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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [RFC PATCH v3 4/7] xen/arm: scmi: introduce SCI SCMI SMC multi-agent driver
On Tue, 11 Mar 2025, Grygorii Strashko wrote:
> From: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
>
> This patch introduces SCI driver to support for ARM EL3 Trusted Firmware-A
> (TF-A) which provides SCMI interface with multi-agnet support, as shown
> below.
>
> +-----------------------------------------+
> | |
> | EL3 TF-A SCMI |
> +-------+--+-------+--+-------+--+-------++
> |shmem0 | |shmem1 | |shmem2 | |shmemX |
> +-----+-+ +---+---+ +--+----+ +---+---+
> smc-id0 | | | |
> agent0 | | | |
> +-----v--------+---------+-----------+----+
> | | | | |
> | | | | |
> +--------------+---------+-----------+----+
> smc-id1 | smc-id2| smc-idX|
> agent1 | agent2 | agentX |
> | | |
> +----v---+ +--v-----+ +--v-----+
> | | | | | |
> | Dom0 | | Dom1 | | DomX |
> | | | | | |
> | | | | | |
> +--------+ +--------+ +--------+
>
> The EL3 SCMI multi-agent firmware expected to provide SCMI SMC/HVC shared
> memory transport for every Agent in the system.
>
> The SCMI Agent transport channel defined by pair:
> - smc-id: SMC/HVC id used for Doorbell
> - shmem: shared memory for messages transfer, Xen page aligned,
> p2m_mmio_direct_nc.
>
> The follwoing SCMI Agents expected to be defined by SCMI FW to enable SCMI
> multi-agent functionality under Xen:
> - Xen manegement agent: trusted agents that accesses to the Base Protocol
> commands to configure agent specific permissions
> - OSPM VM agents: non-trusted agent, one for each Guest domain which is
> allowed direct HW access. At least one OSPM VM agent has to be provided
> by FW if HW is handled only by Dom0 or Driver Domain.
>
> The EL3 SCMI FW expected to implement following Base protocol messages:
> - BASE_DISCOVER_AGENT
> - BASE_RESET_AGENT_CONFIGURATION (optional)
> - BASE_SET_DEVICE_PERMISSIONS (optional)
>
> The SCI SCMI SMC multi-agent driver implements following functionality:
> - It's initialized based on the Host DT SCMI node (only one SCMI interface
> is supported) which describes Xen management agent SCMI interface.
>
> scmi_shm_0 : sram@47ff0000 {
> compatible = "arm,scmi-shmem";
> reg = <0x0 0x47ff0000 0x0 0x1000>;
> };
> firmware {
> scmi: scmi {
> compatible = "arm,scmi-smc";
> arm,smc-id = <0x82000002>; // Xen manegement agent smc-id
> \#address-cells = < 1>;
> \#size-cells = < 0>;
> \#access-controller - cells = < 1>;
> shmem = <&scmi_shm_0>; // Xen manegement agent shmem
>
> protocol@X{
> };
> };
> };
>
> - It obtains Xen specific SCMI Agent's configuration from the Host DT,
> probes Agents and build SCMI Agents list. The Agents configuration
> is taken from:
>
> chosen {
> xen,scmi-secondary-agents = <
> 1 0x82000003 &scmi_shm_1
> 2 0x82000004 &scmi_shm_2
> 3 0x82000005 &scmi_shm_3
> 4 0x82000006 &scmi_shm_4>;
> }
>
> /{
> scmi_shm_1: sram@47ff1000 {
> compatible = "arm,scmi-shmem";
> reg = <0x0 0x47ff1000 0x0 0x1000>;
> };
> scmi_shm_2: sram@47ff2000 {
> compatible = "arm,scmi-shmem";
> reg = <0x0 0x47ff2000 0x0 0x1000>;
> };
> scmi_shm_3: sram@47ff3000 {
> compatible = "arm,scmi-shmem";
> reg = <0x0 0x47ff3000 0x0 0x1000>;
All the shared memory regions need two addresses: the host address and
the guest address. They might be different to avoid address collisions.
The guest address could be optional, and if absent we could assume 1:1.
Also, these nodes under chosen should be documented in
docs/misc/arm/device-tree/booting.txt
> };
> }
> where first item is "agent_id", second - "arm,smc-id", and third -
> "arm,scmi-shmem" for
> this agent_id.
>
> Note that Xen is the only one entry in the system which need to know
> about SCMI multi-agent support.
>
> - It implements the SCI subsystem interface required for configuring and
> enabling SCMI functionality for Dom0/hwdom and Guest domains. To enable
> SCMI functionality for domain it has to be configured with unique supported
> SCMI Agent_id and use corresponding SCMI SMC/HVC shared memory transport
> [smc-id, shmem] defined for this SCMI Agent_id.
> - Once Xen domain is configured it can communicate with EL3 SCMI FW:
> -- zero-copy, the guest domain puts SCMI message in shmem;
> -- the guest triggers SMC/HVC exception with smc-id (doorbell);
> -- the Xen driver catches exception, do checks and synchronously forwards
> it to EL3 FW.
> - the Xen driver sends BASE_RESET_AGENT_CONFIGURATION message to Xen
> management agent channel on domain destroy event. This allows to reset
> resources used by domain and so implement use-case like domain reboot.
>
> Dom0 Enable SCMI SMC:
> - pass dom0_scmi_agent_id=<agent_id> in Xen command line option. if not
> provided
> SCMI will be disabled for Dom0 and all SCMI nodes removed from Dom0 DT.
> The driver updates Dom0 DT SCMI node "arm,smc-id" value and fix up shmem
> node according to assigned agent_id.
I know dom0less is not enabled at this point, but if we had dom0less
support, we would need a way in device tree to specify the agend_id for
every dom0less domain, and ideally we would use the same device tree
binding for dom0 too (or something very similar).
> Guest domains enable SCMI SMC:
> - xl.cfg: add configuration option as below
>
> arm_sci = "type=scmi_smc_multiagent,agent_id=2"
>
> - xl.cfg: enable access to the "arm,scmi-shmem" which should correspond
> assigned agent_id for
> the domain, for example:
>
> iomem = [
> "47ff2,1@22001",
> ]
>
> - DT: add SCMI nodes to the Driver domain partial device tree as in the
> below example. The "arm,smc-id" should correspond assigned agent_id for the
> domain:
>
> passthrough {
> scmi_shm_0: sram@22001000 {
> compatible = "arm,scmi-shmem";
> reg = <0x0 0x22001000 0x0 0x1000>;
> };
>
> firmware {
> compatible = "simple-bus";
> scmi: scmi {
> compatible = "arm,scmi-smc";
> arm,smc-id = <0x82000004>;
> shmem = <&scmi_shm_0>;
> ...
> }
> }
> }
>
> SCMI "4.2.1.1 Device specific access control"
>
> The XEN SCI SCMI SMC multi-agent driver performs "access-controller" provider
> function
> in case EL3 SCMI FW implements SCMI "4.2.1.1 Device specific access control"
> and provides the
> BASE_SET_DEVICE_PERMISSIONS command to configure the devices that an agents
> have access to.
> The DT SCMI node should "#access-controller-cells=<1>" property and DT
> devices should be bound
> to the Xen SCMI.
>
> &i2c1 {
> access-controllers = <&scmi 0>;
> };
>
> The Dom0 and dom0less (TBD) domains DT devices will be processed
> automatically through
> sci_assign_dt_device() call, but to assign SCMI devices from toolstack the
> xl.cfg:"dtdev" property
> shell be used:
>
> dtdev = [
> "/soc/i2c@e6508000",
> ]
>
> xl.cfg:dtdev will contain all nodes which are under SCMI management (not only
> those which are behind IOMMU).
