vgaarbiter: rst-ifiy and polish kerneldoc
Move the documentation into Documentation/gpu, link it up and pull in the kernel doc. No actual text changes except that I did polish the kerneldoc a bit, especially for vga_client_register(). v2: Remove some rst from vga-switcheroo.rst that I don't understand, but which seems to be the reason why the new vgaarbiter.rst sometimes drops out of the sidebar index. v3: Drop one level of headings and clarify the vgaarb one a bit. v4: Fix some typos (Sean). Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Sean Paul <seanpaul@chromium.org> Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-20-git-send-email-daniel.vetter@ffwll.ch
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b754b35b08
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@ -12,3 +12,4 @@ Linux GPU Driver Developer's Guide
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drm-uapi
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drm-uapi
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i915
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i915
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vga-switcheroo
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vga-switcheroo
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vgaarbiter
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@ -1,5 +1,3 @@
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.. _vga_switcheroo:
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==============
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==============
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VGA Switcheroo
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VGA Switcheroo
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==============
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==============
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@ -1,4 +1,4 @@
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===========
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VGA Arbiter
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VGA Arbiter
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===========
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===========
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@ -19,21 +19,8 @@ control bus resources. Therefore an arbitration scheme outside of the X server
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is needed to control the sharing of these resources. This document introduces
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is needed to control the sharing of these resources. This document introduces
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the operation of the VGA arbiter implemented for the Linux kernel.
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the operation of the VGA arbiter implemented for the Linux kernel.
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----------------------------------------------------------------------------
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vgaarb kernel/userspace ABI
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---------------------------
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I. Details and Theory of Operation
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I.1 vgaarb
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I.2 libpciaccess
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I.3 xf86VGAArbiter (X server implementation)
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II. Credits
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III.References
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I. Details and Theory of Operation
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==================================
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I.1 vgaarb
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----------
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The vgaarb is a module of the Linux Kernel. When it is initially loaded, it
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The vgaarb is a module of the Linux Kernel. When it is initially loaded, it
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scans all PCI devices and adds the VGA ones inside the arbitration. The
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scans all PCI devices and adds the VGA ones inside the arbitration. The
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@ -44,42 +31,52 @@ explicitly tell it by calling vga_set_legacy_decoding().
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The kernel exports a char device interface (/dev/vga_arbiter) to the clients,
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The kernel exports a char device interface (/dev/vga_arbiter) to the clients,
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which has the following semantics:
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which has the following semantics:
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open : open user instance of the arbiter. By default, it's attached to
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open
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the default VGA device of the system.
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Opens a user instance of the arbiter. By default, it's attached to the
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default VGA device of the system.
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close : close user instance. Release locks made by the user
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close
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Close a user instance. Release locks made by the user
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read : return a string indicating the status of the target like:
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read
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Return a string indicating the status of the target like:
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"<card_ID>,decodes=<io_state>,owns=<io_state>,locks=<io_state> (ic,mc)"
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"<card_ID>,decodes=<io_state>,owns=<io_state>,locks=<io_state> (ic,mc)"
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An IO state string is of the form {io,mem,io+mem,none}, mc and
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An IO state string is of the form {io,mem,io+mem,none}, mc and
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ic are respectively mem and io lock counts (for debugging/
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ic are respectively mem and io lock counts (for debugging/
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diagnostic only). "decodes" indicate what the card currently
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diagnostic only). "decodes" indicate what the card currently
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decodes, "owns" indicates what is currently enabled on it, and
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decodes, "owns" indicates what is currently enabled on it, and
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"locks" indicates what is locked by this card. If the card is
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"locks" indicates what is locked by this card. If the card is
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unplugged, we get "invalid" then for card_ID and an -ENODEV
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unplugged, we get "invalid" then for card_ID and an -ENODEV
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error is returned for any command until a new card is targeted.
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error is returned for any command until a new card is targeted.
