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@@ -0,0 +1,1205 @@
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+/*
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+ * vgaarb.c
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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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+ * Implements the VGA arbitration. For details refer to
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+ * Documentation/vgaarbiter.txt
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+ */
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+
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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.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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+
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+#include <linux/uaccess.h>
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+
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+#include <linux/vgaarb.h>
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+
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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 does it decodes */
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+ unsigned int owns; /* what does it owns */
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+ unsigned int locks; /* what does 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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+
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+ /* allow IRQ enable/disable hook */
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+ void *cookie;
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+ void (*irq_set_state)(void *cookie, bool enable);
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+ unsigned int (*set_vga_decode)(void *cookie, bool decode);
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+};
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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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+
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+
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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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+
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+static int vga_str_to_iostate(char *buf, int str_size, int *io_state)
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+{
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+ /* we could in theory hand out locks on IO and mem
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+ * separately to userspace but it can cause deadlocks */
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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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+
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+ /* XXX We're not chekcing 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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+
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+#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
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+/* this is only used a cookie - it should not be dereferenced */
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+static struct pci_dev *vga_default;
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+#endif
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+
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+static void vga_arb_device_card_gone(struct pci_dev *pdev);
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+
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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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+
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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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+/* Returns the default VGA device (vgacon's babe) */
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+#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
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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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+#endif
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+
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+static inline void vga_irq_set_state(struct vga_device *vgadev, bool state)
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+{
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+ if (vgadev->irq_set_state)
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+ vgadev->irq_set_state(vgadev->cookie, state);
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+}
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+
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+
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+/* If we don't ever use VGA arb we should avoid
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+ turning off anything anywhere due to old X servers getting
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+ confused about the boot device not being VGA */
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+static void vga_check_first_use(void)
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+{
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+ /* we should inform all GPUs in the system that
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+ * VGA arb has occured and to try and disable resources
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+ * if they can */
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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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+
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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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+ 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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+ /* 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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+
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+ pr_devel("%s: %d\n", __func__, rsrc);
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+ pr_devel("%s: owns: %d\n", __func__, vgadev->owns);
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+
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+ /* Check what resources we need to acquire */
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+ wants = rsrc & ~vgadev->owns;
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+
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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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+
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+ /* Ok, we don't, let's find out how 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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+
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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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+ /* Check if the architecture allows a conflict between those
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+ * 2 devices or if they are on separate domains
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+ */
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+ if (!vga_conflicts(vgadev->pdev, conflict->pdev))
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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 he owns the resource we want. We don't need
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+ * to check "decodes" since it should be impossible to own
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+ * own legacy resources you don't decode unless I have a bug
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+ * in this code...
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+ */
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+ WARN_ON(conflict->owns & ~conflict->decodes);
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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
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+ * them from him
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+ */
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+ vga_irq_set_state(conflict, false);
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+
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+ pci_bits = 0;
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+ if (lwants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM))
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+ pci_bits |= PCI_COMMAND_MEMORY;
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+ if (lwants & (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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+ pci_set_vga_state(conflict->pdev, false, pci_bits,
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+ change_bridge);
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+ conflict->owns &= ~lwants;
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+ /* If he also owned non-legacy, that is no longer the case */
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+ if (lwants & VGA_RSRC_LEGACY_MEM)
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+ conflict->owns &= ~VGA_RSRC_NORMAL_MEM;
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+ if (lwants & VGA_RSRC_LEGACY_IO)
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+ conflict->owns &= ~VGA_RSRC_NORMAL_IO;
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+ }
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+
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+enable_them:
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+ /* ok dude, we got it, everybody conflicting has been disabled, let's
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+ * enable us. Make sure we don't mark a bit in "owns" that we don't
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+ * also have in "decodes". We can lock resources we don't decode but
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+ * not own them.
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+ */
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+ pci_bits = 0;
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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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+ pci_set_vga_state(vgadev->pdev, true, pci_bits, !!(wants & VGA_RSRC_LEGACY_MASK));
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+
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+ vga_irq_set_state(vgadev, true);
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+ vgadev->owns |= (wants & vgadev->decodes);
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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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+
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+ return NULL;
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+}
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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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+ unsigned int old_locks = vgadev->locks;
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+
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+ pr_devel("%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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+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_t wait;
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+ int rc = 0;
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+
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+ vga_check_first_use();
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+ /* The one who calls us should check for this, but lets 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);
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+ 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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+
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+
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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
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+ * need to attach to the conflicting device
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+ */
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+ init_waitqueue_entry(&wait, current);
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+ add_wait_queue(&vga_wait_queue, &wait);
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+ set_current_state(interruptible ?