This commit message is great documentation. Please add it as a text
document under docs/misc/arm
>
> TODO:
> - dom0less is not fully supported yet
> - move memcpy_fro/tomio in separate patch
>
> [1]
> https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> [2]
> https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/access-controllers/access-controllers.yaml
> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> Signed-off-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
> ---
> docs/man/xl.cfg.5.pod.in | 15 +
> docs/misc/xen-command-line.pandoc | 9 +
> tools/libs/light/libxl_arm.c | 4 +
> tools/libs/light/libxl_types.idl | 4 +-
> tools/xl/xl_parse.c | 17 +
> xen/arch/arm/domain_build.c | 3 +-
> xen/arch/arm/firmware/Kconfig | 11 +
> xen/arch/arm/firmware/Makefile | 1 +
> xen/arch/arm/firmware/scmi-proto.h | 164 ++++
> xen/arch/arm/firmware/scmi-shmem.c | 172 ++++
> xen/arch/arm/firmware/scmi-shmem.h | 45 +
> xen/arch/arm/firmware/scmi-smc-multiagent.c | 856 ++++++++++++++++++++
> xen/include/public/arch-arm.h | 3 +
> 13 files changed, 1302 insertions(+), 2 deletions(-)
> create mode 100644 xen/arch/arm/firmware/scmi-proto.h
> create mode 100644 xen/arch/arm/firmware/scmi-shmem.c
> create mode 100644 xen/arch/arm/firmware/scmi-shmem.h
> create mode 100644 xen/arch/arm/firmware/scmi-smc-multiagent.c
>
> diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
> index 7edf272386e3..fc6041724a13 100644
> --- a/docs/man/xl.cfg.5.pod.in
> +++ b/docs/man/xl.cfg.5.pod.in
> @@ -3126,6 +3126,21 @@ single SCMI OSPM agent support.
> Should be used together with B<dom0_scmi_smc_passthrough> Xen command line
> option.
>
> +=item B<scmi_smc_multiagent>
> +
> +Enables ARM SCMI SMC multi-agent support for the guest by enabling SCMI over
> +SMC calls forwarding from domain to the EL3 firmware (like Trusted
> Firmware-A)
> +with a multi SCMI OSPM agent support. The SCMI B<agent_id> should be
> +specified for the guest.
> +
> +=back
> +
> +=item B<agent_id=NUMBER>
> +
> +Specifies a non-zero ARM SCI agent id for the guest. This option is mandatory
> +if the SCMI SMC support is enabled for the guest. The agent ids of domains
> +existing on a single host must be unique.
> +
> =back
>
> =back
> diff --git a/docs/misc/xen-command-line.pandoc
> b/docs/misc/xen-command-line.pandoc
> index 8e50f6b7c7ac..bc3c64d6ec90 100644
> --- a/docs/misc/xen-command-line.pandoc
> +++ b/docs/misc/xen-command-line.pandoc
> @@ -1091,6 +1091,15 @@ which serves as Driver domain. The SCMI will be
> disabled for Dom0/hwdom and
> SCMI nodes removed from Dom0/hwdom device tree.
> (for example, thin Dom0 with Driver domain use-case).
>
> +### dom0_scmi_agent_id (ARM)
> +> `= <integer>`
> +
> +The option is available when `CONFIG_SCMI_SMC_MA` is compiled in, and allows
> to
> +enable SCMI functionality for Dom0 by specifying a non-zero ARM SCMI agent
> id.
> +The SCMI will be disabled for Dom0 if this option is not specified
> +(for example, thin Dom0 or dom0less use-cases).
> +The agent ids of domains existing on a single host must be unique.
> +
> ### dtuart (ARM)
> > `= path [:options]`
>
> diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c
> index d41adea1cefd..cdf5edb299af 100644
> --- a/tools/libs/light/libxl_arm.c
> +++ b/tools/libs/light/libxl_arm.c
> @@ -229,6 +229,10 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
> case LIBXL_ARM_SCI_TYPE_SCMI_SMC:
> config->arch.arm_sci_type = XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC;
> break;
> + case LIBXL_ARM_SCI_TYPE_SCMI_SMC_MULTIAGENT:
> + config->arch.arm_sci_type = XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA;
> + config->arch.arm_sci_agent_id = d_config->b_info.arm_sci.agent_id;
> + break;
> default:
> LOG(ERROR, "Unknown ARM_SCI type %d",
> d_config->b_info.arm_sci.type);
> diff --git a/tools/libs/light/libxl_types.idl
> b/tools/libs/light/libxl_types.idl
> index ea0d30654cdd..e6707c7ca9e7 100644
> --- a/tools/libs/light/libxl_types.idl
> +++ b/tools/libs/light/libxl_types.idl
> @@ -553,11 +553,13 @@ libxl_sve_type = Enumeration("sve_type", [
>
> libxl_arm_sci_type = Enumeration("arm_sci_type", [
> (0, "none"),
> - (1, "scmi_smc")
> + (1, "scmi_smc"),
> + (2, "scmi_smc_multiagent")
> ], init_val = "LIBXL_ARM_SCI_TYPE_NONE")
>
> libxl_arm_sci = Struct("arm_sci", [
> ("type", libxl_arm_sci_type),
> + ("agent_id", uint8)
> ])
>
> libxl_rdm_reserve = Struct("rdm_reserve", [
> diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
> index ac9bf0b25c5a..011222ec55b9 100644
> --- a/tools/xl/xl_parse.c
> +++ b/tools/xl/xl_parse.c
> @@ -1290,6 +1290,7 @@ static int parse_arm_sci_config(XLU_Config *cfg,
> libxl_arm_sci *arm_sci,
> enum {
> STATE_OPTION,
> STATE_TYPE,
> + STATE_AGENT_ID,
> STATE_TERMINAL,
> };
> int ret, state = STATE_OPTION;
> @@ -1305,6 +1306,8 @@ static int parse_arm_sci_config(XLU_Config *cfg,
> libxl_arm_sci *arm_sci,
> *ptr = '\0';
> if (!strcmp(tok, "type")) {
> state = STATE_TYPE;
> + } else if (!strcmp(tok, "agent_id")) {
> + state = STATE_AGENT_ID;
> } else {
> fprintf(stderr, "Unknown ARM_SCI option: %s\n", tok);
> goto parse_error;
> @@ -1324,11 +1327,24 @@ static int parse_arm_sci_config(XLU_Config *cfg,
> libxl_arm_sci *arm_sci,
> tok = ptr + 1;
> }
> break;
> + case STATE_AGENT_ID:
> + if (*ptr == ',' || *ptr == '\0') {
> + state = *ptr == ',' ? STATE_OPTION : STATE_TERMINAL;
> + *ptr = '\0';
> + arm_sci->agent_id = strtoul(tok, NULL, 0);
> + tok = ptr + 1;
> + }
> default:
> break;
> }
> }
>
> + if (arm_sci->type == LIBXL_ARM_SCI_TYPE_SCMI_SMC_MULTIAGENT &&
> + arm_sci->agent_id == 0) {
> + fprintf(stderr, "A non-zero ARM_SCI agent_id must be specified\n");
> + goto parse_error;
> + }
> +
> if (tok != ptr || state != STATE_TERMINAL)
> goto parse_error;
>
> @@ -3042,6 +3058,7 @@ skip_usbdev:
> libxl_arm_sci arm_sci = { 0 };
> if (!parse_arm_sci_config(config, &arm_sci, buf)) {
> b_info->arm_sci.type = arm_sci.type;
> + b_info->arm_sci.agent_id = arm_sci.agent_id;
> } else {
> exit(EXIT_FAILURE);
> }
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 36d28b52a418..9238771a4aac 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -616,7 +616,8 @@ static int __init write_properties(struct domain *d,
> struct kernel_info *kinfo,
> dt_property_name_is_equal(prop, "linux,uefi-mmap-start") ||
> dt_property_name_is_equal(prop, "linux,uefi-mmap-size") ||
> dt_property_name_is_equal(prop,
> "linux,uefi-mmap-desc-size") ||
> - dt_property_name_is_equal(prop, "linux,uefi-mmap-desc-ver"))
> + dt_property_name_is_equal(prop, "linux,uefi-mmap-desc-ver")
> ||
> + dt_property_name_is_equal(prop,
> "xen,scmi-secondary-agents"))
> continue;
>
> if ( dt_property_name_is_equal(prop, "xen,dom0-bootargs") )
> diff --git a/xen/arch/arm/firmware/Kconfig b/xen/arch/arm/firmware/Kconfig
> index 2686ba313898..63fc5eac8d52 100644
> --- a/xen/arch/arm/firmware/Kconfig
> +++ b/xen/arch/arm/firmware/Kconfig
> @@ -29,6 +29,17 @@ config SCMI_SMC
> driver domain.
