[PATCH v6 2/4] firmware: ti_sci: add support for restoring IRQs during resume

Thomas Richard (TI)
2026-04-27T12:22:25Z

Some DM-Firmware are not able to restore the IRQ context after a
suspend-resume. The IRQ_CONTEXT_LOST firmware capability has been
introduced to identify this characteristic. In this case the
responsibility is delegated to the ti_sci driver, which maintains an
internal list of all requested IRQs. This list is updated on each
set()/free() operation, and all IRQs are restored during the resume_noirq()
phase.

Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Kendall Willis <k-willis@ti.com>
Signed-off-by: Thomas Richard (TI) <thomas.richard@bootlin.com>
---
drivers/firmware/ti_sci.c | 153 ++++++++++++++++++++++++++++++++++++++++++----
drivers/firmware/ti_sci.h | 2 +
2 files changed, 144 insertions(+), 11 deletions(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index eaeaaae94142..b5c4324287b0 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -12,6 +12,7 @@
#include <linux/cpu.h>
#include <linux/debugfs.h>
#include <linux/export.h>
+#include <linux/hashtable.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
@@ -87,6 +88,16 @@ struct ti_sci_desc {
int max_msg_size;
};

+/**
+ * struct ti_sci_irq - Description of allocated irqs
+ * @node: Link to hash table
+ * @desc: Description of the irq
+ */
+struct ti_sci_irq {
+ struct hlist_node node;
+ struct ti_sci_msg_req_manage_irq desc;
+};
+
/**
* struct ti_sci_info - Structure representing a TI SCI instance
* @dev: Device pointer
@@ -101,6 +112,7 @@ struct ti_sci_desc {
* @chan_rx: Receive mailbox channel
* @minfo: Message info
* @node: list head
+ * @irqs: List of allocated irqs
* @host_id: Host ID
* @fw_caps: FW/SoC low power capabilities
* @users: Number of users of this instance
@@ -117,6 +129,7 @@ struct ti_sci_info {
struct mbox_chan *chan_tx;
struct mbox_chan *chan_rx;
struct ti_sci_xfers_info minfo;
+ DECLARE_HASHTABLE(irqs, 8);
struct list_head node;
u8 host_id;
u64 fw_caps;
@@ -2301,6 +2314,32 @@ static int ti_sci_manage_irq(const struct ti_sci_handle *handle,
return ret;
}

+/**
+ * ti_sci_irq_hash() - Helper API to compute irq hash for the hash table.
+ * @irq: irq to hash
+ *
+ * Return: the computed hash value.
+ */
+static int ti_sci_irq_hash(struct ti_sci_msg_req_manage_irq *irq)
+{
+ return irq->src_id ^ irq->src_index;
+}
+
+/**
+ * ti_sci_irq_equal() - Helper API to compare two irqs (generic headers are not
+ * compared)
+ * @irq_a: irq_a to compare
+ * @irq_b: irq_b to compare
+ *
+ * Return: true if the two irqs are equal, else false.
+ */
+static bool ti_sci_irq_equal(struct ti_sci_msg_req_manage_irq *irq_a,
+ struct ti_sci_msg_req_manage_irq *irq_b)
+{
+ return !memcmp(&irq_a->valid_params, &irq_b->valid_params,
+ sizeof(*irq_a) - sizeof(irq_a->hdr));
+}
+
/**
* ti_sci_set_irq() - Helper api to configure the irq route between the
* requested source and destination
@@ -2324,15 +2363,43 @@ static int ti_sci_set_irq(const struct ti_sci_handle *handle, u32 valid_params,
u16 dst_host_irq, u16 ia_id, u16 vint,
u16 global_event, u8 vint_status_bit, u8 s_host)
{
+ struct ti_sci_info *info = handle_to_ti_sci_info(handle);
+ struct ti_sci_msg_req_manage_irq *desc;
+ struct ti_sci_irq *irq;
+ int ret;
+
pr_debug("%s: IRQ set with valid_params = 0x%x from src = %d, index = %d, to dst = %d, irq = %d,via ia_id = %d, vint = %d, global event = %d,status_bit = %d\n",
__func__, valid_params, src_id, src_index,
dst_id, dst_host_irq, ia_id, vint, global_event,
vint_status_bit);

