If we load a real hardware DRM driver, we want all firmware drivers to be unloaded. Historically, this was done via remove_conflicting_framebuffers(), but for DRM drivers (like SimpleDRM) we need a new way.
This patch introduces DRIVER_FIRMWARE and DRM apertures to provide a quite similar way to kick out firmware DRM drivers. Additionally, unlike the fbdev equivalent, DRM firmware drivers can now query the system whether a real hardware driver is already loaded and prevent loading themselves.
Whenever a real hardware DRM driver is loaded which claims to provide the boot fw FB, we invalidate the firmware framebuffer. Otherwise, simpledrm could be loaded again, after a real hw-driver was unloaded (which is very unlikely to work, except if hw-drivers reset fw FBs during unload). Note that fbdev doesn't provide such protection against late driver probing.
Signed-off-by: David Herrmann dh.herrmann@gmail.com Tested-by: Stephen Warren swarren@nvidia.com --- drivers/gpu/drm/drm_pci.c | 1 + drivers/gpu/drm/drm_platform.c | 1 + drivers/gpu/drm/drm_stub.c | 118 +++++++++++++++++++++++++++++ drivers/gpu/drm/drm_usb.c | 1 + drivers/gpu/drm/simpledrm/simpledrm.h | 1 + drivers/gpu/drm/simpledrm/simpledrm_drv.c | 3 +- drivers/gpu/drm/simpledrm/simpledrm_main.c | 33 ++++++++ include/drm/drmP.h | 26 +++++++ 8 files changed, 183 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c index 1f96cee..f3de4d6 100644 --- a/drivers/gpu/drm/drm_pci.c +++ b/drivers/gpu/drm/drm_pci.c @@ -378,6 +378,7 @@ int drm_get_pci_dev(struct pci_dev *pdev, const struct pci_device_id *ent, }
list_add_tail(&dev->driver_item, &driver->device_list); + list_add_tail(&dev->global_item, &drm_devlist);
DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n", driver->name, driver->major, driver->minor, driver->patchlevel, diff --git a/drivers/gpu/drm/drm_platform.c b/drivers/gpu/drm/drm_platform.c index f7a18c6..a287429 100644 --- a/drivers/gpu/drm/drm_platform.c +++ b/drivers/gpu/drm/drm_platform.c @@ -94,6 +94,7 @@ static int drm_get_platform_dev(struct platform_device *platdev, }
list_add_tail(&dev->driver_item, &driver->device_list); + list_add_tail(&dev->global_item, &drm_devlist);
mutex_unlock(&drm_global_mutex);
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c index e7eb027..363e47b 100644 --- a/drivers/gpu/drm/drm_stub.c +++ b/drivers/gpu/drm/drm_stub.c @@ -49,6 +49,10 @@ EXPORT_SYMBOL(drm_vblank_offdelay); unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */ EXPORT_SYMBOL(drm_timestamp_precision);
+static bool drm_fw_invalid; /* true if fw FBs have been destroyed */ +LIST_HEAD(drm_devlist); /* device list; protected by global lock */ +EXPORT_SYMBOL(drm_devlist); + /* * Default to use monotonic timestamps for wait-for-vblank and page-flip * complete events. @@ -459,7 +463,9 @@ void drm_put_dev(struct drm_device *dev)
drm_put_minor(&dev->primary);
+ list_del(&dev->global_item); list_del(&dev->driver_item); + kfree(dev->apertures); kfree(dev->devname); kfree(dev); } @@ -484,3 +490,115 @@ void drm_unplug_dev(struct drm_device *dev) mutex_unlock(&drm_global_mutex); } EXPORT_SYMBOL(drm_unplug_dev); + +void drm_unplug_dev_locked(struct drm_device *dev) +{ + /* for a USB device */ + if (drm_core_check_feature(dev, DRIVER_MODESET)) + drm_unplug_minor(dev->control); + drm_unplug_minor(dev->primary); + + drm_device_set_unplugged(dev); + + /* TODO: schedule drm_put_dev if open_count == 0 */ +} +EXPORT_SYMBOL(drm_unplug_dev_locked); + +#define VGA_FB_PHYS 0xa0000 + +static bool apertures_overlap(struct drm_device *dev, + struct apertures_struct *ap, + bool boot) +{ + unsigned int i, j; + struct aperture *a, *b; + + if (!dev->apertures) + return false; + + for (i = 0; i < dev->apertures->count; ++i) { + a = &dev->apertures->ranges[i]; + + if (boot && a->base == VGA_FB_PHYS) + return