> Use with EL3 firmware which supports only single SCMI OSPM agent.
>
> +config SCMI_SMC_MA
> + bool "Enable ARM SCMI SMC multi-agent driver"
> + select ARM_SCI
> + help
> + Enables SCMI SMC/HVC multi-agent in XEN to pass SCMI requests from
> Domains
> + to EL3 firmware (TF-A) which supports multi-agent feature.
> + This feature allows to enable SCMI per Domain using unique SCMI
> agent_id,
> + so Domain is identified by EL3 firmware as an SCMI Agent and can
> access
> + allowed platform resources through dedicated SMC/HVC Shared memory
> based
> + transport.
> +
> endchoice
>
> endmenu
> diff --git a/xen/arch/arm/firmware/Makefile b/xen/arch/arm/firmware/Makefile
> index 71bdefc24afb..37927e690e98 100644
> --- a/xen/arch/arm/firmware/Makefile
> +++ b/xen/arch/arm/firmware/Makefile
> @@ -1,2 +1,3 @@
> obj-$(CONFIG_ARM_SCI) += sci.o
> obj-$(CONFIG_SCMI_SMC) += scmi-smc.o
> +obj-$(CONFIG_SCMI_SMC_MA) += scmi-shmem.o scmi-smc-multiagent.o
> diff --git a/xen/arch/arm/firmware/scmi-proto.h
> b/xen/arch/arm/firmware/scmi-proto.h
> new file mode 100644
> index 000000000000..3f4b9c5d6b7c
> --- /dev/null
> +++ b/xen/arch/arm/firmware/scmi-proto.h
> @@ -0,0 +1,164 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Arm System Control and Management Interface definitions
> + * Version 3.0 (DEN0056C)
> + *
> + * Copyright (c) 2024 EPAM Systems
> + */
> +
> +#ifndef XEN_ARCH_ARM_SCI_SCMI_PROTO_H_
> +#define XEN_ARCH_ARM_SCI_SCMI_PROTO_H_
> +
> +#include <xen/stdint.h>
> +
> +#define SCMI_SHORT_NAME_MAX_SIZE 16
> +
> +/* SCMI status codes. See section 4.1.4 */
> +#define SCMI_SUCCESS 0
> +#define SCMI_NOT_SUPPORTED (-1)
> +#define SCMI_INVALID_PARAMETERS (-2)
> +#define SCMI_DENIED (-3)
> +#define SCMI_NOT_FOUND (-4)
> +#define SCMI_OUT_OF_RANGE (-5)
> +#define SCMI_BUSY (-6)
> +#define SCMI_COMMS_ERROR (-7)
> +#define SCMI_GENERIC_ERROR (-8)
> +#define SCMI_HARDWARE_ERROR (-9)
> +#define SCMI_PROTOCOL_ERROR (-10)
> +
> +/* Protocol IDs */
> +#define SCMI_BASE_PROTOCOL 0x10
> +
> +/* Base protocol message IDs */
> +#define SCMI_BASE_PROTOCOL_VERSION 0x0
> +#define SCMI_BASE_PROTOCOL_ATTIBUTES 0x1
> +#define SCMI_BASE_PROTOCOL_MESSAGE_ATTRIBUTES 0x2
> +#define SCMI_BASE_DISCOVER_AGENT 0x7
> +#define SCMI_BASE_SET_DEVICE_PERMISSIONS 0x9
> +#define SCMI_BASE_RESET_AGENT_CONFIGURATION 0xB
> +
> +typedef struct scmi_msg_header {
> + uint8_t id;
> + uint8_t type;
> + uint8_t protocol;
> + uint32_t status;
> +} scmi_msg_header_t;
> +
> +/* Table 2 Message header format */
> +#define SCMI_HDR_ID GENMASK(7, 0)
> +#define SCMI_HDR_TYPE GENMASK(9, 8)
> +#define SCMI_HDR_PROTO GENMASK(17, 10)
> +
> +#define SCMI_FIELD_GET(_mask, _reg)
> \
> + ((typeof(_mask))(((_reg) & (_mask)) >> (ffs64(_mask) - 1)))
> +#define SCMI_FIELD_PREP(_mask, _val)
> \
> + (((typeof(_mask))(_val) << (ffs64(_mask) - 1)) & (_mask))
> +
> +static inline uint32_t pack_scmi_header(scmi_msg_header_t *hdr)
> +{
> + return SCMI_FIELD_PREP(SCMI_HDR_ID, hdr->id) |
> + SCMI_FIELD_PREP(SCMI_HDR_TYPE, hdr->type) |
> + SCMI_FIELD_PREP(SCMI_HDR_PROTO, hdr->protocol);
> +}
> +
> +static inline void unpack_scmi_header(uint32_t msg_hdr, scmi_msg_header_t
> *hdr)
> +{
> + hdr->id = SCMI_FIELD_GET(SCMI_HDR_ID, msg_hdr);
> + hdr->type = SCMI_FIELD_GET(SCMI_HDR_TYPE, msg_hdr);
> + hdr->protocol = SCMI_FIELD_GET(SCMI_HDR_PROTO, msg_hdr);
> +}
> +
> +static inline int scmi_to_xen_errno(int scmi_status)
> +{
> + if ( scmi_status == SCMI_SUCCESS )
> + return 0;
> +
> + switch ( scmi_status )
> + {
> + case SCMI_NOT_SUPPORTED:
> + return -EOPNOTSUPP;
> + case SCMI_INVALID_PARAMETERS:
> + return -EINVAL;
> + case SCMI_DENIED:
> + return -EACCES;
> + case SCMI_NOT_FOUND:
> + return -ENOENT;
> + case SCMI_OUT_OF_RANGE:
> + return -ERANGE;
> + case SCMI_BUSY:
> + return -EBUSY;
> + case SCMI_COMMS_ERROR:
> + return -ENOTCONN;
> + case SCMI_GENERIC_ERROR:
> + return -EIO;
> + case SCMI_HARDWARE_ERROR:
> + return -ENXIO;
> + case SCMI_PROTOCOL_ERROR:
> + return -EBADMSG;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +/* PROTOCOL_VERSION */
> +#define SCMI_VERSION_MINOR GENMASK(15, 0)
> +#define SCMI_VERSION_MAJOR GENMASK(31, 16)
> +
> +struct scmi_msg_prot_version_p2a {
> + uint32_t version;
> +} __packed;
> +
> +/* BASE PROTOCOL_ATTRIBUTES */
> +#define SCMI_BASE_ATTR_NUM_PROTO GENMASK(7, 0)
> +#define SCMI_BASE_ATTR_NUM_AGENT GENMASK(15, 8)
> +
> +struct scmi_msg_base_attributes_p2a {
> + uint32_t attributes;
> +} __packed;
> +
> +/*
> + * BASE_DISCOVER_AGENT
> + */
> +#define SCMI_BASE_AGENT_ID_OWN 0xFFFFFFFF
> +
> +struct scmi_msg_base_discover_agent_a2p {
> + uint32_t agent_id;
> +} __packed;
> +
> +struct scmi_msg_base_discover_agent_p2a {
> + uint32_t agent_id;
> + char name[SCMI_SHORT_NAME_MAX_SIZE];
> +} __packed;
> +
> +/*
> + * BASE_SET_DEVICE_PERMISSIONS
> + */
> +#define SCMI_BASE_DEVICE_ACCESS_ALLOW BIT(0, UL)
> +
> +struct scmi_msg_base_set_device_permissions_a2p {
> + uint32_t agent_id;
> + uint32_t device_id;
> + uint32_t flags;
> +} __packed;
> +
> +/*
> + * BASE_RESET_AGENT_CONFIGURATION
> + */
> +#define SCMI_BASE_AGENT_PERMISSIONS_RESET BIT(0, UL)
> +
> +struct scmi_msg_base_reset_agent_cfg_a2p {
> + uint32_t agent_id;
> + uint32_t flags;
> +} __packed;
> +
> +#endif /* XEN_ARCH_ARM_SCI_SCMI_PROTO_H_ */
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * tab-width: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/arch/arm/firmware/scmi-shmem.c
> b/xen/arch/arm/firmware/scmi-shmem.c
> new file mode 100644
> index 000000000000..3815c15bed80
> --- /dev/null
> +++ b/xen/arch/arm/firmware/scmi-shmem.c
> @@ -0,0 +1,172 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * SCI SCMI multi-agent driver, using SMC/HVC shmem as transport.
