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Re: [RFC v1 3/5] xen/arm: introduce SCMI-SMC mediator driver
On 14.12.21 11:34, Oleksii Moisieiev wrote:
Hi Oleksii
This is the implementation of SCI interface, called SCMI-SMC driver,
which works as the mediator between XEN Domains and Firmware (SCP, ATF etc).
This allows devices from the Domains to work with clocks, resets and
power-domains without access to CPG.
The following features are implemented:
- request SCMI channels from ATF and pass channels to Domains;
- set device permissions for Domains based on the Domain partial
device-tree. Devices with permissions are able to work with clocks,
resets and power-domains via SCMI;
- redirect scmi messages from Domains to ATF.
Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
---
xen/arch/arm/Kconfig | 2 +
xen/arch/arm/sci/Kconfig | 10 +
xen/arch/arm/sci/Makefile | 1 +
xen/arch/arm/sci/scmi_smc.c | 795 ++++++++++++++++++++++++++++++++++
xen/include/public/arch-arm.h | 1 +
5 files changed, 809 insertions(+)
create mode 100644 xen/arch/arm/sci/Kconfig
create mode 100644 xen/arch/arm/sci/scmi_smc.c
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 186e1db389..02d96c6cfc 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -114,6 +114,8 @@ config SCI
support. It allows guests to control system resourcess via one of
SCI mediators implemented in XEN.
+source "arch/arm/sci/Kconfig"
+
endmenu
menu "ARM errata workaround via the alternative framework"
diff --git a/xen/arch/arm/sci/Kconfig b/xen/arch/arm/sci/Kconfig
new file mode 100644
index 0000000000..9563067ddc
--- /dev/null
+++ b/xen/arch/arm/sci/Kconfig
@@ -0,0 +1,10 @@
+config SCMI_SMC
+ bool "Enable SCMI-SMC mediator driver"
+ default n
+ depends on SCI
+ ---help---
+
+ Enables mediator in XEN to pass SCMI requests from Domains to ATF.
+ This feature allows drivers from Domains to work with System
+ Controllers (such as power,resets,clock etc.). SCP is used as transport
+ for communication.
diff --git a/xen/arch/arm/sci/Makefile b/xen/arch/arm/sci/Makefile
index 837dc7492b..67f2611872 100644
--- a/xen/arch/arm/sci/Makefile
+++ b/xen/arch/arm/sci/Makefile
@@ -1 +1,2 @@
obj-y += sci.o
+obj-$(CONFIG_SCMI_SMC) += scmi_smc.o
diff --git a/xen/arch/arm/sci/scmi_smc.c b/xen/arch/arm/sci/scmi_smc.c
new file mode 100644
index 0000000000..2eb01ea82d
--- /dev/null
+++ b/xen/arch/arm/sci/scmi_smc.c
@@ -0,0 +1,795 @@
+/*
+ * xen/arch/arm/sci/scmi_smc.c
+ *
+ * SCMI mediator driver, using SCP as transport.
