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![Sui Jingfeng](/assets/img/avatar_default.png)
Fix typos, rewrap to fill 78 columns, convert to conventional multi-line style. [bhelgaas: squash and add more fixes] Link: https://lore.kernel.org/r/20230808223412.1743176-7-sui.jingfeng@linux.dev Link: https://lore.kernel.org/r/20230808223412.1743176-9-sui.jingfeng@linux.dev Link: https://lore.kernel.org/r/20230808223412.1743176-10-sui.jingfeng@linux.dev Link: https://lore.kernel.org/r/20230808223412.1743176-11-sui.jingfeng@linux.dev Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
1559 lines
42 KiB
C
1559 lines
42 KiB
C
// SPDX-License-Identifier: MIT
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/*
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* vgaarb.c: Implements VGA arbitration. For details refer to
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* Documentation/gpu/vgaarbiter.rst
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*
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* (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
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* (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com>
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* (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org>
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*/
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#define pr_fmt(fmt) "vgaarb: " fmt
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#define vgaarb_dbg(dev, fmt, arg...) dev_dbg(dev, "vgaarb: " fmt, ##arg)
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#define vgaarb_info(dev, fmt, arg...) dev_info(dev, "vgaarb: " fmt, ##arg)
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#define vgaarb_err(dev, fmt, arg...) dev_err(dev, "vgaarb: " fmt, ##arg)
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/sched/signal.h>
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#include <linux/wait.h>
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#include <linux/spinlock.h>
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#include <linux/poll.h>
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#include <linux/miscdevice.h>
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#include <linux/slab.h>
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#include <linux/screen_info.h>
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#include <linux/vt.h>
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#include <linux/console.h>
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#include <linux/acpi.h>
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#include <linux/uaccess.h>
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#include <linux/vgaarb.h>
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static void vga_arbiter_notify_clients(void);
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/*
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* We keep a list of all VGA devices in the system to speed
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* up the various operations of the arbiter
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*/
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struct vga_device {
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struct list_head list;
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struct pci_dev *pdev;
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unsigned int decodes; /* what it decodes */
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unsigned int owns; /* what it owns */
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unsigned int locks; /* what it locks */
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unsigned int io_lock_cnt; /* legacy IO lock count */
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unsigned int mem_lock_cnt; /* legacy MEM lock count */
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unsigned int io_norm_cnt; /* normal IO count */
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unsigned int mem_norm_cnt; /* normal MEM count */
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bool bridge_has_one_vga;
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bool is_firmware_default; /* device selected by firmware */
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unsigned int (*set_decode)(struct pci_dev *pdev, bool decode);
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};
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static LIST_HEAD(vga_list);
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static int vga_count, vga_decode_count;
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static bool vga_arbiter_used;
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static DEFINE_SPINLOCK(vga_lock);
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static DECLARE_WAIT_QUEUE_HEAD(vga_wait_queue);
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static const char *vga_iostate_to_str(unsigned int iostate)
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{
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/* Ignore VGA_RSRC_IO and VGA_RSRC_MEM */
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iostate &= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
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switch (iostate) {
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case VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM:
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return "io+mem";
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case VGA_RSRC_LEGACY_IO:
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return "io";
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case VGA_RSRC_LEGACY_MEM:
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return "mem";
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}
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return "none";
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}
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static int vga_str_to_iostate(char *buf, int str_size, unsigned int *io_state)
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{
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/*
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* In theory, we could hand out locks on IO and MEM separately to
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* userspace, but this can cause deadlocks.
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*/
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if (strncmp(buf, "none", 4) == 0) {
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*io_state = VGA_RSRC_NONE;
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return 1;
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}
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/* XXX We're not checking the str_size! */
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if (strncmp(buf, "io+mem", 6) == 0)
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goto both;
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else if (strncmp(buf, "io", 2) == 0)
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goto both;
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else if (strncmp(buf, "mem", 3) == 0)
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goto both;
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return 0;
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both:
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*io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
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return 1;
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}
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/* This is only used as a cookie, it should not be dereferenced */
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static struct pci_dev *vga_default;
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/* Find somebody in our list */
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static struct vga_device *vgadev_find(struct pci_dev *pdev)
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{
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struct vga_device *vgadev;
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list_for_each_entry(vgadev, &vga_list, list)
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if (pdev == vgadev->pdev)
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return vgadev;
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return NULL;
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}
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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 is
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* rather dumb and will probably only work properly on single VGA card
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* 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 NULL here.
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* In this case, I assume it will not conflict with any PCI card. If this
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* is not true, I'll have to define two arch hooks for enabling/disabling
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* the VGA default device if that is possible. This may be a problem with
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* real _ISA_ VGA cards, in addition to a PCI one. I don't know at this
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* point how to deal with that card. Can their IOs be disabled at all? If
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* not, then 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 vga_get().
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*/
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struct pci_dev *vga_default_device(void)
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{
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return vga_default;
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}
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EXPORT_SYMBOL_GPL(vga_default_device);
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void vga_set_default_device(struct pci_dev *pdev)
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{
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if (vga_default == pdev)
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return;
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pci_dev_put(vga_default);
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vga_default = pci_dev_get(pdev);
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}
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/**
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* vga_remove_vgacon - deactivate VGA console
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*
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* Unbind and unregister vgacon in case pdev is the default VGA device.
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* Can be called by GPU drivers on initialization to make sure VGA register
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* access done by vgacon will not disturb the device.
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*
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* @pdev: PCI device.
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*/
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#if !defined(CONFIG_VGA_CONSOLE)
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int vga_remove_vgacon(struct pci_dev *pdev)
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{
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return 0;
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}
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#elif !defined(CONFIG_DUMMY_CONSOLE)
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int vga_remove_vgacon(struct pci_dev *pdev)
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{
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return -ENODEV;
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}
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#else
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int vga_remove_vgacon(struct pci_dev *pdev)
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{
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int ret = 0;
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if (pdev != vga_default)
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return 0;
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vgaarb_info(&pdev->dev, "deactivate vga console\n");
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console_lock();
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if (con_is_bound(&vga_con))
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ret = do_take_over_console(&dummy_con, 0,
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MAX_NR_CONSOLES - 1, 1);
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if (ret == 0) {
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ret = do_unregister_con_driver(&vga_con);
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/* Ignore "already unregistered". */
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if (ret == -ENODEV)
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ret = 0;
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}
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console_unlock();
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return ret;
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}
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#endif
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EXPORT_SYMBOL(vga_remove_vgacon);
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/*
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* If we don't ever use VGA arbitration, we should avoid turning off
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* anything anywhere due to old X servers getting confused about the boot
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* device not being VGA.
