Re: radeon-pre-2

Jon Smirl
2004-09-13T15:12:17Z

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On Mon, 13 Sep 2004 12:26:33 +0100, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> Well this is what I came up with so far. It creates a vga class so you
> can bind the drivers to functions of the card (and we can add/remove
> functions later as appropriate), tells functions about each other and
> now implements Linux lock proposal as I understood it.

It needs something to sort out both drivers attaching to the IRQ.

It also needs something to sort out both drivers using pci_drvdata()
to get to their private data. For example in the hotplug routines you
only get passed a pdev and you want to use that to locate your private
data.

It also needs to track pci_enable_device() so that if one driver
unloads it won't turn the device off for the other driver.

VGA routing needs to be supported. I attached the code I was writing
for that. I was in the middle of writing it so it doesn't compile.
This code should be integrated into the VGA driver.

It needs to integrate into VGAcon. VGAcon should require the vga
device before loading. The resource reservation code in VGAcon needs
to be moved to the VGA driver. If you use a command to switch the
active VGA device, VGAcon needs to reset itself for the new device.

VGA driver needs to generate hotplug events for the VGA device that
indicate if they are primary or secondary. If they are secondary there
needs to be a user space reset program that uses the new ROM hooks to
reset the card.

It should support more than two drivers, I forgot to check, does it already?

fbdev takes a snapshot of the video registers when it loads. When you
unload it it writes those registers back. That doesn't work if you
load from an xterm and rmmod it from the command line. It snapshots
the card in graphics mode and then restores it in an environment
expecting text mode.

Something needs to be done for DMA processing. What if I get an
interrupt that the DMA queue has been completed but we've switched to
a driver that doesn't understand DMA? I guess the only safe thing to
do is make sure all DMA queue are finished before releasing control.

--
Jon Smirl
jonsmirl@gmail.com

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===== arch/i386/pci/fixup.c 1.21 vs edited =====
--- 1.21/arch/i386/pci/fixup.c Sun Aug 29 00:21:23 2004
+++ edited/arch/i386/pci/fixup.c Fri Sep 10 01:03:06 2004
@@ -225,7 +225,7 @@
* issue another HALT within 80 ns of the initial HALT, the failure condition
* is avoided.
*/
-static void __init pci_fixup_nforce2(struct pci_dev *dev)
+static void __devinit pci_fixup_nforce2(struct pci_dev *dev)
{
u32 val, fixed_val;
u8 rev;
@@ -290,6 +290,6 @@
}
bus = bus->parent;
}
- pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
+ pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW | IORESOURCE_VGA_ENABLE;
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_video);
===== drivers/pci/Kconfig 1.6 vs edited =====
--- 1.6/drivers/pci/Kconfig Mon Aug 2 04:00:43 2004
+++ edited/drivers/pci/Kconfig Fri Sep 10 01:03:06 2004
@@ -47,3 +47,13 @@

When in doubt, say Y.

+config VGA_CONTROL
+ bool "VGA Control Device"
+ depends on PCI
+ ---help---
+ Provides a VGA Control Device for ensuring that only a single VGA
+ device can be enabled per PCI domain. If a VGA device is removed
+ via hotplug, display is routed to another VGA device if available.
+
+ If you have more than one VGA device, say Y.
+
===== drivers/pci/Makefile 1.41 vs edited =====
--- 1.41/drivers/pci/Makefile Sun Aug 29 00:21:23 2004
+++ edited/drivers/pci/Makefile Sat Sep 11 22:44:22 2004
@@ -28,6 +28,7 @@
obj-$(CONFIG_MIPS) += setup-bus.o setup-irq.o
obj-$(CONFIG_X86_VISWS) += setup-irq.o
obj-$(CONFIG_PCI_MSI) += msi.o
+obj-$(CONFIG_VGA_CONTROL) += vga.o

# Cardbus & CompactPCI use setup-bus
obj-$(CONFIG_HOTPLUG) += setup-bus.o
===== drivers/pci/bus.c 1.9 vs edited =====
--- 1.9/drivers/pci/bus.c Sat Apr 10 18:27:59 2004
+++ edited/drivers/pci/bus.c Sat Sep 11 22:48:04 2004
@@ -100,7 +100,9 @@

pci_proc_attach_device(dev);
pci_create_sysfs_dev_files(dev);
-
+#if CONFIG_VGA_DEVICE
+ pci_vga_add_device(dev);
+#endif
}