+ *
+ * Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
+ * Copyright (C) 2021, EPAM Systems.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <asm/sci/sci.h>
+#include <asm/smccc.h>
+#include <asm/io.h>
+#include <xen/bitops.h>
+#include <xen/config.h>
+#include <xen/sched.h>
+#include <xen/device_tree.h>
+#include <xen/iocap.h>
+#include <xen/init.h>
+#include <xen/err.h>
+#include <xen/lib.h>
+#include <xen/list.h>
+#include <xen/mm.h>
+#include <xen/string.h>
+#include <xen/time.h>
+#include <xen/vmap.h>
+
+#define SCMI_BASE_PROTOCOL 0x10
+#define SCMI_BASE_PROTOCOL_ATTIBUTES 0x1
+#define SCMI_BASE_SET_DEVICE_PERMISSIONS 0x9
+#define SCMI_BASE_RESET_AGENT_CONFIGURATION 0xB
+#define SCMI_BASE_DISCOVER_AGENT 0x7
+
+/* SCMI return codes. See section 4.1.4 of SCMI spec (DEN0056C) */
+#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)
+
+#define DT_MATCH_SCMI_SMC DT_MATCH_COMPATIBLE("arm,scmi-smc")
+
+#define SCMI_SMC_ID "arm,smc-id"
+#define SCMI_SHARED_MEMORY "linux,scmi_mem"
+#define SCMI_SHMEM "shmem"
+
+#define HYP_CHANNEL 0x0
+
+#define HDR_ID GENMASK(7,0)
+#define HDR_TYPE GENMASK(9, 8)
+#define HDR_PROTO GENMASK(17, 10)
+
+/* SCMI protocol, refer to section 4.2.2.2 (DEN0056C) */
+#define MSG_N_AGENTS_MASK GENMASK(15, 8)
+
+#define FIELD_GET(_mask, _reg)\
+ ((typeof(_mask))(((_reg) & (_mask)) >> (ffs64(_mask) - 1)))
+#define FIELD_PREP(_mask, _val)\
+ (((typeof(_mask))(_val) << (ffs64(_mask) - 1)) & (_mask))
+
+typedef struct scmi_msg_header {
+ uint8_t id;
+ uint8_t type;
+ uint8_t protocol;
+} scmi_msg_header_t;
+
+typedef struct scmi_perms_tx {
+ uint32_t agent_id;
+ uint32_t device_id;
+ uint32_t flags;
+} scmi_perms_tx_t;
+
+#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE BIT(0, UL)
+#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR BIT(1, UL)
+
+#define SCMI_ALLOW_ACCESS BIT(0, 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[];
+};
+
+struct scmi_channel {
+ int chan_id;
+ int agent_id;
+ uint32_t func_id;
+ int domain_id;
+ uint64_t paddr;
+ struct scmi_shared_mem *shmem;
+ spinlock_t lock;
+ struct list_head list;
+};
+
+struct scmi_data {
+ struct list_head channel_list;
+ spinlock_t channel_list_lock;
+ bool initialized;
+ u64 shmem_addr, shmem_size;
+};
+
+static struct scmi_data scmi_data;
+
+/*
+ * pack_scmi_header() - packs and returns 32-bit header
+ *
+ * @hdr: pointer to header containing all the information on message id,
+ * protocol id and type id.
+ *
+ * Return: 32-bit packed message header to be sent to the platform.
+ */
+static inline uint32_t pack_scmi_header(scmi_msg_header_t *hdr)
+{
+ return FIELD_PREP(HDR_ID, hdr->id) |
+ FIELD_PREP(HDR_TYPE, hdr->type) |
+ FIELD_PREP(HDR_PROTO, hdr->protocol);
+}
+
+/*
+ * unpack_scmi_header() - unpacks and records message and protocol id
+ *
+ * @msg_hdr: 32-bit packed message header sent from the platform
+ * @hdr: pointer to header to fetch message and protocol id.
+ */
+static inline void unpack_scmi_header(uint32_t msg_hdr, scmi_msg_header_t *hdr)
+{
+ hdr->id = FIELD_GET(HDR_ID, msg_hdr);
+ hdr->type = FIELD_GET(HDR_TYPE, msg_hdr);
+ hdr->protocol = FIELD_GET(HDR_PROTO, msg_hdr);
+}
+
+static inline int channel_is_free(struct scmi_channel *chan_info)
+{
+ return ( chan_info->shmem->channel_status
+ & SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE ) ? 0 : -EBUSY;
+}
+
+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;
+
+ printk(XENLOG_DEBUG "scmi: status =%d len=%d\n",
+ chan_info->shmem->channel_status, len);
+ printk(XENLOG_DEBUG "scmi: header id = %d type = %d, proto = %d\n",
+ hdr->id, hdr->type, hdr->protocol);
+
+ ret = channel_is_free(chan_info);
+ if ( IS_ERR_VALUE(ret) )
+ return ret;
+
+ chan_info->shmem->channel_status = 0x0;
+ /* Writing 0x0 right now, but SCMI_SHMEM_FLAG_INTR_ENABLED can be set */
+ chan_info->shmem->flags = 0x0;
+ chan_info->shmem->length = sizeof(chan_info->shmem->msg_header) + len;
+ chan_info->shmem->msg_header = pack_scmi_header(hdr);
+
+ printk(XENLOG_DEBUG "scmi: Writing to shmem address %p\n",
+ chan_info->shmem);
+ if ( len > 0 && data )
+ memcpy((void *)(chan_info->shmem->msg_payload), data, len);
+
+ arm_smccc_smc(chan_info->func_id, 0, 0, 0, 0, 0, 0, chan_info->chan_id,
+ &resp);
+
+ printk(XENLOG_DEBUG "scmi: scmccc_smc response %d\n", (int)(resp.a0));
+
+ if ( resp.a0 )
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
+static int check_scmi_status(int scmi_status)
+{
+ if ( scmi_status == SCMI_SUCCESS )
+ return 0;
+
+ printk(XENLOG_DEBUG "scmi: Error received: %d\n", scmi_status);
+
+ 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;
Probably we should add a default: here?
