From: Andrew Jones <ajones@xxxxxxxxxxxxxxxx> commit 41cad8284d5e6bf1d49d3c10a6b52ee1ae866a20 upstream. sbi_probe_extension() is specified with "Returns 0 if the given SBI extension ID (EID) is not available, or 1 if it is available unless defined as any other non-zero value by the implementation." Additionally, sbiret.value is a long. Fix the implementation to ensure any nonzero long value is considered a success, rather than only positive int values. Fixes: b9dcd9e41587 ("RISC-V: Add basic support for SBI v0.2") Signed-off-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx> Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20230427163626.101042-1-ajones@xxxxxxxxxxxxxxxx Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/riscv/include/asm/sbi.h | 2 +- arch/riscv/kernel/cpu_ops.c | 2 +- arch/riscv/kernel/sbi.c | 17 ++++++++--------- arch/riscv/kvm/main.c | 2 +- drivers/cpuidle/cpuidle-riscv-sbi.c | 2 +- drivers/perf/riscv_pmu_sbi.c | 2 +- 6 files changed, 13 insertions(+), 14 deletions(-) --- a/arch/riscv/include/asm/sbi.h +++ b/arch/riscv/include/asm/sbi.h @@ -293,7 +293,7 @@ int sbi_remote_hfence_vvma_asid(const st unsigned long start, unsigned long size, unsigned long asid); -int sbi_probe_extension(int ext); +long sbi_probe_extension(int ext); /* Check if current SBI specification version is 0.1 or not */ static inline int sbi_spec_is_0_1(void) --- a/arch/riscv/kernel/cpu_ops.c +++ b/arch/riscv/kernel/cpu_ops.c @@ -27,7 +27,7 @@ const struct cpu_operations cpu_ops_spin void __init cpu_set_ops(int cpuid) { #if IS_ENABLED(CONFIG_RISCV_SBI) - if (sbi_probe_extension(SBI_EXT_HSM) > 0) { + if (sbi_probe_extension(SBI_EXT_HSM)) { if (!cpuid) pr_info("SBI HSM extension detected\n"); cpu_ops[cpuid] = &cpu_ops_sbi; --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -581,19 +581,18 @@ static void sbi_srst_power_off(void) * sbi_probe_extension() - Check if an SBI extension ID is supported or not. * @extid: The extension ID to be probed. * - * Return: Extension specific nonzero value f yes, -ENOTSUPP otherwise. + * Return: 1 or an extension specific nonzero value if yes, 0 otherwise. */ -int sbi_probe_extension(int extid) +long sbi_probe_extension(int extid) { struct sbiret ret; ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_PROBE_EXT, extid, 0, 0, 0, 0, 0); if (!ret.error) - if (ret.value) - return ret.value; + return ret.value; - return -ENOTSUPP; + return 0; } EXPORT_SYMBOL(sbi_probe_extension); @@ -665,26 +664,26 @@ void __init sbi_init(void) if (!sbi_spec_is_0_1()) { pr_info("SBI implementation ID=0x%lx Version=0x%lx\n", sbi_get_firmware_id(), sbi_get_firmware_version()); - if (sbi_probe_extension(SBI_EXT_TIME) > 0) { + if (sbi_probe_extension(SBI_EXT_TIME)) { __sbi_set_timer = __sbi_set_timer_v02; pr_info("SBI TIME extension detected\n"); } else { __sbi_set_timer = __sbi_set_timer_v01; } - if (sbi_probe_extension(SBI_EXT_IPI) > 0) { + if (sbi_probe_extension(SBI_EXT_IPI)) { __sbi_send_ipi = __sbi_send_ipi_v02; pr_info("SBI IPI extension detected\n"); } else { __sbi_send_ipi = __sbi_send_ipi_v01; } - if (sbi_probe_extension(SBI_EXT_RFENCE) > 0) { + if (sbi_probe_extension(SBI_EXT_RFENCE)) { __sbi_rfence = __sbi_rfence_v02; pr_info("SBI RFENCE extension detected\n"); } else { __sbi_rfence = __sbi_rfence_v01; } if ((sbi_spec_version >= sbi_mk_version(0, 3)) && - (sbi_probe_extension(SBI_EXT_SRST) > 0)) { + sbi_probe_extension(SBI_EXT_SRST)) { pr_info("SBI SRST extension detected\n"); pm_power_off = sbi_srst_power_off; sbi_srst_reboot_nb.notifier_call = sbi_srst_reboot; --- a/arch/riscv/kvm/main.c +++ b/arch/riscv/kvm/main.c @@ -84,7 +84,7 @@ int kvm_arch_init(void *opaque) return -ENODEV; } - if (sbi_probe_extension(SBI_EXT_RFENCE) <= 0) { + if (!sbi_probe_extension(SBI_EXT_RFENCE)) { kvm_info("require SBI RFENCE extension\n"); return -ENODEV; } --- a/drivers/cpuidle/cpuidle-riscv-sbi.c +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c @@ -612,7 +612,7 @@ static int __init sbi_cpuidle_init(void) * 2) SBI HSM extension is available */ if ((sbi_spec_version < sbi_mk_version(0, 3)) || - sbi_probe_extension(SBI_EXT_HSM) <= 0) { + !sbi_probe_extension(SBI_EXT_HSM)) { pr_info("HSM suspend not available\n"); return 0; } --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -883,7 +883,7 @@ static int __init pmu_sbi_devinit(void) struct platform_device *pdev; if (sbi_spec_version < sbi_mk_version(0, 3) || - sbi_probe_extension(SBI_EXT_PMU) <= 0) { + !sbi_probe_extension(SBI_EXT_PMU)) { return 0; }