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+ TASK_INTERRUPTIBLE :
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+ TASK_UNINTERRUPTIBLE);
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+ if (signal_pending(current)) {
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+ rc = -EINTR;
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+ break;
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+ }
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+ schedule();
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+ remove_wait_queue(&vga_wait_queue, &wait);
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+ set_current_state(TASK_RUNNING);
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+ }
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+ return rc;
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+}
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+EXPORT_SYMBOL(vga_get);
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+
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+int vga_tryget(struct pci_dev *pdev, unsigned int rsrc)
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+{
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+ struct vga_device *vgadev;
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+ unsigned long flags;
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+ int rc = 0;
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+
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+ vga_check_first_use();
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+
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+ /* The one who calls us should check for this, but lets 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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+ spin_lock_irqsave(&vga_lock, flags);
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+ vgadev = vgadev_find(pdev);
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+ if (vgadev == NULL) {
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+ rc = -ENODEV;
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+ goto bail;
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+ }
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+ if (__vga_tryget(vgadev, rsrc))
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+ rc = -EBUSY;
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+bail:
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+ spin_unlock_irqrestore(&vga_lock, flags);
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+ return rc;
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+}
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+EXPORT_SYMBOL(vga_tryget);
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+
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+void vga_put(struct pci_dev *pdev, unsigned int rsrc)
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+{
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+ struct vga_device *vgadev;
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+ unsigned long flags;
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|
|
+
|
|
|
+ /* The one who calls us should check for this, but lets be sure... */
|
|
|
+ if (pdev == NULL)
|
|
|
+ pdev = vga_default_device();
|
|
|
+ if (pdev == NULL)
|
|
|
+ return;
|
|
|
+ spin_lock_irqsave(&vga_lock, flags);
|
|
|
+ vgadev = vgadev_find(pdev);
|
|
|
+ if (vgadev == NULL)
|
|
|
+ goto bail;
|
|
|
+ __vga_put(vgadev, rsrc);
|
|
|
+bail:
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(vga_put);
|
|
|
+
|
|
|
+/*
|
|
|
+ * Currently, we assume that the "initial" setup of the system is
|
|
|
+ * not sane, that is we come up with conflicting devices and let
|
|
|
+ * the arbiter's client decides if devices decodes or not legacy
|
|
|
+ * things.
|
|
|
+ */
|
|
|
+static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
|
|
|
+{
|
|
|
+ struct vga_device *vgadev;
|
|
|
+ unsigned long flags;
|
|
|
+ struct pci_bus *bus;
|
|
|
+ struct pci_dev *bridge;
|
|
|
+ u16 cmd;
|
|
|
+
|
|
|
+ /* Only deal with VGA class devices */
|
|
|
+ if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
|
|
|
+ return false;
|
|
|
+
|
|
|
+ /* Allocate structure */