> + *
> + * Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> + * Copyright (c) 2025 EPAM Systems
> + */
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#include <asm/io.h>
> +#include <xen/err.h>
> +
> +#include "scmi-proto.h"
> +#include "scmi-shmem.h"
> +
> +/*
> + * Copy data from IO memory space to "real" memory space.
> + */
> +static void __memcpy_fromio(void *to, const volatile void __iomem *from,
> + size_t count)
> +{
> + while ( count && !IS_ALIGNED((unsigned long)from, 4) )
> + {
> + *(u8 *)to = readb_relaxed(from);
> + from++;
> + to++;
> + count--;
> + }
> +
> + while ( count >= 4 )
> + {
> + *(u32 *)to = readl_relaxed(from);
> + from += 4;
> + to += 4;
> + count -= 4;
> + }
> +
> + while ( count )
> + {
> + *(u8 *)to = readb_relaxed(from);
> + from++;
> + to++;
> + count--;
> + }
> +}
> +
> +/*
> + * Copy data from "real" memory space to IO memory space.
> + */
> +static void __memcpy_toio(volatile void __iomem *to, const void *from,
> + size_t count)
> +{
> + while ( count && !IS_ALIGNED((unsigned long)to, 4) )
> + {
> + writeb_relaxed(*(u8 *)from, to);
> + from++;
> + to++;
> + count--;
> + }
> +
> + while ( count >= 4 )
> + {
> + writel_relaxed(*(u32 *)from, to);
> + from += 4;
> + to += 4;
> + count -= 4;
> + }
> +
> + while ( count )
> + {
> + writeb_relaxed(*(u8 *)from, to);
> + from++;
> + to++;
> + count--;
> + }
> +}
> +
> +static inline int
> +shmem_channel_is_free(const volatile struct scmi_shared_mem __iomem *shmem)
> +{
> + return (readl(&shmem->channel_status) &
> + SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE) ? 0 : -EBUSY;
> +}
> +
> +int shmem_put_message(volatile struct scmi_shared_mem __iomem *shmem,
> + scmi_msg_header_t *hdr, void *data, int len)
> +{
> + int ret;
> +
> + if ( (len + sizeof(shmem->msg_header)) > SCMI_SHMEM_MAPPED_SIZE )
> + {
> + printk(XENLOG_ERR "scmi: Wrong size of smc message. Data is
> invalid\n");
> + return -EINVAL;
> + }
> +
> + ret = shmem_channel_is_free(shmem);
> + if ( ret )
> + return ret;
> +
> + writel_relaxed(0x0, &shmem->channel_status);
> + /* Writing 0x0 right now, but "shmem"_FLAG_INTR_ENABLED can be set */
> + writel_relaxed(0x0, &shmem->flags);
> + writel_relaxed(sizeof(shmem->msg_header) + len, &shmem->length);
> + writel(pack_scmi_header(hdr), &shmem->msg_header);
> +
> + if ( len > 0 && data )
> + __memcpy_toio(shmem->msg_payload, data, len);
> +
> + return 0;
> +}
> +
> +int shmem_get_response(const volatile struct scmi_shared_mem __iomem *shmem,
> + scmi_msg_header_t *hdr, void *data, int len)
> +{
> + int recv_len;
> + int ret;
> + int pad = sizeof(hdr->status);
> +
> + if ( len >= SCMI_SHMEM_MAPPED_SIZE - sizeof(shmem) )
> + {
> + printk(XENLOG_ERR
> + "scmi: Wrong size of input smc message. Data may be
> invalid\n");
> + return -EINVAL;
> + }
> +
> + ret = shmem_channel_is_free(shmem);
> + if ( ret )
> + return ret;
> +
> + recv_len = readl(&shmem->length) - sizeof(shmem->msg_header);
> +
> + if ( recv_len < 0 )
> + {
> + printk(XENLOG_ERR
> + "scmi: Wrong size of smc message. Data may be invalid\n");
> + return -EINVAL;
> + }
> +
> + unpack_scmi_header(readl(&shmem->msg_header), hdr);
> +
> + hdr->status = readl(&shmem->msg_payload);
> + recv_len = recv_len > pad ? recv_len - pad : 0;
> +
> + ret = scmi_to_xen_errno(hdr->status);
> + if ( ret ) {
> + printk(XENLOG_DEBUG "scmi: Error received: %d\n", ret);
> + return ret;
> + }
> +
> + if ( recv_len > len )
> + {
> + printk(XENLOG_ERR
> + "scmi: Not enough buffer for message %d, expecting %d\n",
> + recv_len, len);
> + return -EINVAL;
> + }
> +
> + if ( recv_len > 0 )
> + __memcpy_fromio(data, shmem->msg_payload + pad, recv_len);
> +
> + return 0;
> +}
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * tab-width: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/arch/arm/firmware/scmi-shmem.h
> b/xen/arch/arm/firmware/scmi-shmem.h
> new file mode 100644
> index 000000000000..f19e90786824
> --- /dev/null
> +++ b/xen/arch/arm/firmware/scmi-shmem.h
> @@ -0,0 +1,45 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Arm System Control and Management Interface definitions
> + * Version 3.0 (DEN0056C)
> + * Shared Memory based Transport
> + *
> + * Copyright (c) 2024 EPAM Systems
> + */
> +
> +#ifndef XEN_ARCH_ARM_SCI_SCMI_SHMEM_H_
> +#define XEN_ARCH_ARM_SCI_SCMI_SHMEM_H_
> +
> +#include <xen/stdint.h>
> +
> +#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE BIT(0, UL)
> +#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR BIT(1, UL)
> +
> +struct scmi_shared_mem {
> + uint32_t reserved;
> + uint32_t channel_status;
> + uint32_t reserved1[2];
> + uint32_t flags;
> + uint32_t length;
> + uint32_t msg_header;
> + uint8_t msg_payload[];
> +};
> +
> +#define SCMI_SHMEM_MAPPED_SIZE PAGE_SIZE
> +
> +int shmem_put_message(volatile struct scmi_shared_mem __iomem *shmem,
> + scmi_msg_header_t *hdr, void *data, int len);
> +
> +int shmem_get_response(const volatile struct scmi_shared_mem __iomem *shmem,
> + scmi_msg_header_t *hdr, void *data, int len);
> +#endif /* XEN_ARCH_ARM_SCI_SCMI_SHMEM_H_ */
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * tab-width: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/arch/arm/firmware/scmi-smc-multiagent.c
> b/xen/arch/arm/firmware/scmi-smc-multiagent.c
> new file mode 100644
> index 000000000000..293fb30fa6c5
> --- /dev/null
> +++ b/xen/arch/arm/firmware/scmi-smc-multiagent.c
> @@ -0,0 +1,856 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * SCI SCMI multi-agent driver, using SMC/HVC shmem as transport.
