Le 03/08/2023 à 19:33, Nick Desaulniers a écrit :
> Clang didn't recognize the instruction tlbilxlpid. This was fixed in
> clang-18 [0] then backported to clang-17 [1]. To support clang-16 and
> older, rather than using that instruction bare in inline asm, add it to
> ppc-opcode.h and use that macro as is done elsewhere for other
> instructions.
Can you mention that patch in https://github.com/linuxppc/issues/issues/350
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1891
> Link: https://github.com/llvm/llvm-project/issues/64080
> Link:
> https://github.com/llvm/llvm-project/commit/53648ac1d0c953ae6d008864dd2eddb437a92468
> [0]
> Link:
> https://github.com/llvm/llvm-project-release-prs/commit/0af7e5e54a8c7ac665773ac1ada328713e8338f5
> [1]
> Reported-by: kernel test robot
> Closes: https://lore.kernel.org/llvm/202307211945.tspcyohh-...@intel.com/
> Suggested-by: Michael Ellerman
> Signed-off-by: Nick Desaulniers
> ---
> Changes in v2:
> - add 2 missing tabs to PPC_RAW_TLBILX_LPID
> - Link to v1:
> https://lore.kernel.org/r/20230803-ppc_tlbilxlpid-v1-1-84a1bc5cf...@google.com
> ---
> arch/powerpc/include/asm/ppc-opcode.h | 4 +++-
> arch/powerpc/kvm/e500mc.c | 10 +++---
> 2 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/ppc-opcode.h
> b/arch/powerpc/include/asm/ppc-opcode.h
> index ef6972aa33b9..f37d8d8cbec6 100644
> --- a/arch/powerpc/include/asm/ppc-opcode.h
> +++ b/arch/powerpc/include/asm/ppc-opcode.h
> @@ -397,7 +397,8 @@
> #define PPC_RAW_RFCI(0x4c66)
> #define PPC_RAW_RFDI(0x4c4e)
> #define PPC_RAW_RFMCI (0x4c4c)
> -#define PPC_RAW_TLBILX(t, a, b) (0x7c24 | __PPC_T_TLB(t) |
> __PPC_RA0(a) | __PPC_RB(b))
> +#define PPC_RAW_TLBILX_LPID (0x7c24)
> +#define PPC_RAW_TLBILX(t, a, b) (PPC_RAW_TLBILX_LPID |
> __PPC_T_TLB(t) | __PPC_RA0(a) | __PPC_RB(b))
Can we avoid changing PPC_RAW_TLBILX to minimise the churn and minimise
the churn when we remove PPC_RAW_TLBILX_LPID in two years.
> #define PPC_RAW_WAIT_v203 (0x7c7c)
> #define PPC_RAW_WAIT(w, p) (0x7c3c | __PPC_WC(w) | __PPC_PL(p))
> #define PPC_RAW_TLBIE(lp, a)(0x7c000264 | ___PPC_RB(a) |
> ___PPC_RS(lp))
> @@ -616,6 +617,7 @@
> #define PPC_TLBILX(t, a, b) stringify_in_c(.long PPC_RAW_TLBILX(t, a, b))
> #define PPC_TLBILX_ALL(a, b)PPC_TLBILX(0, a, b)
> #define PPC_TLBILX_PID(a, b)PPC_TLBILX(1, a, b)
> +#define PPC_TLBILX_LPID stringify_in_c(.long
> PPC_RAW_TLBILX_LPID)
> #define PPC_TLBILX_VA(a, b) PPC_TLBILX(3, a, b)
> #define PPC_WAIT_v203 stringify_in_c(.long PPC_RAW_WAIT_v203)
> #define PPC_WAIT(w, p) stringify_in_c(.long PPC_RAW_WAIT(w, p))
> diff --git a/arch/powerpc/kvm/e500mc.c b/arch/powerpc/kvm/e500mc.c
> index d58df71ace58..dc054b8b5032 100644
> --- a/arch/powerpc/kvm/e500mc.c
> +++ b/arch/powerpc/kvm/e500mc.c
> @@ -16,10 +16,11 @@
> #include
> #include
>
> -#include
> #include
> -#include
> #include
> +#include
> +#include
> +#include
>
> #include "booke.h"
> #include "e500.h"
> @@ -92,7 +93,10 @@ void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500
> *vcpu_e500)
>
> local_irq_save(flags);
> mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(_e500->vcpu));
> - asm volatile("tlbilxlpid");
> + /* clang-17 and older could not assemble tlbilxlpid.
> + * https://github.com/ClangBuiltLinux/linux/issues/1891
> + */
I think that's the networking subsystem comments style.
Other parts of kernel have /* on its own empty line and the text starts
following line.
> + asm volatile (PPC_TLBILX_LPID);
> mtspr(SPRN_MAS5, 0);
> local_irq_restore(flags);
> }
>
> ---
> base-commit: 7bafbd4027ae86572f308c4ddf93120c90126332
> change-id: 20230803-ppc_tlbilxlpid-cfdbf4fd4f7f
>
> Best regards,
Christophe
