Messages in this thread | | | Date | Wed, 24 Jan 2024 08:03:53 -0600 | From | Lucas De Marchi <> | Subject | Re: Re: [PATCH 1/3] bits: introduce fixed-type genmasks |
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On Wed, Jan 24, 2024 at 09:58:26AM +0200, Jani Nikula wrote: >On Tue, 23 Jan 2024, Lucas De Marchi <lucas.demarchi@intel.com> wrote: >> From: Yury Norov <yury.norov@gmail.com> >> >> Generalize __GENMASK() to support different types, and implement >> fixed-types versions of GENMASK() based on it. The fixed-type version >> allows more strict checks to the min/max values accepted, which is >> useful for defining registers like implemented by i915 and xe drivers >> with their REG_GENMASK*() macros. > >Mmh, the commit message says the fixed-type version allows more strict >checks, but none are actually added. GENMASK_INPUT_CHECK() remains the >same. > >Compared to the i915 and xe versions, this is more lax now. You could >specify GENMASK_U32(63,32) without complaints.
Doing this on top of the this series:
-#define XELPDP_PORT_M2P_COMMAND_TYPE_MASK REG_GENMASK(30, 27) +#define XELPDP_PORT_M2P_COMMAND_TYPE_MASK REG_GENMASK(62, 32)
and I do get a build failure:
./drivers/gpu/drm/i915/display/intel_cx0_phy.c: In function ‘__intel_cx0_read_once’: ./include/linux/bits.h:41:31: error: left shift count >= width of type [-Werror=shift-count-overflow] 41 | (((t)~0ULL - ((t)(1) << (l)) + 1) & \ | ^~
I also tested them individually. All of these fail to build for me:
1) -#define XELPDP_PORT_M2P_COMMAND_TYPE_MASK REG_GENMASK(30, 27) +#define XELPDP_PORT_M2P_COMMAND_TYPE_MASK REG_GENMASK(32, 27)
2) -#define XELPDP_PORT_M2P_COMMAND_TYPE_MASK REG_GENMASK(30, 27) +#define XELPDP_PORT_M2P_COMMAND_TYPE_MASK REG_GENMASK(30, 31)
3) -#define XELPDP_PORT_M2P_COMMAND_TYPE_MASK REG_GENMASK(30, 27) +#define XELPDP_PORT_M2P_COMMAND_TYPE_MASK REG_GENMASK(30, -1)
Lucas De Marchi
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