|
|
|
+ vgadev = kmalloc(sizeof(struct vga_device), GFP_KERNEL);
|
|
|
+ if (vgadev == NULL) {
|
|
|
+ pr_err("vgaarb: failed to allocate pci device\n");
|
|
|
+ /* What to do on allocation failure ? For now, let's
|
|
|
+ * just do nothing, I'm not sure there is anything saner
|
|
|
+ * to be done
|
|
|
+ */
|
|
|
+ return false;
|
|
|
+ }
|
|
|
+
|
|
|
+ memset(vgadev, 0, sizeof(*vgadev));
|
|
|
+
|
|
|
+ /* Take lock & check for duplicates */
|
|
|
+ spin_lock_irqsave(&vga_lock, flags);
|
|
|
+ if (vgadev_find(pdev) != NULL) {
|
|
|
+ BUG_ON(1);
|
|
|
+ goto fail;
|
|
|
+ }
|
|
|
+ vgadev->pdev = pdev;
|
|
|
+
|
|
|
+ /* By default, assume we decode everything */
|
|
|
+ vgadev->decodes = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM |
|
|
|
+ VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
|
|
|
+
|
|
|
+ /* by default mark it as decoding */
|
|
|
+ vga_decode_count++;
|
|
|
+ /* Mark that we "own" resources based on our enables, we will
|
|
|
+ * clear that below if the bridge isn't forwarding
|
|
|
+ */
|
|
|
+ pci_read_config_word(pdev, PCI_COMMAND, &cmd);
|
|
|
+ if (cmd & PCI_COMMAND_IO)
|
|
|
+ vgadev->owns |= VGA_RSRC_LEGACY_IO;
|
|
|
+ if (cmd & PCI_COMMAND_MEMORY)
|
|
|
+ vgadev->owns |= VGA_RSRC_LEGACY_MEM;
|
|
|
+
|
|
|
+ /* Check if VGA cycles can get down to us */
|
|
|
+ bus = pdev->bus;
|
|
|
+ while (bus) {
|
|
|
+ bridge = bus->self;
|
|
|
+ if (bridge) {
|
|
|
+ u16 l;
|
|
|
+ pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
|
|
|
+ &l);
|
|
|
+ if (!(l & PCI_BRIDGE_CTL_VGA)) {
|
|
|
+ vgadev->owns = 0;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ bus = bus->parent;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Deal with VGA default device. Use first enabled one
|
|
|
+ * by default if arch doesn't have it's own hook
|
|
|
+ */
|
|
|
+#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
|
|
|
+ if (vga_default == NULL &&
|
|
|
+ ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK))
|
|
|
+ vga_default = pci_dev_get(pdev);
|
|
|
+#endif
|
|
|
+
|
|
|
+ /* Add to the list */
|
|
|
+ list_add(&vgadev->list, &vga_list);
|
|
|
+ vga_count++;
|
|
|
+ pr_info("vgaarb: device added: PCI:%s,decodes=%s,owns=%s,locks=%s\n",
|
|
|
+ pci_name(pdev),
|
|
|
+ vga_iostate_to_str(vgadev->decodes),
|
|
|
+ vga_iostate_to_str(vgadev->owns),
|
|
|
+ vga_iostate_to_str(vgadev->locks));
|
|
|
+
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+ return true;
|
|
|
+fail:
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+ kfree(vgadev);
|
|
|
+ return false;
|
|
|
+}
|
|
|
+
|
|
|
+static bool vga_arbiter_del_pci_device(struct pci_dev *pdev)
|
|
|
+{
|
|
|
+ struct vga_device *vgadev;
|
|
|
+ unsigned long flags;
|
|
|
+ bool ret = true;
|
|
|
+
|
|
|
+ spin_lock_irqsave(&vga_lock, flags);
|
|
|
+ vgadev = vgadev_find(pdev);
|
|
|
+ if (vgadev == NULL) {
|
|
|
+ ret = false;
|
|
|
+ goto bail;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (vga_default == pdev) {
|
|
|
+ pci_dev_put(vga_default);
|
|
|
+ vga_default = NULL;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM))
|
|
|
+ vga_decode_count--;
|
|
|
+
|
|
|
+ /* Remove entry from list */
|
|
|
+ list_del(&vgadev->list);
|
|
|
+ vga_count--;
|
|
|
+ /* Notify userland driver that the device is gone so it discards
|
|
|
+ * it's copies of the pci_dev pointer
|
|
|
+ */
|
|
|
+ vga_arb_device_card_gone(pdev);
|
|
|
+
|
|
|
+ /* Wake up all possible waiters */
|
|
|
+ wake_up_all(&vga_wait_queue);
|
|
|
+bail:
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+ kfree(vgadev);
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+/* this is called with the lock */
|
|
|
+static inline void vga_update_device_decodes(struct vga_device *vgadev,
|
|
|
+ int new_decodes)
|
|
|
+{
|
|
|
+ int old_decodes;
|
|
|
+ struct vga_device *new_vgadev, *conflict;
|
|
|
+
|
|
|
+ old_decodes = vgadev->decodes;
|
|
|
+ vgadev->decodes = new_decodes;
|
|
|
+
|
|
|
+ pr_info("vgaarb: device changed decodes: PCI:%s,olddecodes=%s,decodes=%s:owns=%s\n",
|
|
|
+ pci_name(vgadev->pdev),
|
|
|
+ vga_iostate_to_str(old_decodes),
|
|
|
+ vga_iostate_to_str(vgadev->decodes),
|
|
|
+ vga_iostate_to_str(vgadev->owns));
|
|
|
+
|
|
|
+
|
|
|