list_for_each_entry(dev, &bus->devices, bus_list) {
===== drivers/pci/pci.h 1.13 vs edited =====
--- 1.13/drivers/pci/pci.h Sun Aug 29 00:21:23 2004
+++ edited/drivers/pci/pci.h Fri Sep 10 01:03:08 2004
@@ -11,6 +11,7 @@
void (*alignf)(void *, struct resource *,
unsigned long, unsigned long),
void *alignf_data);
+int pci_vga_add_device(struct pci_dev *pdev);
/* PCI /proc functions */
#ifdef CONFIG_PROC_FS
extern int pci_proc_attach_device(struct pci_dev *dev);
===== drivers/pci/setup-bus.c 1.25 vs edited =====
--- 1.25/drivers/pci/setup-bus.c Sun Jul 11 08:41:20 2004
+++ edited/drivers/pci/setup-bus.c Fri Sep 10 01:03:09 2004
@@ -51,16 +51,8 @@
struct resource_list head, *list, *tmp;
int idx;

- bus->bridge_ctl &= ~PCI_BRIDGE_CTL_VGA;
-
head.next = NULL;
list_for_each_entry(dev, &bus->devices, bus_list) {
- u16 class = dev->class >> 8;
-
- if (class == PCI_CLASS_DISPLAY_VGA
- || class == PCI_CLASS_NOT_DEFINED_VGA)
- bus->bridge_ctl |= PCI_BRIDGE_CTL_VGA;
-
pdev_sort_resources(dev, &head);
}

@@ -499,12 +491,6 @@

pbus_assign_resources_sorted(bus);

