On Sat, Jun 14 2014 at 04:04:51 PM, Christoffer Dall christoffer.dall@linaro.org wrote:
On Thu, Jun 12, 2014 at 09:30:10AM -0700, Victor Kamensky wrote:
Fix vgic_bitmap_get_reg function to return 'right' word address of 'unsigned long' bitmap value in case of BE 64bit image.
Signed-off-by: Victor Kamensky victor.kamensky@linaro.org
virt/kvm/arm/vgic.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 529c336..b4ffd82 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -101,14 +101,34 @@ static u32 vgic_nr_lr; static unsigned int vgic_maint_irq; +/*
- struct vgic_bitmap contains unions that provide two views of
- the same data. In one case it is an array of registers of
- u32's, and in the other case it is a bitmap of unsigned
- longs.
- This does not work on 64-bit BE systems, because the bitmap access
- will store two consecutive 32-bit words with the higher-addressed
- register's bits at the lower index and the lower-addressed register's
- bits at the higher index.
- Therefore, swizzle the register index when accessing the 32-bit word
- registers to access the right register's value.
- */
+#if defined(CONFIG_CPU_BIG_ENDIAN) && BITS_PER_LONG == 64 +#define REG_OFFSET_SWIZZLE 1 +#else +#define REG_OFFSET_SWIZZLE 0 +#endif
static u32 *vgic_bitmap_get_reg(struct vgic_bitmap *x, int cpuid, u32 offset) { offset >>= 2; if (!offset)
return x->percpu[cpuid].reg;
return x->percpu[cpuid].reg + (offset ^ REG_OFFSET_SWIZZLE);
return x->shared.reg + offset - 1;
return x->shared.reg + ((offset - 1) ^ REG_OFFSET_SWIZZLE);} static int vgic_bitmap_get_irq_val(struct vgic_bitmap *x, -- 1.8.1.4
I had wished there was a cleaner way to abstract this, but I can't think of a cleaner solution, and restructuring the whole thing would be very invasive.
I'm curious to hear from Marc on this one, but you can add:
Reviewed-by: Christoffer Dall christoffer.dall@linaro.org
because it looks correct.
Thanks for picking up my suggestion on the commenting.
I tried hard to find another solution, but I think this is unfortunately the best we can have... ;-)
So: Acked-by: Marc Zyngier narc.zyngier@arm.com
I will have to fold in a similar solution for the vgic-dyn series.
Thanks,
M.