+ }
+
+ return -EINVAL;
+}
+
+static int get_smc_response(struct scmi_channel *chan_info,
+ scmi_msg_header_t *hdr, void *data, int len)
+{
+ int recv_len;
+ int ret;
+
+ printk(XENLOG_DEBUG "scmi: get smc responce msgid %d\n", hdr->id);
+
+ ret = channel_is_free(chan_info);
+ if ( IS_ERR_VALUE(ret) )
+ return ret;
+
+ recv_len = chan_info->shmem->length - sizeof(chan_info->shmem->msg_header);
+
+ if ( recv_len < 0 )
+ {
+ printk(XENLOG_ERR
+ "scmi: Wrong size of smc message. Data may be invalid\n");
+ return -EINVAL;
+ }
+
+ if ( recv_len > len )
+ {
+ printk(XENLOG_ERR
+ "scmi: Not enough buffer for message %d, expecting %d\n",
+ recv_len, len);
+ return -EINVAL;
+ }
+
+ unpack_scmi_header(chan_info->shmem->msg_header, hdr);
+
+ if ( recv_len > 0 )
+ {
+ memcpy(data, chan_info->shmem->msg_payload, recv_len);
+ }
+
+ return 0;
+}
+
+static int do_smc_xfer(struct scmi_channel *channel, scmi_msg_header_t *hdr,
void *tx_data, int tx_size,
+ void *rx_data, int rx_size)
+{
+ int ret = 0;
+
+ if ( !hdr )
+ return -EINVAL;
+
+ spin_lock(&channel->lock);
+
+ ret = send_smc_message(channel, hdr, tx_data, tx_size);
+ if ( ret )
+ goto clean;
+
+ ret = get_smc_response(channel, hdr, rx_data, rx_size);
+clean:
+ spin_unlock(&channel->lock);
+
+ return ret;
+}
+
+static struct scmi_channel *get_channel_by_id(uint8_t chan_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->chan_id == chan_id )
+ {
+ found = true;
+ break;
+ }
+
+ spin_unlock(&scmi_data.channel_list_lock);
+ if ( found )
+ return curr;
+
+ return NULL;
+}
+
+static struct scmi_channel *get_channel_by_domain(uint8_t domain_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->domain_id == domain_id )
+ {
+ found = true;
+ break;
+ }
+
+ spin_unlock(&scmi_data.channel_list_lock);
+ if ( found )
+ return curr;
+
+ return NULL;
+}
+
+static struct scmi_channel *aquire_scmi_channel(int domain_id)
+{
+ struct scmi_channel *curr;
+ bool found = false;
+
+ ASSERT(domain_id != DOMID_INVALID && domain_id >= 0);
+
+ spin_lock(&scmi_data.channel_list_lock);
+ list_for_each_entry(curr, &scmi_data.channel_list, list)
+ if ( (curr->domain_id == DOMID_INVALID)
+ && (curr->chan_id != HYP_CHANNEL) )
+ {
+ curr->domain_id = domain_id;
+ found = true;
+ break;
+ }
+
+ spin_unlock(&scmi_data.channel_list_lock);
+ if ( found )
+ return curr;
+
+ return NULL;
+}
+
+static void relinquish_scmi_channel(struct scmi_channel *channel)
+{
+ spin_lock(&scmi_data.channel_list_lock);
+ ASSERT(channel != NULL);
+ channel->domain_id = DOMID_INVALID;
+ spin_unlock(&scmi_data.channel_list_lock);
+}
+
+static struct scmi_channel *smc_create_channel(uint8_t chan_id,
+ uint32_t func_id, uint64_t addr)
