[PATCH v3 09/12] lib: utils/irqchip: Add APLIC restore function

Nick Hu nick.hu at sifive.com
Tue Jul 8 00:49:37 PDT 2025


Since the APLIC may enter a reset state upon system wake-up from a
platform low power state, adding a restore function to reinitialize
the APLIC.

Signed-off-by: Nick Hu <nick.hu at sifive.com>
Reviewed-by: Yong-Xuan Wang <yongxuan.wang at sifive.com>
Reviewed-by: Cyan Yang <cyan.yang at sifive.com>
---
 include/sbi_utils/irqchip/aplic.h |   3 +
 lib/utils/irqchip/aplic.c         | 160 +++++++++++++++++-------------
 2 files changed, 96 insertions(+), 67 deletions(-)

diff --git a/include/sbi_utils/irqchip/aplic.h b/include/sbi_utils/irqchip/aplic.h
index e31f48a4..ca606d06 100644
--- a/include/sbi_utils/irqchip/aplic.h
+++ b/include/sbi_utils/irqchip/aplic.h
@@ -33,6 +33,7 @@ struct aplic_delegate_data {
 struct aplic_data {
 	/* Private members */
 	struct sbi_irqchip_device irqchip;
+	struct sbi_dlist node;
 	/* Public members */
 	unsigned long addr;
 	unsigned long size;
@@ -48,4 +49,6 @@ struct aplic_data {
 
 int aplic_cold_irqchip_init(struct aplic_data *aplic);
 
+void aplic_restore(void);
+
 #endif
diff --git a/lib/utils/irqchip/aplic.c b/lib/utils/irqchip/aplic.c
index 72906d5d..68f5d107 100644
--- a/lib/utils/irqchip/aplic.c
+++ b/lib/utils/irqchip/aplic.c
@@ -115,6 +115,88 @@
 #define APLIC_DISABLE_ITHRESHOLD	1
 #define APLIC_ENABLE_ITHRESHOLD		0
 
+static SBI_LIST_HEAD(aplic_list);
+static void aplic_writel_msicfg(struct aplic_msicfg_data *msicfg,
+				void *msicfgaddr, void *msicfgaddrH);
+
+static void aplic_init(struct aplic_data *aplic)
+{
+	u32 i, j, tmp;
+	struct aplic_delegate_data *deleg;
+
+	/* Set domain configuration to 0 */
+	writel(0, (void *)(aplic->addr + APLIC_DOMAINCFG));
+
+	/* Disable all interrupts */
+	for (i = 0; i <= aplic->num_source; i += 32)
+		writel(-1U, (void *)(aplic->addr + APLIC_CLRIE_BASE +
+				     (i / 32) * sizeof(u32)));
+
+	/* Set interrupt type and priority for all interrupts */
+	for (i = 1; i <= aplic->num_source; i++) {
+		/* Set IRQ source configuration to 0 */
+		writel(0, (void *)(aplic->addr + APLIC_SOURCECFG_BASE +
+			  (i - 1) * sizeof(u32)));
+		/* Set IRQ target hart index and priority to 1 */
+		writel(APLIC_DEFAULT_PRIORITY, (void *)(aplic->addr +
+						APLIC_TARGET_BASE +
+						(i - 1) * sizeof(u32)));
+	}
+
+	/* Configure IRQ delegation */
+	for (i = 0; i < APLIC_MAX_DELEGATE; i++) {
+		deleg = &aplic->delegate[i];
+		if (!deleg->first_irq || !deleg->last_irq)
+			continue;
+		if (aplic->num_source < deleg->first_irq ||
+		    aplic->num_source < deleg->last_irq)
+			continue;
+		if (deleg->child_index > APLIC_SOURCECFG_CHILDIDX_MASK)
+			continue;
+		if (deleg->first_irq > deleg->last_irq) {
+			tmp = deleg->first_irq;
+			deleg->first_irq = deleg->last_irq;
+			deleg->last_irq = tmp;
+		}
+		for (j = deleg->first_irq; j <= deleg->last_irq; j++)
+			writel(APLIC_SOURCECFG_D | deleg->child_index,
+			       (void *)(aplic->addr + APLIC_SOURCECFG_BASE +
+			       (j - 1) * sizeof(u32)));
+	}
+
+	/* Default initialization of IDC structures */
+	for (i = 0; i < aplic->num_idc; i++) {
+		writel(0, (void *)(aplic->addr + APLIC_IDC_BASE +
+				   i * APLIC_IDC_SIZE + APLIC_IDC_IDELIVERY));
+		writel(0, (void *)(aplic->addr + APLIC_IDC_BASE +
+				   i * APLIC_IDC_SIZE + APLIC_IDC_IFORCE));
+		writel(APLIC_DISABLE_ITHRESHOLD, (void *)(aplic->addr +
+						  APLIC_IDC_BASE +
+						  (i * APLIC_IDC_SIZE) +
+						  APLIC_IDC_ITHRESHOLD));
+	}
+
+	/* MSI configuration */
+	if (aplic->targets_mmode && aplic->has_msicfg_mmode) {
+		aplic_writel_msicfg(&aplic->msicfg_mmode,
+				    (void *)(aplic->addr + APLIC_MMSICFGADDR),
+				    (void *)(aplic->addr + APLIC_MMSICFGADDRH));
+	}
+	if (aplic->targets_mmode && aplic->has_msicfg_smode) {
+		aplic_writel_msicfg(&aplic->msicfg_smode,
+				    (void *)(aplic->addr + APLIC_SMSICFGADDR),
+				    (void *)(aplic->addr + APLIC_SMSICFGADDRH));
+	}
+}
+
+void aplic_restore(void)
+{
+	struct aplic_data *aplic;
+
+	sbi_list_for_each_entry(aplic, &aplic_list, node)
+		aplic_init(aplic);
+}
+
 static void aplic_writel_msicfg(struct aplic_msicfg_data *msicfg,
 				void *msicfgaddr, void *msicfgaddrH)
 {
@@ -168,9 +250,8 @@ static int aplic_check_msicfg(struct aplic_msicfg_data *msicfg)
 int aplic_cold_irqchip_init(struct aplic_data *aplic)
 {
 	int rc;
-	u32 i, j, tmp;
 	struct aplic_delegate_data *deleg;
-	u32 first_deleg_irq, last_deleg_irq;
+	u32 first_deleg_irq, last_deleg_irq, i;
 