- if (bus->bridge_ctl & PCI_BRIDGE_CTL_VGA) {
- /* Propagate presence of the VGA to upstream bridges */
- for (b = bus; b->parent; b = b->parent) {
- b->bridge_ctl |= PCI_BRIDGE_CTL_VGA;
- }
- }
list_for_each_entry(dev, &bus->devices, bus_list) {
b = dev->subordinate;
if (!b)
===== drivers/pci/vga.c 1.1 vs edited =====
--- 1.1/drivers/pci/vga.c Fri Sep 10 01:01:47 2004
+++ edited/drivers/pci/vga.c Sat Sep 11 01:05:37 2004
@@ -1 +1,381 @@
+/*
+ * linux/drivers/char/vga.c
+ *
+ * (C) Copyright 2004 Jon Smirl <jonsmirl@gmail.com>
+ *
+ * VGA control device for ensuring only a single enabled VGA device
+ *
+ * Reuses the DRM major 226, starts minors at VGA_MINOR_BASE, 0x200
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/pci.h>
+#include <linux/major.h>
+#include <linux/vga.h>
+
+struct vga_dev {
+ struct class_device class_dev;
+ struct list_head node;
+ dev_t dev;
+ int enabled;
+};
+#define to_vga_dev(d) container_of(d, struct vga_dev, class_dev)
+
+static struct class *vga_class;
+static struct vga_dev *vga_device;
+static DECLARE_MUTEX(vga_mutex);
+static int vga_initialized; /* = 0 */
+
+/*
+ * Open/close code for vga IO.
+ */
+static int vga_open(struct inode *inode, struct file *filp)
+{
+// const int minor = iminor(inode);
+
+ down(&vga_mutex);
+ up(&vga_mutex);
+
+ return 0;
+}
+
+/*
+ */
+static int vga_release(struct inode *inode, struct file *filp)
+{
+ down(&vga_mutex);
+ up(&vga_mutex);
+
+ return 0;
+}
+
+/*
+ */
+static int
+vga_ioctl(struct inode *inode, struct file *filp,
+ unsigned int command, unsigned long arg)
+{
+ return 0;
+}
+
+static struct file_operations vga_fops = {
+ .open = vga_open,
+ .release= vga_release,
+ .ioctl = vga_ioctl,
+ .owner = THIS_MODULE,
+};
+
+static struct cdev vga_cdev = {
+ .kobj = {.name = "vga", },
+ .owner = THIS_MODULE,
+};
+
+static void bridge_yes(drm_device_t *dev)
+{
+ struct pci_dev *bridge;
+ struct pci_bus *bus;
+
+ /* Make sure the bridges route to us */
+ bus = dev->pdev->bus;
+ while (bus) {
+ bridge = bus->self;
+ if (bridge) {
+ pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &pbus->bridge_ctl);
+ pbus->bridge_ctl |= PCI_BRIDGE_CTL_VGA;
+ pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, pbus->bridge_ctl);
+ }
+ bus = bus->parent;
+ }
+}
+
+static void bridge_no(drm_device_t *dev)
+{
+ struct pci_dev *bridge;
+ struct pci_bus *bus;
+
+ /* Make sure the bridges don't route to us */
+ bus = dev->pdev->bus;
+ while (bus) {
+ bridge = bus->self;
+ if (bridge) {
+ pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &pbus->bridge_ctl);
+ pbus->bridge_ctl &= ~PCI_BRIDGE_CTL_VGA;
+ pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, pbus->bridge_ctl);
+ }
+ bus = bus->parent;
+ }
+}
+
+
+/* sysfs for VGA device */
+static ssize_t vga_device_show(struct device *dev, char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ return sprintf(bus, "%d\n", (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_VGA_ENABLE) != 0);
+}
+static ssize_t vga_device_store(struct device *dev, const char *buf, size_t count)
+{
+ return count;
+}
+static struct device_attribute vga_device_attr = __ATTR(vga, S_IRUGO|S_IWUSR, vga_device_show, vga_device_store);
+
+/* sysfs for VGA routing bridge */
+static ssize_t vga_bridge_show(struct device *dev, char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ u16 l;
+
+ /* don't trust the shadow PCI_BRIDGE_CTL_VGA in pdev */
+ /* user space may change hardware without telling the kernel */
+ pci_read_config_word(pdev, PCI_BRIDGE_CONTROL, &l);
+ return sprintf(buf, "%d\n", (l & PCI_BRIDGE_CTL_VGA) != 0);
+}
+static struct device_attribute vga_bridge_attr = __ATTR(vga, S_IRUGO, vga_bridge_show, NULL);
+
+/* sysfs for VGA root legacy space */
+static ssize_t vga_root_show(struct class_device *class_dev, char *buf)
+{
+ struct vga_dev *vga = to_vga_dev(class_dev);
+ return sprintf(buf, "%d\n", vga->enabled);
+}
+static ssize_t vga_root_store(struct class_device *class_dev, const char *buf, size_t count)
+{
+ char *endp;
+ struct vga_dev *vga = to_vga_dev(class_dev);
+
+ vga->enabled = (simple_strtoul(buf, &endp, 0) != 0);
+ return count;
+}
+static struct class_device_attribute vga_root_attr = __ATTR(vga, S_IRUGO|S_IWUSR, vga_root_show, vga_root_store);
+
+/* sysfs for /class/vga/vga0/dev */
+static ssize_t show_dev(struct class_device *class_dev, char *buf)
+{
+ struct vga_dev *vga = to_vga_dev(class_dev);
+ return print_dev_t(buf, vga->dev);
+}
+CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL);
+
+int pci_vga_add_device(struct pci_dev *pdev)
+{
+ char name[20];
+ int class = pdev->class >> 8;
+
+ if (!vga_initialized)
+ return -EACCES;
+
+ if (class == PCI_CLASS_DISPLAY_VGA) {
+ device_create_file(&pdev->dev, &vga_device_attr);
+ snprintf(name, sizeof(name), "%04x:%02x:%02x.%d", pci_domain_nr(pdev->bus),
+ pdev->bus->number, PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
+ sysfs_create_link(&vga_device->class_dev.kobj, &pdev->dev.kobj, name);
+ return 0;
+ }
+
+ if ((class == PCI_CLASS_BRIDGE_PCI) || (class == PCI_CLASS_BRIDGE_CARDBUS)) {
+ device_create_file(&pdev->dev, &vga_bridge_attr);
+ }
+
+ return 0;
+}
+
+static int __init vga_init(void)
+{
+ int ret;
