On Thu, Sep 03, 2020 at 08:01:41PM +0000, Yazen Ghannam wrote:
> From: Yazen Ghannam <[email protected]>
>
> Define macros to get individual bits and bitfields. Use these to make
> the code more readable.
>
> Signed-off-by: Yazen Ghannam <[email protected]>
> ---
> Link:
> https://lkml.kernel.org/r/[email protected]
>
> v1 -> v2:
> * New patch based on comments for v1 Patch 2.
>
> arch/x86/kernel/cpu/mce/amd.c | 46 +++++++++++++++++------------------
> 1 file changed, 23 insertions(+), 23 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
> index 1e0510fd5afc..90c3ad61ae19 100644
> --- a/arch/x86/kernel/cpu/mce/amd.c
> +++ b/arch/x86/kernel/cpu/mce/amd.c
> @@ -675,6 +675,9 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
> deferred_error_interrupt_enable(c);
> }
>
> +#define get_bits(x, msb, lsb) ((x & GENMASK_ULL(msb, lsb)) >> lsb)
> +#define get_bit(x, bit) ((x >> bit) & BIT(0))
> +
> #define DF_F0_FABRICINSTINFO3 0x50
> #define DF_F0_MMIOHOLE 0x104
> #define DF_F0_DRAMBASEADDR 0x110
> @@ -704,7 +707,7 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8
> umc, u64 *sys_addr)
>
> /* Remove HiAddrOffset from normalized address, if enabled: */
> if (tmp & BIT(0)) {
> - u64 hi_addr_offset = (tmp & GENMASK_ULL(31, 20)) << 8;
> + u64 hi_addr_offset = get_bits(tmp, 31, 20) << 28;
>
> /* Check if base 1 is used. */
> if (norm_addr >= hi_addr_offset) {
> @@ -723,10 +726,10 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8
> umc, u64 *sys_addr)
> goto out_err;
> }
>
> - lgcy_mmio_hole_en = tmp & BIT(1);
> - intlv_num_chan = (tmp >> 4) & 0xF;
> - intlv_addr_sel = (tmp >> 8) & 0x7;
> - dram_base_addr = (tmp & GENMASK_ULL(31, 12)) << 16;
> + lgcy_mmio_hole_en = get_bit(tmp, 1);
> + intlv_num_chan = get_bits(tmp, 7, 4);
> + intlv_addr_sel = get_bits(tmp, 10, 8);
> + dram_base_addr = get_bits(tmp, 31, 12) << 28;
I can't say that those macros make it more readable. Now I have to go
lookup what the arguments are. I guess I can imagine what the msb and
lsb is but meh...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