+ /* if we own the decodes we should move them along to
|
|
|
+ another card */
|
|
|
+ if ((vgadev->owns & old_decodes) && (vga_count > 1)) {
|
|
|
+ /* set us to own nothing */
|
|
|
+ vgadev->owns &= ~old_decodes;
|
|
|
+ list_for_each_entry(new_vgadev, &vga_list, list) {
|
|
|
+ if ((new_vgadev != vgadev) &&
|
|
|
+ (new_vgadev->decodes & VGA_RSRC_LEGACY_MASK)) {
|
|
|
+ pr_info("vgaarb: transferring owner from PCI:%s to PCI:%s\n", pci_name(vgadev->pdev), pci_name(new_vgadev->pdev));
|
|
|
+ conflict = __vga_tryget(new_vgadev, VGA_RSRC_LEGACY_MASK);
|
|
|
+ if (!conflict)
|
|
|
+ __vga_put(new_vgadev, VGA_RSRC_LEGACY_MASK);
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ /* change decodes counter */
|
|
|
+ if (old_decodes != new_decodes) {
|
|
|
+ if (new_decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM))
|
|
|
+ vga_decode_count++;
|
|
|
+ else
|
|
|
+ vga_decode_count--;
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+void __vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes, bool userspace)
|
|
|
+{
|
|
|
+ struct vga_device *vgadev;
|
|
|
+ unsigned long flags;
|
|
|
+
|
|
|
+ decodes &= VGA_RSRC_LEGACY_MASK;
|
|
|
+
|
|
|
+ spin_lock_irqsave(&vga_lock, flags);
|
|
|
+ vgadev = vgadev_find(pdev);
|
|
|
+ if (vgadev == NULL)
|
|
|
+ goto bail;
|
|
|
+
|
|
|
+ /* don't let userspace futz with kernel driver decodes */
|
|
|
+ if (userspace && vgadev->set_vga_decode)
|
|
|
+ goto bail;
|
|
|
+
|
|
|
+ /* update the device decodes + counter */
|
|
|
+ vga_update_device_decodes(vgadev, decodes);
|
|
|
+
|
|
|
+ /* XXX if somebody is going from "doesn't decode" to "decodes" state
|
|
|
+ * here, additional care must be taken as we may have pending owner
|
|
|
+ * ship of non-legacy region ...
|
|
|
+ */
|
|
|
+bail:
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+}
|
|
|
+
|
|
|
+void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes)
|
|
|
+{
|
|
|
+ __vga_set_legacy_decoding(pdev, decodes, false);
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(vga_set_legacy_decoding);
|
|
|
+
|
|
|
+/* call with NULL to unregister */
|
|
|
+int vga_client_register(struct pci_dev *pdev, void *cookie,
|
|
|
+ void (*irq_set_state)(void *cookie, bool state),
|
|
|
+ unsigned int (*set_vga_decode)(void *cookie, bool decode))
|
|
|
+{
|
|
|
+ int ret = -1;
|
|
|
+ struct vga_device *vgadev;
|
|
|
+ unsigned long flags;
|
|
|
+
|
|
|
+ spin_lock_irqsave(&vga_lock, flags);
|
|
|
+ vgadev = vgadev_find(pdev);
|
|
|
+ if (!vgadev)
|
|
|
+ goto bail;
|
|
|
+
|
|
|
+ vgadev->irq_set_state = irq_set_state;
|
|
|
+ vgadev->set_vga_decode = set_vga_decode;
|
|
|
+ vgadev->cookie = cookie;
|
|
|
+ ret = 0;
|
|
|
+
|
|
|
+bail:
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+ return ret;
|
|
|
+
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(vga_client_register);
|
|
|
+
|
|
|
+/*
|
|
|
+ * Char driver implementation
|
|
|
+ *
|
|
|
+ * Semantics is:
|
|
|
+ *
|
|
|
+ * open : open user instance of the arbitrer. by default, it's
|
|
|
+ * attached to the default VGA device of the system.
|
|
|
+ *
|
|
|
+ * close : close user instance, release locks
|
|
|
+ *
|
|
|
+ * read : return a string indicating the status of the target.
|
|
|
+ * an IO state string is of the form {io,mem,io+mem,none},
|
|
|
+ * mc and ic are respectively mem and io lock counts (for
|
|
|
+ * debugging/diagnostic only). "decodes" indicate what the
|
|
|
+ * card currently decodes, "owns" indicates what is currently
|
|
|
+ * enabled on it, and "locks" indicates what is locked by this
|
|
|
+ * card. If the card is unplugged, we get "invalid" then for
|
|
|
+ * card_ID and an -ENODEV error is returned for any command
|
|
|
+ * until a new card is targeted
|
|
|
+ *
|
|
|
+ * "<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> : acquires 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 complexifies the implementation
|
|
|
+ * a bit, but makes the arbiter more tolerant to userspace problems and able
|
|
|
+ * to properly cleanup in all cases when a process dies.
|
|
|
+ * Currently, a max of 16 cards simultaneously can have locks issued from
|
|
|
+ * userspace for a given user (file descriptor instance) of the arbiter.