> + *
> + * Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> + * Copyright (c) 2025 EPAM Systems
> + */
> +
> +#include <xen/acpi.h>
> +
> +#include <xen/device_tree.h>
> +#include <xen/init.h>
> +#include <xen/iocap.h>
> +#include <xen/err.h>
> +#include <xen/libfdt/libfdt.h>
> +#include <xen/param.h>
> +#include <xen/sched.h>
> +#include <xen/vmap.h>
> +
> +#include <asm/firmware/sci.h>
> +#include <asm/smccc.h>
> +
> +#include "scmi-proto.h"
> +#include "scmi-shmem.h"
> +
> +#define SCMI_AGENT_ID_INVALID 0xFF
> +
> +static uint8_t __initdata opt_dom0_scmi_agent_id = SCMI_AGENT_ID_INVALID;
> +integer_param("dom0_scmi_agent_id", opt_dom0_scmi_agent_id);
> +
> +#define SCMI_SECONDARY_AGENTS "xen,scmi-secondary-agents"
> +
> +#define HYP_CHANNEL 0x0
> +
> +
> +struct scmi_channel {
> + uint32_t agent_id;
> + uint32_t func_id;
> + domid_t domain_id;
> + uint64_t paddr;
> + uint64_t len;
> + struct scmi_shared_mem __iomem *shmem;
> + spinlock_t lock;
> + struct list_head list;
> +};
> +
> +struct scmi_data {
> + struct list_head channel_list;
> + spinlock_t channel_list_lock;
> + uint32_t func_id;
> + bool initialized;
> + uint32_t shmem_phandle;
> + struct dt_device_node *dt_dev;
> +};
> +
> +static struct scmi_data scmi_data;
> +
> +static int send_smc_message(struct scmi_channel *chan_info,
> + scmi_msg_header_t *hdr, void *data, int len)
> +{
> + struct arm_smccc_res resp;
> + int ret;
> +
> + ret = shmem_put_message(chan_info->shmem, hdr, data, len);
> + if ( ret )
> + return ret;
> +
> + arm_smccc_1_1_smc(chan_info->func_id, 0, 0, 0, 0, 0, 0, 0, &resp);
> +
> + if ( resp.a0 )
> + return -EOPNOTSUPP;
> +
> + return 0;
> +}
> +
> +static int do_smc_xfer(struct scmi_channel *chan_info, scmi_msg_header_t
> *hdr,
> + void *tx_data, int tx_size, void *rx_data, int
> rx_size)
> +{
> + int ret = 0;
> +
> + ASSERT(chan_info && chan_info->shmem);
> +
> + if ( !hdr )
> + return -EINVAL;
> +
> + spin_lock(&chan_info->lock);
> +
> + printk(XENLOG_DEBUG
> + "scmi: agent_id = %d msg_id = %x type = %d, proto = %x\n",
> + chan_info->agent_id, hdr->id, hdr->type, hdr->protocol);
> +
> + ret = send_smc_message(chan_info, hdr, tx_data, tx_size);
> + if ( ret )
> + goto clean;
> +
> + ret = shmem_get_response(chan_info->shmem, hdr, rx_data, rx_size);
This lock is not per-CPU and it is held across a potentially
long-running SMC call. Could that be an issue? Do we want to move the
SMC call out of the lock?
> +clean:
> + printk(XENLOG_DEBUG
> + "scmi: get smc response agent_id = %d msg_id = %x proto = %x
> res=%d\n",
> + chan_info->agent_id, hdr->id, hdr->protocol, ret);
> +
> + spin_unlock(&chan_info->lock);
> +
> + return ret;
> +}
> +
> +static struct scmi_channel *get_channel_by_id(uint32_t agent_id)
> +{
> + struct scmi_channel *curr;
> + bool found = false;
> +
> + spin_lock(&scmi_data.channel_list_lock);
> + list_for_each_entry(curr, &scmi_data.channel_list, list)
> + {
> + if ( curr->agent_id == agent_id )
> + {
> + found = true;
> + break;
> + }
> + }
> +
> + spin_unlock(&scmi_data.channel_list_lock);
> + if ( found )
> + return curr;
> +
> + return NULL;
> +}
> +
> +static struct scmi_channel *aquire_scmi_channel(struct domain *d,
> + uint32_t agent_id)
The spelling is acquire
> +{
> + struct scmi_channel *curr;
> + struct scmi_channel *ret = ERR_PTR(-ENOENT);
> +
> + spin_lock(&scmi_data.channel_list_lock);
> + list_for_each_entry(curr, &scmi_data.channel_list, list)
> + {
> + if ( curr->agent_id == agent_id )
> + {
> + if ( curr->domain_id != DOMID_INVALID )
> + {
> + ret = ERR_PTR(-EEXIST);
> + break;
> + }
> +
> + curr->domain_id = d->domain_id;
> + ret = curr;
> + break;
> + }
> + }
> +
> + spin_unlock(&scmi_data.channel_list_lock);
> +
> + return ret;
> +}
> +
> +static void relinquish_scmi_channel(struct scmi_channel *channel)
> +{
> + ASSERT(channel != NULL);
> +
> + spin_lock(&scmi_data.channel_list_lock);
> + channel->domain_id = DOMID_INVALID;
> + spin_unlock(&scmi_data.channel_list_lock);
> +}
> +
> +static int map_channel_memory(struct scmi_channel *channel)
> +{
> + ASSERT( channel && channel->paddr );
> + channel->shmem = ioremap_nocache(channel->paddr, SCMI_SHMEM_MAPPED_SIZE);
> + if ( !channel->shmem )
> + return -ENOMEM;
> +
> + channel->shmem->channel_status = SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
> + printk(XENLOG_DEBUG "scmi: Got shmem %lx after vmap %p\n",
> channel->paddr,
> + channel->shmem);
> +
> + return 0;
> +}
> +
> +static void unmap_channel_memory(struct scmi_channel *channel)
> +{
> + ASSERT( channel && channel->shmem );
> + iounmap(channel->shmem);
> + channel->shmem = NULL;
> +}
> +
> +static struct scmi_channel *smc_create_channel(uint32_t agent_id,
> + uint32_t func_id, uint64_t
> addr)
Could be __init
> +{
> + struct scmi_channel *channel;
> +
> + channel = get_channel_by_id(agent_id);
> + if ( channel )
> + return ERR_PTR(EEXIST);
> +
> + channel = xmalloc(struct scmi_channel);
> + if ( !channel )
> + return ERR_PTR(ENOMEM);
> +
> + spin_lock_init(&channel->lock);
> + channel->agent_id = agent_id;
> + channel->func_id = func_id;
> + channel->domain_id = DOMID_INVALID;
> + channel->shmem = NULL;
> + channel->paddr = addr;
> + list_add_tail(&channel->list, &scmi_data.channel_list);
> + return channel;
> +}
> +
> +static void free_channel_list(void)
> +{
> + struct scmi_channel *curr, *_curr;
> +
> + list_for_each_entry_safe (curr, _curr, &scmi_data.channel_list, list)
> + {
> + list_del(&curr->list);
> + xfree(curr);
> + }
> +}
> +
> +static int scmi_dt_read_hyp_channel_addr(struct dt_device_node *scmi_node,
> + u64 *addr, u64 *size)
Could be __init
> +{
> + struct dt_device_node *shmem_node;
> + const __be32 *prop;
> +
> + prop = dt_get_property(scmi_node, "shmem", NULL);
> + if ( !prop )
> + return -EINVAL;
> +
> + shmem_node = dt_find_node_by_phandle(be32_to_cpup(prop));
> + if ( IS_ERR_OR_NULL(shmem_node) )
> + {
> + printk(XENLOG_ERR
> + "scmi: Device tree error, can't parse reserved memory %ld\n",
> + PTR_ERR(shmem_node));
> + return PTR_ERR(shmem_node);
> + }
> +
> + return dt_device_get_address(shmem_node, 0, addr, size);
> +}
> +
> +/*
> + * Handle Dom0 SCMI specific DT nodes
> + *
> + * Make a decision on copying SCMI specific nodes into Dom0 device tree.
