diff options
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-mmio.h')
| -rw-r--r-- | virt/kvm/arm/vgic/vgic-mmio.h | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h index 0b3ecf9d100e..84961b4e4422 100644 --- a/virt/kvm/arm/vgic/vgic-mmio.h +++ b/virt/kvm/arm/vgic/vgic-mmio.h @@ -50,15 +50,15 @@ extern struct kvm_io_device_ops kvm_io_gic_ops; #define VGIC_ADDR_IRQ_MASK(bits) (((bits) * 1024 / 8) - 1) /* - * (addr & mask) gives us the byte offset for the INT ID, so we want to - * divide this with 'bytes per irq' to get the INT ID, which is given - * by '(bits) / 8'. But we do this with fixed-point-arithmetic and - * take advantage of the fact that division by a fraction equals - * multiplication with the inverted fraction, and scale up both the - * numerator and denominator with 8 to support at most 64 bits per IRQ: + * (addr & mask) gives us the _byte_ offset for the INT ID. + * We multiply this by 8 the get the _bit_ offset, then divide this by + * the number of bits to learn the actual INT ID. + * But instead of a division (which requires a "long long div" implementation), + * we shift by the binary logarithm of <bits>. + * This assumes that <bits> is a power of two. */ #define VGIC_ADDR_TO_INTID(addr, bits) (((addr) & VGIC_ADDR_IRQ_MASK(bits)) * \ - 64 / (bits) / 8) + 8 >> ilog2(bits)) /* * Some VGIC registers store per-IRQ information, with a different number @@ -96,7 +96,7 @@ unsigned long vgic_data_mmio_bus_to_host(const void *val, unsigned int len); void vgic_data_host_to_mmio_bus(void *buf, unsigned int len, unsigned long data); -unsigned long extract_bytes(unsigned long data, unsigned int offset, +unsigned long extract_bytes(u64 data, unsigned int offset, unsigned int num); u64 update_64bit_reg(u64 reg, unsigned int offset, unsigned int len, @@ -162,12 +162,10 @@ unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev); unsigned int vgic_v3_init_dist_iodev(struct vgic_io_device *dev); -#ifdef CONFIG_KVM_ARM_VGIC_V3 u64 vgic_sanitise_outer_cacheability(u64 reg); u64 vgic_sanitise_inner_cacheability(u64 reg); u64 vgic_sanitise_shareability(u64 reg); u64 vgic_sanitise_field(u64 reg, u64 field_mask, int field_shift, u64 (*sanitise_fn)(u64)); -#endif #endif |
