lib: utils/irqchip/aplic: add MSI mode support with IMSIC parent linking

Add parent_unique_id fields to struct aplic_data for
IMSIC parent linking in MSI mode. Store parent IMSIC unique_id
during FDT parsing of the APLIC node.

Add aplic_is_msi_mode() complementing aplic_is_direct_mode() to
consolidate delivery mode detection. Add APLIC_TARGET_EIID() macro
for packing the EIID field into the TARGET register.

Add parent_unique_id and parent_irq_map fields to struct aplic_data.
parent_unique_id identifies the upstream IMSIC irqchip device resolved
via sbi_irqchip_find_device() during hwirq_setup. parent_irq_map is
a per-source array allocated at cold init time to track the EIID
assigned by the IMSIC for each APLIC source.

Restore aplic_writel_msicfg() and re-introduce MSI address register
programming in aplic_init(), gated on aplic_is_msi_mode(). Set the
DOMAINCFG_DM bit to switch the hardware to MSI delivery mode when
no IDC structures are present.

Add aplic_program_msi_target() to pack hart_index, guest_index, and
EIID into the APLIC_TARGET register. Add aplic_write_msi() as the
sbi_irqchip write_msi callback that extracts EIID and hart_index from
the MSI message and calls aplic_program_msi_target(). Add
aplic_msi_callback() as the MSI receive callback that dispatches to
sbi_irqchip_process_hwirq() on the APLIC chip.

Extend aplic_hwirq_setup() with an MSI path that resolves the parent
IMSIC chip by parent_unique_id, registers an MSI route via
sbi_irqchip_register_msi(), and stores the allocated EIID in
parent_irq_map for the source being configured.

Extend aplic_hwirq_set_affinity() with an MSI path that delegates
affinity reprogramming to the parent IMSIC chip via
sbi_irqchip_set_affinity() using the stored parent_irq_map entry.

Guard warm_init, process_hwirqs, and hwirq_eoi with early returns in
MSI mode as interrupt delivery and acknowledgement are handled by the
IMSIC in that configuration.

Signed-off-by: Oza Pawandeep <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Anup Patel <[email protected]>

2 files changed, 7 insertions, 0 deletions

diff --git a/include/sbi/sbi_irqchip.h b/include/sbi/sbi_irqchip.h
index e778d747..ea012635 100644
--- a/include/sbi/sbi_irqchip.h
+++ b/include/sbi/sbi_irqchip.h
@@ -107,6 +107,12 @@ int sbi_irqchip_unmask_hwirq(struct sbi_irqchip_device *chip, u32 hwirq);
 /** Mask a hardware interrupt */
 int sbi_irqchip_mask_hwirq(struct sbi_irqchip_device *chip, u32 hwirq);
 
+/** Helper to set private data in sbi_irqchip_hwirq_data */
+int sbi_irqchip_set_hwirq_priv(struct sbi_irqchip_device *chip, u32 hwirq, void *priv);
+
+/** Helper to retrieve data from sbi_irqchip_hwirq_data */
+void *sbi_irqchip_get_hwirq_priv(struct sbi_irqchip_device *chip, u32 hwirq);
+
 /** Default raw hardware interrupt handler */
 int sbi_irqchip_raw_handler_default(struct sbi_irqchip_device *chip, u32 hwirq);
 
diff --git a/include/sbi_utils/irqchip/aplic.h b/include/sbi_utils/irqchip/aplic.h
index 3461d1c7..8d6d871e 100644
--- a/include/sbi_utils/irqchip/aplic.h
+++ b/include/sbi_utils/irqchip/aplic.h
@@ -36,6 +36,7 @@ struct aplic_data {
 	struct sbi_dlist node;
 	/* Public members */
 	u32 unique_id;
+	u32 parent_unique_id;
 	unsigned long addr;
 	unsigned long size;
 	unsigned long num_idc;