diff options
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/video/Makefile | 2 | ||||
| -rw-r--r-- | drivers/video/aperture.c | 351 | ||||
| -rw-r--r-- | drivers/video/backlight/tps65217_bl.c | 10 | ||||
| -rw-r--r-- | drivers/video/console/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/video/fbdev/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/video/fbdev/core/fbcon.c | 13 | ||||
| -rw-r--r-- | drivers/video/fbdev/core/fbmem.c | 22 | ||||
| -rw-r--r-- | drivers/video/fbdev/efifb.c | 11 | ||||
| -rw-r--r-- | drivers/video/fbdev/simplefb.c | 11 |
10 files changed, 387 insertions, 47 deletions
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 427a993c7f57..0587e21abad9 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -5,6 +5,12 @@ menu "Graphics support" +config APERTURE_HELPERS + bool + help + Support tracking and hand-over of aperture ownership. Required + by graphics drivers for firmware-provided framebuffers. + if HAS_IOMEM config HAVE_FB_ATMEL diff --git a/drivers/video/Makefile b/drivers/video/Makefile index df7650adede9..5bb6b452cc83 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -1,4 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_APERTURE_HELPERS) += aperture.o obj-$(CONFIG_VGASTATE) += vgastate.o obj-$(CONFIG_HDMI) += hdmi.o diff --git a/drivers/video/aperture.c b/drivers/video/aperture.c new file mode 100644 index 000000000000..538f2d40acda --- /dev/null +++ b/drivers/video/aperture.c @@ -0,0 +1,351 @@ +// SPDX-License-Identifier: MIT + +#include <linux/aperture.h> +#include <linux/device.h> +#include <linux/fb.h> /* for old fbdev helpers */ +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/vgaarb.h> + +/** + * DOC: overview + * + * A graphics device might be supported by different drivers, but only one + * driver can be active at any given time. Many systems load a generic + * graphics drivers, such as EFI-GOP or VESA, early during the boot process. + * During later boot stages, they replace the generic driver with a dedicated, + * hardware-specific driver. To take over the device the dedicated driver + * first has to remove the generic driver. Aperture functions manage + * ownership of framebuffer memory and hand-over between drivers. + * + * Graphics drivers should call aperture_remove_conflicting_devices() + * at the top of their probe function. The function removes any generic + * driver that is currently associated with the given framebuffer memory. + * An example for a graphics device on the platform bus is shown below. + * + * .. code-block:: c + * + * static int example_probe(struct platform_device *pdev) + * { + * struct resource *mem; + * resource_size_t base, size; + * int ret; + * + * mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + * if (!mem) + * return -ENODEV; + * base = mem->start; + * size = resource_size(mem); + * + * ret = aperture_remove_conflicting_devices(base, size, false, "example"); + * if (ret) + * return ret; + * + * // Initialize the hardware + * ... + * + * return 0; + * } + * + * static const struct platform_driver example_driver = { + * .probe = example_probe, + * ... + * }; + * + * The given example reads the platform device's I/O-memory range from the + * device instance. An active framebuffer will be located within this range. + * The call to aperture_remove_conflicting_devices() releases drivers that + * have previously claimed ownership of the range and are currently driving + * output on the framebuffer. If successful, the new driver can take over + * the device. + * + * While the given example uses a platform device, the aperture helpers work + * with every bus that has an addressable framebuffer. In the case of PCI, + * device drivers can also call aperture_remove_conflicting_pci_devices() and + * let the function detect the apertures automatically. Device drivers without + * knowledge of the framebuffer's location can call + * aperture_remove_all_conflicting_devices(), which removes