[PATCH v4 3/3] riscv: Call riscv_user_isa_enable() only on the boot hart

Samuel Holland samuel.holland at sifive.com
Wed Aug 14 01:10:56 PDT 2024


Now that the [ms]envcfg CSR value is maintained per thread, not per
hart, riscv_user_isa_enable() only needs to be called once during boot,
to set the value for the init task. This also allows it to be marked as
__init.

Reviewed-by: Andrew Jones <ajones at ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley at microchip.com>
Reviewed-by: Deepak Gupta <debug at rivosinc.com>
Signed-off-by: Samuel Holland <samuel.holland at sifive.com>
---

Changes in v4:
 - Rebase on riscv/for-next (v6.11-rc)
 - Add Conor's Reviewed-by tags from v2 (missed in v3)

Changes in v3:
 - Drop use of __initdata due to conflicts with cpufeature.c refactoring

Changes in v2:
 - Rebase on riscv/for-next

 arch/riscv/include/asm/cpufeature.h | 2 +-
 arch/riscv/kernel/cpufeature.c      | 4 ++--
 arch/riscv/kernel/smpboot.c         | 2 --
 3 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index 45f9c1171a48..ce9a995730c1 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -31,7 +31,7 @@ DECLARE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
 /* Per-cpu ISA extensions. */
 extern struct riscv_isainfo hart_isa[NR_CPUS];
 
-void riscv_user_isa_enable(void);
+void __init riscv_user_isa_enable(void);
 
 #define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size, _validate) {	\
 	.name = #_name,									\
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index df3e7e8d6d78..b3b9735cb19a 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -919,12 +919,12 @@ unsigned long riscv_get_elf_hwcap(void)
 	return hwcap;
 }
 
-void riscv_user_isa_enable(void)
+void __init riscv_user_isa_enable(void)
 {
 	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_ZICBOZ))
 		current->thread.envcfg |= ENVCFG_CBZE;
 	else if (any_cpu_has_zicboz)
-		pr_warn_once("Zicboz disabled as it is unavailable on some harts\n");
+		pr_warn("Zicboz disabled as it is unavailable on some harts\n");
 }
 
 #ifdef CONFIG_RISCV_ALTERNATIVE
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 0f8f1c95ac38..e36d20205bd7 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -233,8 +233,6 @@ asmlinkage __visible void smp_callin(void)
 	numa_add_cpu(curr_cpuid);
 	set_cpu_online(curr_cpuid, true);
 
-	riscv_user_isa_enable();
-
 	/*
 	 * Remote cache and TLB flushes are ignored while the CPU is offline,
 	 * so flush them both right now just in case.
-- 
2.45.1




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