[PATCH v1 09/17] xen/riscv: add helper to check APLIC MSI mode

This helper can be used outside aplic.c to determine whether MSI mode
is enabled. A follow-up patch uses it to decide whether the guest
IMSIC state should be saved/restored.

Signed-off-by: Oleksii Kurochko <[email protected]>
---
 xen/arch/riscv/aplic.c             | 9 +++++++--
 xen/arch/riscv/include/asm/aplic.h | 2 ++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/xen/arch/riscv/aplic.c b/xen/arch/riscv/aplic.c
index 87f2134bc561..1ce844cd2162 100644
--- a/xen/arch/riscv/aplic.c
+++ b/xen/arch/riscv/aplic.c
@@ -93,6 +93,11 @@ void aplic_hw_write_reg(unsigned int offset, uint32_t value)
     spin_unlock_irqrestore(&aplic.lock, flags);
 }
 
+bool has_msi_support(void)
+{
+    return readl(&aplic.regs->domaincfg) & APLIC_DOMAINCFG_DM;
+}
+
 static void __init aplic_init_hw_interrupts(void)
 {
     unsigned int i;
@@ -185,7 +190,7 @@ static void cf_check aplic_irq_enable(struct irq_desc *desc)
      *       If APLIC without MSI interrupts is required in the future,
      *       this function will need to be updated accordingly.
      */
-    ASSERT(readl(&aplic.regs->domaincfg) & APLIC_DOMAINCFG_DM);
+    ASSERT(has_msi_support());
 
     ASSERT(spin_is_locked(&desc->lock));
 
@@ -216,7 +221,7 @@ static void cf_check aplic_irq_disable(struct irq_desc *desc)
      *       If APLIC without MSI interrupts is required in the future,
      *       this function will need to be updated accordingly.
      */
-    ASSERT(readl(&aplic.regs->domaincfg) & APLIC_DOMAINCFG_DM);
+    ASSERT(has_msi_support());
 
     ASSERT(spin_is_locked(&desc->lock));
 
diff --git a/xen/arch/riscv/include/asm/aplic.h b/xen/arch/riscv/include/asm/aplic.h
index 4ae5fb8f26d1..9a0b23351154 100644
--- a/xen/arch/riscv/include/asm/aplic.h
+++ b/xen/arch/riscv/include/asm/aplic.h
@@ -144,4 +144,6 @@ struct aplic_regs {
 uint32_t aplic_hw_read_reg(unsigned int offset, uint32_t mask);
 void aplic_hw_write_reg(unsigned int offset, uint32_t value);
 
+bool has_msi_support(void);
+
 #endif /* ASM_RISCV_APLIC_H */
-- 
2.54.0