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write : write a command to the arbiter. List of commands:
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write
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Write a command to the arbiter. List of commands:
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target <card_ID> : switch target to card <card_ID> (see below)
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target <card_ID>
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lock <io_state> : acquires locks on target ("none" is an invalid io_state)
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switch target to card <card_ID> (see below)
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trylock <io_state> : non-blocking acquire locks on target (returns EBUSY if
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lock <io_state>
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unsuccessful)
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acquires locks on target ("none" is an invalid io_state)
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unlock <io_state> : release locks on target
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trylock <io_state>
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unlock all : release all locks on target held by this user (not
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non-blocking acquire locks on target (returns EBUSY if
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implemented yet)
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unsuccessful)
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decodes <io_state> : set the legacy decoding attributes for the card
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unlock <io_state>
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release locks on target
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unlock all
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release all locks on target held by this user (not implemented
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yet)
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decodes <io_state>
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set the legacy decoding attributes for the card
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poll : event if something changes on any card (not just the
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poll
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target)
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event if something changes on any card (not just the target)
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card_ID is of the form "PCI:domain:bus:dev.fn". It can be set to "default"
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card_ID is of the form "PCI:domain:bus:dev.fn". It can be set to "default"
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to go back to the system default card (TODO: not implemented yet). Currently,
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to go back to the system default card (TODO: not implemented yet). Currently,
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only PCI is supported as a prefix, but the userland API may support other bus
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only PCI is supported as a prefix, but the userland API may support other bus
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types in the future, even if the current kernel implementation doesn't.
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types in the future, even if the current kernel implementation doesn't.
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Note about locks:
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Note about locks:
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@ -97,29 +94,35 @@ in the arbiter.
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There is also an in-kernel API of the arbiter in case DRM, vgacon, or other
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There is also an in-kernel API of the arbiter in case DRM, vgacon, or other
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drivers want to use it.
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drivers want to use it.
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In-kernel interface
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-------------------
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I.2 libpciaccess
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.. kernel-doc:: include/linux/vgaarb.h
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----------------
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:internal:
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.. kernel-doc:: drivers/gpu/vga/vgaarb.c
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:export:
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libpciaccess
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------------
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To use the vga arbiter char device it was implemented an API inside the
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To use the vga arbiter char device it was implemented an API inside the
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libpciaccess library. One field was added to struct pci_device (each device
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libpciaccess library. One field was added to struct pci_device (each device
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on the system):
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on the system)::
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/* the type of resource decoded by the device */
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/* the type of resource decoded by the device */
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int vgaarb_rsrc;
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int vgaarb_rsrc;
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Besides it, in pci_system were added:
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Besides it, in pci_system were added::
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int vgaarb_fd;
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int vgaarb_fd;
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int vga_count;
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int vga_count;
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struct pci_device *vga_target;
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struct pci_device *vga_target;
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struct pci_device *vga_default_dev;
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struct pci_device *vga_default_dev;
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The vga_count is used to track how many cards are being arbitrated, so for
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The vga_count is used to track how many cards are being arbitrated, so for
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instance, if there is only one card, then it can completely escape arbitration.
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instance, if there is only one card, then it can completely escape arbitration.
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These functions below acquire VGA resources for the given card and mark those
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These functions below acquire VGA resources for the given card and mark those
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resources as locked. If the resources requested are "normal" (and not legacy)
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resources as locked. If the resources requested are "normal" (and not legacy)
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resources, the arbiter will first check whether the card is doing legacy
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resources, the arbiter will first check whether the card is doing legacy
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@ -136,44 +139,44 @@ VGA memory and IO afaik). If the card already owns the resources, the function
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succeeds. vga_arb_trylock() will return (-EBUSY) instead of blocking. Nested
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succeeds. vga_arb_trylock() will return (-EBUSY) instead of blocking. Nested
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calls are supported (a per-resource counter is maintained).
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calls are supported (a per-resource counter is maintained).
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Set the target device of this client. ::
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Set the target device of this client.
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int pci_device_vgaarb_set_target (struct pci_device *dev);
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int pci_device_vgaarb_set_target (struct pci_device *dev);
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For instance, in x86 if two devices on the same bus want to lock different
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For instance, in x86 if two devices on the same bus want to lock different
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resources, both will succeed (lock). If devices are in different buses and
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resources, both will succeed (lock). If devices are in different buses and
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trying to lock different resources, only the first who tried succeeds.
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trying to lock different resources, only the first who tried succeeds. ::
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int pci_device_vgaarb_lock (void);
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int pci_device_vgaarb_lock (void);
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int pci_device_vgaarb_trylock (void);
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int pci_device_vgaarb_trylock (void);
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Unlock resources of device.
