diff options
author | David Herrmann <dh.herrmann@gmail.com> | 2016-11-15 13:01:58 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2016-11-16 09:38:23 +0100 |
commit | f96acec8c8020807429d21324547f4b904c37177 (patch) | |
tree | e69e6c294d332d2fed78748076350f5a3b67d415 /arch/x86/kernel/sysfb_simplefb.c | |
parent | 9164b4ceb7b492a77c7fe770a4b9d1375c9cd45a (diff) | |
download | op-kernel-dev-f96acec8c8020807429d21324547f4b904c37177.zip op-kernel-dev-f96acec8c8020807429d21324547f4b904c37177.tar.gz |
x86/sysfb: Fix lfb_size calculation
The screen_info.lfb_size field is shifted by 16 bits *only* in case of
VBE. This has historical reasons since VBE advertised it similarly.
However, in case of EFI framebuffers, the size is no longer shifted. Fix
the x86 simple-framebuffer setup code to use the correct size in the
non-VBE case.
While at it, avoid variable abbreviations and rename 'len' to 'length',
and use the correct types matching the screen_info definition.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Gundersen <teg@jklm.no>
Link: http://lkml.kernel.org/r/20161115120158.15388-3-dh.herrmann@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/sysfb_simplefb.c')
-rw-r--r-- | arch/x86/kernel/sysfb_simplefb.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/arch/x86/kernel/sysfb_simplefb.c b/arch/x86/kernel/sysfb_simplefb.c index 35b8641..85195d4 100644 --- a/arch/x86/kernel/sysfb_simplefb.c +++ b/arch/x86/kernel/sysfb_simplefb.c @@ -66,8 +66,8 @@ __init int create_simplefb(const struct screen_info *si, { struct platform_device *pd; struct resource res; - unsigned long len; - u64 base; + u64 base, size; + u32 length; /* * If the 64BIT_BASE capability is set, ext_lfb_base will contain the @@ -82,11 +82,20 @@ __init int create_simplefb(const struct screen_info *si, return -EINVAL; } - /* don't use lfb_size as it may contain the whole VMEM instead of only - * the part that is occupied by the framebuffer */ - len = mode->height * mode->stride; - len = PAGE_ALIGN(len); - if (len > (u64)si->lfb_size << 16) { + /* + * Don't use lfb_size as IORESOURCE size, since it may contain the + * entire VMEM, and thus require huge mappings. Use just the part we + * need, that is, the part where the framebuffer is located. But verify + * that it does not exceed the advertised VMEM. + * Note that in case of VBE, the lfb_size is shifted by 16 bits for + * historical reasons. + */ + size = si->lfb_size; + if (si->orig_video_isVGA == VIDEO_TYPE_VLFB) + size <<= 16; + length = mode->height * mode->stride; + length = PAGE_ALIGN(length); + if (length > size) { printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n"); return -EINVAL; } @@ -96,7 +105,7 @@ __init int create_simplefb(const struct screen_info *si, res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; res.name = simplefb_resname; res.start = base; - res.end = res.start + len - 1; + res.end = res.start + length - 1; if (res.end <= res.start) return -EINVAL; |