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*/
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static void vga_check_first_use(void)
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{
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/*
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* Inform all GPUs in the system that VGA arbitration has occurred
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* so they can disable resources if possible.
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*/
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if (!vga_arbiter_used) {
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vga_arbiter_used = true;
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vga_arbiter_notify_clients();
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}
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}
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static struct vga_device *__vga_tryget(struct vga_device *vgadev,
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unsigned int rsrc)
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{
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struct device *dev = &vgadev->pdev->dev;
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unsigned int wants, legacy_wants, match;
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struct vga_device *conflict;
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unsigned int pci_bits;
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u32 flags = 0;
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/*
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* Account for "normal" resources to lock. If we decode the legacy,
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* counterpart, we need to request it as well
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*/
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if ((rsrc & VGA_RSRC_NORMAL_IO) &&
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(vgadev->decodes & VGA_RSRC_LEGACY_IO))
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rsrc |= VGA_RSRC_LEGACY_IO;
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if ((rsrc & VGA_RSRC_NORMAL_MEM) &&
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(vgadev->decodes & VGA_RSRC_LEGACY_MEM))
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rsrc |= VGA_RSRC_LEGACY_MEM;
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vgaarb_dbg(dev, "%s: %d\n", __func__, rsrc);
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vgaarb_dbg(dev, "%s: owns: %d\n", __func__, vgadev->owns);
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/* Check what resources we need to acquire */
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wants = rsrc & ~vgadev->owns;
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/* We already own everything, just mark locked & bye bye */
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if (wants == 0)
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goto lock_them;
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/*
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* We don't need to request a legacy resource, we just enable
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* appropriate decoding and go.
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*/
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legacy_wants = wants & VGA_RSRC_LEGACY_MASK;
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if (legacy_wants == 0)
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goto enable_them;
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/* Ok, we don't, let's find out who we need to kick off */
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list_for_each_entry(conflict, &vga_list, list) {
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unsigned int lwants = legacy_wants;
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unsigned int change_bridge = 0;
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/* Don't conflict with myself */
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if (vgadev == conflict)
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continue;
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/*
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* We have a possible conflict. Before we go further, we must
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* check if we sit on the same bus as the conflicting device.
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* If we don't, then we must tie both IO and MEM resources
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* together since there is only a single bit controlling
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* VGA forwarding on P2P bridges.
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*/
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if (vgadev->pdev->bus != conflict->pdev->bus) {
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change_bridge = 1;
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lwants = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
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}
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/*
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* Check if the guy has a lock on the resource. If he does,
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* return the conflicting entry.
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*/
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if (conflict->locks & lwants)
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return conflict;
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/*
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* Ok, now check if it owns the resource we want. We can
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* lock resources that are not decoded; therefore a device
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* can own resources it doesn't decode.
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*/
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match = lwants & conflict->owns;
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if (!match)
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continue;
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/*
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* Looks like he doesn't have a lock, we can steal them
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* from him.
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*/
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flags = 0;
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pci_bits = 0;
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/*
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* If we can't control legacy resources via the bridge, we
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* also need to disable normal decoding.
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*/
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if (!conflict->bridge_has_one_vga) {
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if ((match & conflict->decodes) & VGA_RSRC_LEGACY_MEM)
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pci_bits |= PCI_COMMAND_MEMORY;
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if ((match & conflict->decodes) & VGA_RSRC_LEGACY_IO)
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pci_bits |= PCI_COMMAND_IO;
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if (pci_bits)
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flags |= PCI_VGA_STATE_CHANGE_DECODES;
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}
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if (change_bridge)
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flags |= PCI_VGA_STATE_CHANGE_BRIDGE;
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pci_set_vga_state(conflict->pdev, false, pci_bits, flags);
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conflict->owns &= ~match;
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/* If we disabled normal decoding, reflect it in owns */
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if (pci_bits & PCI_COMMAND_MEMORY)
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conflict->owns &= ~VGA_RSRC_NORMAL_MEM;
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if (pci_bits & PCI_COMMAND_IO)
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conflict->owns &= ~VGA_RSRC_NORMAL_IO;
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}
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enable_them:
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/*
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* Ok, we got it, everybody conflicting has been disabled, let's
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* enable us. Mark any bits in "owns" regardless of whether we
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* decoded them. We can lock resources we don't decode, therefore
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* we must track them via "owns".
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*/
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flags = 0;
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pci_bits = 0;
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if (!vgadev->bridge_has_one_vga) {
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flags |= PCI_VGA_STATE_CHANGE_DECODES;
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if (wants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM))
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pci_bits |= PCI_COMMAND_MEMORY;
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if (wants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO))
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pci_bits |= PCI_COMMAND_IO;
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}
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if (wants & VGA_RSRC_LEGACY_MASK)
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flags |= PCI_VGA_STATE_CHANGE_BRIDGE;
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pci_set_vga_state(vgadev->pdev, true, pci_bits, flags);
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vgadev->owns |= wants;
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lock_them:
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vgadev->locks |= (rsrc & VGA_RSRC_LEGACY_MASK);
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if (rsrc & VGA_RSRC_LEGACY_IO)
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vgadev->io_lock_cnt++;
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if (rsrc & VGA_RSRC_LEGACY_MEM)
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vgadev->mem_lock_cnt++;
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if (rsrc & VGA_RSRC_NORMAL_IO)
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vgadev->io_norm_cnt++;
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if (rsrc & VGA_RSRC_NORMAL_MEM)
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vgadev->mem_norm_cnt++;
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return NULL;
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}
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static void __vga_put(struct vga_device *vgadev, unsigned int rsrc)
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{
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struct device *dev = &vgadev->pdev->dev;
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unsigned int old_locks = vgadev->locks;
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vgaarb_dbg(dev, "%s\n", __func__);
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/*
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* Update our counters and account for equivalent legacy resources
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* if we decode them.