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Unlock resources of device. ::
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int pci_device_vgaarb_unlock (void);
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int pci_device_vgaarb_unlock (void);
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Indicates to the arbiter if the card decodes legacy VGA IOs, legacy VGA
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Indicates to the arbiter if the card decodes legacy VGA IOs, legacy VGA
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Memory, both, or none. All cards default to both, the card driver (fbdev for
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Memory, both, or none. All cards default to both, the card driver (fbdev for
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example) should tell the arbiter if it has disabled legacy decoding, so the
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example) should tell the arbiter if it has disabled legacy decoding, so the
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card can be left out of the arbitration process (and can be safe to take
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card can be left out of the arbitration process (and can be safe to take
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interrupts at any time.
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interrupts at any time. ::
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int pci_device_vgaarb_decodes (int new_vgaarb_rsrc);
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int pci_device_vgaarb_decodes (int new_vgaarb_rsrc);
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Connects to the arbiter device, allocates the struct
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Connects to the arbiter device, allocates the struct ::
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int pci_device_vgaarb_init (void);
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int pci_device_vgaarb_init (void);
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Close the connection
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Close the connection ::
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void pci_device_vgaarb_fini (void);
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void pci_device_vgaarb_fini (void);
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xf86VGAArbiter (X server implementation)
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I.3 xf86VGAArbiter (X server implementation)
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----------------------------------------
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--------------------------------------------
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(TODO)
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X server basically wraps all the functions that touch VGA registers somehow.
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X server basically wraps all the functions that touch VGA registers somehow.
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References
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II. Credits
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----------
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===========
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Benjamin Herrenschmidt (IBM?) started this work when he discussed such design
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Benjamin Herrenschmidt (IBM?) started this work when he discussed such design
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with the Xorg community in 2005 [1, 2]. In the end of 2007, Paulo Zanoni and
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with the Xorg community in 2005 [1, 2]. In the end of 2007, Paulo Zanoni and
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@ -182,11 +185,7 @@ enhancing the kernel code to adapt as a kernel module and also did the
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implementation of the user space side [3]. Now (2009) Tiago Vignatti and Dave
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implementation of the user space side [3]. Now (2009) Tiago Vignatti and Dave
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Airlie finally put this work in shape and queued to Jesse Barnes' PCI tree.
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Airlie finally put this work in shape and queued to Jesse Barnes' PCI tree.
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0) http://cgit.freedesktop.org/xorg/xserver/commit/?id=4b42448a2388d40f257774fbffdccaea87bd0347
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III. References
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1) http://lists.freedesktop.org/archives/xorg/2005-March/006663.html
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==============
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2) http://lists.freedesktop.org/archives/xorg/2005-March/006745.html
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3) http://lists.freedesktop.org/archives/xorg/2007-October/029507.html
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[0] http://cgit.freedesktop.org/xorg/xserver/commit/?id=4b42448a2388d40f257774fbffdccaea87bd0347
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[1] http://lists.freedesktop.org/archives/xorg/2005-March/006663.html
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[2] http://lists.freedesktop.org/archives/xorg/2005-March/006745.html
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[3] http://lists.freedesktop.org/archives/xorg/2007-October/029507.html
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@ -131,7 +131,24 @@ static struct vga_device *vgadev_find(struct pci_dev *pdev)
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return NULL;
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return NULL;
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}
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}
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/* Returns the default VGA device (vgacon's babe) */
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/**
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* vga_default_device - return the default VGA device, for vgacon
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*
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* This can be defined by the platform. The default implementation
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* is rather dumb and will probably only work properly on single
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* vga card setups and/or x86 platforms.
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*
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* If your VGA default device is not PCI, you'll have to return
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* NULL here. In this case, I assume it will not conflict with
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* any PCI card. If this is not true, I'll have to define two archs
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* hooks for enabling/disabling the VGA default device if that is
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* possible. This may be a problem with real _ISA_ VGA cards, in
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* addition to a PCI one. I don't know at this point how to deal
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* with that card. Can theirs IOs be disabled at all ? If not, then
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* I suppose it's a matter of having the proper arch hook telling
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* us about it, so we basically never allow anybody to succeed a
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* vga_get()...