true; + + for (j = 0; ap && j < ap->count; ++j) { + b = &ap->ranges[j]; + if (a->base <= b->base && a->base + a->size > b->base) + return true; + if (b->base <= a->base && b->base + b->size > a->base) + return true; + } + } + + return false; +} + +/** + * Kick out firmware + * + * Virtually unplug any firmware graphics devices which overlap the given + * region. This must be called with the global-drm-mutex locked. + * This calls the kick_out_firmware() callback on any firmware DRM driver and + * after that remove_conflicting_framebuffers() to remove legacy fbdev + * framebuffers. + */ +void drm_kick_out_firmware(struct apertures_struct *ap, bool boot) +{ + struct drm_device *dev; + + if (boot) + drm_fw_invalid = true; + + list_for_each_entry(dev, &drm_devlist, global_item) { + if (!drm_core_check_feature(dev, DRIVER_FIRMWARE)) + continue; + if (apertures_overlap(dev, ap, boot)) { + DRM_INFO("kicking out firmware %s\n", + dev->devname); + dev->driver->kick_out_firmware(dev); + } + } + +#ifdef CONFIG_FB + remove_conflicting_framebuffers(ap, "DRM", boot); +#endif +} +EXPORT_SYMBOL(drm_kick_out_firmware); + +/** + * Verify that no driver uses firmware FBs + * + * Whenever you register a firmware framebuffer driver, you should store the + * apertures in @ap and test whether any other registered driver already + * claimed this area. Hence, if this function returns true, you should _not_ + * register your driver! + */ +bool drm_is_firmware_used(struct apertures_struct *ap) +{ + struct drm_device *dev; + unsigned int i; + bool boot = false; + + /* If a real DRM driver was loaded once, we cannot assume that the + * firmware framebuffers are still valid. */ + if (drm_fw_invalid) + return true; + + for (i = 0; ap && i < ap->count; ++i) { + if (ap->ranges[i].base == VGA_FB_PHYS) { + boot = true; + break; + } + } + + list_for_each_entry(dev, &drm_devlist, global_item) { + if (dev->apert_boot && boot) + return true; + if (apertures_overlap(dev, ap, false)) + return true; + } + + return false; +} +EXPORT_SYMBOL(drm_is_firmware_used); diff --git a/drivers/gpu/drm/drm_usb.c b/drivers/gpu/drm/drm_usb.c index 8766472..b672cf2 100644 --- a/drivers/gpu/drm/drm_usb.c +++ b/drivers/gpu/drm/drm_usb.c @@ -56,6 +56,7 @@ int drm_get_usb_dev(struct usb_interface *interface, goto err_g3;
list_add_tail(&dev->driver_item, &driver->device_list); + list_add_tail(&dev->global_item, &drm_devlist);
mutex_unlock(&drm_global_mutex);
diff --git a/drivers/gpu/drm/simpledrm/simpledrm.h b/drivers/gpu/drm/simpledrm/simpledrm.h index b854981..c093ad5 100644 --- a/drivers/gpu/drm/simpledrm/simpledrm.h +++ b/drivers/gpu/drm/simpledrm/simpledrm.h @@ -53,6 +53,7 @@ struct sdrm_device {
int sdrm_drm_load(struct drm_device *ddev, unsigned long flags); int sdrm_drm_unload(struct drm_device *ddev); +void sdrm_drm_kick_out_firmware(struct drm_device *ddev); int sdrm_drm_mmap(struct file *filp, struct vm_area_struct *vma); int sdrm_pdev_init(struct sdrm_device *sdrm); void sdrm_pdev_destroy(struct sdrm_device *sdrm); diff --git a/drivers/gpu/drm/simpledrm/simpledrm_drv.c b/drivers/gpu/drm/simpledrm/simpledrm_drv.c index 8a34051..aea702c 100644 --- a/drivers/gpu/drm/simpledrm/simpledrm_drv.c +++ b/drivers/gpu/drm/simpledrm/simpledrm_drv.c @@ -33,9 +33,10 @@ static const struct file_operations sdrm_drm_fops = { };
static struct drm_driver sdrm_drm_driver = { - .driver_features = DRIVER_MODESET | DRIVER_GEM, + .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_FIRMWARE, .load = sdrm_drm_load, .unload = sdrm_drm_unload, + .kick_out_firmware = sdrm_drm_kick_out_firmware, .fops = &sdrm_drm_fops,
.gem_init_object = sdrm_gem_init_object, diff --git a/drivers/gpu/drm/simpledrm/simpledrm_main.c b/drivers/gpu/drm/simpledrm/simpledrm_main.c index 497542d..38571c2 100644 --- a/drivers/gpu/drm/simpledrm/simpledrm_main.c +++ b/drivers/gpu/drm/simpledrm/simpledrm_main.c @@ -267,6 +267,21 @@ int sdrm_drm_load(struct drm_device *ddev, unsigned long flags) if (ret) goto err_name;