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*/
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if ((rsrc & VGA_RSRC_NORMAL_IO) && vgadev->io_norm_cnt > 0) {
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vgadev->io_norm_cnt--;
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if (vgadev->decodes & VGA_RSRC_LEGACY_IO)
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rsrc |= VGA_RSRC_LEGACY_IO;
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}
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if ((rsrc & VGA_RSRC_NORMAL_MEM) && vgadev->mem_norm_cnt > 0) {
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vgadev->mem_norm_cnt--;
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if (vgadev->decodes & VGA_RSRC_LEGACY_MEM)
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rsrc |= VGA_RSRC_LEGACY_MEM;
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}
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if ((rsrc & VGA_RSRC_LEGACY_IO) && vgadev->io_lock_cnt > 0)
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vgadev->io_lock_cnt--;
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if ((rsrc & VGA_RSRC_LEGACY_MEM) && vgadev->mem_lock_cnt > 0)
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vgadev->mem_lock_cnt--;
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/*
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* Just clear lock bits, we do lazy operations so we don't really
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* have to bother about anything else at this point.
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*/
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if (vgadev->io_lock_cnt == 0)
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vgadev->locks &= ~VGA_RSRC_LEGACY_IO;
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if (vgadev->mem_lock_cnt == 0)
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vgadev->locks &= ~VGA_RSRC_LEGACY_MEM;
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/*
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* Kick the wait queue in case somebody was waiting if we actually
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* released something.
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*/
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if (old_locks != vgadev->locks)
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wake_up_all(&vga_wait_queue);
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}
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/**
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* vga_get - acquire & lock 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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* Acquire VGA resources for the given card and mark those resources
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* 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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* decoding for that type of resource. If yes, the lock is "converted" into
|
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* a 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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{
|
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struct vga_device *vgadev, *conflict;
|
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unsigned long flags;
|
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wait_queue_entry_t wait;
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int rc = 0;
|
|
|
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vga_check_first_use();
|
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/* The caller should check for this, but let's be sure */
|
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if (pdev == NULL)
|
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pdev = vga_default_device();
|
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if (pdev == NULL)
|
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return 0;
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|
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for (;;) {
|
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spin_lock_irqsave(&vga_lock, flags);
|
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vgadev = vgadev_find(pdev);
|
|
if (vgadev == NULL) {
|
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spin_unlock_irqrestore(&vga_lock, flags);
|
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rc = -ENODEV;
|
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break;
|
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}
|
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conflict = __vga_tryget(vgadev, rsrc);
|
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spin_unlock_irqrestore(&vga_lock, flags);
|
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if (conflict == NULL)
|
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break;
|
|
|
|
/*
|
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* We have a conflict; we wait until somebody kicks the
|
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* work queue. Currently we have one work queue that we
|
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* kick each time some resources are released, but it would
|
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* be fairly easy to have a per-device one so that we only
|
|
* need to attach to the conflicting device.
|
|
*/
|
|
init_waitqueue_entry(&wait, current);
|
|
add_wait_queue(&vga_wait_queue, &wait);
|
|
set_current_state(interruptible ?
|
|
TASK_INTERRUPTIBLE :
|
|
TASK_UNINTERRUPTIBLE);
|
|
if (interruptible && signal_pending(current)) {
|
|
__set_current_state(TASK_RUNNING);
|
|
remove_wait_queue(&vga_wait_queue, &wait);
|
|
rc = -ERESTARTSYS;
|
|
break;
|
|
}
|
|
schedule();
|
|
remove_wait_queue(&vga_wait_queue, &wait);
|
|
}
|
|
return rc;
|
|
}
|
|
EXPORT_SYMBOL(vga_get);
|
|
|
|
/**
|
|
* vga_tryget - try to acquire & lock legacy VGA resources
|
|
* @pdev: PCI device of VGA card or NULL for system default
|
|
* @rsrc: bit mask of resources to acquire and lock
|
|
*
|
|
* 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().
|
|
*
|
|
* Returns:
|
|
*
|
|
* 0 on success, negative error code on failure.
|
|
*/
|
|
static int vga_tryget(struct pci_dev *pdev, unsigned int rsrc)
|
|
{
|
|
struct vga_device *vgadev;
|
|
unsigned long flags;
|
|
int rc = 0;
|
|
|
|
vga_check_first_use();
|
|
|
|
/* The caller should check for this, but let's be sure */
|
|
if (pdev == NULL)
|
|
pdev = vga_default_device();
|
|
if (pdev == NULL)
|
|
return 0;
|
|
spin_lock_irqsave(&vga_lock, flags);
|
|
vgadev = vgadev_find(pdev);
|
|
if (vgadev == NULL) {
|
|
rc = -ENODEV;
|
|
goto bail;
|
|
}
|
|
if (__vga_tryget(vgadev, rsrc))
|
|
rc = -EBUSY;
|
|
bail:
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* vga_put - release lock on legacy VGA resources
|
|
* @pdev: PCI device of VGA card or NULL for system default
|
|
* @rsrc: bit mask of resource to release
|
|
*
|
|
* 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 caller should check for this, but let's be sure */
|
|
if (pdev == NULL)
|
|
pdev = vga_default_device();
|
|
if (pdev == NULL)
|
|
return;
|
|
spin_lock_irqsave(&vga_lock, flags);
|
|
vgadev = vgadev_find(pdev);
|
|
if (vgadev == NULL)
|
|
goto bail;
|
|
__vga_put(vgadev, rsrc);
|
|
bail:
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(vga_put);
|
|
|
|
static bool vga_is_firmware_default(struct pci_dev *pdev)
|
|
{
|
|
#if defined(CONFIG_X86) || defined(CONFIG_IA64)
|
|
u64 base = screen_info.lfb_base;
|
|
u64 size = screen_info.lfb_size;
|
|
struct resource *r;
|
|
u64 limit;
|
|
|
|
/* Select the device owning the boot framebuffer if there is one */
|
|
|
|
if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
|
|
base |= (u64)screen_info.ext_lfb_base << 32;
|
|
|
|
limit = base + size;
|
|
|
|
/* Does firmware framebuffer belong to us? */
|
|
pci_dev_for_each_resource(pdev, r) {
|
|
if (resource_type(r) != IORESOURCE_MEM)
|
|
continue;
|
|
|
|
if (!r->start || !r->end)
|
|
continue;
|
|
|
|
if (base < r->start || limit >= r->end)
|
|
continue;
|
|
|
|
return true;
|
|
}
|
|
#endif
|
|
return false;
|
|
}
|
|
|
|
static bool vga_arb_integrated_gpu(struct device *dev)
|
|
{
|
|
#if defined(CONFIG_ACPI)
|
|
struct acpi_device *adev = ACPI_COMPANION(dev);
|
|
|
|
return adev && !strcmp(acpi_device_hid(adev), ACPI_VIDEO_HID);
|
|
#else
|
|
return false;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Return true if vgadev is a better default VGA device than the best one
|
|
* we've seen so far.
