From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752511AbeBAMci (ORCPT ); Thu, 1 Feb 2018 07:32:38 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:49492 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752463AbeBAMcf (ORCPT ); Thu, 1 Feb 2018 07:32:35 -0500 Subject: Re: [PATCH v3 14/18] firmware/psci: Expose SMCCC version through psci_ops To: Marc Zyngier , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Cc: Catalin Marinas , Will Deacon , Peter Maydell , Christoffer Dall , Lorenzo Pieralisi , Mark Rutland , Ard Biesheuvel , Andrew Jones , Hanjun Guo , Jayachandran C , Jon Masters , Russell King - ARM Linux References: <20180201114657.7323-1-marc.zyngier@arm.com> <20180201114657.7323-15-marc.zyngier@arm.com> From: Robin Murphy Message-ID: <87705115-ca05-4d35-a169-51e1f3676133@arm.com> Date: Thu, 1 Feb 2018 12:32:31 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180201114657.7323-15-marc.zyngier@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/02/18 11:46, Marc Zyngier wrote: > Since PSCI 1.0 allows the SMCCC version to be (indirectly) probed, > let's do that at boot time, and expose the version of the calling > convention as part of the psci_ops structure. > > Acked-by: Lorenzo Pieralisi > Signed-off-by: Marc Zyngier > --- > drivers/firmware/psci.c | 19 +++++++++++++++++++ > include/linux/psci.h | 6 ++++++ > 2 files changed, 25 insertions(+) > > diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c > index e9493da2b111..8631906c414c 100644 > --- a/drivers/firmware/psci.c > +++ b/drivers/firmware/psci.c > @@ -61,6 +61,7 @@ bool psci_tos_resident_on(int cpu) > > struct psci_operations psci_ops = { > .conduit = PSCI_CONDUIT_NONE, > + .smccc_version = SMCCC_VERSION_1_0, > }; > > typedef unsigned long (psci_fn)(unsigned long, unsigned long, > @@ -511,6 +512,23 @@ static void __init psci_init_migrate(void) > pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid); > } > > +static void __init psci_init_smccc(u32 ver) > +{ > + int feature; > + > + feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID); > + > + if (feature != PSCI_RET_NOT_SUPPORTED) { > + ver = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0); > + if (ver != ARM_SMCCC_VERSION_1_1) > + psci_ops.smccc_version = SMCCC_VERSION_1_0; AFAICS, unless you somehow run psci_probe() twice *and* have schizophrenic firmware, this assignment now does precisely nothing. With the condition flipped and the redundant else case removed (or an explanation of why I'm wrong...) Reviewed-by: Robin Murphy > + else > + psci_ops.smccc_version = SMCCC_VERSION_1_1; > + } > + > + pr_info("SMC Calling Convention v1.%d\n", psci_ops.smccc_version); > +} > + > static void __init psci_0_2_set_functions(void) > { > pr_info("Using standard PSCI v0.2 function IDs\n"); > @@ -559,6 +577,7 @@ static int __init psci_probe(void) > psci_init_migrate(); > > if (PSCI_VERSION_MAJOR(ver) >= 1) { > + psci_init_smccc(ver); > psci_init_cpu_suspend(); > psci_init_system_suspend(); > } > diff --git a/include/linux/psci.h b/include/linux/psci.h > index f2679e5faa4f..8b1b3b5935ab 100644 > --- a/include/linux/psci.h > +++ b/include/linux/psci.h > @@ -31,6 +31,11 @@ enum psci_conduit { > PSCI_CONDUIT_HVC, > }; > > +enum smccc_version { > + SMCCC_VERSION_1_0, > + SMCCC_VERSION_1_1, > +}; > + > struct psci_operations { > u32 (*get_version)(void); > int (*cpu_suspend)(u32 state, unsigned long entry_point); > @@ -41,6 +46,7 @@ struct psci_operations { > unsigned long lowest_affinity_level); > int (*migrate_info_type)(void); > enum psci_conduit conduit; > + enum smccc_version smccc_version; > }; > > extern struct psci_operations psci_ops; >