- return ti_sci_manage_irq(handle, valid_params, src_id, src_index,
- dst_id, dst_host_irq, ia_id, vint,
- global_event, vint_status_bit, s_host,
- TI_SCI_MSG_SET_IRQ);
+ ret = ti_sci_manage_irq(handle, valid_params, src_id, src_index,
+ dst_id, dst_host_irq, ia_id, vint,
+ global_event, vint_status_bit, s_host,
+ TI_SCI_MSG_SET_IRQ);
+
+ if (ret || !(info->fw_caps & MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST))
+ return ret;
+
+ irq = kzalloc_obj(*irq, GFP_KERNEL);
+ if (!irq)
+ return -ENOMEM;
+
+ desc = &irq->desc;
+ desc->valid_params = valid_params;
+ desc->src_id = src_id;
+ desc->src_index = src_index;
+ desc->dst_id = dst_id;
+ desc->dst_host_irq = dst_host_irq;
+ desc->ia_id = ia_id;
+ desc->vint = vint;
+ desc->global_event = global_event;
+ desc->vint_status_bit = vint_status_bit;
+ desc->secondary_host = s_host;
+
+ hash_add(info->irqs, &irq->node, ti_sci_irq_hash(desc));
+
+ return 0;
}

/**
@@ -2358,15 +2425,46 @@ static int ti_sci_free_irq(const struct ti_sci_handle *handle, u32 valid_params,
u16 dst_host_irq, u16 ia_id, u16 vint,
u16 global_event, u8 vint_status_bit, u8 s_host)
{
+ struct ti_sci_info *info = handle_to_ti_sci_info(handle);
+ struct ti_sci_msg_req_manage_irq irq_desc;
+ struct ti_sci_irq *this_irq;
+ struct hlist_node *tmp_node;
+ int ret;
+
pr_debug("%s: IRQ release with valid_params = 0x%x from src = %d, index = %d, to dst = %d, irq = %d,via ia_id = %d, vint = %d, global event = %d,status_bit = %d\n",
__func__, valid_params, src_id, src_index,
dst_id, dst_host_irq, ia_id, vint, global_event,
vint_status_bit);

- return ti_sci_manage_irq(handle, valid_params, src_id, src_index,
- dst_id, dst_host_irq, ia_id, vint,
- global_event, vint_status_bit, s_host,
- TI_SCI_MSG_FREE_IRQ);
+ ret = ti_sci_manage_irq(handle, valid_params, src_id, src_index,
+ dst_id, dst_host_irq, ia_id, vint,
+ global_event, vint_status_bit, s_host,
+ TI_SCI_MSG_FREE_IRQ);
+
+ if (ret || !(info->fw_caps & MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST))
+ return ret;
+
+ irq_desc.valid_params = valid_params;
+ irq_desc.src_id = src_id;
+ irq_desc.src_index = src_index;
+ irq_desc.dst_id = dst_id;
+ irq_desc.dst_host_irq = dst_host_irq;
+ irq_desc.ia_id = ia_id;
+ irq_desc.vint = vint;
+ irq_desc.global_event = global_event;
+ irq_desc.vint_status_bit = vint_status_bit;
+ irq_desc.secondary_host = s_host;
+
+ hash_for_each_possible_safe(info->irqs, this_irq, tmp_node, node,
+ ti_sci_irq_hash(&irq_desc)) {
+ if (ti_sci_irq_equal(&irq_desc, &this_irq->desc)) {
+ hlist_del(&this_irq->node);
+ kfree(this_irq);
+ return 0;
+ }
+ }
+
+ return 0;
}

/**
@@ -3847,7 +3945,10 @@ static int ti_sci_suspend_noirq(struct device *dev)
static int ti_sci_resume_noirq(struct device *dev)
{
struct ti_sci_info *info = dev_get_drvdata(dev);
- int ret = 0;
+ struct ti_sci_msg_req_manage_irq *irq_desc;
+ struct ti_sci_irq *irq;
+ struct hlist_node *tmp_node;
+ int ret = 0, i;
u32 source;
u64 time;
u8 pin;
@@ -3859,6 +3960,32 @@ static int ti_sci_resume_noirq(struct device *dev)
return ret;
}