|
|
*/
|
|
static bool vga_is_boot_device(struct vga_device *vgadev)
|
|
{
|
|
struct vga_device *boot_vga = vgadev_find(vga_default_device());
|
|
struct pci_dev *pdev = vgadev->pdev;
|
|
u16 cmd, boot_cmd;
|
|
|
|
/*
|
|
* We select the default VGA device in this order:
|
|
* Firmware framebuffer (see vga_arb_select_default_device())
|
|
* Legacy VGA device (owns VGA_RSRC_LEGACY_MASK)
|
|
* Non-legacy integrated device (see vga_arb_select_default_device())
|
|
* Non-legacy discrete device (see vga_arb_select_default_device())
|
|
* Other device (see vga_arb_select_default_device())
|
|
*/
|
|
|
|
/*
|
|
* We always prefer a firmware default device, so if we've already
|
|
* found one, there's no need to consider vgadev.
|
|
*/
|
|
if (boot_vga && boot_vga->is_firmware_default)
|
|
return false;
|
|
|
|
if (vga_is_firmware_default(pdev)) {
|
|
vgadev->is_firmware_default = true;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* A legacy VGA device has MEM and IO enabled and any bridges
|
|
* leading to it have PCI_BRIDGE_CTL_VGA enabled so the legacy
|
|
* resources ([mem 0xa0000-0xbffff], [io 0x3b0-0x3bb], etc) are
|
|
* routed to it.
|
|
*
|
|
* We use the first one we find, so if we've already found one,
|
|
* vgadev is no better.
|
|
*/
|
|
if (boot_vga &&
|
|
(boot_vga->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)
|
|
return false;
|
|
|
|
if ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)
|
|
return true;
|
|
|
|
/*
|
|
* If we haven't found a legacy VGA device, accept a non-legacy
|
|
* device. It may have either IO or MEM enabled, and bridges may
|
|
* not have PCI_BRIDGE_CTL_VGA enabled, so it may not be able to
|
|
* use legacy VGA resources. Prefer an integrated GPU over others.
|
|
*/
|
|
pci_read_config_word(pdev, PCI_COMMAND, &cmd);
|
|
if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
|
|
|
|
/*
|
|
* An integrated GPU overrides a previous non-legacy
|
|
* device. We expect only a single integrated GPU, but if
|
|
* there are more, we use the *last* because that was the
|
|
* previous behavior.
|
|
*/
|
|
if (vga_arb_integrated_gpu(&pdev->dev))
|
|
return true;
|
|
|
|
/*
|
|
* We prefer the first non-legacy discrete device we find.
|
|
* If we already found one, vgadev is no better.
|
|
*/
|
|
if (boot_vga) {
|
|
pci_read_config_word(boot_vga->pdev, PCI_COMMAND,
|
|
&boot_cmd);
|
|
if (boot_cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Vgadev has neither IO nor MEM enabled. If we haven't found any
|
|
* other VGA devices, it is the best candidate so far.
|
|
*/
|
|
if (!boot_vga)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Rules for using a bridge to control a VGA descendant decoding: if a bridge
|
|
* has only one VGA descendant then it can be used to control the VGA routing
|
|
* for that device. It should always use the bridge closest to the device to
|
|
* control it. If a bridge has a direct VGA descendant, but also have a sub-
|
|
* bridge VGA descendant then we cannot use that bridge to control the direct
|
|
* VGA descendant. So for every device we register, we need to iterate all
|
|
* its parent bridges so we can invalidate any devices using them properly.
|
|
*/
|
|
static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev)
|
|
{
|
|
struct vga_device *same_bridge_vgadev;
|
|
struct pci_bus *new_bus, *bus;
|
|
struct pci_dev *new_bridge, *bridge;
|
|
|
|
vgadev->bridge_has_one_vga = true;
|
|
|
|
if (list_empty(&vga_list)) {
|
|
vgaarb_info(&vgadev->pdev->dev, "bridge control possible\n");
|
|
return;
|
|
}
|
|
|
|
/* 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 */
|
|
list_for_each_entry(same_bridge_vgadev, &vga_list, list) {
|
|
bus = same_bridge_vgadev->pdev->bus;
|
|
bridge = bus->self;
|
|
|
|
/* See if it shares a bridge with this device */
|
|
if (new_bridge == bridge) {
|
|
/*
|
|
* If its direct parent bridge is the same
|
|
* as any bridge of this device then it can't
|
|
* be used for that device.
|
|
*/
|
|
same_bridge_vgadev->bridge_has_one_vga = false;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
if (bridge && bridge == vgadev->pdev->bus->self)
|
|
vgadev->bridge_has_one_vga = false;
|
|
|
|
bus = bus->parent;
|
|
}
|
|
}
|
|
new_bus = new_bus->parent;
|
|
}
|
|
|
|
if (vgadev->bridge_has_one_vga)
|
|
vgaarb_info(&vgadev->pdev->dev, "bridge control possible\n");
|
|
else
|
|
vgaarb_info(&vgadev->pdev->dev, "no bridge control possible\n");
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct vga_device *vgadev;
|
|
unsigned long flags;
|
|
struct pci_bus *bus;
|
|
struct pci_dev *bridge;
|
|
u16 cmd;
|
|
|
|
/* Only deal with VGA class devices */
|
|
if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
|
|
return false;
|
|
|
|
/* Allocate structure */
|
|
vgadev = 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
|
|
* nothing, I'm not sure there is anything saner to be done.