all known devices. + * + * Drivers that are susceptible to being removed by other drivers, such as + * generic EFI or VESA drivers, have to register themselves as owners of their + * framebuffer apertures. Ownership of the framebuffer memory is achieved + * by calling devm_aperture_acquire_for_platform_device(). If successful, the + * driveris the owner of the framebuffer range. The function fails if the + * framebuffer is already owned by another driver. See below for an example. + * + * .. code-block:: c + * + * static int generic_probe(struct platform_device *pdev) + * { + * struct resource *mem; + * resource_size_t base, size; + * + * mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + * if (!mem) + * return -ENODEV; + * base = mem->start; + * size = resource_size(mem); + * + * ret = devm_aperture_acquire_for_platform_device(pdev, base, size); + * if (ret) + * return ret; + * + * // Initialize the hardware + * ... + * + * return 0; + * } + * + * static int generic_remove(struct platform_device *) + * { + * // Hot-unplug the device + * ... + * + * return 0; + * } + * + * static const struct platform_driver generic_driver = { + * .probe = generic_probe, + * .remove = generic_remove, + * ... + * }; + * + * The similar to the previous example, the generic driver claims ownership + * of the framebuffer memory from its probe function. This will fail if the + * memory range, or parts of it, is already owned by another driver. + * + * If successful, the generic driver is now subject to forced removal by + * another driver. This only works for platform drivers that support hot + * unplugging. When a driver calls aperture_remove_conflicting_devices() + * et al for the registered framebuffer range, the aperture helpers call + * platform_device_unregister() and the generic driver unloads itself. The + * generic driver also has to provide a remove function to make this work. + * Once hot unplugged fro mhardware, it may not access the device's + * registers, framebuffer memory, ROM, etc afterwards. + */ + +struct aperture_range { + struct device *dev; + resource_size_t base; + resource_size_t size; + struct list_head lh; + void (*detach)(struct device *dev); +}; + +static LIST_HEAD(apertures); +static DEFINE_MUTEX(apertures_lock); + +static bool overlap(resource_size_t base1, resource_size_t end1, + resource_size_t base2, resource_size_t end2) +{ + return (base1 < end2) && (end1 > base2); +} + +static void devm_aperture_acquire_release(void *data) +{ + struct aperture_range *ap = data; + bool detached = !ap->dev; + + if (detached) + return; + + mutex_lock(&apertures_lock); + list_del(&ap->lh); + mutex_unlock(&apertures_lock); +} + +static int devm_aperture_acquire(struct device *dev, + resource_size_t base, resource_size_t size, + void (*detach)(struct device *)) +{ + size_t end = base + size; + struct list_head *pos; + struct aperture_range *ap; + + mutex_lock(&apertures_lock); + + list_for_each(pos, &apertures) { + ap = container_of(pos, struct aperture_range, lh); + if (overlap(base, end, ap->base, ap->base + ap->size)) { + mutex_unlock(&apertures_lock); + return -EBUSY; + } + } + + ap = devm_kzalloc(dev, sizeof(*ap), GFP_KERNEL); + if (!ap) { + mutex_unlock(&apertures_lock); + return -ENOMEM; + } + + ap->dev = dev; + ap->base = base; + ap->size = size; + ap->detach = detach; + INIT_LIST_HEAD(&ap->lh); + + list_add(&ap->lh, &apertures); + + mutex_unlock(&apertures_lock); + + return devm_add_action_or_reset(dev, devm_aperture_acquire_release, ap); +} + +static void aperture_detach_platform_device(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + + /* + * Remove the device from the device hierarchy. This is the right thing + * to do for firmware-based DRM drivers, such as EFI, VESA or VGA. After + * the new driver takes over the hardware, the firmware device's state + * will be lost. + * + * For non-platform devices, a new callback would be required. + * + * If the aperture helpers ever