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*/
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struct pci_dev *vga_default_device(void)
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struct pci_dev *vga_default_device(void)
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{
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{
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return vga_default;
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return vga_default;
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@ -356,6 +373,40 @@ static void __vga_put(struct vga_device *vgadev, unsigned int rsrc)
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wake_up_all(&vga_wait_queue);
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wake_up_all(&vga_wait_queue);
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}
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}
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/**
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* vga_get - acquire & locks VGA resources
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* @pdev: pci device of the VGA card or NULL for the system default
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* @rsrc: bit mask of resources to acquire and lock
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* @interruptible: blocking should be interruptible by signals ?
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*
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* This function acquires VGA resources for the given card and mark those
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* resources locked. If the resource requested are "normal" (and not legacy)
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* resources, the arbiter will first check whether the card is doing legacy
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* decoding for that type of resource. If yes, the lock is "converted" into a
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* legacy resource lock.
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*
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* The arbiter will first look for all VGA cards that might conflict and disable
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* their IOs and/or Memory access, including VGA forwarding on P2P bridges if
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* necessary, so that the requested resources can be used. Then, the card is
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* marked as locking these resources and the IO and/or Memory accesses are
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* enabled on the card (including VGA forwarding on parent P2P bridges if any).
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*
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* This function will block if some conflicting card is already locking one of
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* the required resources (or any resource on a different bus segment, since P2P
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* bridges don't differentiate VGA memory and IO afaik). You can indicate
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* whether this blocking should be interruptible by a signal (for userland
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* interface) or not.
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*
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* Must not be called at interrupt time or in atomic context. If the card
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* already owns the resources, the function succeeds. Nested calls are
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* supported (a per-resource counter is maintained)
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*
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* On success, release the VGA resource again with vga_put().
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*
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* Returns:
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*
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* 0 on success, negative error code on failure.
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*/
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int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
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int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
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{
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{
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struct vga_device *vgadev, *conflict;
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struct vga_device *vgadev, *conflict;
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@ -408,6 +459,21 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
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}
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}
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EXPORT_SYMBOL(vga_get);
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EXPORT_SYMBOL(vga_get);
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/**
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* vga_tryget - try to acquire & lock legacy VGA resources
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* @pdev: pci devivce of VGA card or NULL for system default
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* @rsrc: bit mask of resources to acquire and lock
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*
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* This function performs the same operation as vga_get(), but will return an
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* error (-EBUSY) instead of blocking if the resources are already locked by
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* another card. It can be called in any context
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*
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* On success, release the VGA resource again with vga_put().
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*
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* Returns:
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*
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* 0 on success, negative error code on failure.
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*/
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int vga_tryget(struct pci_dev *pdev, unsigned int rsrc)
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int vga_tryget(struct pci_dev *pdev, unsigned int rsrc)
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{
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{
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struct vga_device *vgadev;
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struct vga_device *vgadev;
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@ -435,6 +501,16 @@ bail:
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}
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}
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EXPORT_SYMBOL(vga_tryget);
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EXPORT_SYMBOL(vga_tryget);
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/**
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* vga_put - release lock on legacy VGA resources
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* @pdev: pci device of VGA card or NULL for system default
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* @rsrc: but mask of resource to release
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*
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||||||
|
* 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.
|
||||||
|
*/
|
||||||
void vga_put(struct pci_dev *pdev, unsigned int rsrc)
|
void vga_put(struct pci_dev *pdev, unsigned int rsrc)
|
||||||
{
|
{
|
||||||
struct vga_device *vgadev;
|
struct vga_device *vgadev;
|
||||||
|
@ -716,7 +792,37 @@ void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes)
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL(vga_set_legacy_decoding);
|
EXPORT_SYMBOL(vga_set_legacy_decoding);
|
||||||
|
|
||||||
/* call with NULL to unregister */
|
/**
|
||||||
|
* vga_client_register - register or unregister a VGA arbitration client
|
||||||
|
* @pdev: pci device of the VGA client
|
||||||
|
* @cookie: client cookie to be used in callbacks
|
||||||
|
* @irq_set_state: irq state change callback
|
||||||
|
* @set_vga_decode: vga decode change callback
|
||||||
|
*
|
||||||
|
* Clients have two callback mechanisms they can use.