+ switch (pm_suspend_target_state) {
+ case PM_SUSPEND_MEM:
+ if (info->fw_caps & MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST) {
+ hash_for_each_safe(info->irqs, i, tmp_node, irq, node) {
+ irq_desc = &irq->desc;
+ ret = ti_sci_manage_irq(&info->handle,
+ irq_desc->valid_params,
+ irq_desc->src_id,
+ irq_desc->src_index,
+ irq_desc->dst_id,
+ irq_desc->dst_host_irq,
+ irq_desc->ia_id,
+ irq_desc->vint,
+ irq_desc->global_event,
+ irq_desc->vint_status_bit,
+ irq_desc->secondary_host,
+ TI_SCI_MSG_SET_IRQ);
+ if (ret)
+ return ret;
+ }
+ }
+ break;
+ default:
+ break;
+ }
+
ret = ti_sci_msg_cmd_lpm_wake_reason(&info->handle, &source, &time, &pin, &mode);
/* Do not fail to resume on error as the wake reason is not critical */
if (!ret)
@@ -4014,13 +4141,14 @@ static int ti_sci_probe(struct platform_device *pdev)
}

ti_sci_msg_cmd_query_fw_caps(&info->handle, &info->fw_caps);
- dev_dbg(dev, "Detected firmware capabilities: %s%s%s%s%s%s\n",
+ dev_dbg(dev, "Detected firmware capabilities: %s%s%s%s%s%s%s\n",
info->fw_caps & MSG_FLAG_CAPS_GENERIC ? "Generic" : "",
info->fw_caps & MSG_FLAG_CAPS_LPM_PARTIAL_IO ? " Partial-IO" : "",
info->fw_caps & MSG_FLAG_CAPS_LPM_DM_MANAGED ? " DM-Managed" : "",
info->fw_caps & MSG_FLAG_CAPS_LPM_ABORT ? " LPM-Abort" : "",
info->fw_caps & MSG_FLAG_CAPS_IO_ISOLATION ? " IO-Isolation" : "",
- info->fw_caps & MSG_FLAG_CAPS_LPM_BOARDCFG_MANAGED ? " BoardConfig-Managed" : ""
+ info->fw_caps & MSG_FLAG_CAPS_LPM_BOARDCFG_MANAGED ? " BoardConfig-Managed" : "",
+ info->fw_caps & MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST ? " IRQ-Context-Lost" : ""
);

ti_sci_setup_ops(info);
@@ -4053,6 +4181,9 @@ static int ti_sci_probe(struct platform_device *pdev)
list_add_tail(&info->node, &ti_sci_list);
mutex_unlock(&ti_sci_list_mutex);

+ if (info->fw_caps & MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST)
+ hash_init(info->irqs);
+
ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
if (ret) {
dev_err(dev, "platform_populate failed %pe\n", ERR_PTR(ret));
diff --git a/drivers/firmware/ti_sci.h b/drivers/firmware/ti_sci.h
index d90de59e29eb..67f16e8c69a1 100644
--- a/drivers/firmware/ti_sci.h
+++ b/drivers/firmware/ti_sci.h
@@ -151,6 +151,7 @@ struct ti_sci_msg_req_reboot {
* MSG_FLAG_CAPS_LPM_ABORT: Abort entry to LPM
* MSG_FLAG_CAPS_IO_ISOLATION: IO Isolation support
* MSG_FLAG_CAPS_LPM_BOARDCFG_MANAGED: LPM config done statically for the DM via boardcfg
+ * MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST: DM is not able to restore IRQ context
*
* Response to a generic message with message type TI_SCI_MSG_QUERY_FW_CAPS
* providing currently available SOC/firmware capabilities. SoC that don't
@@ -164,6 +165,7 @@ struct ti_sci_msg_resp_query_fw_caps {
#define MSG_FLAG_CAPS_LPM_ABORT TI_SCI_MSG_FLAG(9)
#define MSG_FLAG_CAPS_IO_ISOLATION TI_SCI_MSG_FLAG(7)
#define MSG_FLAG_CAPS_LPM_BOARDCFG_MANAGED TI_SCI_MSG_FLAG(12)
+#define MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST TI_SCI_MSG_FLAG(14)
#define MSG_MASK_CAPS_LPM GENMASK_ULL(4, 1)
u64 fw_caps;
} __packed;

--
2.53.0