+{
+ struct scmi_channel *channel;
+ mfn_t mfn;
+
+ channel = get_channel_by_id(chan_id);
+ if ( channel )
+ return ERR_PTR(EEXIST);
+
+ channel = xmalloc(struct scmi_channel);
+ if ( !channel )
+ return ERR_PTR(ENOMEM);
+
+ channel->chan_id = chan_id;
+ channel->func_id = func_id;
+ channel->domain_id = DOMID_INVALID;
+ mfn = maddr_to_mfn(addr);
+ channel->shmem = vmap(&mfn, 1);
+ if ( !channel->shmem )
+ {
+ xfree(channel);
+ return ERR_PTR(ENOMEM);
+ }
+
+ printk(XENLOG_DEBUG "scmi: Got shmem after vmap %p\n", channel->shmem);
+ channel->paddr = addr;
+ channel->shmem->channel_status = SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
+ spin_lock_init(&channel->lock);
+ spin_lock(&scmi_data.channel_list_lock);
+ list_add(&channel->list, &scmi_data.channel_list);
+ spin_unlock(&scmi_data.channel_list_lock);
+ return channel;
+}
+
+static int map_memory_to_domain(struct domain *d, uint64_t addr, uint64_t len)
+{
+ return iomem_permit_access(d, paddr_to_pfn(addr),
+ paddr_to_pfn(PAGE_ALIGN(addr + len -1)));
+}
+
+static int unmap_memory_from_domain(struct domain *d, uint64_t addr,
+ uint64_t len)
+{
+ return iomem_deny_access(d, paddr_to_pfn(addr),
+ paddr_to_pfn(PAGE_ALIGN(addr + len -1)));
+}
I wonder, why we need an extra level of indirection here. And if this is
really needed, I wonder why map(unmap)_memory* name was chosen, as there
is no memory mapping/unmapping really happens here.
+
+static int dt_update_domain_range(struct domain *d, uint64_t addr,
+ uint64_t size)
Looks like *d is not used in this function.
+{
+ struct dt_device_node *shmem_node;
+ __be32 *hw_reg;
+ const struct dt_property *pp;
+ uint32_t len;
+
+ shmem_node = dt_find_compatible_node(NULL, NULL, "arm,scmi-shmem");
+
+ if ( !shmem_node )
+ {
+ printk(XENLOG_ERR "scmi: Unable to find %s node in DT\n", SCMI_SHMEM);
+ return -EINVAL;
+ }
+
+ pp = dt_find_property(shmem_node, "reg", &len);
+ if ( !pp )
+ {
+ printk(XENLOG_ERR "scmi: Unable to find regs entry in shmem node\n");
+ return -ENOENT;
+ }
+
+ hw_reg = pp->value;
+ dt_set_range(&hw_reg, shmem_node, addr, size);
+
+ return 0;
+}
+
+static void free_channel_list(void)
+{
+ struct scmi_channel *curr, *_curr;
+
+ spin_lock(&scmi_data.channel_list_lock);
+ list_for_each_entry_safe (curr, _curr, &scmi_data.channel_list, list)
+ {
+ vunmap(curr->shmem);
+ list_del(&curr->list);
+ xfree(curr);
+ }
+
+ spin_unlock(&scmi_data.channel_list_lock);
+}
+
+static __init bool scmi_probe(struct dt_device_node *scmi_node)
Generic question to consider ...
If probe fails for some reason (so we cannot use mediator in Xen) what
should we do with SCMI nodes in domain's device-tree (leave as is, drop,
etc)?
