[PATCH 01/10] lib: irqchip: add S-mode notification helpers

[Raymond Mao]

From: Raymond Mao <raymond.mao at riscstar.com>

Add irqchip helpers to set/clear S-mode notification (SEIP-based),
In addition to set/clear, expose a get API to read the current
notification state so upper layers can do edge-triggered notification.

Signed-off-by: Raymond Mao <raymond.mao at riscstar.com>
---
 include/sbi/sbi_irqchip.h | 24 ++++++++++++++++++++++++
 lib/sbi/sbi_irqchip.c     | 18 +++++++++++++++++-
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/include/sbi/sbi_irqchip.h b/include/sbi/sbi_irqchip.h
index 77b54110..7f23615a 100644
--- a/include/sbi/sbi_irqchip.h
+++ b/include/sbi/sbi_irqchip.h
@@ -110,4 +110,28 @@ int sbi_irqchip_init(struct sbi_scratch *scratch, bool cold_boot);
 /** Exit interrupt controllers */
 void sbi_irqchip_exit(struct sbi_scratch *scratch);
 
+/**
+ * Notify S-mode for a pending virtual interrupt on this hart.
+ *
+ * The irqchip layer abstracts the notification mechanism; on platforms that
+ * use SEIP, this sets mip.SEIP.
+ */
+int sbi_irqchip_notify_smode_set(void);
+
+/**
+ * Clear S-mode notification for virtual interrupts on this hart.
+ *
+ * The irqchip layer abstracts the notification mechanism; on platforms that
+ * use SEIP, this clears mip.SEIP.
+ */
+void sbi_irqchip_notify_smode_clear(void);
+
+/**
+ * Read S-mode notification state for virtual interrupts on this hart.
+ *
+ * The irqchip layer abstracts the notification mechanism; on platforms that
+ * use SEIP, this reads mip.SEIP.
+ */
+bool sbi_irqchip_notify_smode_get(void);
+
 #endif
diff --git a/lib/sbi/sbi_irqchip.c b/lib/sbi/sbi_irqchip.c
index f8599fa6..e022d534 100644
--- a/lib/sbi/sbi_irqchip.c
+++ b/lib/sbi/sbi_irqchip.c
@@ -122,7 +122,7 @@ int sbi_irqchip_raw_handler_default(struct sbi_irqchip_device *chip, u32 hwirq)
 	sbi_printf("[IRQCHIP] Calling hwirq %u raw handler callback\n", hwirq);
 	rc = h->callback(hwirq, h->priv);
 
-	if (chip->hwirq_eoi) {
+	if (chip->hwirq_eoi && rc != SBI_EALREADY) {
 		sbi_printf("[IRQCHIP] Calling EOI of hwirq %u\n", hwirq);
 		chip->hwirq_eoi(chip, hwirq);
 	}
@@ -320,3 +320,19 @@ void sbi_irqchip_exit(struct sbi_scratch *scratch)
 	if (hd && hd->chip && hd->chip->process_hwirqs)
 		csr_clear(CSR_MIE, MIP_MEIP);
 }
+
+int sbi_irqchip_notify_smode_set(void)
+{
+	csr_set(CSR_MIP, MIP_SEIP);
+	return 0;
+}
+
+void sbi_irqchip_notify_smode_clear(void)
+{
+	csr_clear(CSR_MIP, MIP_SEIP);
+}
+
+bool sbi_irqchip_notify_smode_get(void)
+{
+	return !!(csr_read(CSR_MIP) & MIP_SEIP);
+}
-- 
2.25.1