GIC: Add APIs to enable and disable interrupt

API documentation updated.

Change-Id: Ice7511f8df5356851001d2f7dc2a46cfe318f9ba
Co-authored-by: Yousuf A <yousuf.sait@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

4 files changed, 110 insertions, 0 deletions

diff --git a/drivers/arm/gic/v2/gicv2_main.c b/drivers/arm/gic/v2/gicv2_main.c
index e33353a8..e0058ad1 100644
--- a/drivers/arm/gic/v2/gicv2_main.c
+++ b/drivers/arm/gic/v2/gicv2_main.c
@@ -288,3 +288,37 @@ unsigned int gicv2_get_interrupt_active(unsigned int id)
 
 	return gicd_get_isactiver(driver_data->gicd_base, id);
 }
+
+/*******************************************************************************
+ * This function enables the interrupt identified by id.
+ ******************************************************************************/
+void gicv2_enable_interrupt(unsigned int id)
+{
+	assert(driver_data);
+	assert(driver_data->gicd_base);
+	assert(id <= MAX_SPI_ID);
+
+	/*
+	 * Ensure that any shared variable updates depending on out of band
+	 * interrupt trigger are observed before enabling interrupt.
+	 */
+	dsbishst();
+	gicd_set_isenabler(driver_data->gicd_base, id);
+}
+
+/*******************************************************************************
+ * This function disables the interrupt identified by id.
+ ******************************************************************************/
+void gicv2_disable_interrupt(unsigned int id)
+{
+	assert(driver_data);
+	assert(driver_data->gicd_base);
+	assert(id <= MAX_SPI_ID);
+
+	/*
+	 * Disable interrupt, and ensure that any shared variable updates
+	 * depending on out of band interrupt trigger are observed afterwards.
+	 */
+	gicd_set_icenabler(driver_data->gicd_base, id);
+	dsbishst();
+}
diff --git a/drivers/arm/gic/v3/gicv3_helpers.c b/drivers/arm/gic/v3/gicv3_helpers.c
index 81d50ad4..ee874f92 100644
--- a/drivers/arm/gic/v3/gicv3_helpers.c
+++ b/drivers/arm/gic/v3/gicv3_helpers.c
@@ -173,6 +173,17 @@ void gicr_set_isenabler0(uintptr_t base, unsigned int id)
 
 /*
  * Accessor to set the bit corresponding to interrupt ID in GIC Re-distributor
+ * ICENABLER0.
+ */
+void gicr_set_icenabler0(uintptr_t base, unsigned int id)
+{
+	unsigned bit_num = id & ((1 << ICENABLER_SHIFT) - 1);
+
+	gicr_write_icenabler0(base, (1 << bit_num));
+}
+
+/*
+ * Accessor to set the bit corresponding to interrupt ID in GIC Re-distributor
  * ISACTIVER0.
  */
 unsigned int gicr_get_isactiver0(uintptr_t base, unsigned int id)
diff --git a/drivers/arm/gic/v3/gicv3_main.c b/drivers/arm/gic/v3/gicv3_main.c
index 08cf0957..b3231993 100644
--- a/drivers/arm/gic/v3/gicv3_main.c
+++ b/drivers/arm/gic/v3/gicv3_main.c
@@ -805,3 +805,67 @@ unsigned int gicv3_get_interrupt_active(unsigned int id, unsigned int proc_num)
 
 	return value;
 }
+
+/*******************************************************************************
+ * This function enables the interrupt identified by id. The proc_num
+ * is used if the interrupt is SGI or PPI, and programs the corresponding
+ * Redistributor interface.
+ ******************************************************************************/
+void gicv3_enable_interrupt(unsigned int id, unsigned int proc_num)
+{
+	assert(gicv3_driver_data);
+	assert(gicv3_driver_data->gicd_base);
+	assert(proc_num < gicv3_driver_data->rdistif_num);
+	assert(gicv3_driver_data->rdistif_base_addrs);
+	assert(id <= MAX_SPI_ID);
+
+	/*
+	 * Ensure that any shared variable updates depending on out of band
+	 * interrupt trigger are observed before enabling interrupt.
+	 */
+	dsbishst();
+	if (id < MIN_SPI_ID) {
+		/* For SGIs and PPIs */
+		gicr_set_isenabler0(
+				gicv3_driver_data->rdistif_base_addrs[proc_num],
+				id);
+	} else {
+		gicd_set_isenabler(gicv3_driver_data->gicd_base, id);
+	}
+}
+
+/*******************************************************************************
+ * This function disables the interrupt identified by id. The proc_num
+ * is used if the interrupt is SGI or PPI, and programs the corresponding
+ * Redistributor interface.
+ ******************************************************************************/
+void gicv3_disable_interrupt(unsigned int id, unsigned int proc_num)
+{
+	assert(gicv3_driver_data);
+	assert(gicv3_driver_data->gicd_base);
+	assert(proc_num < gicv3_driver_data->rdistif_num);
+	assert(gicv3_driver_data->rdistif_base_addrs);
+	assert(id <= MAX_SPI_ID);
+
+	/*
+	 * Disable interrupt, and ensure that any shared variable updates
+	 * depending on out of band interrupt trigger are observed afterwards.
+	 */
+	if (id < MIN_SPI_ID) {
+		/* For SGIs and PPIs */
+		gicr_set_icenabler0(
+				gicv3_driver_data->rdistif_base_addrs[proc_num],
+				id);
+
+		/* Write to clear enable requires waiting for pending writes */
+		gicr_wait_for_pending_write(
+				gicv3_driver_data->rdistif_base_addrs[proc_num]);
+	} else {
+		gicd_set_icenabler(gicv3_driver_data->gicd_base, id);
+
+		/* Write to clear enable requires waiting for pending writes */
+		gicd_wait_for_pending_write(gicv3_driver_data->gicd_base);
+	}
+
+	dsbishst();
+}
diff --git a/drivers/arm/gic/v3/gicv3_private.h b/drivers/arm/gic/v3/gicv3_private.h
index bb8ad9ae..19fce2e7 100644
--- a/drivers/arm/gic/v3/gicv3_private.h
+++ b/drivers/arm/gic/v3/gicv3_private.h
@@ -71,6 +71,7 @@ unsigned int gicr_get_isactiver0(uintptr_t base, unsigned int id);
 void gicd_set_igrpmodr(uintptr_t base, unsigned int id);
 void gicr_set_igrpmodr0(uintptr_t base, unsigned int id);
 void gicr_set_isenabler0(uintptr_t base, unsigned int id);
+void gicr_set_icenabler0(uintptr_t base, unsigned int id);
 void gicr_set_igroupr0(uintptr_t base, unsigned int id);
 void gicd_clr_igrpmodr(uintptr_t base, unsigned int id);
 void gicr_clr_igrpmodr0(uintptr_t base, unsigned int id);