From mboxrd@z Thu Jan 1 00:00:00 1970 From: victor.kamensky@linaro.org (Victor Kamensky) Date: Tue, 11 Feb 2014 21:57:23 -0800 Subject: [PATCH 5/5] ARM64: KVM: fix vgic_bitmap_get_reg function for BE 64bit case In-Reply-To: <1392184643-6108-1-git-send-email-victor.kamensky@linaro.org> References: <1392184643-6108-1-git-send-email-victor.kamensky@linaro.org> Message-ID: <1392184643-6108-6-git-send-email-victor.kamensky@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- virt/kvm/arm/vgic.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 7e11458..e56c5f8 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -96,14 +96,37 @@ static u32 vgic_nr_lr; static unsigned int vgic_maint_irq; +/* + * struct vgic_bitmap is union that provides two view of + * the same data. In one case it is array of registers of + * u32 type (.reg). And in another it is bitmap, which is + * array of 'unsgined long' (.reg_ul). It works all well in + * case of 32bit (u32 and 'unsigned long' have the same size). + * It works ok in 64bit LE case, where 'unsigned long' + * size is 8 bytes, while u32 is 4 bytes, and least siginificant + * word of 'unsigned long' matches lower index of .reg array. + * It breaks in 64bit BE case. In this case word sized + * register of even index actually resides in least significant + * word of 'unsigned long' which has address at offset plus 4 + * bytes. And word sized register of odd index resides at most + * significant of 'unsigned long' which has offset minus 4 + * bytes. Define REG_OFFSET_SWIZZLE that would help to + * change offset of register in case of BE 64bit system. + */ +#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); else - 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