+ dev_t dev;
+ int minor = 0;
+ struct pci_dev *pdev = NULL;
+
+ vga_initialized = 1;
+ dev = MKDEV(DRM_MAJOR, VGA_MINOR_BASE);
+
+ if (register_chrdev_region(dev, VGA_MINOR_MAX, "vga"))
+ goto err_i1;
+
+ cdev_init(&vga_cdev, &vga_fops);
+ if (cdev_add(&vga_cdev, dev, VGA_MINOR_MAX)) {
+ kobject_put(&vga_cdev.kobj);
+ goto err_i2;
+ }
+
+ vga_class = kmalloc(sizeof(*vga_class), GFP_KERNEL);
+ if (!vga_class)
+ goto err_i3;
+ memset(vga_class, 0x00, sizeof(*vga_class));
+
+ vga_class->name = "vga";
+ if ((ret = class_register(vga_class)))
+ goto err_i4;
+
+ vga_device = kmalloc(sizeof(*vga_device), GFP_KERNEL);
+ if (!vga_device)
+ goto err_i5;
+ memset(vga_device, 0x00, sizeof(*vga_device));
+
+ vga_device->dev = MKDEV(DRM_MAJOR, VGA_MINOR_BASE + minor);
+ vga_device->class_dev.dev = NULL;
+ vga_device->class_dev.class = vga_class;
+ snprintf(vga_device->class_dev.class_id, BUS_ID_SIZE, "vga%d", minor);
+
+ if ((ret = class_device_register(&vga_device->class_dev)))
+ goto err_i6;
+
+ class_device_create_file(&vga_device->class_dev, &class_device_attr_dev);
+ class_device_create_file(&vga_device->class_dev, &vga_root_attr);
+
+ while ((pdev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, pdev)) != NULL)
+ pci_vga_add_device(pdev);
+
+ printk(KERN_INFO "VGA control device 1.0 initialized\n");
+
+ return 0;
+
+err_i6:
+ kfree(vga_device);
+err_i5:
+ class_unregister(vga_class);
+err_i4:
+ kfree(vga_class);
+err_i3:
+ cdev_del(&vga_cdev);
+err_i2:
+ unregister_chrdev_region(dev, VGA_MINOR_MAX);
+err_i1:
+ printk(KERN_ERR "error initializing VGA control device\n");
+ return 1;
+}
+
+static void __exit vga_exit(void)
+{
+ class_device_unregister(&vga_device->class_dev);
+ kfree(vga_device);
+ class_unregister(vga_class);
+ kfree(vga_class);
+ cdev_del(&vga_cdev);
+ unregister_chrdev_region(MKDEV(DRM_MAJOR, VGA_MINOR_BASE), VGA_MINOR_MAX);
+}
+
+__initcall(vga_init);
+__exitcall(vga_exit);
+
+
+
+/*
+ * 0 - Disable all VGA and cards
+ * 1 - Enable only active card and VGA (assumes other devices are disabled)
+ * 2 - Enable all pci devices
+ *
+ * This is a driver specific function accessed via DRM(stub)
+ * doing it this way allows for driver specific overrides if needed
+ */
+#define VE_DISABLE 0
+#define VE_ACTIVE 1
+#define VE_ENABLE 2
+int DRM(vgaenable)(int enable, int clear_active) {
+ int i;
+ drm_device_t *dev;
+
+ switch (enable) {
+ case VE_DISABLE:
+ /* disable all VGA and all devices */
+ /* loop over all the driver's cards */
+ for (i = 0; i < DRM(numdevs); i++) {
+ dev = &DRM(device)[i];
+ if (clear_active)
+ dev->vga_active = FALSE;
+
+ bridge_yes(dev);
+ /* 0x3CC and 0x3C2 are correct, it's not a typo */
+ outb(~0x03 & inb(0x3CC), 0x3C2);
+ outb(~0x01 & inb(0x3C3), 0x3C3);
+ outb(~0x08 & inb(0x46e8), 0x46e8);
+ outb(~0x01 & inb(0x102), 0x102);
+ pci_disable_device(dev->pdev);
+ bridge_no(dev);
+ }
+ return 0;
+ case VE_ACTIVE:
+ /* enable device and VGA on active device */
+ /* loop over all the driver's cards */
+ for (i = 0; i < DRM(numdevs); i++) {
+ dev = &DRM(device)[i];
+ if (!dev->vga_active)
+ continue;
+ /* this assumes all other potential VGA devices are disabled */
+ bridge_yes(dev);
+ pci_enable_device(dev->pdev);
+ /* 0x3CC and 0x3C2 are correct, it's not a typo */
+ outb(0x03 | inb(0x3CC), 0x3C2);
+ outb(0x01 | inb(0x3C3), 0x3C3);
+ outb(0x08 | inb(0x46e8), 0x46e8);
+ outb(0x01 | inb(0x102), 0x102);
+ return 0;
+ }
+ return 0;
+ case VE_ENABLE:
+ /* loop over all the driver's cards */
+ for (i = 0; i < DRM(numdevs); i++) {
+ dev = &DRM(device)[i];
+ pci_enable_device(dev->pdev);
+ }
+ return 0;
+ default:
+ return -1;
+ }
+}
+
+/*
+ * VGA_ENABLE_ACTIVE=0 - Make sure all DRM VGAs are disabled, if this one not active reenable active VGA
+ * VGA_ENABLE_THIS=1 - Make sure all DRM VGAs are disabled and enable this DRM VGA, mark as active VGA
+ * Used while resetting a board
+ * VGA_DISABLE_ALL=2 - Disable all DRM VGA and devices, remember active VGA
+ */
+int DRM(vga_enable)( DRM_IOCTL_ARGS ) {
+ DRM_DEVICE;
+ drm_file_t *filp_priv;
+ drm_vga_enable_t ve;
+ struct drm_stub_info *pStub;
+
+ DRM_GET_PRIV_WITH_RETURN( filp_priv, filp );
+
+ DRM_COPY_FROM_USER_IOCTL( ve, ( drm_vga_enable_t* )data, sizeof( ve ) );
+
+ if ((ve.enable < VGA_ENABLE_ACTIVE) || (ve.enable > VGA_DISABLE_ALL))
+ return -1;
+
+ /* First disable all VGA and all devices */
+ /* loop over all drivers */
+ pStub = &DRM(stub_info);
+ do {
+ /* clear the active device if enable 1 */
+ pStub->vgaenable(VE_DISABLE, (ve.enable == VGA_ENABLE_THIS));
+ pStub = pStub->next;
+ } while (pStub != &DRM(stub_info));
+
+ if (ve.enable == VGA_DISABLE_ALL)
+ return 0;
+
+ /* Mark us active if requested */
+ if (ve.enable == VGA_ENABLE_THIS)
+ dev->vga_active = TRUE;
+
+ /* Now enable VGA on the target device */
+ /* loop over all drivers; don't know where the device is */
+ pStub = &DRM(stub_info);
+ do {
+ pStub->vgaenable(VE_ACTIVE, 0);
+ pStub = pStub->next;
+ } while (pStub != &DRM(stub_info));
+
+ /* Reenable all PCI devices but don't touch VGA state */
+ pStub = &DRM(stub_info);
+ do {
+ pStub->vgaenable(VE_ENABLE, 0);
+ pStub = pStub->next;
+ } while (pStub != &DRM(stub_info));
+
+ return 0;
+}