need to handle native drivers, this call + * would only have to unplug the DRM device, so that the hardware device + * stays around after detachment. + */ + platform_device_unregister(pdev); +} + +/** + * devm_aperture_acquire_for_platform_device - Acquires ownership of an aperture + * on behalf of a platform device. + * @pdev: the platform device to own the aperture + * @base: the aperture's byte offset in physical memory + * @size: the aperture size in bytes + * + * Installs the given device as the new owner of the aperture. The function + * expects the aperture to be provided by a platform device. If another + * driver takes over ownership of the aperture, aperture helpers will then + * unregister the platform device automatically. All acquired apertures are + * released automatically when the underlying device goes away. + * + * The function fails if the aperture, or parts of it, is currently + * owned by another device. To evict current owners, callers should use + * remove_conflicting_devices() et al. before calling this function. + * + * Returns: + * 0 on success, or a negative errno value otherwise. + */ +int devm_aperture_acquire_for_platform_device(struct platform_device *pdev, + resource_size_t base, + resource_size_t size) +{ + return devm_aperture_acquire(&pdev->dev, base, size, aperture_detach_platform_device); +} +EXPORT_SYMBOL(devm_aperture_acquire_for_platform_device); + +static void aperture_detach_devices(resource_size_t base, resource_size_t size) +{ + resource_size_t end = base + size; + struct list_head *pos, *n; + + mutex_lock(&apertures_lock); + + list_for_each_safe(pos, n, &apertures) { + struct aperture_range *ap = container_of(pos, struct aperture_range, lh); + struct device *dev = ap->dev; + + if (WARN_ON_ONCE(!dev)) + continue; + + if (!overlap(base, end, ap->base, ap->base + ap->size)) + continue; + + ap->dev = NULL; /* detach from device */ + list_del(&ap->lh); + + ap->detach(dev); + } + + mutex_unlock(&apertures_lock); +} + +/** + * aperture_remove_conflicting_devices - remove devices in the given range + * @base: the aperture's base address in physical memory + * @size: aperture size in bytes + * @primary: also kick vga16fb if present; only relevant for VGA devices + * @name: a descriptive name of the requesting driver + * + * This function removes devices that own apertures within @base and @size. + * + * Returns: + * 0 on success, or a negative errno code otherwise + */ +int aperture_remove_conflicting_devices(resource_size_t base, resource_size_t size, + bool primary, const char *name) +{ +#if IS_REACHABLE(CONFIG_FB) + struct apertures_struct *a; + int ret; + + a = alloc_apertures(1); + if (!a) + return -ENOMEM; + + a->ranges[0].base = base; + a->ranges[0].size = size; + + ret = remove_conflicting_framebuffers(a, name, primary); + kfree(a); + + if (ret) + return ret; +#endif + + aperture_detach_devices(base, size); + + return 0; +} +EXPORT_SYMBOL(aperture_remove_conflicting_devices); + +/** + * aperture_remove_conflicting_pci_devices - remove existing framebuffers for PCI devices + * @pdev: PCI device + * @name: a descriptive name of the requesting driver + * + * This function removes devices that own apertures within any of @pdev's + * memory bars. The function assumes that PCI device with shadowed ROM + * drives a primary display and therefore kicks out vga16fb as well. + * + * Returns: + * 0 on success, or a negative errno code otherwise + */ +int aperture_remove_conflicting_pci_devices(struct pci_dev *pdev, const char *name) +{ + resource_size_t base, size; + int bar, ret; + + /* + * WARNING: Apparently we must kick fbdev drivers before vgacon, + * otherwise the vga fbdev driver falls over. + */ +#if IS_REACHABLE(CONFIG_FB) + ret = remove_conflicting_pci_framebuffers(pdev, name); + if (ret) + return ret; +#endif + ret = vga_remove_vgacon(pdev); + if (ret) + return ret; + + for (bar = 0; bar < PCI_STD_NUM_BARS; ++bar) { + if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) + continue; + base = pci_resource_start(pdev, bar); + size = pci_resource_len(pdev, bar); + aperture_detach_devices(base, size); + } + + return 0; + +} +EXPORT_SYMBOL(aperture_remove_conflicting_pci_devices); diff --git a/drivers/video/backlight/tps65217_bl.c b/drivers/video/backlight/tps65217_bl.c index 8457166f357f..d96d713fe7db 100644 --- a/drivers/video/backlight/tps65217_bl.c +++ b/drivers/video/backlight/tps65217_bl.