| Message ID | 20160902082245.7119-3-dh.herrmann@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Sep 2, 2016 at 10:22 AM, David Herrmann <dh.herrmann@gmail.com> wrote: > 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> Reviewed-by: Tom Gundersen <teg@jklm.no> > --- > arch/x86/kernel/sysfb_simplefb.c | 25 +++++++++++++++++-------- > 1 file 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; > > -- > 2.9.3 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
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;
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> --- arch/x86/kernel/sysfb_simplefb.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-)