|
|
|
+ *
|
|
|
+ * If the device is hot-unplugged, there is a hook inside the module to notify
|
|
|
+ * they being added/removed in the system and automatically added/removed in
|
|
|
+ * the arbiter.
|
|
|
+ */
|
|
|
+
|
|
|
+#define MAX_USER_CARDS 16
|
|
|
+#define PCI_INVALID_CARD ((struct pci_dev *)-1UL)
|
|
|
+
|
|
|
+/*
|
|
|
+ * Each user has an array of these, tracking which cards have locks
|
|
|
+ */
|
|
|
+struct vga_arb_user_card {
|
|
|
+ struct pci_dev *pdev;
|
|
|
+ unsigned int mem_cnt;
|
|
|
+ unsigned int io_cnt;
|
|
|
+};
|
|
|
+
|
|
|
+struct vga_arb_private {
|
|
|
+ struct list_head list;
|
|
|
+ struct pci_dev *target;
|
|
|
+ struct vga_arb_user_card cards[MAX_USER_CARDS];
|
|
|
+ spinlock_t lock;
|
|
|
+};
|
|
|
+
|
|
|
+static LIST_HEAD(vga_user_list);
|
|
|
+static DEFINE_SPINLOCK(vga_user_lock);
|
|
|
+
|
|
|
+
|
|
|
+/*
|
|
|
+ * This function gets a string in the format: "PCI:domain:bus:dev.fn" and
|
|
|
+ * returns the respective values. If the string is not in this format,
|
|
|
+ * it returns 0.
|
|
|
+ */
|
|
|
+static int vga_pci_str_to_vars(char *buf, int count, unsigned int *domain,
|
|
|
+ unsigned int *bus, unsigned int *devfn)
|
|
|
+{
|
|
|
+ int n;
|
|
|
+ unsigned int slot, func;
|
|
|
+
|
|
|
+
|
|
|
+ n = sscanf(buf, "PCI:%x:%x:%x.%x", domain, bus, &slot, &func);
|
|
|
+ if (n != 4)
|
|
|
+ return 0;
|
|
|
+
|
|
|
+ *devfn = PCI_DEVFN(slot, func);
|
|
|
+
|
|
|
+ return 1;
|
|
|
+}
|
|
|
+
|
|
|
+static ssize_t vga_arb_read(struct file *file, char __user * buf,
|
|
|
+ size_t count, loff_t *ppos)
|
|
|
+{
|
|
|
+ struct vga_arb_private *priv = file->private_data;
|
|
|
+ struct vga_device *vgadev;
|
|
|
+ struct pci_dev *pdev;
|
|
|
+ unsigned long flags;
|
|
|
+ size_t len;
|
|
|
+ int rc;
|
|
|
+ char *lbuf;
|
|
|
+
|
|
|
+ lbuf = kmalloc(1024, GFP_KERNEL);
|
|
|
+ if (lbuf == NULL)
|
|
|
+ return -ENOMEM;
|
|
|
+
|
|
|
+ /* Shields against vga_arb_device_card_gone (pci_dev going
|
|
|
+ * away), and allows access to vga list
|
|
|
+ */
|
|
|
+ spin_lock_irqsave(&vga_lock, flags);
|
|
|
+
|
|
|
+ /* If we are targetting the default, use it */
|
|
|
+ pdev = priv->target;
|
|
|
+ if (pdev == NULL || pdev == PCI_INVALID_CARD) {
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+ len = sprintf(lbuf, "invalid");
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Find card vgadev structure */
|
|
|
+ vgadev = vgadev_find(pdev);
|
|
|
+ if (vgadev == NULL) {
|
|
|
+ /* Wow, it's not in the list, that shouldn't happen,
|
|
|
+ * let's fix us up and return invalid card
|
|
|
+ */
|
|
|
+ if (pdev == priv->target)
|
|
|
+ vga_arb_device_card_gone(pdev);
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+ len = sprintf(lbuf, "invalid");
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Fill the buffer with infos */
|
|
|
+ len = snprintf(lbuf, 1024,
|
|
|
+ "count:%d,PCI:%s,decodes=%s,owns=%s,locks=%s(%d:%d)\n",
|
|
|
+ vga_decode_count, pci_name(pdev),
|
|
|
+ vga_iostate_to_str(vgadev->decodes),
|
|
|
+ vga_iostate_to_str(vgadev->owns),
|
|
|
+ vga_iostate_to_str(vgadev->locks),
|
|
|
+ vgadev->io_lock_cnt, vgadev->mem_lock_cnt);
|
|
|
+
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+done:
