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| author | Marc Zyngier <marc.zyngier@arm.com> | 2014-04-28 19:50:06 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2014-05-03 22:20:31 +0100 |
| commit | f774b7d10e2155e52b92dfce2f8cb099a6d6d0e6 (patch) | |
| tree | dc85b3e72c8e5ece7a5c9dd567bda52d6011635c /arch | |
| parent | da6e4cb67c6dd1f72257c0a4a97c26dc4e80d3a7 (diff) | |
| download | linux-f774b7d10e2155e52b92dfce2f8cb099a6d6d0e6.tar.bz2 | |
arm64: fixmap: fix missing sub-page offset for earlyprintk
Commit d57c33c5daa4 (add generic fixmap.h) added (among other
similar things) set_fixmap_io to deal with early ioremap of devices.
More recently, commit bf4b558eba92 (arm64: add early_ioremap support)
converted the arm64 earlyprintk to use set_fixmap_io. A side effect of
this conversion is that my virtual machines have stopped booting when
I pass "earlyprintk=uart8250-8bit,0x3f8" to the guest kernel.
Turns out that the new earlyprintk code doesn't care at all about
sub-page offsets, and just assumes that the earlyprintk device will
be page-aligned. Obviously, that doesn't play well with the above example.
Further investigation shows that set_fixmap_io uses __set_fixmap instead
of __set_fixmap_offset. A fix is to introduce a set_fixmap_offset_io that
uses the latter, and to remove the superflous call to fix_to_virt
(which only returns the value that set_fixmap_io has already given us).
With this applied, my VMs are back in business. Tested on a Cortex-A57
platform with kvmtool as platform emulation.
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kernel/early_printk.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/arm64/kernel/early_printk.c b/arch/arm64/kernel/early_printk.c index ffbbdde7aba1..2dc36d00addf 100644 --- a/arch/arm64/kernel/early_printk.c +++ b/arch/arm64/kernel/early_printk.c @@ -143,10 +143,8 @@ static int __init setup_early_printk(char *buf) } /* no options parsing yet */ - if (paddr) { - set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr); - early_base = (void __iomem *)fix_to_virt(FIX_EARLYCON_MEM_BASE); - } + if (paddr) + early_base = (void __iomem *)set_fixmap_offset_io(FIX_EARLYCON_MEM_BASE, paddr); printch = match->printch; early_console = &early_console_dev; |