+{
+ struct dt_device_node *shmem_node;
+ int ret, i;
+ struct scmi_channel *channel, *agent_channel;
+ int n_agents;
+ scmi_msg_header_t hdr;
+ struct rx_t {
+ int32_t status;
+ uint32_t attributes;
+ } rx;
+
+ uint32_t func_id;
+
+ ASSERT(scmi_node != NULL);
+
+ INIT_LIST_HEAD(&scmi_data.channel_list);
+ spin_lock_init(&scmi_data.channel_list_lock);
+
+ if ( !dt_property_read_u32(scmi_node, SCMI_SMC_ID, &func_id) )
+ {
+ printk(XENLOG_ERR "scmi: Unable to read smc-id from DT\n");
+ return false;
+ }
+
+ shmem_node = dt_find_node_by_name(NULL, SCMI_SHARED_MEMORY);
+ if ( IS_ERR_OR_NULL(shmem_node) )
+ {
+ printk(XENLOG_ERR
+ "scmi: Device tree error, can't parse shmem phandle %ld\n",
+ PTR_ERR(shmem_node));
+ return false;
+ }
+
+ ret = dt_device_get_address(shmem_node, 0, &scmi_data.shmem_addr,
+ &scmi_data.shmem_size);
+ if ( IS_ERR_VALUE(ret) )
+ return false;
+
+ channel = smc_create_channel(HYP_CHANNEL, func_id, scmi_data.shmem_addr);
+ if ( IS_ERR(channel) )
+ return false;
+
+ 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 clean;
+
+ ret = check_scmi_status(rx.status);
+ if ( ret )
+ goto clean;
+
+ n_agents = FIELD_GET(MSG_N_AGENTS_MASK, rx.attributes);
+ printk(XENLOG_DEBUG "scmi: Got agent count %d\n", n_agents);
+
+ n_agents = (n_agents > scmi_data.shmem_size / PAGE_SIZE) ?
+ scmi_data.shmem_size / PAGE_SIZE : n_agents;
+
+ for ( i = 1; i < n_agents; i++ )
+ {
+ uint32_t tx_agent_id = 0xFFFFFFFF;
+ struct {
+ int32_t status;
+ uint32_t agent_id;
+ char name[16];
+ } da_rx;
+
+ agent_channel = smc_create_channel(i, func_id, scmi_data.shmem_addr +
+ i * PAGE_SIZE);
+ if ( IS_ERR(agent_channel) )
+ {
+ ret = PTR_ERR(agent_channel);
+ goto clean;
+ }
+
+ hdr.id = SCMI_BASE_DISCOVER_AGENT;
+ hdr.type = 0;
+ hdr.protocol = SCMI_BASE_PROTOCOL;
+
+ ret = do_smc_xfer(agent_channel, &hdr, &tx_agent_id,
+ sizeof(tx_agent_id), &da_rx, sizeof(da_rx));
+ if ( ret )
+ goto clean;
+
+ ret = check_scmi_status(da_rx.status);
+ if ( ret )
+ goto clean;
+
+ printk(XENLOG_DEBUG "scmi: status=0x%x id=0x%x name=%s\n",
+ da_rx.status, da_rx.agent_id, da_rx.name);
+
+ agent_channel->agent_id = da_rx.agent_id;
+ }
+
+ scmi_data.initialized = true;
+ return true;
+
+clean:
+ free_channel_list();
+ return ret == 0;
+}
+
+static int scmi_domain_init(struct domain *d)
+{
+ struct scmi_channel *channel;
+ int ret;
+
+ if ( !scmi_data.initialized )
+ return 0;
+
+ channel = aquire_scmi_channel(d->domain_id);
+ if ( IS_ERR_OR_NULL(channel) )
+ return -ENOENT;
+
+ printk(XENLOG_INFO "scmi: Aquire SCMI channel id = 0x%x , domain_id = %d"
+ "paddr = 0x%lx\n", channel->chan_id, channel->domain_id,
+ channel->paddr);
It seems this breaks build on Arm32:
scmi_smc.c: In function ‘scmi_domain_init’:
/home/otyshchenko/xen/xen/include/xen/config.h:53:24: error: format
‘%lx’ expects argument of type ‘long unsigned int’, but argument 4 has
type ‘uint64_t {aka long long unsigned int}’ [-Werror=format=]
#define XENLOG_INFO "<2>"
^
scmi_smc.c:569:12: note: in expansion of macro ‘XENLOG_INFO’
printk(XENLOG_INFO "scmi: Aquire SCMI channel id = 0x%x ,
