Re: [PATCH 0/1] arm64/tools/sysreg: Add Sysreg128/SysregFields128

[Mark Rutland <mark.rutland@arm.com>]

On Thu, Aug 01, 2024 at 11:14:35AM +0530, Anshuman Khandual wrote:
> FEAT_SYSREG128 enables 128 bit wide system registers which also need to be
> defined in (arch/arm64/toos/sysreg) for auto mask generation. This adds two
> new field types i.e Sysreg128 and SysregFields128 for that same purpose. It
> utilizes recently added macro GENMASK_U128() while also adding some helpers
> such as define_field_128() and parse_bitdef_128().
> 
> This patch applies after the following series which adds GENMASK_U128()
> 
> https://lore.kernel.org/all/20240725054808.286708-1-anshuman.khandual@arm.com/

Is that patch merged or not? It wouod make a lot more sense to send them
together as one series.

> 
> A. Example for SysregFields128
> 
> ------------------------------
> SysregFields128 TTBRx_D128_EL1
> Res0   127:88
> Field  87:80   BADDR_HIGH
> Res0   79:64
> Field  63:48   ASID
> Field  47:5    BADDR_LOW
> Res0   4:3
> Field  2:1     SKL
> Field  0       CnP
> EndSysregFields128
> ------------------------------

Ok, so we get the definitions, but do we have all the other helpers we'd
need to make that useable, i.e.

* read_sysreg() and write_sysreg() variants that can use MRRS/MSRR

* Macros for assembly to use these?

* Other bitfield manipulation helpers that can operate on U128, e.g.
  FIELD_GET() and FIELD_PREP() ?

Without end-to-end usage this is a bit academic. If the U128 definitions
are oainful to use from asm we might want separate hi64/lo64
definitions.

Mark.

> The above input generates the following macros
> 
> #define TTBRx_D128_EL1_BADDR_HIGH                       GENMASK_U128(87, 80)
> #define TTBRx_D128_EL1_BADDR_HIGH_MASK                  GENMASK_U128(87, 80)
> #define TTBRx_D128_EL1_BADDR_HIGH_SHIFT                 80
> #define TTBRx_D128_EL1_BADDR_HIGH_WIDTH                 8
> 
> #define TTBRx_D128_EL1_ASID                             GENMASK_U128(63, 48)
> #define TTBRx_D128_EL1_ASID_MASK                        GENMASK_U128(63, 48)
> #define TTBRx_D128_EL1_ASID_SHIFT                       48
> #define TTBRx_D128_EL1_ASID_WIDTH                       16
> 
> #define TTBRx_D128_EL1_BADDR_LOW                        GENMASK_U128(47, 5)
> #define TTBRx_D128_EL1_BADDR_LOW_MASK                   GENMASK_U128(47, 5)
> #define TTBRx_D128_EL1_BADDR_LOW_SHIFT                  5
> #define TTBRx_D128_EL1_BADDR_LOW_WIDTH                  43
> 
> #define TTBRx_D128_EL1_SKL                              GENMASK_U128(2, 1)
> #define TTBRx_D128_EL1_SKL_MASK                         GENMASK_U128(2, 1)
> #define TTBRx_D128_EL1_SKL_SHIFT                        1
> #define TTBRx_D128_EL1_SKL_WIDTH                        2
> 
> #define TTBRx_D128_EL1_CnP                              GENMASK_U128(0, 0)
> #define TTBRx_D128_EL1_CnP_MASK                         GENMASK_U128(0, 0)
> #define TTBRx_D128_EL1_CnP_SHIFT                        0
> #define TTBRx_D128_EL1_CnP_WIDTH                        1
> 
> #define TTBRx_D128_EL1_RES0                             (UL(0) | GENMASK_U128(127, 88) | GENMASK_U128(79, 64) | GENMASK_U128(4, 3))
> #define TTBRx_D128_EL1_RES1                             (UL(0))
> #define TTBRx_D128_EL1_UNKN                             (UL(0))
> 
> B. Example Sysreg128
> 
> ------------------------------
> Sysreg128      TTBR1_D128_EL1  3       0       2       0       1
> Res0   127:88
> Field  87:80   BADDR_HIGH
> Res0   79:64
> Field  63:48   ASID
> Field  47:5    BADDR_LOW
> Res0   4:3
> Field  2:1     SKL
> Field  0       CnP
> EndSysreg128
> ------------------------------
> 
> The above input generates the following macros
> 
> #define REG_TTBR1_D128_EL1                              S3_0_C2_C0_1
> #define SYS_TTBR1_D128_EL1                              sys_reg(3, 0, 2, 0, 1)
> #define SYS_TTBR1_D128_EL1_Op0                          3
> #define SYS_TTBR1_D128_EL1_Op1                          0
> #define SYS_TTBR1_D128_EL1_CRn                          2
> #define SYS_TTBR1_D128_EL1_CRm                          0
> #define SYS_TTBR1_D128_EL1_Op2                          1
> 
> #define TTBR1_D128_EL1_BADDR_HIGH                       GENMASK_U128(87, 80)
> #define TTBR1_D128_EL1_BADDR_HIGH_MASK                  GENMASK_U128(87, 80)
> #define TTBR1_D128_EL1_BADDR_HIGH_SHIFT                 80
> #define TTBR1_D128_EL1_BADDR_HIGH_WIDTH                 8
> 
> #define TTBR1_D128_EL1_ASID                             GENMASK_U128(63, 48)
> #define TTBR1_D128_EL1_ASID_MASK                        GENMASK_U128(63, 48)
> #define TTBR1_D128_EL1_ASID_SHIFT                       48
> #define TTBR1_D128_EL1_ASID_WIDTH                       16
> 
> #define TTBR1_D128_EL1_BADDR_LOW                        GENMASK_U128(47, 5)
> #define TTBR1_D128_EL1_BADDR_LOW_MASK                   GENMASK_U128(47, 5)
> #define TTBR1_D128_EL1_BADDR_LOW_SHIFT                  5
> #define TTBR1_D128_EL1_BADDR_LOW_WIDTH                  43
> 
> #define TTBR1_D128_EL1_SKL                              GENMASK_U128(2, 1)
> #define TTBR1_D128_EL1_SKL_MASK                         GENMASK_U128(2, 1)
> #define TTBR1_D128_EL1_SKL_SHIFT                        1
> #define TTBR1_D128_EL1_SKL_WIDTH                        2
> 
> #define TTBR1_D128_EL1_CnP                              GENMASK_U128(0, 0)
> #define TTBR1_D128_EL1_CnP_MASK                         GENMASK_U128(0, 0)
> #define TTBR1_D128_EL1_CnP_SHIFT                        0
> #define TTBR1_D128_EL1_CnP_WIDTH                        1
> 
> #define TTBR1_D128_EL1_RES0                             (UL(0) | GENMASK_U128(127, 88) | GENMASK_U128(79, 64) | GENMASK_U128(4, 3))
> #define TTBR1_D128_EL1_RES1                             (UL(0))
> #define TTBR1_D128_EL1_UNKN                             (UL(0))
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Mark Brown <broonie@kernel.org>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> 
> Anshuman Khandual (1):
>   arm64/tools/sysreg: Add Sysreg128/SysregFields128
> 
>  arch/arm64/tools/gen-sysreg.awk | 231 ++++++++++++++++++++++++++++++++
>  1 file changed, 231 insertions(+)
> 
> -- 
> 2.30.2
> 
>