev_is_vga(pdev))
    - return 0;
    -
    /*
    * For now, we're only interested in devices added and removed.
    * I didn't test this thing here, so someone needs to double check
    @@ -1580,8 +1537,8 @@ static struct miscdevice vga_arb_device = {

    static int __init vga_arb_device_init(void)
    {
    - struct pci_dev *pdev = NULL;
    int rc;
    + struct pci_dev *pdev;

    rc = misc_register(&vga_arb_device);
    if (rc < 0)
    @@ -1589,22 +1546,12 @@ static int __init vga_arb_device_init(void)

    bus_register_notifier(&pci_bus_type, &pci_notifier);

    - /*
    - * We add all PCI devices satisfying VGA class in the arbiter
    - * by default, but we ignore the programming interface byte
    - * intentionally.
    - */
    - do {
    - pdev = pci_get_class_masked(PCI_CLASS_DISPLAY_VGA << 8, 0xFFFF00, pdev);
    - if (pdev && pci_dev_is_vga(pdev))
    - vga_arbiter_add_pci_device(pdev);
    - } while (pdev);
    -
    - do {
    - pdev = pci_get_class_masked(PCI_CLASS_NOT_DEFINED_VGA << 8, 0xFFFF00, pdev);
    - if (pdev && pci_dev_is_vga(pdev))
    - vga_arbiter_add_pci_device(pdev);
    - } while (pdev);
    + /* Add all VGA class PCI devices 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("loaded\n");
    return rc;
    diff --git a/include/linux/pci.h b/include/linux/pci.h
    index 14dc5ab4a1d2..c69a2cc1f412 100644
    --- a/include/linux/pci.h
    +++ b/include/linux/pci.h
    @@ -1180,9 +1180,6 @@ struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn);
    struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
    unsigned int devfn);
    struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from);
    -struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int mask,
    - struct pci_dev *from);
    -
    int pci_dev_present(const struct pci_device_id *ids);

    int pci_bus_read_config_byte(struct pci_bus *bus, unsigned int devfn,
    @@ -1898,10 +1895,6 @@ static inline struct pci_dev *pci_get_class(unsigned int class,
    struct pci_dev *from)
    { return NULL; }

    -static inline struct pci_dev *pci_get_class_masked(unsigned int class,
    - unsigned int mask,
    - struct pci_dev *from)
    -{ return NULL; }

    static inline int pci_dev_present(const struct pci_device_id *ids)
    { return 0; }
    \
     
     \ /
      Last update: 2023-08-24 00:31    [W:2.573 / U:0.288 seconds]
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