domain_id = %d"
^~~~~~~~~~~
scmi_smc.c:570:25: note: format string is defined here
"paddr = 0x%lx\n", channel->chan_id, channel->domain_id,
~~^
%llx
+
+ if ( is_hardware_domain(d) )
+ {
+ ret = map_memory_to_domain(d, scmi_data.shmem_addr,
+ scmi_data.shmem_size);
+ if ( IS_ERR_VALUE(ret) )
+ goto error;
+
+ ret = dt_update_domain_range(d, channel->paddr, PAGE_SIZE);
+ if ( IS_ERR_VALUE(ret) )
+ {
+ int rc = unmap_memory_from_domain(d, scmi_data.shmem_addr,
+ scmi_data.shmem_size);
+ if ( rc )
+ printk(XENLOG_ERR "Unable to unmap_memory_from_domain\n");
+
+ goto error;
+ }
+ }
+
+ d->arch.sci = channel;
+
+ return 0;
+error:
+ relinquish_scmi_channel(channel);
+
+ return ret;
+}
+
+static int scmi_add_device_by_devid(struct domain *d, uint32_t scmi_devid)
+{
+ struct scmi_channel *channel, *agent_channel;
+ scmi_msg_header_t hdr;
+ scmi_perms_tx_t tx;
+ struct rx_t {
+ int32_t status;
+ uint32_t attributes;
+ } rx;
+ int ret;
+
+ if ( !scmi_data.initialized )
+ return 0;
+
+ printk(XENLOG_DEBUG "scmi: scmi_devid = %d\n", scmi_devid);
+
+ agent_channel = get_channel_by_domain(d->domain_id);
+ if ( IS_ERR_OR_NULL(agent_channel) )
+ return PTR_ERR(agent_channel);
+
+ channel = get_channel_by_id(HYP_CHANNEL);
+ if ( IS_ERR_OR_NULL(channel) )
+ return PTR_ERR(channel);
+
+ hdr.id = SCMI_BASE_SET_DEVICE_PERMISSIONS;
+ hdr.type = 0;
+ hdr.protocol = SCMI_BASE_PROTOCOL;
+
+ tx.agent_id = agent_channel->agent_id;
+ tx.device_id = scmi_devid;
+ tx.flags = SCMI_ALLOW_ACCESS;
+
+ ret = do_smc_xfer(channel, &hdr, &tx, sizeof(tx), &rx, sizeof(&rx));
+ if ( IS_ERR_VALUE(ret) )
+ return ret;
+
+ ret = check_scmi_status(rx.status);
+ if ( IS_ERR_VALUE(ret) )
+ return ret;
+
+ return 0;
+}
+
+static int scmi_add_dt_device(struct domain *d, struct dt_device_node *dev)
+{
+ uint32_t scmi_devid;
+
+ if ( (!scmi_data.initialized) || (!d->arch.sci) )
+ return 0;
+
+ if ( !dt_property_read_u32(dev, "scmi_devid", &scmi_devid) )
+ return 0;
+
+ printk(XENLOG_INFO "scmi: dt_node = %s\n", dt_node_full_name(dev));
+
+ return scmi_add_device_by_devid(d, scmi_devid);
+}
+
+static int scmi_relinquish_resources(struct domain *d)
+{
+ int ret;
+ struct scmi_channel *channel, *agent_channel;
+ scmi_msg_header_t hdr;
+ struct reset_agent_tx {
+ uint32_t agent_id;
+ uint32_t flags;
+ } tx;
+ uint32_t rx;
+
+ if ( !d->arch.sci )
+ return 0;
+
+ agent_channel = d->arch.sci;
+
+ 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), &rx, sizeof(rx));
+ if ( ret )
+ return ret;
+
+ ret = check_scmi_status(rx);
+
+ return ret;
+}
+
+static void scmi_domain_destroy(struct domain *d)
+{
+ struct scmi_channel *channel;
+
+ if ( !d->arch.sci )
+ return;
+
+ channel = d->arch.sci;
+ spin_lock(&channel->lock);
+
+ relinquish_scmi_channel(channel);
+ printk(XENLOG_DEBUG "scmi: Free domain %d\n", d->domain_id);
+
+ d->arch.sci = NULL;
+
+ unmap_memory_from_domain(d, channel->paddr, PAGE_SIZE);
I didn't manage to find where corresponding map_memory_from_domain() is
called for a non-hardware domain (it seems that scmi_domain_init() only
directly handles hardware domain case).