|
|
|
+
|
|
|
+ /* Copy that to user */
|
|
|
+ if (len > count)
|
|
|
+ len = count;
|
|
|
+ rc = copy_to_user(buf, lbuf, len);
|
|
|
+ kfree(lbuf);
|
|
|
+ if (rc)
|
|
|
+ return -EFAULT;
|
|
|
+ return len;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * TODO: To avoid parsing inside kernel and to improve the speed we may
|
|
|
+ * consider use ioctl here
|
|
|
+ */
|
|
|
+static ssize_t vga_arb_write(struct file *file, const char __user * buf,
|
|
|
+ size_t count, loff_t *ppos)
|
|
|
+{
|
|
|
+ struct vga_arb_private *priv = file->private_data;
|
|
|
+ struct vga_arb_user_card *uc = NULL;
|
|
|
+ struct pci_dev *pdev;
|
|
|
+
|
|
|
+ unsigned int io_state;
|
|
|
+
|
|
|
+ char *kbuf, *curr_pos;
|
|
|
+ size_t remaining = count;
|
|
|
+
|
|
|
+ int ret_val;
|
|
|
+ int i;
|
|
|
+
|
|
|
+
|
|
|
+ kbuf = kmalloc(count + 1, GFP_KERNEL);
|
|
|
+ if (!kbuf)
|
|
|
+ return -ENOMEM;
|
|
|
+
|
|
|
+ if (copy_from_user(kbuf, buf, count)) {
|
|
|
+ kfree(kbuf);
|
|
|
+ return -EFAULT;
|
|
|
+ }
|
|
|
+ curr_pos = kbuf;
|
|
|
+ kbuf[count] = '\0'; /* Just to make sure... */
|
|
|
+
|
|
|
+ if (strncmp(curr_pos, "lock ", 5) == 0) {
|
|
|
+ curr_pos += 5;
|
|
|
+ remaining -= 5;
|
|
|
+
|
|
|
+ pr_devel("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_devel("client 0x%p called 'unlock'\n", priv);
|
|
|
+
|
|
|
+ if (strncmp(curr_pos, "all", 3) == 0)
|
|
|
+ io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
|
|
|
+ else {
|
|
|
+ if (!vga_str_to_iostate
|
|
|
+ (curr_pos, remaining, &io_state)) {
|
|
|
+ ret_val = -EPROTO;
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+ /* TODO: Add this?
|
|
|
+ if (io_state == VGA_RSRC_NONE) {
|
|
|
+ ret_val = -EPROTO;
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+ */
|
|
|
+ }
|
|
|
+
|
|
|
+ pdev = priv->target;
|
|
|
+ if (priv->target == NULL) {
|
|
|
+ ret_val = -ENODEV;
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+ for (i = 0; i < MAX_USER_CARDS; i++) {
|
|
|
+ if (priv->cards[i].pdev == pdev)
|
|
|
+ uc = &priv->cards[i];
|
|
|
+ }
|
|
|
+
|
|
|
+ if (!uc)
|
|
|
+ return -EINVAL;
|
|
|
+
|
|
|
+ if (io_state & VGA_RSRC_LEGACY_IO && uc->io_cnt == 0)
|
|
|
+ return -EINVAL;
|
|
|
+
|
|
|
+ if (io_state & VGA_RSRC_LEGACY_MEM && uc->mem_cnt == 0)
|
|
|
+ return -EINVAL;
|
|
|
+
|
|
|
+ vga_put(pdev, io_state);
|
|
|
+
|
|
|
+ if (io_state & VGA_RSRC_LEGACY_IO)
|
|
|
+ uc->io_cnt--;
|
|
|
+ if (io_state & VGA_RSRC_LEGACY_MEM)
|
|
|
+ uc->mem_cnt--;
|
|
|
+
|
|
|
+ ret_val = count;
|
|
|
+ goto done;
|
|
|
+ } else if (strncmp(curr_pos, "trylock ", 8) == 0) {
|
|
|
+ curr_pos += 8;
|
|
|
+ remaining -= 8;
|
|
|
+
|
|
|
+ pr_devel("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_devel("client 0x%p called 'target'\n", priv);
|
|
|
+ /* if target is default */
|
|
|
+ if (!strncmp(buf, "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_bus_and_slot(bus, devfn);
|
|
|
+ if (!pdev) {
|
|
|
+ pr_info("vgaarb: invalid PCI address!\n");
|
|
|
+ ret_val = -ENODEV;
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ vgadev = vgadev_find(pdev);
|
|
|
+ if (vgadev == NULL) {
|
|
|
+ pr_info("vgaarb: this pci device is not a vga device\n");