|
||||||
|
*
|
||||||
|
* @irq_set_state callback: If a client can't disable its GPUs VGA
|
||||||
|
* resources, then we need to be able to ask it to turn off its irqs when we
|
||||||
|
* turn off its mem and io decoding.
|
||||||
|
*
|
||||||
|
* @set_vga_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.
|
||||||
|
*
|
||||||
|
* This function does not check whether a client for @pdev has been registered
|
||||||
|
* already.
|
||||||
|
*
|
||||||
|
* To unregister just call this function with @irq_set_state and @set_vga_decode
|
||||||
|
* both set to NULL for the same @pdev as originally used to register them.
|
||||||
|
*
|
||||||
|
* Returns: 0 on success, -1 on failure
|
||||||
|
*/
|
||||||
int vga_client_register(struct pci_dev *pdev, void *cookie,
|
int vga_client_register(struct pci_dev *pdev, void *cookie,
|
||||||
void (*irq_set_state)(void *cookie, bool state),
|
void (*irq_set_state)(void *cookie, bool state),
|
||||||
unsigned int (*set_vga_decode)(void *cookie,
|
unsigned int (*set_vga_decode)(void *cookie,
|
||||||
|
|
|
@ -73,34 +73,6 @@ static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
|
||||||
unsigned int decodes) { };
|
unsigned int decodes) { };
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
/**
|
|
||||||
* vga_get - acquire & locks 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) 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.
|
|
||||||
* 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 necessary, so that the requested resources can
|
|
||||||
* be used. Then, the card is marked as locking these resources and
|
|
||||||
* the IO and/or Memory accesse are enabled on the card (including
|
|
||||||
* VGA forwarding on parent P2P bridges if any).
|
|
||||||
* This function will block if some conflicting card is already locking
|
|
||||||
* one of the required resources (or any resource on a different bus
|
|
||||||
* segment, since P2P bridges don't differenciate VGA memory and IO
|
|
||||||
* afaik). You can indicate whether this blocking should be interruptible
|
|
||||||
* by a signal (for userland interface) or not.
|
|
||||||
* Must not be called at interrupt time or in atomic context.
|
|
||||||
* If the card already owns the resources, the function succeeds.
|
|
||||||
* Nested calls are supported (a per-resource counter is maintained)
|
|
||||||
*/
|
|
||||||
|
|
||||||
#if defined(CONFIG_VGA_ARB)
|
#if defined(CONFIG_VGA_ARB)
|
||||||
extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
|
extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
|
||||||
#else
|
#else
|
||||||
|
@ -108,11 +80,14 @@ static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interrupt
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* vga_get_interruptible
|
* vga_get_interruptible
|
||||||
|
* @pdev: pci device of the VGA card or NULL for the system default
|
||||||
|
* @rsrc: bit mask of resources to acquire and lock
|
||||||
*
|
*
|
||||||
* Shortcut to vga_get
|
* Shortcut to vga_get with interruptible set to true.
|
||||||
|
*
|
||||||
|
* On success, release the VGA resource again with vga_put().
|
||||||
*/
|
*/
|
||||||
|
|
||||||
static inline int vga_get_interruptible(struct pci_dev *pdev,
|
static inline int vga_get_interruptible(struct pci_dev *pdev,
|
||||||
unsigned int rsrc)
|
unsigned int rsrc)
|
||||||
{
|
{
|
||||||
|
@ -120,47 +95,26 @@ static inline int vga_get_interruptible(struct pci_dev *pdev,
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* vga_get_uninterruptible
|
* vga_get_uninterruptible - shortcut to vga_get()
|
||||||
|
* @pdev: pci device of the VGA card or NULL for the system default
|
||||||
|
* @rsrc: bit mask of resources to acquire and lock
|
||||||
*
|
*
|
||||||
* Shortcut to vga_get
|
* Shortcut to vga_get with interruptible set to false.
|
||||||
|
*
|
||||||
|
* On success, release the VGA resource again with vga_put().
