[PATCH 1/1] soc: qcom: smp2p: add feature negotiation and ssr ack feature support

Deepak Kumar Singh
2021-09-30T15:32:57Z

This patch adds feature negotiation and ssr ack feature between
local and remote host. Local host can negotiate on common features
supported with remote host.
---
drivers/soc/qcom/smp2p.c | 151 ++++++++++++++++++++++++++++++++---------------
1 file changed, 104 insertions(+), 47 deletions(-)

diff --git a/drivers/soc/qcom/smp2p.c b/drivers/soc/qcom/smp2p.c
index 38585a7..1c6ad1c 100644
--- a/drivers/soc/qcom/smp2p.c
+++ b/drivers/soc/qcom/smp2p.c
@@ -14,7 +14,6 @@
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/platform_device.h>
-#include <linux/pm_wakeirq.h>
#include <linux/regmap.h>
#include <linux/soc/qcom/smem.h>
#include <linux/soc/qcom/smem_state.h>
@@ -41,8 +40,11 @@
#define SMP2P_MAX_ENTRY_NAME 16

#define SMP2P_FEATURE_SSR_ACK 0x1
+#define SMP2P_FLAGS_RESTART_DONE_BIT 0
+#define SMP2P_FLAGS_RESTART_ACK_BIT 1

#define SMP2P_MAGIC 0x504d5324
+#define SMP2P_FEATURES SMP2P_FEATURE_SSR_ACK

/**
* struct smp2p_smem_item - in memory communication structure
@@ -113,7 +115,6 @@ struct smp2p_entry {
* struct qcom_smp2p - device driver context
* @dev: device driver handle
* @in: pointer to the inbound smem item
- * @out: pointer to the outbound smem item
* @smem_items: ids of the two smem items
* @valid_entries: already scanned inbound entries
* @local_pid: processor id of the inbound edge
@@ -136,6 +137,10 @@ struct qcom_smp2p {

unsigned valid_entries;

+ bool ssr_ack_enabled;
+ bool ssr_ack;
+ bool open;
+
unsigned local_pid;
unsigned remote_pid;

@@ -163,22 +168,59 @@ static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
}
}

-/**
- * qcom_smp2p_intr() - interrupt handler for incoming notifications
- * @irq: unused
- * @data: smp2p driver context
- *
- * Handle notifications from the remote side to handle newly allocated entries
- * or any changes to the state bits of existing entries.
- */
-static irqreturn_t qcom_smp2p_intr(int irq, void *data)
+static bool qcom_smp2p_check_ssr(struct qcom_smp2p *smp2p)
+{
+ struct smp2p_smem_item *in = smp2p->in;
+ bool restart;
+
+ if (!smp2p->ssr_ack_enabled)
+ return false;
+
+ restart = in->flags & BIT(SMP2P_FLAGS_RESTART_DONE_BIT);
+ if (restart == smp2p->ssr_ack)
+ return false;
+
+ return true;
+}
+
+static void qcom_smp2p_do_ssr_ack(struct qcom_smp2p *smp2p)
+{
+ struct smp2p_smem_item *out = smp2p->out;
+ u32 ack;
+ u32 val;
+
+ ack = !smp2p->ssr_ack;
+ smp2p->ssr_ack = ack;
+ ack = ack << SMP2P_FLAGS_RESTART_ACK_BIT;
+
+ val = out->flags & ~BIT(SMP2P_FLAGS_RESTART_ACK_BIT);
+ val |= ack;
+ out->flags = val;
+
+ qcom_smp2p_kick(smp2p);
+}
+
+static void qcom_smp2p_negotiate(struct qcom_smp2p *smp2p)
+{
+ struct smp2p_smem_item *out = smp2p->out;
+ struct smp2p_smem_item *in = smp2p->in;
+ u32 features;
+
+ if (in->version == out->version) {
+ features = in->features & out->features;
+ out->features = features;
+
+ if (features & SMP2P_FEATURE_SSR_ACK)
+ smp2p->ssr_ack_enabled = true;
+
+ smp2p->open = true;
+ }
+}
+
+static void qcom_smp2p_notify_in(struct qcom_smp2p *smp2p)
{
struct smp2p_smem_item *in;
struct smp2p_entry *entry;
- struct qcom_smp2p *smp2p = data;
- unsigned smem_id = smp2p->smem_items[SMP2P_INBOUND];
- unsigned pid = smp2p->remote_pid;
- size_t size;
int irq_pin;
u32 status;
char buf[SMP2P_MAX_ENTRY_NAME];
@@ -187,18 +229,6 @@ static irqreturn_t qcom_smp2p_intr(int irq, void *data)

in = smp2p->in;

