[RFC PATCH 7/8] KVM: arm64: vgic-its: fix compatability with 32-bit

[Andre Przywara]

Hi,

On 21/10/16 10:36, Vladimir Murzin wrote:
> Evaluate GITS_BASER_ENTRY_SIZE once as an int data (GITS_BASER<n>'s
> Entry Size is 5-bit wide only), so when used as divider no reference
> to __aeabi_uldivmod is generated when build for AArch32.
> 
> Use unsigned long long for GITS_BASER_PAGE_SIZE_* since they are
> used in conjunction with 64-bit data.
> 
> Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>

Looks good to me, thanks for fixing this!

Reviewed-by: Andre Przywara <andre.przywara at arm.com>

Cheers,
Andre.

> ---
>  include/linux/irqchip/arm-gic-v3.h |    8 ++++----
>  virt/kvm/arm/vgic/vgic-its.c       |   11 ++++++-----
>  2 files changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index 5118d3a..e808f8a 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -295,10 +295,10 @@
>  #define GITS_BASER_InnerShareable					\
>  	GIC_BASER_SHAREABILITY(GITS_BASER, InnerShareable)
>  #define GITS_BASER_PAGE_SIZE_SHIFT	(8)
> -#define GITS_BASER_PAGE_SIZE_4K		(0UL << GITS_BASER_PAGE_SIZE_SHIFT)
> -#define GITS_BASER_PAGE_SIZE_16K	(1UL << GITS_BASER_PAGE_SIZE_SHIFT)
> -#define GITS_BASER_PAGE_SIZE_64K	(2UL << GITS_BASER_PAGE_SIZE_SHIFT)
> -#define GITS_BASER_PAGE_SIZE_MASK	(3UL << GITS_BASER_PAGE_SIZE_SHIFT)
> +#define GITS_BASER_PAGE_SIZE_4K		(0ULL << GITS_BASER_PAGE_SIZE_SHIFT)
> +#define GITS_BASER_PAGE_SIZE_16K	(1ULL << GITS_BASER_PAGE_SIZE_SHIFT)
> +#define GITS_BASER_PAGE_SIZE_64K	(2ULL << GITS_BASER_PAGE_SIZE_SHIFT)
> +#define GITS_BASER_PAGE_SIZE_MASK	(3ULL << GITS_BASER_PAGE_SIZE_SHIFT)
>  #define GITS_BASER_PAGES_MAX		256
>  #define GITS_BASER_PAGES_SHIFT		(0)
>  #define GITS_BASER_NR_PAGES(r)		(((r) & 0xff) + 1)
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 4660a7d..8c2b3cd 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -632,21 +632,22 @@ static bool vgic_its_check_id(struct vgic_its *its, u64 baser, int id)
>  	int index;
>  	u64 indirect_ptr;
>  	gfn_t gfn;
> +	int esz = GITS_BASER_ENTRY_SIZE(baser);
>  
>  	if (!(baser & GITS_BASER_INDIRECT)) {
>  		phys_addr_t addr;
>  
> -		if (id >= (l1_tbl_size / GITS_BASER_ENTRY_SIZE(baser)))
> +		if (id >= (l1_tbl_size / esz))
>  			return false;
>  
> -		addr = BASER_ADDRESS(baser) + id * GITS_BASER_ENTRY_SIZE(baser);
> +		addr = BASER_ADDRESS(baser) + id * esz;
>  		gfn = addr >> PAGE_SHIFT;
>  
>  		return kvm_is_visible_gfn(its->dev->kvm, gfn);
>  	}
>  
>  	/* calculate and check the index into the 1st level */
> -	index = id / (SZ_64K / GITS_BASER_ENTRY_SIZE(baser));
> +	index = id / (SZ_64K / esz);
>  	if (index >= (l1_tbl_size / sizeof(u64)))
>  		return false;
>  
> @@ -670,8 +671,8 @@ static bool vgic_its_check_id(struct vgic_its *its, u64 baser, int id)
>  	indirect_ptr &= GENMASK_ULL(51, 16);
>  
>  	/* Find the address of the actual entry */
> -	index = id % (SZ_64K / GITS_BASER_ENTRY_SIZE(baser));
> -	indirect_ptr += index * GITS_BASER_ENTRY_SIZE(baser);
> +	index = id % (SZ_64K / esz);
> +	indirect_ptr += index * esz;
>  	gfn = indirect_ptr >> PAGE_SHIFT;
>  
>  	return kvm_is_visible_gfn(its->dev->kvm, gfn);
>