> + * For SCMI multi-agent case:
> + * - shmem nodes will not be copied and generated instead if SCMI
> + * is enabled for Dom0
> + * - scmi node will be copied if SCMI is enabled for Dom0
> + */
> +static bool scmi_dt_handle_node(struct domain *d, struct dt_device_node
> *node)
> +{
> + static const struct dt_device_match skip_matches[] __initconst = {
> + DT_MATCH_COMPATIBLE("arm,scmi-shmem"),
> + { /* sentinel */ },
> + };
> + static const struct dt_device_match scmi_matches[] __initconst = {
> + DT_MATCH_PATH("/firmware/scmi"),
> + { /* sentinel */ },
> + };
> +
> + if ( !scmi_data.initialized )
> + return false;
> +
> + /* always drop shmem */
> + if ( dt_match_node(skip_matches, node) )
> + {
> + dt_dprintk(" Skip scmi shmem\n");
> + return true;
> + }
> +
> + /* drop scmi if not enabled */
> + if ( dt_match_node(scmi_matches, node) && !sci_domain_is_enabled(d) )
> + {
> + dt_dprintk(" Skip scmi node\n");
> + return true;
> + }
> +
> + return false;
> +}
> +
> +/*
> + * Finalize Dom0 SCMI specific DT nodes
> + *
> + * if SCMI is enabled for Dom0:
> + * - generate shmem node
> + * - map SCMI shmem MMIO into Dom0
> + */
> +static int scmi_dt_finalize(struct domain *d, void *fdt)
> +{
> + __be32 reg[GUEST_ROOT_ADDRESS_CELLS + GUEST_ROOT_SIZE_CELLS];
> + struct scmi_channel *channel;
> + int nodeoffset;
> + __be32 *cells;
> + __be32 val;
> + char buf[64];
> + int res, rc;
> +
> + if ( !sci_domain_is_enabled(d) )
> + return 0;
> +
> + channel = d->arch.sci_data;
> +
> + /*
> + * Replace "arm,smc-id" with proper value assigned for Dom0 SCMI channel
> + */
> + nodeoffset = fdt_node_offset_by_compatible(fdt, -1, "arm,scmi-smc");
> + if ( nodeoffset < 0 )
> + return -ENODEV;
> +
> + cells = (__be32 *)&val;
> + dt_set_cell(&cells, 1, channel->func_id);
> + res = fdt_setprop_inplace(fdt, nodeoffset, "arm,smc-id", &val,
> sizeof(val));
> + if ( res )
> + return -EINVAL;
> +
> + /*
> + * All SCMI shmem nodes should be removed from Dom0 DT at this point, so
> + * the shmem node for Dom0 need to be generated from SCMI channel
> assigned
> + * to Dom0.
> + * The original SCMI shmem node from platform DT is used by Xen SCMI
> driver
> + * itself as privileged channel (agent_id=0) to manage other SCMI
> + * agents (domains).
Wouldn't it be better not to add those nodes to dom0 device tree at all
in the first place? Why adding them, then removing them?
I think it is best to skip them in handle_node and only add the ones
that are correct for dom0 here. Similarly, I don't think we should
replace the value of arm,smc-id in place: we should skip it the first
time around and generate one now.
> + */
> + snprintf(buf, sizeof(buf), "scmi-shmem@%lx", channel->paddr);
> +
> + res = fdt_begin_node(fdt, buf);
> + if ( res )
> + return res;
> +
> + res = fdt_property_string(fdt, "compatible", "arm,scmi-shmem");
> + if ( res )
> + return res;
> +
> + cells = ®[0];
> +
> + dt_child_set_range(&cells, GUEST_ROOT_ADDRESS_CELLS,
> GUEST_ROOT_SIZE_CELLS,
> + channel->paddr, SCMI_SHMEM_MAPPED_SIZE);
> +
> + res = fdt_property(fdt, "reg", reg, sizeof(reg));
> + if ( res )
> + return res;
> +
> + res = fdt_property_cell(fdt, "phandle", scmi_data.shmem_phandle);
> + if ( res )
> + return res;
> +
> + res = fdt_end_node(fdt);
> + if ( res )
> + return res;
> +
> + /*
> + * Map SCMI shmem into Dom0 here as shmem nodes are excluded from
> + * generic Dom0 DT processing
> + */
> + res = iomem_permit_access(d, paddr_to_pfn(channel->paddr),
> + paddr_to_pfn(channel->paddr +
> + SCMI_SHMEM_MAPPED_SIZE - 1));
> + if ( res )
> + return res;
> +
> + res = map_regions_p2mt(d, gaddr_to_gfn(channel->paddr),
> + PFN_UP(SCMI_SHMEM_MAPPED_SIZE),
> + maddr_to_mfn(channel->paddr), p2m_mmio_direct_nc);
> + if ( res )
> + {
> + rc = iomem_deny_access(d, paddr_to_pfn(channel->paddr),
> + paddr_to_pfn(channel->paddr +
> + SCMI_SHMEM_MAPPED_SIZE - 1));
> + if ( rc )
> + printk(XENLOG_ERR "scmi: Unable to deny iomem access , err =
> %d\n",
> + rc);
> + }
> +
> + return res;
> +}
> +
> +static int scmi_assign_device(uint32_t agent_id, uint32_t device_id,
> + uint32_t flags)
> +{
> + struct scmi_msg_base_set_device_permissions_a2p tx;
> + struct scmi_channel *channel;
> + scmi_msg_header_t hdr;
> + int ret;
> +
> + channel = get_channel_by_id(HYP_CHANNEL);
> + if ( !channel )
> + return -EINVAL;
> +
> + hdr.id = SCMI_BASE_SET_DEVICE_PERMISSIONS;
> + hdr.type = 0;
> + hdr.protocol = SCMI_BASE_PROTOCOL;
> +
> + tx.agent_id = agent_id;
> + tx.device_id = device_id;
> + tx.flags = flags;
> +
> + ret = do_smc_xfer(channel, &hdr, &tx, sizeof(tx), NULL, 0);
> + if ( ret == -EOPNOTSUPP )
> + return 0;
> +
> + return ret;
> +}
> +
> +static int scmi_dt_assign_device(struct domain *d,
> + struct dt_phandle_args *ac_spec)
> +{
> + struct scmi_channel *agent_channel;
> + uint32_t scmi_device_id = ac_spec->args[0];
> + int ret;
> +
> + if ( !d->arch.sci_data )
> + return 0;
> +
> + /* The access-controllers is specified for DT dev, but it's not a SCMI */
> + if ( ac_spec->np != scmi_data.dt_dev )
> + return 0;
> +
> + agent_channel = d->arch.sci_data;
> +
> + spin_lock(&agent_channel->lock);
> +
> + ret = scmi_assign_device(agent_channel->agent_id, scmi_device_id,
> + SCMI_BASE_DEVICE_ACCESS_ALLOW);
> + if ( ret )
> + {
> + printk(XENLOG_ERR
> + "scmi: could not assign dev for %pd agent:%d dev_id:%u (%d)",
> + d, agent_channel->agent_id, scmi_device_id, ret);
> + }
> +
> + spin_unlock(&agent_channel->lock);
> + return ret;
> +}
> +
> +static __init int collect_agents(struct dt_device_node *scmi_node)
> +{
> + const struct dt_device_node *chosen_node;
> + const __be32 *prop;
> + u32 len, i;
We don't use u32 in Xen anymore. Please use uint32_t instead. However,
in this case, I think i should be unsigned int by our coding style.
