On 23/08/2025 03:26, Stefano Stabellini wrote:
> On Tue, 22 Jul 2025, Oleksii Moisieiev wrote:
>> From: Grygorii Strashko <grygorii_stras...@epam.com>
>>
>> The introduced SCI (System Control Interface) subsystem provides unified
>> interface to integrate in Xen SCI drivers which adds support for ARM
>> firmware (EL3, SCP) based software interfaces (like SCMI) that are used in
>> system management. The SCI subsystem allows to add drivers for different FW
>> interfaces or have different drivers for the same FW interface (for example,
>> SCMI with different transports).
>>
>> This patch updates SCMI over SMC calls handling layer, introduced by
>> commit 3e322bef8bc0 ("xen/arm: firmware: Add SCMI over SMC calls handling
>> layer"), to be SCI driver:
>> - convert to DT device;
>> - convert to SCI Xen interface.
>>
>> There are no functional changes in general, the driver is just adopted
>> to the SCI interface.
>>
>> Signed-off-by: Grygorii Strashko <grygorii_stras...@epam.com>
>> Signed-off-by: Oleksii Moisieiev <oleksii_moisie...@epam.com>
>> ---
>>
>>
>>
>> xen/arch/arm/firmware/Kconfig | 13 ++-
>> xen/arch/arm/firmware/scmi-smc.c | 93 +++++++++++---------
>> xen/arch/arm/include/asm/firmware/scmi-smc.h | 41 ---------
>> xen/arch/arm/vsmc.c | 5 +-
>> xen/include/public/arch-arm.h | 1 +
>> 5 files changed, 64 insertions(+), 89 deletions(-)
>> delete mode 100644 xen/arch/arm/include/asm/firmware/scmi-smc.h
>>
>> diff --git a/xen/arch/arm/firmware/Kconfig b/xen/arch/arm/firmware/Kconfig
>> index fc7918c7fc..bbf88fbb9a 100644
>> --- a/xen/arch/arm/firmware/Kconfig
>> +++ b/xen/arch/arm/firmware/Kconfig
>> @@ -8,9 +8,18 @@ config ARM_SCI
>>
>> menu "Firmware Drivers"
>>
>> +choice
>> + prompt "ARM SCI driver type"
>> + default SCMI_SMC
>> + help
>> + Choose which ARM SCI driver to enable.
>> +
>> +config ARM_SCI_NONE
>> + bool "none"
>> +
>> config SCMI_SMC
>> bool "Forward SCMI over SMC calls from hwdom to EL3 firmware"
>> - default y
>> + select ARM_SCI
>> help
>> This option enables basic awareness for SCMI calls using SMC as
>> doorbell mechanism and Shared Memory for transport ("arm,scmi-smc"
>> @@ -18,4 +27,6 @@ config SCMI_SMC
>> firmware node is used to trap and forward corresponding SCMI SMCs
>> to firmware running at EL3, for calls coming from the hardware domain.
>>
>> +endchoice
>> +
>> endmenu
>> diff --git a/xen/arch/arm/firmware/scmi-smc.c
>> b/xen/arch/arm/firmware/scmi-smc.c
>> index 33473c04b1..13d1137592 100644
>> --- a/xen/arch/arm/firmware/scmi-smc.c
>> +++ b/xen/arch/arm/firmware/scmi-smc.c
>> @@ -9,6 +9,7 @@
>> * Copyright 2024 NXP
>> */
>>
>> +#include <asm/device.h>
>> #include <xen/acpi.h>
>> #include <xen/device_tree.h>
>> #include <xen/errno.h>
>> @@ -16,12 +17,11 @@
>> #include <xen/sched.h>
>> #include <xen/types.h>
>>
>> +#include <asm/firmware/sci.h>
>> #include <asm/smccc.h>
>> -#include <asm/firmware/scmi-smc.h>
>>
>> #define SCMI_SMC_ID_PROP "arm,smc-id"
>>
>> -static bool __ro_after_init scmi_enabled;
>> static uint32_t __ro_after_init scmi_smc_id;
>>
>> /*
>> @@ -41,14 +41,11 @@ static bool scmi_is_valid_smc_id(uint32_t fid)
>> *
>> * Returns true if SMC was handled (regardless of response), false
>> otherwise.
>> */
>> -bool scmi_handle_smc(struct cpu_user_regs *regs)
>> +static bool scmi_handle_smc(struct cpu_user_regs *regs)
>> {
>> uint32_t fid = (uint32_t)get_user_reg(regs, 0);
>> struct arm_smccc_res res;
>>
>> - if ( !scmi_enabled )
>> - return false;
>> -
>> if ( !scmi_is_valid_smc_id(fid) )
>> return false;
>>
>> @@ -78,49 +75,45 @@ bool scmi_handle_smc(struct cpu_user_regs *regs)
>> return true;
>> }
>>
>> -static int __init scmi_check_smccc_ver(void)
>> +static int scmi_smc_domain_init(struct domain *d,
>> + struct xen_domctl_createdomain *config)
>> {
>> - if ( smccc_ver < ARM_SMCCC_VERSION_1_1 )
>> - {
>> - printk(XENLOG_WARNING
>> - "SCMI: No SMCCC 1.1 support, SCMI calls forwarding
>> disabled\n");
>> - return -ENOSYS;
>> - }
>> + if ( !is_hardware_domain(d) )
>> + return 0;
> Should we also check for config->arch.sci_type ==
> XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC ?
>
Current changes assume that only SCMI_SMC is present. This check was
added in the subsequent patch when multiagent was introduced.
>> + d->arch.sci_enabled = true;
>> + printk(XENLOG_DEBUG "SCMI: %pd init\n", d);
>> return 0;
>> }
