On Thu, 2016-08-18 at 14:10 +0100, Suzuki K Poulose wrote: > On systems with mismatched i/d cache min line sizes, we need to use > the smallest size possible across all CPUs. This will be done by fetching > the system wide safe value from CPU feature infrastructure. > However the some special users(e.g kexec, hibernate) would need the line > size on the CPU (rather than the system wide), when the system wide > feature may not be accessible. Provide another helper which will fetch > cache line size on the current CPU. > > Cc: James Morse <[email protected]> > Cc: Geoff Levand <[email protected]> > Signed-off-by: Suzuki K Poulose <[email protected]> > --- > arch/arm64/include/asm/assembler.h | 24 ++++++++++++++++++++---- > arch/arm64/kernel/hibernate-asm.S | 2 +- > arch/arm64/kernel/relocate_kernel.S | 2 +- > 3 files changed, 22 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/include/asm/assembler.h > b/arch/arm64/include/asm/assembler.h > index d5025c6..a4bb3f5 100644 > --- a/arch/arm64/include/asm/assembler.h > +++ b/arch/arm64/include/asm/assembler.h > @@ -218,9 +218,10 @@ lr .req x30 // link register > .endm > > /* > - * dcache_line_size - get the minimum D-cache line size from the CTR > register. > + * raw_dcache_line_size - get the minimum D-cache line size on this CPU > + * from the CTR register. > */ > - .macro dcache_line_size, reg, tmp > + .macro raw_dcache_line_size, reg, tmp > mrs \tmp, ctr_el0 // read CTR > ubfm \tmp, \tmp, #16, #19 // cache line size encoding > mov \reg, #4 // bytes per word > @@ -228,9 +229,17 @@ lr .req x30 // link register > .endm
... > +++ b/arch/arm64/kernel/relocate_kernel.S > @@ -34,7 +34,7 @@ ENTRY(arm64_relocate_new_kernel) > /* Setup the list loop variables. */ > mov x17, x1 /* x17 = kimage_start */ > mov x16, x0 /* x16 = kimage_head */ > - dcache_line_size x15, x0 /* x15 = dcache line size */ > + raw_dcache_line_size x15, x0 /* x15 = dcache line size */ > mov x14, xzr /* x14 = entry ptr */ > mov x13, xzr /* x13 = copy dest */ Since this is just renaming dcache_line_size to raw_dcache_line_size, and for kexec's relocate_kernel we need to know about the CPU we are running on, this part of the change looks good. Reviewed by: Geoff Levand <[email protected]>