> + chosen_node = dt_find_node_by_path("/chosen");
> + if ( !chosen_node )
> + {
> + printk(XENLOG_ERR "scmi: chosen node not found\n");
> + return -ENOENT;
> + }
> +
> + prop = dt_get_property(chosen_node, SCMI_SECONDARY_AGENTS, &len);
> + if ( !prop )
> + {
> + printk(XENLOG_WARNING "scmi: No %s property found\n",
> + SCMI_SECONDARY_AGENTS);
> + return -ENODEV;
> + }
> +
> + if ( len % (3 * sizeof(u32)) )
> + {
> + printk(XENLOG_ERR "scmi: Invalid length of %s property: %d\n",
> + SCMI_SECONDARY_AGENTS, len);
> + return -EINVAL;
> + }
> +
> + for ( i = 0 ; i < len / (3 * sizeof(u32)) ; i++ )
> + {
> + u32 agent_id = be32_to_cpu(*prop++);
> + u32 smc_id = be32_to_cpu(*prop++);
> + u32 shmem_phandle = be32_to_cpu(*prop++);
> + struct dt_device_node *node = dt_find_node_by_phandle(shmem_phandle);
> + u64 addr, size;
> + int ret;
> +
> + if ( !node )
> + {
> + printk(XENLOG_ERR"scmi: Could not find shmem node for agent
> %d\n",
> + agent_id);
> + return -EINVAL;
> + }
> +
> + ret = dt_device_get_address(node, 0, &addr, &size);
> + if ( ret )
> + {
> + printk(XENLOG_ERR
> + "scmi: Could not read shmem address for agent %d: %d",
> + agent_id, ret);
> + return ret;
> + }
> +
> + if ( !IS_ALIGNED(size, SCMI_SHMEM_MAPPED_SIZE) )
> + {
> + printk(XENLOG_ERR "scmi: shmem memory is not aligned\n");
> + return -EINVAL;
> + }
> +
> + ret = PTR_RET(smc_create_channel(agent_id, smc_id, addr));
> + if ( ret )
> + {
> + printk(XENLOG_ERR "scmi: Could not create channel for agent %d:
> %d",
> + agent_id, ret);
> + return ret;
> + }
> +
> + printk(XENLOG_DEBUG "scmi: Agent %d SMC %X addr %lx\n", agent_id,
> + smc_id, addr);
> + }
> +
> + return 0;
> +}
> +
> +static int scmi_domain_init(struct domain *d,
> + struct xen_domctl_createdomain *config)
> +{
> + struct scmi_channel *channel;
> + int ret;
> +
> + if ( !scmi_data.initialized )
> + return 0;
> +
> + /*
> + * Special case for Dom0 - the SCMI support is enabled basing on
> + * "dom0_sci_agent_id" Xen command line parameter
> + */
> + if ( is_hardware_domain(d) ) {
coding style
> + if ( opt_dom0_scmi_agent_id != SCMI_AGENT_ID_INVALID )
> + {
> + config->arch.arm_sci_type =
> XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA;
> + config->arch.arm_sci_agent_id = opt_dom0_scmi_agent_id;
> + } else
> + config->arch.arm_sci_type = XEN_DOMCTL_CONFIG_ARM_SCI_NONE;
> + }
> +
> + if ( config->arch.arm_sci_type == XEN_DOMCTL_CONFIG_ARM_SCI_NONE )
> + return 0;
> +
> + channel = aquire_scmi_channel(d, config->arch.arm_sci_agent_id);
> + if ( IS_ERR(channel) )
> + {
> + printk(XENLOG_ERR"scmi: Failed to acquire SCMI channel for agent_id
> %u: %ld\n",
> + config->arch.arm_sci_agent_id, PTR_ERR(channel));
> + return PTR_ERR(channel);
> + }
> +
> + printk(XENLOG_INFO"scmi: Acquire channel id = 0x%x, domain_id = %d paddr
> = 0x%lx\n",
> + channel->agent_id, channel->domain_id, channel->paddr);
> +
> + /*
> + * Dom0 (if present) needs to have an access to the guest memory range
> + * to satisfy iomem_access_permitted() check in
> XEN_DOMCTL_iomem_permission
> + * domctl.
Yeah... that check needs to change
> + */
> + if ( hardware_domain && !is_hardware_domain(d) )
> + {
> + ret = iomem_permit_access(hardware_domain,
> paddr_to_pfn(channel->paddr),
> + paddr_to_pfn(channel->paddr + PAGE_SIZE -
> 1));
> + if ( ret )
> + goto error;
> + }
> +
> + d->arch.sci_data = channel;
> + d->arch.sci_enabled = true;
> +
> + return 0;
> +
> +error:
> + relinquish_scmi_channel(channel);
> + return ret;
> +}
> +
> +int scmi_domain_sanitise_config(struct xen_domctl_createdomain *config)
> +{
> + if ( config->arch.arm_sci_type != XEN_DOMCTL_CONFIG_ARM_SCI_NONE &&
> + config->arch.arm_sci_type != XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA )
> + {
> + dprintk(XENLOG_INFO, "scmi: Unsupported ARM_SCI type\n");
> + return -EINVAL;
> + }
> + else if ( config->arch.arm_sci_type ==
> + XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA &&
> + config->arch.arm_sci_agent_id == 0 )
> + {
> + dprintk(XENLOG_INFO,
> + "scmi: A zero ARM SCMI agent_id is not supported\n");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int scmi_relinquish_resources(struct domain *d)
> +{
> + int ret;
> + struct scmi_channel *channel, *agent_channel;
> + scmi_msg_header_t hdr;
> + struct scmi_msg_base_reset_agent_cfg_a2p tx;
> +
> + if ( !d->arch.sci_data )
> + return 0;
> +
> + agent_channel = d->arch.sci_data;
> +
> + spin_lock(&agent_channel->lock);
> + tx.agent_id = agent_channel->agent_id;
> + spin_unlock(&agent_channel->lock);
> +
> + channel = get_channel_by_id(HYP_CHANNEL);
> + if ( !channel )
> + {
> + printk(XENLOG_ERR
> + "scmi: Unable to get Hypervisor scmi channel for domain %d\n",
> + d->domain_id);
> + return -EINVAL;
> + }
> +
> + hdr.id = SCMI_BASE_RESET_AGENT_CONFIGURATION;
> + hdr.type = 0;
> + hdr.protocol = SCMI_BASE_PROTOCOL;
> +
> + tx.flags = 0;
> +
> + ret = do_smc_xfer(channel, &hdr, &tx, sizeof(tx), NULL, 0);
> + if ( ret == -EOPNOTSUPP )
> + return 0;
> +
> + return ret;
> +}
> +
> +static void scmi_domain_destroy(struct domain *d)
> +{
> + struct scmi_channel *channel;
> +
> + if ( !d->arch.sci_data )
> + return;
> +
> + channel = d->arch.sci_data;
> + spin_lock(&channel->lock);
> +
> + relinquish_scmi_channel(channel);
> + printk(XENLOG_DEBUG "scmi: Free domain %d\n", d->domain_id);
> +
> + d->arch.sci_data = NULL;
> + d->arch.sci_enabled = true;
> +
> + spin_unlock(&channel->lock);
> +}
> +
> +static bool scmi_handle_call(struct cpu_user_regs *regs)
> +{
> + uint32_t fid = (uint32_t)get_user_reg(regs, 0);
> + struct scmi_channel *agent_channel;
> + struct domain *d = current->domain;
> + struct arm_smccc_res resp;
> + bool res = false;
