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| author | Alex Deucher <alexander.deucher@amd.com> | 2021-12-23 06:41:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-01-11 17:35:16 +0300 |
| commit | fa3d8456f7cd7d20acaa2223241c4e171dc8b740 (patch) | |
| tree | fed17261672fb62e0bc0973ef8dd4876103c2c68 /drivers/video | |
| parent | 9ca97a693aa8b86e8424f0047198ea3ab997d50f (diff) | |
| download | linux-fa3d8456f7cd7d20acaa2223241c4e171dc8b740.tar.xz | |
fbdev: fbmem: add a helper to determine if an aperture is used by a fw fb
commit 9a45ac2320d0a6ae01880a30d4b86025fce4061b upstream.
Add a function for drivers to check if the a firmware initialized
fb is corresponds to their aperture. This allows drivers to check if the
device corresponds to what the firmware set up as the display device.
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=215203
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1840
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/core/fbmem.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 7420d2c16e47..7bd5e2a4a9da 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1760,6 +1760,53 @@ int remove_conflicting_framebuffers(struct apertures_struct *a, EXPORT_SYMBOL(remove_conflicting_framebuffers); /** + * is_firmware_framebuffer - detect if firmware-configured framebuffer matches + * @a: memory range, users of which are to be checked + * + * This function checks framebuffer devices (initialized by firmware/bootloader) + * which use memory range described by @a. If @a matchesm the function returns + * true, otherwise false. + */ +bool is_firmware_framebuffer(struct apertures_struct *a) +{ + bool do_free = false; + bool found = false; + int i; + + if (!a) { + a = alloc_apertures(1); + if (!a) + return false; + + a->ranges[0].base = 0; + a->ranges[0].size = ~0; + do_free = true; + } + + mutex_lock(®istration_lock); + /* check all firmware fbs and kick off if the base addr overlaps */ + for_each_registered_fb(i) { + struct apertures_struct *gen_aper; + + if (!(registered_fb[i]->flags & FBINFO_MISC_FIRMWARE)) + continue; + + gen_aper = registered_fb[i]->apertures; + if (fb_do_apertures_overlap(gen_aper, a)) { + found = true; + break; + } + } + mutex_unlock(®istration_lock); + + if (do_free) + kfree(a); + + return found; +} +EXPORT_SYMBOL(is_firmware_framebuffer); + +/** * remove_conflicting_pci_framebuffers - remove firmware-configured framebuffers for PCI devices * @pdev: PCI device * @name: requesting driver name |