- /* Acquire smem item, if not already found */
- if (!in) {
- in = qcom_smem_get(pid, smem_id, &size);
- if (IS_ERR(in)) {
- dev_err(smp2p->dev,
- "Unable to acquire remote smp2p item\n");
- return IRQ_HANDLED;
- }
-
- smp2p->in = in;
- }
-
/* Match newly created entries */
for (i = smp2p->valid_entries; i < in->valid_entries; i++) {
list_for_each_entry(entry, &smp2p->inbound, node) {
@@ -210,7 +240,7 @@ static irqreturn_t qcom_smp2p_intr(int irq, void *data)
}
}
smp2p->valid_entries = i;
-
+
/* Fire interrupts based on any value changes */
list_for_each_entry(entry, &smp2p->inbound, node) {
/* Ignore entries not yet allocated by the remote side */
@@ -237,7 +267,52 @@ static irqreturn_t qcom_smp2p_intr(int irq, void *data)
}
}
}
+}
+
+/**
+ * qcom_smp2p_intr() - interrupt handler for incoming notifications
+ * @irq: unused
+ * @data: smp2p driver context
+ *
+ * Handle notifications from the remote side to handle newly allocated entries
+ * or any changes to the state bits of existing entries.
+ */
+static irqreturn_t qcom_smp2p_intr(int irq, void *data)
+{
+ struct smp2p_smem_item *in;
+ struct qcom_smp2p *smp2p = data;
+ unsigned int smem_id = smp2p->smem_items[SMP2P_INBOUND];
+ unsigned int pid = smp2p->remote_pid;
+ size_t size;

+ in = smp2p->in;
+
+ /* Acquire smem item, if not already found */
+ if (!in) {
+ in = qcom_smem_get(pid, smem_id, &size);
+ if (IS_ERR(in)) {
+ dev_err(smp2p->dev,
+ "Unable to acquire remote smp2p item\n");
+ goto out;
+ }
+
+ smp2p->in = in;
+ }
+
+ if (!smp2p->open)
+ qcom_smp2p_negotiate(smp2p);
+
+ if (smp2p->open) {
+ bool do_restart;
+
+ do_restart = qcom_smp2p_check_ssr(smp2p);
+ qcom_smp2p_notify_in(smp2p);
+
+ if (do_restart)
+ qcom_smp2p_do_ssr_ack(smp2p);
+ }
+
+out:
return IRQ_HANDLED;
}

@@ -393,6 +468,7 @@ static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
out->remote_pid = smp2p->remote_pid;
out->total_entries = SMP2P_MAX_ENTRY;
out->valid_entries = 0;
+ out->features = SMP2P_FEATURES;

/*
* Make sure the rest of the header is written before we validate the
@@ -539,26 +615,9 @@ static int qcom_smp2p_probe(struct platform_device *pdev)
goto unwind_interfaces;
}

- /*
- * Treat smp2p interrupt as wakeup source, but keep it disabled
- * by default. User space can decide enabling it depending on its
- * use cases. For example if remoteproc crashes and device wants
- * to handle it immediatedly (e.g. to not miss phone calls) it can
- * enable wakeup source from user space, while other devices which
- * do not have proper autosleep feature may want to handle it with
- * other wakeup events (e.g. Power button) instead waking up immediately.
- */
- device_set_wakeup_capable(&pdev->dev, true);
-
- ret = dev_pm_set_wake_irq(&pdev->dev, irq);
- if (ret)
- goto set_wake_irq_fail;

return 0;

-set_wake_irq_fail:
- dev_pm_clear_wake_irq(&pdev->dev);
-
unwind_interfaces:
list_for_each_entry(entry, &smp2p->inbound, node)
irq_domain_remove(entry->domain);
@@ -583,8 +642,6 @@ static int qcom_smp2p_remove(struct platform_device *pdev)
struct qcom_smp2p *smp2p = platform_get_drvdata(pdev);
struct smp2p_entry *entry;

- dev_pm_clear_wake_irq(&pdev->dev);
-
list_for_each_entry(entry, &smp2p->inbound, node)
irq_domain_remove(entry->domain);

--
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