> +
> + if ( !sci_domain_is_enabled(d) )
> + return false;
> +
> + agent_channel = d->arch.sci_data;
> + spin_lock(&agent_channel->lock);
> +
> + if ( agent_channel->func_id != fid )
> + {
> + res = false;
> + goto unlock;
> + }
> +
> + arm_smccc_1_1_smc(fid,
> + get_user_reg(regs, 1),
> + get_user_reg(regs, 2),
> + get_user_reg(regs, 3),
> + get_user_reg(regs, 4),
> + get_user_reg(regs, 5),
> + get_user_reg(regs, 6),
> + get_user_reg(regs, 7),
> + &resp);
> +
> + set_user_reg(regs, 0, resp.a0);
> + set_user_reg(regs, 1, resp.a1);
> + set_user_reg(regs, 2, resp.a2);
> + set_user_reg(regs, 3, resp.a3);
> + res = true;
> +unlock:
> + spin_unlock(&agent_channel->lock);
> +
> + return res;
> +}
> +
> +static const struct sci_mediator_ops scmi_ops = {
> + .domain_init = scmi_domain_init,
> + .domain_destroy = scmi_domain_destroy,
> + .relinquish_resources = scmi_relinquish_resources,
> + .handle_call = scmi_handle_call,
> + .dom0_dt_handle_node = scmi_dt_handle_node,
> + .dom0_dt_finalize = scmi_dt_finalize,
> + .domain_sanitise_config = scmi_domain_sanitise_config,
> + .assign_dt_device = scmi_dt_assign_device,
> +};
> +
> +static int __init scmi_check_smccc_ver(void)
> +{
> + if ( smccc_ver < ARM_SMCCC_VERSION_1_1 )
> + {
> + printk(XENLOG_WARNING
> + "scmi: No SMCCC 1.1 support, SCMI calls forwarding
> disabled\n");
> + return -ENOSYS;
> + }
> +
> + return 0;
> +}
> +
> +static __init int scmi_probe(struct dt_device_node *scmi_node, const void
> *data)
> +{
> + u64 addr, size;
> + int ret, i;
> + struct scmi_channel *channel, *agent_channel;
> + int n_agents;
> + scmi_msg_header_t hdr;
> + struct scmi_msg_base_attributes_p2a rx;
> +
> + ASSERT(scmi_node != NULL);
> +
> + INIT_LIST_HEAD(&scmi_data.channel_list);
> + spin_lock_init(&scmi_data.channel_list_lock);
> +
> + if ( !acpi_disabled )
> + {
> + printk(XENLOG_WARNING "scmi: is not supported when using ACPI\n");
> + return -EINVAL;
> + }
> +
> + ret = scmi_check_smccc_ver();
> + if ( ret )
> + return ret;
> +
> + if ( !dt_property_read_u32(scmi_node, "arm,smc-id", &scmi_data.func_id) )
> + {
> + printk(XENLOG_ERR "scmi: unable to read smc-id from DT\n");
> + return -ENOENT;
> + }
> +
> + /* save shmem phandle and re-use it fro Dom0 DT shmem node */
> + if ( !dt_property_read_u32(scmi_node, "shmem", &scmi_data.shmem_phandle)
> )
> + {
> + printk(XENLOG_ERR "scmi: unable to read shmem phandle from DT\n");
> + return -ENOENT;
> + }
> +
> + ret = scmi_dt_read_hyp_channel_addr(scmi_node, &addr, &size);
> + if ( IS_ERR_VALUE(ret) )
> + return -ENOENT;
> +
> + if ( !IS_ALIGNED(size, SCMI_SHMEM_MAPPED_SIZE) )
> + {
> + printk(XENLOG_ERR "scmi: shmem memory is not aligned\n");
> + return -EINVAL;
> + }
> +
> + scmi_data.dt_dev = scmi_node;
> +
> + channel = smc_create_channel(HYP_CHANNEL, scmi_data.func_id, addr);
> + if ( IS_ERR(channel) )
> + goto out;
> +
> + ret = map_channel_memory(channel);
> + if ( ret )
> + goto out;
> +
> + channel->domain_id = DOMID_XEN;
> +
> + hdr.id = SCMI_BASE_PROTOCOL_ATTIBUTES;
> + hdr.type = 0;
> + hdr.protocol = SCMI_BASE_PROTOCOL;
> +
> + ret = do_smc_xfer(channel, &hdr, NULL, 0, &rx, sizeof(rx));
> + if ( ret )
> + goto error;
> +
> + n_agents = SCMI_FIELD_GET(SCMI_BASE_ATTR_NUM_AGENT, rx.attributes);
> + printk(XENLOG_DEBUG "scmi: Got agent count %d\n", n_agents);
> +
> + ret = collect_agents(scmi_node);
> + if ( ret )
> + goto error;
> +
> + i = 1;
> +
> + list_for_each_entry(agent_channel, &scmi_data.channel_list, list)
> + {
> + struct scmi_msg_base_discover_agent_p2a da_rx;
> + struct scmi_msg_base_discover_agent_a2p da_tx;
> +
> + ret = map_channel_memory(agent_channel);
> + if ( ret )
> + goto error;
> +
> + hdr.id = SCMI_BASE_DISCOVER_AGENT;
> + hdr.type = 0;
> + hdr.protocol = SCMI_BASE_PROTOCOL;
> +
> + da_tx.agent_id = agent_channel->agent_id;
> +
> + ret = do_smc_xfer(agent_channel, &hdr, &da_tx,
> + sizeof(da_tx), &da_rx, sizeof(da_rx));
> + if ( agent_channel->domain_id != DOMID_XEN )
> + unmap_channel_memory(agent_channel);
> + if ( ret )
> + goto error;
> +
> + printk(XENLOG_DEBUG "id=0x%x name=%s\n",
> + da_rx.agent_id, da_rx.name);
> +
> + agent_channel->agent_id = da_rx.agent_id;
> +
> + if ( i > n_agents )
> + break;
> +
> + i++;
> + }
> +
> + ret = sci_register(&scmi_ops);
> + if (ret) {
> + printk(XENLOG_ERR "SCMI: mediator already registered (ret = %d)\n",
> + ret);
> + return ret;
> + }
> +
> + scmi_data.initialized = true;
> + goto out;
> +
> +error:
> + unmap_channel_memory(channel);
> + free_channel_list();
> +out:
> + return ret;
> +}
> +
> +static const struct dt_device_match scmi_smc_match[] __initconst = {
> + DT_MATCH_COMPATIBLE("arm,scmi-smc"),
> + { /* sentinel */ },
> +};
> +
> +DT_DEVICE_START(gicv3, "SCMI SMC MEDIATOR", DEVICE_ARM_SCI)
scmi_smc_ma instead of gicv3?
> + .dt_match = scmi_smc_match,
> + .init = scmi_probe,
> +DT_DEVICE_END
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * tab-width: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
> index 095b1a23e30c..30e46de6d7a0 100644
> --- a/xen/include/public/arch-arm.h
> +++ b/xen/include/public/arch-arm.h
> @@ -329,6 +329,7 @@ DEFINE_XEN_GUEST_HANDLE(vcpu_guest_context_t);
>
> #define XEN_DOMCTL_CONFIG_ARM_SCI_NONE 0
> #define XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC 1
> +#define XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA 2
>
> struct xen_arch_domainconfig {
> /* IN/OUT */
> @@ -355,6 +356,8 @@ struct xen_arch_domainconfig {
> uint32_t clock_frequency;
> /* IN */
> uint8_t arm_sci_type;
> + /* IN */
> + uint8_t arm_sci_agent_id;
> };
> #endif /* __XEN__ || __XEN_TOOLS__ */
>
> --
> 2.34.1
>
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