From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> Implement pv_kick with SBI guest implementation, and add SBI_EXT_PVLOCK extension detection. The backend part is in the KVM pvqspinlock patch. Reviewed-by: Leonardo Bras <leobras@xxxxxxxxxx> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> Signed-off-by: Guo Ren <guoren@xxxxxxxxxx> --- arch/riscv/include/asm/sbi.h | 6 ++++++ arch/riscv/kernel/qspinlock_paravirt.c | 7 ++++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 8f748d9e1b85..318b3dd92958 100644 --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -31,6 +31,7 @@ enum sbi_ext_id { SBI_EXT_SRST = 0x53525354, SBI_EXT_PMU = 0x504D55, SBI_EXT_DBCN = 0x4442434E, + SBI_EXT_PVLOCK = 0xAB0401, /* Experimentals extensions must lie within this range */ SBI_EXT_EXPERIMENTAL_START = 0x08000000, @@ -250,6 +251,11 @@ enum sbi_ext_dbcn_fid { SBI_EXT_DBCN_CONSOLE_WRITE_BYTE = 2, }; +/* kick cpu out of wfi */ +enum sbi_ext_pvlock_fid { + SBI_EXT_PVLOCK_KICK_CPU = 0, +}; + #define SBI_SPEC_VERSION_DEFAULT 0x1 #define SBI_SPEC_VERSION_MAJOR_SHIFT 24 #define SBI_SPEC_VERSION_MAJOR_MASK 0x7f diff --git a/arch/riscv/kernel/qspinlock_paravirt.c b/arch/riscv/kernel/qspinlock_paravirt.c index 85ff5a3ec234..7d1b99412222 100644 --- a/arch/riscv/kernel/qspinlock_paravirt.c +++ b/arch/riscv/kernel/qspinlock_paravirt.c @@ -11,6 +11,8 @@ void pv_kick(int cpu) { + sbi_ecall(SBI_EXT_PVLOCK, SBI_EXT_PVLOCK_KICK_CPU, + cpuid_to_hartid_map(cpu), 0, 0, 0, 0, 0); return; } @@ -25,7 +27,7 @@ void pv_wait(u8 *ptr, u8 val) if (READ_ONCE(*ptr) != val) goto out; - /* wait_for_interrupt(); */ + wait_for_interrupt(); out: local_irq_restore(flags); } @@ -49,6 +51,9 @@ void __init pv_qspinlock_init(void) if(sbi_get_firmware_id() != SBI_EXT_BASE_IMPL_ID_KVM) return; + if (!sbi_probe_extension(SBI_EXT_PVLOCK)) + return; + pr_info("PV qspinlocks enabled\n"); __pv_init_lock_hash(); -- 2.40.1