Re: [kvm-unit-tests PATCH v11 3/8] riscv: Use asm-offsets to generate SBI_EXT_HSM values

[Andrew Jones <andrew.jones@linux.dev>]

On Mon, Mar 17, 2025 at 05:46:48PM +0100, Clément Léger wrote:
> Replace hardcoded values with generated ones using sbi-asm-offset. This
> allows to directly use ASM_SBI_EXT_HSM and ASM_SBI_EXT_HSM_STOP in
> assembly.
> 
> Signed-off-by: Clément Léger <cleger@rivosinc.com>
> Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
> ---
>  riscv/Makefile          |  2 +-
>  riscv/sbi-asm.S         |  6 ++++--
>  riscv/sbi-asm-offsets.c | 11 +++++++++++
>  riscv/.gitignore        |  1 +
>  4 files changed, 17 insertions(+), 3 deletions(-)
>  create mode 100644 riscv/sbi-asm-offsets.c
>  create mode 100644 riscv/.gitignore
> 
> diff --git a/riscv/Makefile b/riscv/Makefile
> index ae9cf02a..02d2ac39 100644
> --- a/riscv/Makefile
> +++ b/riscv/Makefile
> @@ -87,7 +87,7 @@ CFLAGS += -ffreestanding
>  CFLAGS += -O2
>  CFLAGS += -I $(SRCDIR)/lib -I $(SRCDIR)/lib/libfdt -I lib -I $(SRCDIR)/riscv
>  
> -asm-offsets = lib/riscv/asm-offsets.h
> +asm-offsets = lib/riscv/asm-offsets.h riscv/sbi-asm-offsets.h
>  include $(SRCDIR)/scripts/asm-offsets.mak
>  
>  .PRECIOUS: %.aux.o
> diff --git a/riscv/sbi-asm.S b/riscv/sbi-asm.S
> index f4185496..51f46efd 100644
> --- a/riscv/sbi-asm.S
> +++ b/riscv/sbi-asm.S
> @@ -6,6 +6,8 @@
>   */
>  #include <asm/asm.h>
>  #include <asm/csr.h>
> +#include <asm/asm-offsets.h>
> +#include <generated/sbi-asm-offsets.h>

Doing this causes sbi-asm.o to depend on generated files, so I had to add
the change below to the Makefile in order for 'make -j' to work.

Thanks,
drew


diff --git a/riscv/Makefile b/riscv/Makefile
index 02d2ac392f11..e4dba6772377 100644
--- a/riscv/Makefile
+++ b/riscv/Makefile
@@ -19,6 +19,8 @@ all: $(tests)

 $(TEST_DIR)/sbi-deps = $(TEST_DIR)/sbi-asm.o $(TEST_DIR)/sbi-fwft.o

+all_deps += $($(TEST_DIR)/sbi-deps)
+
 # When built for EFI sieve needs extra memory, run with e.g. '-m 256' on QEMU
 $(TEST_DIR)/sieve.$(exe): AUXFLAGS = 0x1

@@ -134,7 +136,7 @@ else
 endif

 generated-files = $(asm-offsets)
-$(tests:.$(exe)=.o) $(cstart.o) $(cflatobjs): $(generated-files)
+$(tests:.$(exe)=.o) $(cstart.o) $(cflatobjs) $(all_deps): $(generated-files)

 arch_clean: asm_offsets_clean
        $(RM) $(TEST_DIR)/*.{o,flat,elf,so,efi,debug} \

>  
>  #include "sbi-tests.h"
>  
> @@ -57,8 +59,8 @@ sbi_hsm_check:
>  7:	lb	t0, 0(t1)
>  	pause
>  	beqz	t0, 7b
> -	li	a7, 0x48534d	/* SBI_EXT_HSM */
> -	li	a6, 1		/* SBI_EXT_HSM_HART_STOP */
> +	li	a7, ASM_SBI_EXT_HSM
> +	li	a6, ASM_SBI_EXT_HSM_HART_STOP
>  	ecall
>  8:	pause
>  	j	8b
> diff --git a/riscv/sbi-asm-offsets.c b/riscv/sbi-asm-offsets.c
> new file mode 100644
> index 00000000..bd37b6a2
> --- /dev/null
> +++ b/riscv/sbi-asm-offsets.c
> @@ -0,0 +1,11 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include <kbuild.h>
> +#include <asm/sbi.h>
> +
> +int main(void)
> +{
> +	DEFINE(ASM_SBI_EXT_HSM, SBI_EXT_HSM);
> +	DEFINE(ASM_SBI_EXT_HSM_HART_STOP, SBI_EXT_HSM_HART_STOP);
> +
> +	return 0;
> +}
> diff --git a/riscv/.gitignore b/riscv/.gitignore
> new file mode 100644
> index 00000000..0a8c5a36
> --- /dev/null
> +++ b/riscv/.gitignore
> @@ -0,0 +1 @@
> +/*-asm-offsets.[hs]
> -- 
> 2.47.2
>