git: 4b4ab8c3107f - main - linuxkpi: Add linux/vgaarb.h
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Date: Thu, 18 Aug 2022 09:10:18 UTC
The branch main has been updated by manu:
URL: https://cgit.FreeBSD.org/src/commit/?id=4b4ab8c3107f8a95db76a7dfe50485715c8b3703
commit 4b4ab8c3107f8a95db76a7dfe50485715c8b3703
Author: Emmanuel Vadot <manu@FreeBSD.org>
AuthorDate: 2022-08-09 09:42:43 +0000
Commit: Emmanuel Vadot <manu@FreeBSD.org>
CommitDate: 2022-08-18 07:47:15 +0000
linuxkpi: Add linux/vgaarb.h
Needed by drm-kmod.
Reviewed by: bz
Obtained from: Linux
Sponsored by: Beckhoff Automation GmbH & Co. KG
Differential Revision: https://reviews.freebsd.org/D36104
---
sys/compat/linuxkpi/common/include/linux/vgaarb.h | 254 ++++++++++++++++++++++
1 file changed, 254 insertions(+)
diff --git a/sys/compat/linuxkpi/common/include/linux/vgaarb.h b/sys/compat/linuxkpi/common/include/linux/vgaarb.h
new file mode 100644
index 000000000000..853927f1c049
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/vgaarb.h
@@ -0,0 +1,254 @@
+/*
+ * The VGA aribiter manages VGA space routing and VGA resource decode to
+ * allow multiple VGA devices to be used in a system in a safe way.
+ *
+ * (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
+ * (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com>
+ * (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef _LINUXKPI_LINUX_VGA_H_
+#define _LINUXKPI_LINUX_VGA_H_
+
+#include <video/vga.h>
+
+/* Legacy VGA regions */
+#define VGA_RSRC_NONE 0x00
+#define VGA_RSRC_LEGACY_IO 0x01
+#define VGA_RSRC_LEGACY_MEM 0x02
+#define VGA_RSRC_LEGACY_MASK (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)
+/* Non-legacy access */
+#define VGA_RSRC_NORMAL_IO 0x04
+#define VGA_RSRC_NORMAL_MEM 0x08
+
+/* Passing that instead of a pci_dev to use the system "default"
+ * device, that is the one used by vgacon. Archs will probably
+ * have to provide their own vga_default_device();
+ */
+#define VGA_DEFAULT_DEVICE (NULL)
+
+struct pci_dev;
+
+/* For use by clients */
+
+/**
+ * vga_set_legacy_decoding
+ *
+ * @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 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
+ * interrupts at any time.
+ */
+#if defined(CONFIG_VGA_ARB)
+extern void vga_set_legacy_decoding(struct pci_dev *pdev,
+ unsigned int decodes);
+#else
+static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
+ unsigned int decodes) { };
+#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)
+extern int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible);
+#else
+static inline int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) { return 0; }
+#endif
+
+/**
+ * vga_get_interruptible
+ *
+ * Shortcut to vga_get
+ */
+
+static inline int vga_get_interruptible(struct pci_dev *pdev,
+ unsigned int rsrc)
+{
+ return vga_get(pdev, rsrc, 1);
+}
+
+/**
+ * vga_get_uninterruptible
+ *
+ * Shortcut to vga_get
+ */
+
+static inline int vga_get_uninterruptible(struct pci_dev *pdev,
+ unsigned int rsrc)
+{
+ 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)
+extern int vga_tryget(struct pci_dev *pdev, unsigned int rsrc);
+#else
+static inline int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) { return 0; }
+#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)
+extern void vga_put(struct pci_dev *pdev, unsigned int rsrc);
+#else
+#define vga_put(pdev, rsrc)
+#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
+extern struct pci_dev *vga_default_device(void);
+extern void vga_set_default_device(struct pci_dev *pdev);
+#else
+static inline struct pci_dev *vga_default_device(void) { return NULL; };
+static inline void vga_set_default_device(struct pci_dev *pdev) { };
+#endif
+
+/**
+ * vga_conflicts
+ *
+ * Architectures should define this if they have several
+ * independent PCI domains that can afford concurrent VGA
+ * decoding
+ */
+
+#ifndef __ARCH_HAS_VGA_CONFLICT
+static inline int vga_conflicts(struct pci_dev *p1, struct pci_dev *p2)
+{
+ return 1;
+}
+#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)
+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 state));
+#else
+static inline 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 state))
+{
+ return 0;
+}
+#endif
+
+#endif /* _LINUXKPI_LINUX_VGA_H_ */