|
||||||
*/
|
*/
|
||||||
|
|
||||||
static inline int vga_get_uninterruptible(struct pci_dev *pdev,
|
static inline int vga_get_uninterruptible(struct pci_dev *pdev,
|
||||||
unsigned int rsrc)
|
unsigned int rsrc)
|
||||||
{
|
{
|
||||||
return vga_get(pdev, rsrc, 0);
|
return vga_get(pdev, rsrc, 0);
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
|
||||||
* vga_tryget - try to acquire & lock legacy VGA resources
|
|
||||||
*
|
|
||||||
* @pdev: pci devivce 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
|
|
||||||
*/
|
|
||||||
|
|
||||||
#if defined(CONFIG_VGA_ARB)
|
#if defined(CONFIG_VGA_ARB)
|
||||||
extern int vga_tryget(struct pci_dev *pdev, unsigned int rsrc);
|
extern int vga_tryget(struct pci_dev *pdev, unsigned int rsrc);
|
||||||
#else
|
#else
|
||||||
static inline int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) { return 0; }
|
static inline int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) { return 0; }
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
/**
|
|
||||||
* 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
|
|
||||||
*
|
|
||||||
* This function 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.
|
|
||||||
*/
|
|
||||||
|
|
||||||
#if defined(CONFIG_VGA_ARB)
|
#if defined(CONFIG_VGA_ARB)
|
||||||
extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
|
extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
|
||||||
#else
|
#else
|
||||||
|
@ -168,25 +122,6 @@ extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
|
|
||||||
/**
|
|
||||||
* vga_default_device
|
|
||||||
*
|
|
||||||
* 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()...
|
|
||||||
*/
|
|
||||||
|
|
||||||
#ifdef CONFIG_VGA_ARB
|
#ifdef CONFIG_VGA_ARB
|
||||||
extern struct pci_dev *vga_default_device(void);
|
extern struct pci_dev *vga_default_device(void);
|
||||||
extern void vga_set_default_device(struct pci_dev *pdev);
|
extern void vga_set_default_device(struct pci_dev *pdev);
|
||||||
|
@ -195,14 +130,11 @@ static inline struct pci_dev *vga_default_device(void) { return NULL; };
|
||||||
static inline void vga_set_default_device(struct pci_dev *pdev) { };
|
static inline void vga_set_default_device(struct pci_dev *pdev) { };
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
/**
|
/*
|
||||||
* vga_conflicts
|
* Architectures should define this if they have several
|
||||||
*
|
* independent PCI domains that can afford concurrent VGA
|
||||||
* Architectures should define this if they have several
|
* decoding
|
||||||
* independent PCI domains that can afford concurrent VGA
|
|
||||||
* decoding
|
|
||||||
*/
|
*/
|
||||||
|
|
||||||
#ifndef __ARCH_HAS_VGA_CONFLICT
|
#ifndef __ARCH_HAS_VGA_CONFLICT
|
||||||
static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
|
static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
|
||||||
{
|
{
|
||||||
|
@ -210,34 +142,6 @@ static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
|
||||||
}
|
}
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
/**
|
|
||||||
* vga_client_register
|
|
||||||
*
|
|
||||||
* @pdev: pci device of the VGA client
|
|
||||||
* @cookie: client cookie to be used in callbacks
|
|
||||||
* @irq_set_state: irq state change callback
|
|
||||||
* @set_vga_decode: vga decode change callback
|
|
||||||
*
|
|
||||||
* return value: 0 on success, -1 on failure
|
|
||||||
* Register a client with the VGA arbitration logic
|
|
||||||
*
|
|
||||||
* Clients have two callback mechanisms they can use.
|
|
||||||
* irq enable/disable callback -
|
|
||||||
* If a client can't disable its GPUs VGA resources, then we
|
|
||||||
* need to be able to ask it to turn off its irqs when we
|
|
||||||
* turn off its mem and io decoding.
|
|
||||||
* set_vga_decode
|
|
||||||
* 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.
|
|
||||||
* They driver will get a callback when VGA arbitration is first used
|
|
||||||
* by userspace since we some older X servers have issues.
|
|
||||||
*/
|
|
||||||
#if defined(CONFIG_VGA_ARB)
|
#if defined(CONFIG_VGA_ARB)
|
||||||
int vga_client_register(struct pci_dev *pdev, void *cookie,
|
int vga_client_register(struct pci_dev *pdev, void *cookie,
|
||||||
void (*irq_set_state)(void *cookie, bool state),
|
void (*irq_set_state)(void *cookie, bool state),
|
||||||
|
|
Loading…
Reference in New Issue