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * tps65217_bl.c * @@ -5,15 +6,6 @@ * * Copyright (C) 2012 Matthias Kaehlcke * Author: Matthias Kaehlcke <matthias@kaehlcke.net> - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation version 2. - * - * This program is distributed "as is" WITHOUT ANY WARRANTY of any - * kind, whether express or implied; without even the implied warranty - * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. */ #include <linux/kernel.h> diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig index 40c50fa2dd70..22cea5082ac4 100644 --- a/drivers/video/console/Kconfig +++ b/drivers/video/console/Kconfig @@ -10,6 +10,7 @@ config VGA_CONSOLE depends on !4xx && !PPC_8xx && !SPARC && !M68K && !PARISC && !SUPERH && \ (!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER) && \ !ARM64 && !ARC && !MICROBLAZE && !OPENRISC && !S390 && !UML + select APERTURE_HELPERS if (DRM || FB || VFIO_PCI_CORE) default y help Saying Y here will allow you to use Linux in text mode through a diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig index f2a6b81e45c4..cfc55273dc5d 100644 --- a/drivers/video/fbdev/Kconfig +++ b/drivers/video/fbdev/Kconfig @@ -455,6 +455,7 @@ config FB_ATARI config FB_OF bool "Open Firmware frame buffer device support" depends on (FB = y) && PPC && (!PPC_PSERIES || PCI) + select APERTURE_HELPERS select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT @@ -527,6 +528,7 @@ config FB_IMSTT config FB_VGA16 tristate "VGA 16-color graphics support" depends on FB && (X86 || PPC) + select APERTURE_HELPERS select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT @@ -551,7 +553,7 @@ config FB_STI BIOS routines contained in a ROM chip in HP PA-RISC based machines. Enabling this option will implement the linux framebuffer device using calls to the STI BIOS routines for initialisation. - + If you enable this option, you will get a planar framebuffer device /dev/fb which will work on the most common HP graphic cards of the NGLE family, including the artist chips (in the 7xx and Bxxx series), @@ -617,6 +619,7 @@ config FB_UVESA config FB_VESA bool "VESA VGA graphics support" depends on (FB = y) && X86 + select APERTURE_HELPERS select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT @@ -630,6 +633,7 @@ config FB_VESA config FB_EFI bool "EFI-based Framebuffer Support" depends on (FB = y) && !IA64 && EFI + select APERTURE_HELPERS select DRM_PANEL_ORIENTATION_QUIRKS select FB_CFB_FILLRECT select FB_CFB_COPYAREA @@ -2190,6 +2194,7 @@ config FB_SIMPLE tristate "Simple framebuffer support" depends on FB depends on !DRM_SIMPLEDRM + select APERTURE_HELPERS select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 1a9aa12cf886..f114242b5a70 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -125,8 +125,8 @@ static int logo_lines; enums. */ static int logo_shown = FBCON_LOGO_CANSHOW; /* console mappings */ -static int first_fb_vc; -static int last_fb_vc = MAX_NR_CONSOLES - 1; +static unsigned int first_fb_vc; +static unsigned int last_fb_vc = MAX_NR_CONSOLES - 1; static int fbcon_is_default = 1; static int primary_device = -1; static int fbcon_has_console_bind; @@ -440,10 +440,12 @@ static int __init fb_console_setup(char *this_opt) options += 3; if (*options) first_fb_vc = simple_strtoul(options, &options, 10) - 1; - if (first_fb_vc < 0) + if (first_fb_vc >= MAX_NR_CONSOLES) first_fb_vc = 0; if (*options++ == '-') last_fb_vc = simple_strtoul(options, &options, 10) - 1; + if (last_fb_vc < first_fb_vc || last_fb_vc >= MAX_NR_CONSOLES) + last_fb_vc = MAX_NR_CONSOLES - 1; fbcon_is_default = 0; continue; } @@ -1758,8 +1760,6 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b, case SM_UP: if (count > vc->vc_rows) /* Maximum realistic size */ count = vc->vc_rows; - if (logo_shown >= 0) - goto redraw_up; switch (fb_scrollmode(p)) { case SCROLL_MOVE: fbcon_redraw_blit(vc, info, p, t, b - t - count, @@ -1848,8 +1848,6 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b, case SM_DOWN: if (count > vc->vc_rows) /* Maximum realistic size */ count = vc->vc_rows; - if (logo_shown >= 0) - goto redraw_down; switch (fb_scrollmode(p)) { case SCROLL_MOVE: fbcon_redraw_blit(vc, info, p, b - 1, b - t - count, @@ -2182,7 +2180,6 @@ static int fbcon_switch(struct vc_data *vc) if (logo_shown == FBCON_LOGO_DRAW) { logo_shown = fg_console; - /* This is protected above by initmem_freed */ fb_show_logo(info, ops->rotate); update_region(vc, vc->vc_origin + vc->vc_size_row * vc->vc_top, diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 7ee6eb2fa715..02b0cf2cfafe 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1568,6 +1568,7 @@ static void do_remove_conflicting_framebuffers(struct apertures_struct *a, { int i; +restart_removal: /* check all firmware fbs and kick off if the base addr overlaps */ for_each_registered_fb(i) { struct apertures_struct *gen_aper; @@ -1600,12 +1601,23 @@ static void do_remove_conflicting_framebuffers(struct apertures_struct *a, pr_warn("fb%d: no device set\n", i); do_unregister_framebuffer(registered_fb[i]); } else if (dev_is_platform(device)) { - registered_fb[i]->forced_out = true; + /* + * Drop the lock because if the device is unregistered, its + * driver will call to unregister_framebuffer(), that takes + * this lock. + */ + mutex_unlock(®istration_lock); platform_device_unregister(to_platform_device(device)); + mutex_lock(®istration_lock); } else { pr_warn("fb%d: cannot remove device\n", i); do_unregister_framebuffer(registered_fb[i]); } + /* + * Restart the removal loop now that the device has been + * unregistered and its associated framebuffer gone. + */ + goto restart_removal; } } } @@ -1876,13 +1888,9 @@ EXPORT_SYMBOL(register_framebuffer); void unregister_framebuffer(struct fb_info *fb_info) { - bool forced_out = fb_info->forced_out; - - if (!forced_out) - mutex_lock(®istration_lock); + mutex_lock(®istration_lock); do_unregister_framebuffer(fb_info); - if (!forced_out) - mutex_unlock(®istration_lock); + mutex_unlock(®istration_lock); } EXPORT_SYMBOL(unregister_framebuffer); diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c index b3d5f884c544..16c1aaae9afa 100644 --- a/drivers/video/fbdev/efifb.c +++ b/drivers/video/fbdev/efifb.c @@ -358,17 +358,6 @@ static int efifb_probe(struct platform_device *dev) char *option = NULL; efi_memory_desc_t md; - /* - * Generic drivers must not be registered if a framebuffer exists. - * If a native driver was probed, the display hardware was already - * taken and attempting to use the system framebuffer is dangerous. - */ - if (num_registered_fb > 0) { - dev_err(&dev->dev, - "efifb: a framebuffer is already registered\n"); - return -EINVAL; - } - if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled) return -ENODEV; diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c index f96ce8801be4..cf2a90ecd64e 100644 --- a/drivers/video/fbdev/simplefb.c +++ b/drivers/video/fbdev/simplefb.c @@ -418,17 +418,6 @@ static int simplefb_probe(struct platform_device *pdev) struct simplefb_par *par; struct resource *res, *mem; - /* - * Generic drivers must not be registered if a framebuffer exists. - * If a native driver was probed, the display hardware was already - * taken and attempting to use the system framebuffer is dangerous. - */ - if (num_registered_fb > 0) { - dev_err(&pdev->dev, - "simplefb: a framebuffer is already registered\n"); - return -EINVAL; - } - if (fb_get_options("simplefb", NULL)) return -ENODEV; |