On Fri, 15 Sept 2023 at 18:17, Bjorn Andersson andersson@kernel.org wrote:
On Wed, Jun 07, 2023 at 10:23:45AM +0530, Kathiravan T wrote:
During SCM probe, to identify the SCM convention, scm call is made with SMC_CONVENTION_ARM_64 followed by SMC_CONVENTION_ARM_32. Based on the result what convention to be used is decided.
IPQ chipsets starting from IPQ807x, supports both 32bit and 64bit kernel variants, however TZ firmware runs in 64bit mode. When running on 32bit kernel, scm call is made with SMC_CONVENTION_ARM_64 is causing the system crash, due to the difference in the register sets between ARM and AARCH64, which is accessed by the TZ.
To avoid this, use SMC_CONVENTION_ARM_64 only on ARM64 builds.
My memory of this is cloudy, but I feel the logic is complicated because early 64-bit boards all used 32-bit TZ. So, I really would like Elliot's input before picking this change.
But this codepath is not changed by this patch. Only the 32-bit codepath is altered.
Regards, Bjorn
Cc: stable@vger.kernel.org Fixes: 9a434cee773a ("firmware: qcom_scm: Dynamically support SMCCC and legacy conventions") Signed-off-by: Kathiravan T quic_kathirav@quicinc.com
Changes in V2: - Added the Fixes tag and cc'd stable mailing list
drivers/firmware/qcom_scm.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c index fde33acd46b7..db6754db48a0 100644 --- a/drivers/firmware/qcom_scm.c +++ b/drivers/firmware/qcom_scm.c @@ -171,6 +171,7 @@ static enum qcom_scm_convention __get_convention(void) if (likely(qcom_scm_convention != SMC_CONVENTION_UNKNOWN)) return qcom_scm_convention;
+#if IS_ENABLED(CONFIG_ARM64) /* * Device isn't required as there is only one argument - no device * needed to dma_map_single to secure world @@ -191,6 +192,7 @@ static enum qcom_scm_convention __get_convention(void) forced = true; goto found; } +#endif
probed_convention = SMC_CONVENTION_ARM_32; ret = __scm_smc_call(NULL, &desc, probed_convention, &res, true);-- 2.17.1