Or perhaps, it is called indirectly at do_domctl(): case
XEN_DOMCTL_iomem_permission:?
I wonder, do we really need to call this here? Taking into the account
that unmap_memory_from_domain() doesn't actually unmap anything, but
only removes a range from the iomem_caps rangeset
for the domain to be destroyed and all involved rangesets (including
iomem_caps) will be removed soon at rangeset_domain_destroy() anyway. Or
I missed something?
+ spin_unlock(&channel->lock);
+ return;
empty return could be dropped, I think.
+}
+
+static bool scmi_handle_call(struct domain *d, void *args)
+{
+ bool res = false;
+ struct scmi_channel *agent_channel;
+ struct arm_smccc_res resp;
+ struct cpu_user_regs *regs = args;
+
+ if ( !d->arch.sci )
+ return false;
+
+ agent_channel = d->arch.sci;
+ spin_lock(&agent_channel->lock);
+
+ if ( agent_channel->func_id != regs->x0 )
This also breaks build on Arm32:
scmi_smc.c: In function ‘scmi_handle_call’:
scmi_smc.c:736:42: error: ‘struct cpu_user_regs’ has no member named
‘x0’; did you mean ‘r0’?
if ( agent_channel->func_id != regs->x0 )
^~
r0
cc1: all warnings being treated as errors
***
BTW, I noticed that xen/arch/arm/traps.c contains the following
construct, probably we might want something similar here?
#ifdef CONFIG_ARM_64
#define HYPERCALL_RESULT_REG(r) (r)->x0
[snip]
#else
#define HYPERCALL_RESULT_REG(r) (r)->r0
[snip]
#endif
This RFC patch series, so I think, there is no serious issues at the
moment, this is rather to let you know for the future (when you drop RFC
tag).
I have to admit, I often forget to build-test on Arm32 also))
+ {
+ printk(XENLOG_ERR "scmi: func_id mismatch, exiting\n");
+ goto unlock;
+ }
+
+ arm_smccc_smc(agent_channel->func_id, 0, 0, 0, 0, 0, 0,
+ agent_channel->chan_id, &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 int scmi_get_channel_paddr(void *scmi_ops,
+ struct xen_arch_domainconfig *config)
+{
+ struct scmi_channel *agent_channel = scmi_ops;
+
+ if ( !agent_channel )
+ return -EINVAL;
+
+ config->sci_agent_paddr = agent_channel->paddr;
+ return 0;
+}
+
+static const struct dt_device_match scmi_smc_match[] __initconst =
+{
+ DT_MATCH_SCMI_SMC,
+ { /* sentinel */ },
+};
+
+static const struct sci_mediator_ops scmi_ops =
+{
+ .probe = scmi_probe,
+ .domain_init = scmi_domain_init,
+ .domain_destroy = scmi_domain_destroy,
+ .add_dt_device = scmi_add_dt_device,
+ .relinquish_resources = scmi_relinquish_resources,
+ .handle_call = scmi_handle_call,
+ .get_channel_info = scmi_get_channel_paddr
+};
+
+REGISTER_SCI_MEDIATOR(scmi_smc, "SCMI-SMC", XEN_DOMCTL_CONFIG_SCI_SCMI_SMC,
+ scmi_smc_match, &scmi_ops);
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
index 9180be5e86..a67237942d 100644
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -315,6 +315,7 @@ DEFINE_XEN_GUEST_HANDLE(vcpu_guest_context_t);
#define XEN_DOMCTL_CONFIG_TEE_OPTEE 1
#define XEN_DOMCTL_CONFIG_SCI_NONE 0
+#define XEN_DOMCTL_CONFIG_SCI_SCMI_SMC 1
struct xen_arch_domainconfig {
/* IN/OUT */
--
Regards,
Oleksandr Tyshchenko
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