|
|
*/
|
|
return false;
|
|
}
|
|
|
|
/* Take lock & check for duplicates */
|
|
spin_lock_irqsave(&vga_lock, flags);
|
|
if (vgadev_find(pdev) != NULL) {
|
|
BUG_ON(1);
|
|
goto fail;
|
|
}
|
|
vgadev->pdev = pdev;
|
|
|
|
/* By default, assume we decode everything */
|
|
vgadev->decodes = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM |
|
|
VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
|
|
|
|
/* By default, mark it as decoding */
|
|
vga_decode_count++;
|
|
|
|
/*
|
|
* Mark that we "own" resources based on our enables, we will
|
|
* clear that below if the bridge isn't forwarding.
|
|
*/
|
|
pci_read_config_word(pdev, PCI_COMMAND, &cmd);
|
|
if (cmd & PCI_COMMAND_IO)
|
|
vgadev->owns |= VGA_RSRC_LEGACY_IO;
|
|
if (cmd & PCI_COMMAND_MEMORY)
|
|
vgadev->owns |= VGA_RSRC_LEGACY_MEM;
|
|
|
|
/* Check if VGA cycles can get down to us */
|
|
bus = pdev->bus;
|
|
while (bus) {
|
|
bridge = bus->self;
|
|
if (bridge) {
|
|
u16 l;
|
|
|
|
pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &l);
|
|
if (!(l & PCI_BRIDGE_CTL_VGA)) {
|
|
vgadev->owns = 0;
|
|
break;
|
|
}
|
|
}
|
|
bus = bus->parent;
|
|
}
|
|
|
|
if (vga_is_boot_device(vgadev)) {
|
|
vgaarb_info(&pdev->dev, "setting as boot VGA device%s\n",
|
|
vga_default_device() ?
|
|
" (overriding previous)" : "");
|
|
vga_set_default_device(pdev);
|
|
}
|
|
|
|
vga_arbiter_check_bridge_sharing(vgadev);
|
|
|
|
/* Add to the list */
|
|
list_add_tail(&vgadev->list, &vga_list);
|
|
vga_count++;
|
|
vgaarb_info(&pdev->dev, "VGA device added: decodes=%s,owns=%s,locks=%s\n",
|
|
vga_iostate_to_str(vgadev->decodes),
|
|
vga_iostate_to_str(vgadev->owns),
|
|
vga_iostate_to_str(vgadev->locks));
|
|
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
return true;
|
|
fail:
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
kfree(vgadev);
|
|
return false;
|
|
}
|
|
|
|
static bool vga_arbiter_del_pci_device(struct pci_dev *pdev)
|
|
{
|
|
struct vga_device *vgadev;
|
|
unsigned long flags;
|
|
bool ret = true;
|
|
|
|
spin_lock_irqsave(&vga_lock, flags);
|
|
vgadev = vgadev_find(pdev);
|
|
if (vgadev == NULL) {
|
|
ret = false;
|
|
goto bail;
|
|
}
|
|
|
|
if (vga_default == pdev)
|
|
vga_set_default_device(NULL);
|
|
|
|
if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM))
|
|
vga_decode_count--;
|
|
|
|
/* Remove entry from list */
|
|
list_del(&vgadev->list);
|
|
vga_count--;
|
|
|
|
/* Wake up all possible waiters */
|
|
wake_up_all(&vga_wait_queue);
|
|
bail:
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
kfree(vgadev);
|
|
return ret;
|
|
}
|
|
|
|
/* Called with the lock */
|
|
static void vga_update_device_decodes(struct vga_device *vgadev,
|
|
unsigned int new_decodes)
|
|
{
|
|
struct device *dev = &vgadev->pdev->dev;
|
|
unsigned int old_decodes = vgadev->decodes;
|
|
unsigned int decodes_removed = ~new_decodes & old_decodes;
|
|
unsigned int decodes_unlocked = vgadev->locks & decodes_removed;
|
|
|
|
vgadev->decodes = new_decodes;
|
|
|
|
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));
|
|
|
|
/* If we removed locked decodes, lock count goes to zero, and release */
|
|
if (decodes_unlocked) {
|
|
if (decodes_unlocked & VGA_RSRC_LEGACY_IO)
|
|
vgadev->io_lock_cnt = 0;
|
|
if (decodes_unlocked & VGA_RSRC_LEGACY_MEM)
|
|
vgadev->mem_lock_cnt = 0;
|
|
__vga_put(vgadev, decodes_unlocked);
|
|
}
|
|
|
|
/* Change decodes counter */
|
|
if (old_decodes & VGA_RSRC_LEGACY_MASK &&
|
|
!(new_decodes & VGA_RSRC_LEGACY_MASK))
|
|
vga_decode_count--;
|
|
if (!(old_decodes & VGA_RSRC_LEGACY_MASK) &&
|
|
new_decodes & VGA_RSRC_LEGACY_MASK)
|
|
vga_decode_count++;
|
|
vgaarb_dbg(dev, "decoding count now is: %d\n", vga_decode_count);
|
|
}
|
|
|
|
static void __vga_set_legacy_decoding(struct pci_dev *pdev,
|
|
unsigned int decodes,
|
|
bool userspace)
|
|
{
|
|
struct vga_device *vgadev;
|
|
unsigned long flags;
|
|
|
|
decodes &= VGA_RSRC_LEGACY_MASK;
|
|
|
|
spin_lock_irqsave(&vga_lock, flags);
|
|
vgadev = vgadev_find(pdev);
|
|
if (vgadev == NULL)
|
|
goto bail;
|
|
|
|
/* Don't let userspace futz with kernel driver decodes */
|
|
if (userspace && vgadev->set_decode)
|
|
goto bail;
|
|
|
|
/* Update the device decodes + counter */
|
|
vga_update_device_decodes(vgadev, decodes);
|
|
|
|
/*
|
|
* XXX If somebody is going from "doesn't decode" to "decodes"
|
|
* state here, additional care must be taken as we may have pending
|
|
* ownership of non-legacy region.