+ ddev->apertures = alloc_apertures(1); + if (!ddev->apertures) { + ret = -ENOMEM; + goto err_pdev; + } + + ddev->apertures->ranges[0].base = sdrm->fb_base; + ddev->apertures->ranges[0].size = sdrm->fb_size; + + if (drm_is_firmware_used(ddev->apertures)) { + dev_info(ddev->dev, "firmware framebuffer is already in use\n"); + ret = -EBUSY; + goto err_apert; + } + drm_mode_config_init(ddev); ddev->mode_config.min_width = 0; ddev->mode_config.min_height = 0; @@ -308,6 +323,9 @@ int sdrm_drm_load(struct drm_device *ddev, unsigned long flags)
err_cleanup: drm_mode_config_cleanup(ddev); +err_apert: + kfree(ddev->apertures); +err_pdev: sdrm_pdev_destroy(sdrm); err_name: kfree(ddev->devname); @@ -328,3 +346,18 @@ int sdrm_drm_unload(struct drm_device *ddev)
return 0; } + +void sdrm_drm_kick_out_firmware(struct drm_device *ddev) +{ + struct sdrm_device *sdrm = ddev->dev_private; + + mutex_lock(&ddev->struct_mutex); + + sdrm_fbdev_cleanup(sdrm); + drm_unplug_dev_locked(ddev); + if (sdrm->fb_obj) + sdrm_gem_unmap_object(sdrm->fb_obj); + sdrm_pdev_destroy(sdrm); + + mutex_unlock(&ddev->struct_mutex); +} diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 2907341..d197033 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -46,6 +46,7 @@ #include <linux/miscdevice.h> #include <linux/fs.h> #include <linux/init.h> +#include <linux/fb.h> #include <linux/file.h> #include <linux/platform_device.h> #include <linux/pci.h> @@ -146,6 +147,7 @@ int drm_err(const char *func, const char *format, ...); #define DRIVER_MODESET 0x2000 #define DRIVER_PRIME 0x4000 #define DRIVER_RENDER 0x8000 +#define DRIVER_FIRMWARE 0x10000
#define DRIVER_BUS_PCI 0x1 #define DRIVER_BUS_PLATFORM 0x2 @@ -966,6 +968,23 @@ struct drm_driver { struct drm_device *dev, uint32_t handle);
+ /** + * kick_out_firmware - kick out firmware driver + * @dev: DRM device + * + * Iff this driver has DRIVER_FIRMWARE set, this function is called + * when a real hw-driver is loaded and claims the framebuffer memory + * that is mapped by the firmware driver. This is called with the + * global drm mutex held. + * Drivers should unmap any memory-mappings, disable the device and + * schedule a driver removal. + * + * Note that a driver setting DRIVER_FIRMWARE is supposed to also set + * the "apertures" information on @dev. It is used to match the memory + * regions that are used by firmware drivers. + */ + void (*kick_out_firmware) (struct drm_device *dev); + /* Driver private ops for this object */ const struct vm_operations_struct *gem_vm_ops;
@@ -1087,6 +1106,7 @@ struct drm_pending_vblank_event { */ struct drm_device { struct list_head driver_item; /**< list of devices per driver */ + struct list_head global_item; /**< global list of devices */ char *devname; /**< For /proc/interrupts */ int if_version; /**< Highest interface version set */
@@ -1218,6 +1238,8 @@ struct drm_device { int switch_power_state;
atomic_t unplugged; /* device has been unplugged or gone away */ + struct apertures_struct *apertures; /**< fbmem apertures */ + bool apert_boot; /**< true if mapped as boot fb */ };
#define DRM_SWITCH_POWER_ON 0 @@ -1457,6 +1479,10 @@ extern void drm_master_put(struct drm_master **master); extern void drm_put_dev(struct drm_device *dev); extern int drm_put_minor(struct drm_minor **minor); extern void drm_unplug_dev(struct drm_device *dev); +extern void drm_unplug_dev_locked(struct drm_device *dev); +extern void drm_kick_out_firmware(struct apertures_struct *ap, bool boot); +extern bool drm_is_firmware_used(struct apertures_struct *ap); +extern struct list_head drm_devlist; extern unsigned int drm_debug; extern unsigned int drm_rnodes;