 	/* Sanity checks */
 	if (!aplic ||
@@ -188,81 +269,23 @@ int aplic_cold_irqchip_init(struct aplic_data *aplic)
 			return rc;
 	}
 
-	/* Set domain configuration to 0 */
-	writel(0, (void *)(aplic->addr + APLIC_DOMAINCFG));
-
-	/* Disable all interrupts */
-	for (i = 0; i <= aplic->num_source; i += 32)
-		writel(-1U, (void *)(aplic->addr + APLIC_CLRIE_BASE +
-				     (i / 32) * sizeof(u32)));
-
-	/* Set interrupt type and priority for all interrupts */
-	for (i = 1; i <= aplic->num_source; i++) {
-		/* Set IRQ source configuration to 0 */
-		writel(0, (void *)(aplic->addr + APLIC_SOURCECFG_BASE +
-			  (i - 1) * sizeof(u32)));
-		/* Set IRQ target hart index and priority to 1 */
-		writel(APLIC_DEFAULT_PRIORITY, (void *)(aplic->addr +
-						APLIC_TARGET_BASE +
-						(i - 1) * sizeof(u32)));
-	}
+	/* Init the APLIC registers */
+	aplic_init(aplic);
 
-	/* Configure IRQ delegation */
+	/*
+	 * Add APLIC region to the root domain if:
+	 * 1) It targets M-mode of any HART directly or via MSIs
+	 * 2) All interrupts are delegated to some child APLIC
+	 */
 	first_deleg_irq = -1U;
 	last_deleg_irq = 0;
 	for (i = 0; i < APLIC_MAX_DELEGATE; i++) {
 		deleg = &aplic->delegate[i];
-		if (!deleg->first_irq || !deleg->last_irq)
-			continue;
-		if (aplic->num_source < deleg->first_irq ||
-		    aplic->num_source < deleg->last_irq)
-			continue;
-		if (APLIC_SOURCECFG_CHILDIDX_MASK < deleg->child_index)
-			continue;
-		if (deleg->first_irq > deleg->last_irq) {
-			tmp = deleg->first_irq;
-			deleg->first_irq = deleg->last_irq;
-			deleg->last_irq = tmp;
-		}
 		if (deleg->first_irq < first_deleg_irq)
 			first_deleg_irq = deleg->first_irq;
 		if (last_deleg_irq < deleg->last_irq)
 			last_deleg_irq = deleg->last_irq;
-		for (j = deleg->first_irq; j <= deleg->last_irq; j++)
-			writel(APLIC_SOURCECFG_D | deleg->child_index,
-				(void *)(aplic->addr + APLIC_SOURCECFG_BASE +
-				(j - 1) * sizeof(u32)));
-	}
-
-	/* Default initialization of IDC structures */
-	for (i = 0; i < aplic->num_idc; i++) {
-		writel(0, (void *)(aplic->addr + APLIC_IDC_BASE +
-			  i * APLIC_IDC_SIZE + APLIC_IDC_IDELIVERY));
-		writel(0, (void *)(aplic->addr + APLIC_IDC_BASE +
-			  i * APLIC_IDC_SIZE + APLIC_IDC_IFORCE));
-		writel(APLIC_DISABLE_ITHRESHOLD, (void *)(aplic->addr +
-						  APLIC_IDC_BASE +
-						  (i * APLIC_IDC_SIZE) +
-						  APLIC_IDC_ITHRESHOLD));
-	}
-
-	/* MSI configuration */
-	if (aplic->targets_mmode && aplic->has_msicfg_mmode) {
-		aplic_writel_msicfg(&aplic->msicfg_mmode,
-				(void *)(aplic->addr + APLIC_MMSICFGADDR),
-				(void *)(aplic->addr + APLIC_MMSICFGADDRH));
-	}
-	if (aplic->targets_mmode && aplic->has_msicfg_smode) {
-		aplic_writel_msicfg(&aplic->msicfg_smode,
-				(void *)(aplic->addr + APLIC_SMSICFGADDR),
-				(void *)(aplic->addr + APLIC_SMSICFGADDRH));
 	}
-
-	/*
-	 * Add APLIC region to the root domain if:
-	 * 1) It targets M-mode of any HART directly or via MSIs
-	 * 2) All interrupts are delegated to some child APLIC
-	 */
 	if (aplic->targets_mmode ||
 	    ((first_deleg_irq < last_deleg_irq) &&
 	    (last_deleg_irq == aplic->num_source) &&
@@ -278,5 +301,8 @@ int aplic_cold_irqchip_init(struct aplic_data *aplic)
 	/* Register irqchip device */
 	sbi_irqchip_add_device(&aplic->irqchip);
 
+	/* Attach to the aplic list */
+	sbi_list_add_tail(&aplic->node, &aplic_list);
+
 	return 0;
 }
-- 
2.17.1




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