|
|
*/
|
|
bail:
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
}
|
|
|
|
/**
|
|
* vga_set_legacy_decoding
|
|
* @pdev: PCI device of the VGA card
|
|
* @decodes: bit mask of what legacy regions the card decodes
|
|
*
|
|
* 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
|
|
* interrupts at any time.
|
|
*/
|
|
void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes)
|
|
{
|
|
__vga_set_legacy_decoding(pdev, decodes, false);
|
|
}
|
|
EXPORT_SYMBOL(vga_set_legacy_decoding);
|
|
|
|
/**
|
|
* vga_client_register - register or unregister a VGA arbitration client
|
|
* @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
|
|
* 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.
|
|
*
|
|
* Does not check whether a client for @pdev has been registered already.
|
|
*
|
|
* 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))
|
|
{
|
|
unsigned long flags;
|
|
struct vga_device *vgadev;
|
|
|
|
spin_lock_irqsave(&vga_lock, flags);
|
|
vgadev = vgadev_find(pdev);
|
|
if (vgadev)
|
|
vgadev->set_decode = set_decode;
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
if (!vgadev)
|
|
return -ENODEV;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(vga_client_register);
|
|
|
|
/*
|
|
* Char driver implementation
|
|
*
|
|
* Semantics is:
|
|
*
|
|
* 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
|
|
*
|
|
* read : Return a string indicating the status of the target.
|
|
* An IO state string is of the form {io,mem,io+mem,none},
|
|
* mc and ic are respectively mem and io lock counts (for
|
|
* debugging/diagnostic only). "decodes" indicate what the
|
|
* card currently decodes, "owns" indicates what is currently
|
|
* enabled on it, and "locks" indicates what is locked by this
|
|
* card. If the card is unplugged, we get "invalid" then for
|
|
* card_ID and an -ENODEV error is returned for any command
|
|
* until a new card is targeted
|
|
*
|
|
* "<card_ID>,decodes=<io_state>,owns=<io_state>,locks=<io_state> (ic,mc)"
|
|
*
|
|
* 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> : 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
|
|
* decodes <io_state> : set the legacy decoding attributes for the card
|
|
*
|
|
* poll : event if something change on any card (not just the target)
|
|
*
|
|
* card_ID is of the form "PCI:domain:bus:dev.fn". It can be set to "default"
|
|
* to go back to the system default card (TODO: not implemented yet).
|
|
* Currently, only PCI is supported as a prefix, but the userland API may
|
|
* support other bus types in the future, even if the current kernel
|
|
* implementation doesn't.
|
|
*
|
|
* Note about locks:
|
|
*
|
|
* The driver keeps track of which user has what locks on which card. It
|
|
* supports stacking, like the kernel one. This 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
|
|
* 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 */
|
|
struct vga_arb_user_card {
|
|
struct pci_dev *pdev;
|
|
unsigned int mem_cnt;
|
|
unsigned int io_cnt;
|
|
};
|
|
|
|
struct vga_arb_private {
|
|
struct list_head list;
|
|
struct pci_dev *target;
|
|
struct vga_arb_user_card cards[MAX_USER_CARDS];
|
|
spinlock_t lock;
|
|
};
|
|
|
|
static LIST_HEAD(vga_user_list);
|
|
static DEFINE_SPINLOCK(vga_user_lock);
|
|
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
int n;
|
|
unsigned int slot, func;
|
|
|
|
n = sscanf(buf, "PCI:%x:%x:%x.%x", domain, bus, &slot, &func);
|
|
if (n != 4)
|
|
return 0;
|
|
|
|
*devfn = PCI_DEVFN(slot, func);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static ssize_t vga_arb_read(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct vga_arb_private *priv = file->private_data;
|
|
struct vga_device *vgadev;
|
|
struct pci_dev *pdev;
|
|
unsigned long flags;
|
|
size_t len;
|
|
int rc;
|
|
char *lbuf;
|
|
|
|
lbuf = kmalloc(1024, GFP_KERNEL);
|
|
if (lbuf == NULL)
|
|
return -ENOMEM;
|
|
|
|
/* Protect vga_list */
|
|
spin_lock_irqsave(&vga_lock, flags);
|
|
|
|
/* If we are targeting the default, use it */
|
|
pdev = priv->target;
|
|
if (pdev == NULL || pdev == PCI_INVALID_CARD) {
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
len = sprintf(lbuf, "invalid");
|
|
goto done;
|
|
}
|
|
|
|
/* Find card vgadev structure */
|
|
vgadev = vgadev_find(pdev);
|
|
if (vgadev == NULL) {
|
|
/*
|
|
* Wow, it's not in the list, that shouldn't happen, let's
|
|
* fix us up and return invalid card.