===== include/linux/ioport.h 1.15 vs edited =====
--- 1.15/include/linux/ioport.h Sun Aug 29 00:21:23 2004
+++ edited/include/linux/ioport.h Fri Sep 10 01:03:10 2004
@@ -41,7 +41,6 @@
#define IORESOURCE_CACHEABLE 0x00004000
#define IORESOURCE_RANGELENGTH 0x00008000
#define IORESOURCE_SHADOWABLE 0x00010000
-#define IORESOURCE_BUS_HAS_VGA 0x00080000

#define IORESOURCE_DISABLED 0x10000000
#define IORESOURCE_UNSET 0x20000000
@@ -86,6 +85,7 @@
#define IORESOURCE_ROM_ENABLE (1<<0) /* ROM is enabled, same as PCI_ROM_ADDRESS_ENABLE */
#define IORESOURCE_ROM_SHADOW (1<<1) /* ROM is copy at C000:0 */
#define IORESOURCE_ROM_COPY (1<<2) /* ROM is alloc'd copy, resource field overlaid */
+#define IORESOURCE_VGA_ENABLE (1<<3) /* VGA device is active */

/* PC/ISA/whatever - the normal PC address spaces: IO and memory */
extern struct resource ioport_resource;
===== include/linux/major.h 1.12 vs edited =====
--- 1.12/include/linux/major.h Fri Mar 19 00:59:29 2004
+++ edited/include/linux/major.h Fri Sep 10 21:29:53 2004
@@ -160,6 +160,7 @@

#define OSST_MAJOR 206 /* OnStream-SCx0 SCSI tape */

+#define DRM_MAJOR 226 /* Direct Rendering Manager */
#define IBM_TTY3270_MAJOR 227
#define IBM_FS3270_MAJOR 228

===== include/linux/vga.h 1.1 vs edited =====
--- 1.1/include/linux/vga.h Fri Sep 10 01:01:47 2004
+++ edited/include/linux/vga.h Fri Sep 10 21:41:00 2004
@@ -1 +1,14 @@
+/*
+ * include/linux/vga.h
+ *
+ * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
+ *
+ * VGA control device for ensuring only a single enabled VGA device
+ */

+/* VGA device shares it's major device number with the DRM devices */
+/* DRM_MAJOR defines the major number in major.h */
+
+#define VGA_MINOR_BASE 0x200 /* First VGA minor starts here */
+#define VGA_MINOR_MAX 16
+