Unverified Commit 41cad828 authored by Andrew Jones's avatar Andrew Jones Committed by Palmer Dabbelt
Browse files

RISC-V: Align SBI probe implementation with spec 



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: b9dcd9e4 ("RISC-V: Add basic support for SBI v0.2")
Signed-off-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Reviewed-by: default avatarConor Dooley <conor.dooley@microchip.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230427163626.101042-1-ajones@ventanamicro.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent e4ef93ed

arch/riscv/include/asm/sbi.h

+1 −1
Original line number Diff line number Diff line
@@ -295,7 +295,7 @@ int sbi_remote_hfence_vvma_asid(const struct cpumask *cpu_mask, 
				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)

arch/riscv/kernel/cpu_ops.c

+1 −1
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ const struct cpu_operations cpu_ops_spinwait = { 
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;

arch/riscv/kernel/sbi.c

+8 −9
Original line number Diff line number Diff line
@@ -524,19 +524,18 @@ 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 -ENOTSUPP;

	return 0;

}

EXPORT_SYMBOL(sbi_probe_extension);
@@ -599,26 +598,26 @@ 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;

arch/riscv/kvm/main.c

+1 −1
Original line number Diff line number Diff line
@@ -75,7 +75,7 @@ static int __init riscv_kvm_init(void) 
		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;

	}

drivers/cpuidle/cpuidle-riscv-sbi.c

+1 −1
Original line number Diff line number Diff line
@@ -613,7 +613,7 @@ 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;

	}