|
|
|
+ pci_dev_put(pdev);
|
|
|
+ ret_val = -ENODEV;
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+
|
|
|
+ priv->target = pdev;
|
|
|
+ for (i = 0; i < MAX_USER_CARDS; i++) {
|
|
|
+ if (priv->cards[i].pdev == pdev)
|
|
|
+ break;
|
|
|
+ if (priv->cards[i].pdev == NULL) {
|
|
|
+ priv->cards[i].pdev = pdev;
|
|
|
+ priv->cards[i].io_cnt = 0;
|
|
|
+ priv->cards[i].mem_cnt = 0;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ if (i == MAX_USER_CARDS) {
|
|
|
+ pr_err("vgaarb: maximum user cards number reached!\n");
|
|
|
+ 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_devel("vgaarb: client 0x%p called 'decodes'\n", priv);
|
|
|
+
|
|
|
+ if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) {
|
|
|
+ ret_val = -EPROTO;
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+ pdev = priv->target;
|
|
|
+ if (priv->target == NULL) {
|
|
|
+ ret_val = -ENODEV;
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+
|
|
|
+ __vga_set_legacy_decoding(pdev, io_state, true);
|
|
|
+ ret_val = count;
|
|
|
+ goto done;
|
|
|
+ }
|
|
|
+ /* If we got here, the message written is not part of the protocol! */
|
|
|
+ kfree(kbuf);
|
|
|
+ return -EPROTO;
|
|
|
+
|
|
|
+done:
|
|
|
+ kfree(kbuf);
|
|
|
+ return ret_val;
|
|
|
+}
|
|
|
+
|
|
|
+static unsigned int vga_arb_fpoll(struct file *file, poll_table * wait)
|
|
|
+{
|
|
|
+ struct vga_arb_private *priv = file->private_data;
|
|
|
+
|
|
|
+ pr_devel("%s\n", __func__);
|
|
|
+
|
|
|
+ if (priv == NULL)
|
|
|
+ return -ENODEV;
|
|
|
+ poll_wait(file, &vga_wait_queue, wait);
|
|
|
+ return POLLIN;
|
|
|
+}
|
|
|
+
|
|
|
+static int vga_arb_open(struct inode *inode, struct file *file)
|
|
|
+{
|
|
|
+ struct vga_arb_private *priv;
|
|
|
+ unsigned long flags;
|
|
|
+
|
|
|
+ pr_devel("%s\n", __func__);
|
|
|
+
|
|
|
+ priv = kmalloc(sizeof(struct vga_arb_private), GFP_KERNEL);
|
|
|
+ if (priv == NULL)
|
|
|
+ return -ENOMEM;
|
|
|
+ memset(priv, 0, sizeof(*priv));
|
|
|
+ spin_lock_init(&priv->lock);
|
|
|
+ file->private_data = priv;
|
|
|
+
|
|
|
+ spin_lock_irqsave(&vga_user_lock, flags);
|
|
|
+ list_add(&priv->list, &vga_user_list);
|
|
|
+ spin_unlock_irqrestore(&vga_user_lock, flags);
|
|
|
+
|
|
|
+ /* Set the client' lists of locks */
|
|
|
+ priv->target = vga_default_device(); /* Maybe this is still null! */
|
|
|
+ priv->cards[0].pdev = priv->target;
|
|
|
+ priv->cards[0].io_cnt = 0;
|
|
|
+ priv->cards[0].mem_cnt = 0;
|
|
|
+
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+static int vga_arb_release(struct inode *inode, struct file *file)
|
|
|
+{
|
|
|
+ struct vga_arb_private *priv = file->private_data;
|
|
|
+ struct vga_arb_user_card *uc;
|
|
|
+ unsigned long flags;
|
|
|
+ int i;
|
|
|
+
|
|
|
+ pr_devel("%s\n", __func__);
|
|
|
+
|
|
|
+ if (priv == NULL)
|
|
|
+ return -ENODEV;
|
|
|
+
|
|
|
+ spin_lock_irqsave(&vga_user_lock, flags);
|
|
|
+ list_del(&priv->list);
|
|
|
+ for (i = 0; i < MAX_USER_CARDS; i++) {
|
|
|
+ uc = &priv->cards[i];
|
|
|
+ if (uc->pdev == NULL)
|
|
|
+ continue;
|
|
|
+ pr_devel("uc->io_cnt == %d, uc->mem_cnt == %d\n",
|
|
|
+ uc->io_cnt, uc->mem_cnt);
|
|
|
+ while (uc->io_cnt--)
|
|
|