|
|
*/
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
len = sprintf(lbuf, "invalid");
|
|
goto done;
|
|
}
|
|
|
|
/* 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),
|
|
vga_iostate_to_str(vgadev->decodes),
|
|
vga_iostate_to_str(vgadev->owns),
|
|
vga_iostate_to_str(vgadev->locks),
|
|
vgadev->io_lock_cnt, vgadev->mem_lock_cnt);
|
|
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
done:
|
|
|
|
/* Copy that to user */
|
|
if (len > count)
|
|
len = count;
|
|
rc = copy_to_user(buf, lbuf, len);
|
|
kfree(lbuf);
|
|
if (rc)
|
|
return -EFAULT;
|
|
return len;
|
|
}
|
|
|
|
/*
|
|
* TODO: To avoid parsing inside kernel and to improve the speed we may
|
|
* consider use ioctl here
|
|
*/
|
|
static ssize_t vga_arb_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct vga_arb_private *priv = file->private_data;
|
|
struct vga_arb_user_card *uc = NULL;
|
|
struct pci_dev *pdev;
|
|
|
|
unsigned int io_state;
|
|
|
|
char kbuf[64], *curr_pos;
|
|
size_t remaining = count;
|
|
|
|
int ret_val;
|
|
int i;
|
|
|
|
if (count >= sizeof(kbuf))
|
|
return -EINVAL;
|
|
if (copy_from_user(kbuf, buf, count))
|
|
return -EFAULT;
|
|
curr_pos = kbuf;
|
|
kbuf[count] = '\0';
|
|
|
|
if (strncmp(curr_pos, "lock ", 5) == 0) {
|
|
curr_pos += 5;
|
|
remaining -= 5;
|
|
|
|
pr_debug("client 0x%p called 'lock'\n", priv);
|
|
|
|
if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) {
|
|
ret_val = -EPROTO;
|
|
goto done;
|
|
}
|
|
if (io_state == VGA_RSRC_NONE) {
|
|
ret_val = -EPROTO;
|
|
goto done;
|
|
}
|
|
|
|
pdev = priv->target;
|
|
if (priv->target == NULL) {
|
|
ret_val = -ENODEV;
|
|
goto done;
|
|
}
|
|
|
|
vga_get_uninterruptible(pdev, io_state);
|
|
|
|
/* Update the client's locks lists */
|
|
for (i = 0; i < MAX_USER_CARDS; i++) {
|
|
if (priv->cards[i].pdev == pdev) {
|
|
if (io_state & VGA_RSRC_LEGACY_IO)
|
|
priv->cards[i].io_cnt++;
|
|
if (io_state & VGA_RSRC_LEGACY_MEM)
|
|
priv->cards[i].mem_cnt++;
|
|
break;
|
|
}
|
|
}
|
|
|
|
ret_val = count;
|
|
goto done;
|
|
} else if (strncmp(curr_pos, "unlock ", 7) == 0) {
|
|
curr_pos += 7;
|
|
remaining -= 7;
|
|
|
|
pr_debug("client 0x%p called 'unlock'\n", priv);
|
|
|
|
if (strncmp(curr_pos, "all", 3) == 0)
|
|
io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
|
|
else {
|
|
if (!vga_str_to_iostate
|
|
(curr_pos, remaining, &io_state)) {
|
|
ret_val = -EPROTO;
|
|
goto done;
|
|
}
|
|
/* TODO: Add this?
|
|
if (io_state == VGA_RSRC_NONE) {
|
|
ret_val = -EPROTO;
|
|
goto done;
|
|
}
|
|
*/
|
|
}
|
|
|
|
pdev = priv->target;
|
|
if (priv->target == NULL) {
|
|
ret_val = -ENODEV;
|
|
goto done;
|
|
}
|
|
for (i = 0; i < MAX_USER_CARDS; i++) {
|
|
if (priv->cards[i].pdev == pdev)
|
|
uc = &priv->cards[i];
|
|
}
|
|
|
|
if (!uc) {
|
|
ret_val = -EINVAL;
|
|
goto done;
|
|
}
|
|
|
|
if (io_state & VGA_RSRC_LEGACY_IO && uc->io_cnt == 0) {
|
|
ret_val = -EINVAL;
|
|
goto done;
|
|
}
|
|
|
|
if (io_state & VGA_RSRC_LEGACY_MEM && uc->mem_cnt == 0) {
|
|
ret_val = -EINVAL;
|
|
goto done;
|
|
}
|
|
|
|
vga_put(pdev, io_state);
|
|
|
|
if (io_state & VGA_RSRC_LEGACY_IO)
|
|
uc->io_cnt--;
|
|
if (io_state & VGA_RSRC_LEGACY_MEM)
|
|
uc->mem_cnt--;
|
|
|
|
ret_val = count;
|
|
goto done;
|
|
} else if (strncmp(curr_pos, "trylock ", 8) == 0) {
|
|
curr_pos += 8;
|
|
remaining -= 8;
|
|
|
|
pr_debug("client 0x%p called 'trylock'\n", priv);
|
|
|
|
if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) {
|
|
ret_val = -EPROTO;
|
|
goto done;
|
|
}
|
|
/* TODO: Add this?
|
|
if (io_state == VGA_RSRC_NONE) {
|
|
ret_val = -EPROTO;
|
|
goto done;
|
|
}
|
|
*/
|
|
|
|
pdev = priv->target;
|
|
if (priv->target == NULL) {
|
|
ret_val = -ENODEV;
|
|
goto done;
|
|
}
|
|
|
|
if (vga_tryget(pdev, io_state)) {
|
|
/* Update the client's locks lists... */
|
|
for (i = 0; i < MAX_USER_CARDS; i++) {
|
|
if (priv->cards[i].pdev == pdev) {
|
|
if (io_state & VGA_RSRC_LEGACY_IO)
|
|
priv->cards[i].io_cnt++;
|
|
if (io_state & VGA_RSRC_LEGACY_MEM)
|
|
priv->cards[i].mem_cnt++;
|
|
break;
|
|
}
|
|
}
|
|
ret_val = count;
|
|
goto done;
|
|
} else {
|
|
ret_val = -EBUSY;
|
|
goto done;
|
|
}
|
|
|
|
} else if (strncmp(curr_pos, "target ", 7) == 0) {
|
|
unsigned int domain, bus, devfn;
|
|
struct vga_device *vgadev;
|
|
|
|
curr_pos += 7;
|
|
remaining -= 7;
|
|
pr_debug("client 0x%p called 'target'\n", priv);
|
|
/* If target is default */
|
|
if (!strncmp(curr_pos, "default", 7))
|
|
pdev = pci_dev_get(vga_default_device());
|
|
else {
|
|
if (!vga_pci_str_to_vars(curr_pos, remaining,
|
|
&domain, &bus, &devfn)) {
|
|
ret_val = -EPROTO;
|
|
goto done;
|
|
}
|
|
pdev = pci_get_domain_bus_and_slot(domain, bus, devfn);
|
|
if (!pdev) {
|
|
pr_debug("invalid PCI address %04x:%02x:%02x.%x\n",
|
|
domain, bus, PCI_SLOT(devfn),
|
|
PCI_FUNC(devfn));
|
|
ret_val = -ENODEV;
|
|
goto done;
|
|
}
|
|
|
|
pr_debug("%s ==> %04x:%02x:%02x.%x pdev %p\n", curr_pos,
|
|
domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
|
|
pdev);
|
|
}
|
|
|
|
vgadev = vgadev_find(pdev);
|
|
pr_debug("vgadev %p\n", vgadev);
|
|
if (vgadev == NULL) {
|
|
if (pdev) {
|
|
vgaarb_dbg(&pdev->dev, "not a VGA device\n");
|
|
pci_dev_put(pdev);
|
|
}
|
|
|
|
ret_val = -ENODEV;
|
|
goto done;
|
|
}
|
|
|
|
priv->target = pdev;
|
|
for (i = 0; i < MAX_USER_CARDS; i++) {
|
|
if (priv->cards[i].pdev == pdev)
|
|
break;
|
|
if (priv->cards[i].pdev == NULL) {
|
|
priv->cards[i].pdev = pdev;
|
|
priv->cards[i].io_cnt = 0;
|
|
priv->cards[i].mem_cnt = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (i == MAX_USER_CARDS) {
|
|
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? */
|
|
ret_val = -ENOMEM;
|
|
goto done;
|
|
}
|
|
|
|
ret_val = count;
|
|
pci_dev_put(pdev);
|
|
goto done;
|
|
|
|
|
|
} else if (strncmp(curr_pos, "decodes ", 8) == 0) {
|
|
curr_pos += 8;
|
|
remaining -= 8;
|
|
pr_debug("client 0x%p called 'decodes'\n", priv);
|
|
|
|
if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) {
|
|
ret_val = -EPROTO;
|
|
goto done;
|
|
}
|
|
pdev = priv->target;
|
|
if (priv->target == NULL) {
|
|
ret_val = -ENODEV;
|
|
goto done;
|
|
}
|
|
|
|
__vga_set_legacy_decoding(pdev, io_state, true);
|
|
ret_val = count;
|
|
goto done;
|
|
}
|
|
/* If we got here, the message written is not part of the protocol! */
|
|
return -EPROTO;
|
|
|
|
done:
|
|
return ret_val;
|
|
}
|
|
|
|
static __poll_t vga_arb_fpoll(struct file *file, poll_table *wait)
|
|
{
|
|
pr_debug("%s\n", __func__);
|
|
|
|
poll_wait(file, &vga_wait_queue, wait);
|
|
return EPOLLIN;
|
|
}
|
|
|
|
static int vga_arb_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct vga_arb_private *priv;
|
|
unsigned long flags;
|
|
|
|
pr_debug("%s\n", __func__);
|
|
|
|
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
|
|
if (priv == NULL)
|
|
return -ENOMEM;
|
|
spin_lock_init(&priv->lock);
|
|
file->private_data = priv;
|
|
|
|
spin_lock_irqsave(&vga_user_lock, flags);
|
|
list_add(&priv->list, &vga_user_list);
|
|
spin_unlock_irqrestore(&vga_user_lock, flags);
|
|
|
|
/* Set the client'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;
|
|
priv->cards[0].mem_cnt = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int vga_arb_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct vga_arb_private *priv = file->private_data;
|
|
struct vga_arb_user_card *uc;
|
|
unsigned long flags;
|
|
int i;
|
|
|
|
pr_debug("%s\n", __func__);
|
|
|
|
spin_lock_irqsave(&vga_user_lock, flags);
|
|
list_del(&priv->list);
|
|
for (i = 0; i < MAX_USER_CARDS; i++) {
|
|
uc = &priv->cards[i];
|
|
if (uc->pdev == NULL)
|
|
continue;
|
|
vgaarb_dbg(&uc->pdev->dev, "uc->io_cnt == %d, uc->mem_cnt == %d\n",
|
|
uc->io_cnt, uc->mem_cnt);
|
|
while (uc->io_cnt--)
|
|
vga_put(uc->pdev, VGA_RSRC_LEGACY_IO);
|
|
while (uc->mem_cnt--)
|
|
vga_put(uc->pdev, VGA_RSRC_LEGACY_MEM);
|
|
}
|
|
spin_unlock_irqrestore(&vga_user_lock, flags);
|
|
|
|
kfree(priv);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
unsigned int new_decodes;
|
|
bool new_state;
|
|
|
|
if (!vga_arbiter_used)
|
|
return;
|
|
|
|
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) {
|
|
new_decodes = vgadev->set_decode(vgadev->pdev,
|
|
new_state);
|
|
vga_update_device_decodes(vgadev, new_decodes);
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&vga_lock, flags);
|
|
}
|
|
|
|
static int pci_notify(struct notifier_block *nb, unsigned long action,
|
|
void *data)
|
|
{
|
|
struct device *dev = data;
|
|
struct pci_dev *pdev = to_pci_dev(dev);
|
|
bool notify = false;
|
|
|
|
vgaarb_dbg(dev, "%s\n", __func__);
|
|
|
|
/*
|
|
* For now, we're only interested in devices added and removed.
|
|
* I didn't test this thing here, so someone needs to double check
|
|
* for the cases of hot-pluggable VGA cards.
|
|
*/
|
|
if (action == BUS_NOTIFY_ADD_DEVICE)
|
|
notify = vga_arbiter_add_pci_device(pdev);
|
|
else if (action == BUS_NOTIFY_DEL_DEVICE)
|
|
notify = vga_arbiter_del_pci_device(pdev);
|
|
|
|
if (notify)
|
|
vga_arbiter_notify_clients();
|
|
return 0;
|
|
}
|
|
|
|
static struct notifier_block pci_notifier = {
|
|
.notifier_call = pci_notify,
|
|
};
|
|
|
|
static const struct file_operations vga_arb_device_fops = {
|
|
.read = vga_arb_read,
|
|
.write = vga_arb_write,
|
|
.poll = vga_arb_fpoll,
|
|
.open = vga_arb_open,
|
|
.release = vga_arb_release,
|
|
.llseek = noop_llseek,
|
|
};
|
|
|
|
static struct miscdevice vga_arb_device = {
|
|
MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops
|
|
};
|
|
|
|
static int __init vga_arb_device_init(void)
|
|
{
|
|
int rc;
|
|
struct pci_dev *pdev;
|
|
|
|
rc = misc_register(&vga_arb_device);
|
|
if (rc < 0)
|
|
pr_err("error %d registering device\n", rc);
|
|
|
|
bus_register_notifier(&pci_bus_type, &pci_notifier);
|
|
|
|
/* 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;
|
|
}
|
|
subsys_initcall_sync(vga_arb_device_init);
|