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path: root/drivers/firmware/efi/earlycon.c
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2020-05-12efi/earlycon: Fix early printk for wider fontsDave Young1-6/+8
When I play with terminus fonts I noticed the efi early printk does not work because the earlycon code assumes font width is 8. Here add the code to adapt with larger fonts. Tested with all kinds of kernel built-in fonts on my laptop. Also tested with a local draft patch for 14x28 !bold terminus font. Signed-off-by: Dave Young <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]>
2019-12-25efi/earlycon: Fix write-combine mapping on x86Arvind Sankar1-9/+7
On x86, until PAT is initialized, WC translates into UC-. Since we calculate and store pgprot_writecombine(PAGE_KERNEL) when earlycon is initialized, this means we actually use UC- mappings instead of WC mappings, which makes scrolling very slow. Instead store a boolean flag to indicate whether we want to use writeback or write-combine mappings, and recalculate the actual pgprot_t we need on every mapping. Once PAT is initialized, we will start using write-combine mappings, which speeds up the scrolling considerably. Signed-off-by: Arvind Sankar <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Hans de Goede <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Fixes: 69c1f396f25b ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation") Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-12-08efi/earlycon: Remap entire framebuffer after page initializationAndy Shevchenko1-0/+40
When commit: 69c1f396f25b ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation") moved the x86 specific EFI earlyprintk implementation to a shared location, it also tweaked the behaviour. In particular, it dropped a trick with full framebuffer remapping after page initialization, leading to two regressions: 1) very slow scrolling after page initialization, 2) kernel hang when the 'keep_bootcon' command line argument is passed. Putting the tweak back fixes #2 and mitigates #1, i.e., it limits the slow behavior to the early boot stages, presumably due to eliminating heavy map()/unmap() operations per each pixel line on the screen. [ ardb: ensure efifb is unmapped again unless keep_bootcon is in effect. ] [ mingo: speling fixes. ] Signed-off-by: Andy Shevchenko <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Cc: Arvind Sankar <[email protected]> Cc: Bhupesh Sharma <[email protected]> Cc: Masayoshi Mizuma <[email protected]> Cc: [email protected] Fixes: 69c1f396f25b ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation") Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-02-04efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementationArd Biesheuvel1-0/+206
Move the x86 EFI earlyprintk implementation to a shared location under drivers/firmware and tweak it slightly so we can expose it as an earlycon implementation (which is generic) rather than earlyprintk (which is only implemented for a few architectures) This also involves switching to write-combine mappings by default (which is required on ARM since device mappings lack memory semantics, and so memcpy/memset may not be used on them), and adding support for shared memory framebuffers on cache coherent non-x86 systems (which do not tolerate mismatched attributes). Note that 32-bit ARM does not populate its struct screen_info early enough for earlycon=efifb to work, so it is disabled there. Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Alexander Graf <[email protected]> Cc: AKASHI Takahiro <[email protected]> Cc: Bjorn Andersson <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Heinrich Schuchardt <[email protected]> Cc: Jeffrey Hugo <[email protected]> Cc: Lee Jones <[email protected]> Cc: Leif Lindholm <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Jones <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Sai Praneeth Prakhya <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>