arch/tile: parameterize system PLs to support KVM port

While not a port to KVM (yet), this change modifies the kernel
to be able to build either at PL1 or at PL2 with a suitable
config switch.  Pushing up this change avoids handling branch
merge issues going forward with the KVM work.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/kernel/irq.c b/arch/tile/kernel/irq.c
index 596c600..394d554 100644
--- a/arch/tile/kernel/irq.c
+++ b/arch/tile/kernel/irq.c
@@ -61,9 +61,9 @@
 
 #if CHIP_HAS_IPI()
 /* Use SPRs to manipulate device interrupts. */
-#define mask_irqs(irq_mask) __insn_mtspr(SPR_IPI_MASK_SET_1, irq_mask)
-#define unmask_irqs(irq_mask) __insn_mtspr(SPR_IPI_MASK_RESET_1, irq_mask)
-#define clear_irqs(irq_mask) __insn_mtspr(SPR_IPI_EVENT_RESET_1, irq_mask)
+#define mask_irqs(irq_mask) __insn_mtspr(SPR_IPI_MASK_SET_K, irq_mask)
+#define unmask_irqs(irq_mask) __insn_mtspr(SPR_IPI_MASK_RESET_K, irq_mask)
+#define clear_irqs(irq_mask) __insn_mtspr(SPR_IPI_EVENT_RESET_K, irq_mask)
 #else
 /* Use HV to manipulate device interrupts. */
 #define mask_irqs(irq_mask) hv_disable_intr(irq_mask)
@@ -89,16 +89,16 @@
 	 * masked by a previous interrupt.  Then, mask out the ones
 	 * we're going to handle.
 	 */
-	unsigned long masked = __insn_mfspr(SPR_IPI_MASK_1);
-	original_irqs = __insn_mfspr(SPR_IPI_EVENT_1) & ~masked;
-	__insn_mtspr(SPR_IPI_MASK_SET_1, original_irqs);
+	unsigned long masked = __insn_mfspr(SPR_IPI_MASK_K);
+	original_irqs = __insn_mfspr(SPR_IPI_EVENT_K) & ~masked;
+	__insn_mtspr(SPR_IPI_MASK_SET_K, original_irqs);
 #else
 	/*
 	 * Hypervisor performs the equivalent of the Gx code above and
 	 * then puts the pending interrupt mask into a system save reg
 	 * for us to find.
 	 */
-	original_irqs = __insn_mfspr(SPR_SYSTEM_SAVE_1_3);
+	original_irqs = __insn_mfspr(SPR_SYSTEM_SAVE_K_3);
 #endif
 	remaining_irqs = original_irqs;
 
@@ -225,7 +225,7 @@
 	/* Enable interrupt delivery. */
 	unmask_irqs(~0UL);
 #if CHIP_HAS_IPI()
-	raw_local_irq_unmask(INT_IPI_1);
+	raw_local_irq_unmask(INT_IPI_K);
 #endif
 }