+ vga_put(uc->pdev, VGA_RSRC_LEGACY_IO);
|
|
|
+ while (uc->mem_cnt--)
|
|
|
+ vga_put(uc->pdev, VGA_RSRC_LEGACY_MEM);
|
|
|
+ }
|
|
|
+ spin_unlock_irqrestore(&vga_user_lock, flags);
|
|
|
+
|
|
|
+ kfree(priv);
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+static void vga_arb_device_card_gone(struct pci_dev *pdev)
|
|
|
+{
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * callback any registered clients to let them know we have a
|
|
|
+ * change in VGA cards
|
|
|
+ */
|
|
|
+static void vga_arbiter_notify_clients(void)
|
|
|
+{
|
|
|
+ struct vga_device *vgadev;
|
|
|
+ unsigned long flags;
|
|
|
+ uint32_t new_decodes;
|
|
|
+ bool new_state;
|
|
|
+
|
|
|
+ if (!vga_arbiter_used)
|
|
|
+ return;
|
|
|
+
|
|
|
+ spin_lock_irqsave(&vga_lock, flags);
|
|
|
+ list_for_each_entry(vgadev, &vga_list, list) {
|
|
|
+ if (vga_count > 1)
|
|
|
+ new_state = false;
|
|
|
+ else
|
|
|
+ new_state = true;
|
|
|
+ if (vgadev->set_vga_decode) {
|
|
|
+ new_decodes = vgadev->set_vga_decode(vgadev->cookie, new_state);
|
|
|
+ vga_update_device_decodes(vgadev, new_decodes);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ spin_unlock_irqrestore(&vga_lock, flags);
|
|
|
+}
|
|
|
+
|
|
|
+static int pci_notify(struct notifier_block *nb, unsigned long action,
|
|
|
+ void *data)
|
|
|
+{
|
|
|
+ struct device *dev = data;
|
|
|
+ struct pci_dev *pdev = to_pci_dev(dev);
|
|
|
+ bool notify = false;
|
|
|
+
|
|
|
+ pr_devel("%s\n", __func__);
|
|
|
+
|
|
|
+ /* For now we're only intereted in devices added and removed. I didn't
|
|
|
+ * test this thing here, so someone needs to double check for the
|
|
|
+ * cases of hotplugable vga cards. */
|
|
|
+ if (action == BUS_NOTIFY_ADD_DEVICE)
|
|
|
+ notify = vga_arbiter_add_pci_device(pdev);
|
|
|
+ else if (action == BUS_NOTIFY_DEL_DEVICE)
|
|
|
+ notify = vga_arbiter_del_pci_device(pdev);
|
|
|
+
|
|
|
+ if (notify)
|
|
|
+ vga_arbiter_notify_clients();
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+static struct notifier_block pci_notifier = {
|
|
|
+ .notifier_call = pci_notify,
|
|
|
+};
|
|
|
+
|
|
|
+static const struct file_operations vga_arb_device_fops = {
|
|
|
+ .read = vga_arb_read,
|
|
|
+ .write = vga_arb_write,
|
|
|
+ .poll = vga_arb_fpoll,
|
|
|
+ .open = vga_arb_open,
|
|
|
+ .release = vga_arb_release,
|
|
|
+};
|
|
|
+
|
|
|
+static struct miscdevice vga_arb_device = {
|
|
|
+ MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops
|
|
|
+};
|
|
|
+
|
|
|
+static int __init vga_arb_device_init(void)
|
|
|
+{
|
|
|
+ int rc;
|
|
|
+ struct pci_dev *pdev;
|
|
|
+
|
|
|
+ rc = misc_register(&vga_arb_device);
|
|
|
+ if (rc < 0)
|
|
|
+ pr_err("vgaarb: error %d registering device\n", rc);
|
|
|
+
|
|
|
+ bus_register_notifier(&pci_bus_type, &pci_notifier);
|
|
|
+
|
|
|
+ /* We add all pci devices satisfying vga class in the arbiter by
|
|
|
+ * default */
|
|
|
+ pdev = NULL;
|
|
|
+ while ((pdev =
|
|
|
+ pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
|
|
|
+ PCI_ANY_ID, pdev)) != NULL)
|
|
|
+ vga_arbiter_add_pci_device(pdev);
|
|
|
+
|
|
|
+ pr_info("vgaarb: loaded\n");
|
|
|
+ return rc;
|
|
|
+}
|
|
|
+subsys_initcall(vga_arb_device_init);
|