diff options
authorMarc Zyngier <marc.zyngier@arm.com>2014-04-28 19:50:06 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2014-05-03 22:20:31 +0100
commitf774b7d10e2155e52b92dfce2f8cb099a6d6d0e6 (patch)
parentda6e4cb67c6dd1f72257c0a4a97c26dc4e80d3a7 (diff)
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>
2 files changed, 5 insertions, 4 deletions
diff --git a/arch/arm64/kernel/early_printk.c b/arch/arm64/kernel/early_printk.c
index ffbbdde7aba..2dc36d00add 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;
diff --git a/include/asm-generic/fixmap.h b/include/asm-generic/fixmap.h
index 5a64ca4621f..f23174fb9ec 100644
--- a/include/asm-generic/fixmap.h
+++ b/include/asm-generic/fixmap.h
@@ -93,5 +93,8 @@ static inline unsigned long virt_to_fix(const unsigned long vaddr)
#define set_fixmap_io(idx, phys) \
__set_fixmap(idx, phys, FIXMAP_PAGE_IO)
+#define set_fixmap_offset_io(idx, phys) \
+ __set_fixmap_offset(idx, phys, FIXMAP_PAGE_IO)
#endif /* __ASSEMBLY__ */
#endif /* __ASM_GENERIC_FIXMAP_H */