[SPARC64]: Sun4v interrupt handling.

Sun4v has 4 interrupt queues: cpu, device, resumable errors,
and non-resumable errors.  A set of head/tail offset pointers
help maintain a work queue in physical memory.  The entries
are 64-bytes in size.

Each queue is allocated then registered with the hypervisor
as we bring cpus up.

The two error queues each get a kernel side buffer that we
use to quickly empty the main interrupt queue before we
call up to C code to log the event and possibly take evasive
action.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 349 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/sun4v_ivec.S b/arch/sparc64/kernel/sun4v_ivec.S
new file mode 100644
index 00000000000..d9d442017d3
--- /dev/null
+++ b/arch/sparc64/kernel/sun4v_ivec.S
@@ -0,0 +1,349 @@
+/* sun4v_ivec.S: Sun4v interrupt vector handling.
+ *
+ * Copyright (C) 2006 <davem@davemloft.net>
+ */
+
+#include <asm/cpudata.h>
+#include <asm/intr_queue.h>
+
+	.text
+	.align	32
+
+sun4v_cpu_mondo:
+	/* Head offset in %g2, tail offset in %g4.
+	 * If they are the same, no work.
+	 */
+	mov	INTRQ_CPU_MONDO_HEAD, %g2
+	ldxa	[%g2] ASI_QUEUE, %g2
+	mov	INTRQ_CPU_MONDO_TAIL, %g4
+	ldxa	[%g4] ASI_QUEUE, %g4
+	cmp	%g2, %g4
+	be,pn	%xcc, sun4v_cpu_mondo_queue_empty
+	 nop
+
+	/* Get &trap_block[smp_processor_id()] into %g3.  */
+	__GET_CPUID(%g1)
+	sethi	%hi(trap_block), %g3
+	sllx	%g1, TRAP_BLOCK_SZ_SHIFT, %g7
+	or	%g3, %lo(trap_block), %g3
+	add	%g3, %g7, %g3
+
+	/* Get CPU mondo queue base phys address into %g7.  */
+	ldx	[%g3 + TRAP_PER_CPU_CPU_MONDO_PA], %g7
+
+	/* Now get the cross-call arguments and handler PC, same
+	 * layout as sun4u:
+	 *
+	 * 1st 64-bit word: low half is 32-bit PC, put into %g3 and jmpl to it
+	 *                  high half is context arg to MMU flushes, into %g5
+	 * 2nd 64-bit word: 64-bit arg, load into %g1
+	 * 3rd 64-bit word: 64-bit arg, load into %g7
+	 */
+	ldxa	[%g7 + %g2] ASI_PHYS_USE_EC, %g3
+	add	%g2, 0x8, %g2
+	srlx	%g3, 32, %g5
+	ldxa	[%g7 + %g2] ASI_PHYS_USE_EC, %g1
+	add	%g2, 0x8, %g2
+	srl	%g3, 0, %g3
+	ldxa	[%g7 + %g2] ASI_PHYS_USE_EC, %g7
+	add	%g2, 0x40 - 0x8 - 0x8, %g2
+
+	/* Update queue head pointer.  */
+	sethi	%hi(8192 - 1), %g4
+	or	%g4, %lo(8192 - 1), %g4
+	and	%g2, %g4, %g2
+
+	mov	INTRQ_CPU_MONDO_HEAD, %g4
+	stxa	%g2, [%g4] ASI_QUEUE
+	membar	#Sync
+
+	jmpl	%g3, %g0
+	 nop
+
+sun4v_cpu_mondo_queue_empty:
+	retry
+
+sun4v_dev_mondo:
+	/* Head offset in %g2, tail offset in %g4.  */
+	mov	INTRQ_DEVICE_MONDO_HEAD, %g2
+	ldxa	[%g2] ASI_QUEUE, %g2
+	mov	INTRQ_DEVICE_MONDO_TAIL, %g4
+	ldxa	[%g4] ASI_QUEUE, %g4
+	cmp	%g2, %g4
+	be,pn	%xcc, sun4v_dev_mondo_queue_empty
+	 nop
+
+	/* Get &trap_block[smp_processor_id()] into %g3.  */
+	__GET_CPUID(%g1)
+	sethi	%hi(trap_block), %g3
+	sllx	%g1, TRAP_BLOCK_SZ_SHIFT, %g7
+	or	%g3, %lo(trap_block), %g3
+	add	%g3, %g7, %g3
+
+	/* Get DEV mondo queue base phys address into %g5.  */
+	ldx	[%g3 + TRAP_PER_CPU_DEV_MONDO_PA], %g5
+
+	/* Load IVEC into %g3.  */
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	add	%g2, 0x40, %g2
+
+	/* XXX There can be a full 64-byte block of data here.
+	 * XXX This is how we can get at MSI vector data.
+	 * XXX Current we do not capture this, but when we do we'll
+	 * XXX need to add a 64-byte storage area in the struct ino_bucket
+	 * XXX or the struct irq_desc.
+	 */
+
+	/* Update queue head pointer, this frees up some registers.  */
+	sethi	%hi(8192 - 1), %g4
+	or	%g4, %lo(8192 - 1), %g4
+	and	%g2, %g4, %g2
+
+	mov	INTRQ_DEVICE_MONDO_HEAD, %g4
+	stxa	%g2, [%g4] ASI_QUEUE
+	membar	#Sync
+
+	/* Get &__irq_work[smp_processor_id()] into %g1.  */
+	sethi	%hi(__irq_work), %g4
+	sllx	%g1, 6, %g1
+	or	%g4, %lo(__irq_work), %g4
+	add	%g4, %g1, %g1
+
+	/* Get &ivector_table[IVEC] into %g4.  */
+	sethi	%hi(ivector_table), %g4
+	sllx	%g3, 5, %g3
+	or	%g4, %lo(ivector_table), %g4
+	add	%g4, %g3, %g4
+
+	/* Load IRQ %pil into %g5.  */
+	ldub	[%g4 + 0x04], %g5
+
+	/* Insert ivector_table[] entry into __irq_work[] queue.  */
+	sllx	%g5, 2, %g3
+	lduw	[%g1 + %g3], %g2	/* g2 = irq_work(cpu, pil) */
+	stw	%g2, [%g4 + 0x00]	/* bucket->irq_chain = g2 */
+	stw	%g4, [%g1 + %g3]	/* irq_work(cpu, pil) = bucket */
+
+	/* Signal the interrupt by setting (1 << pil) in %softint.  */
+	mov	1, %g2
+	sllx	%g2, %g5, %g2
+	wr	%g2, 0x0, %set_softint
+
+sun4v_dev_mondo_queue_empty:
+	retry
+
+sun4v_res_mondo:
+	/* Head offset in %g2, tail offset in %g4.  */
+	mov	INTRQ_RESUM_MONDO_HEAD, %g2
+	ldxa	[%g2] ASI_QUEUE, %g2
+	mov	INTRQ_RESUM_MONDO_TAIL, %g4
+	ldxa	[%g4] ASI_QUEUE, %g4
+	cmp	%g2, %g4
+	be,pn	%xcc, sun4v_res_mondo_queue_empty
+	 nop
+
+	/* Get &trap_block[smp_processor_id()] into %g3.  */
+	__GET_CPUID(%g1)
+	sethi	%hi(trap_block), %g3
+	sllx	%g1, TRAP_BLOCK_SZ_SHIFT, %g7
+	or	%g3, %lo(trap_block), %g3
+	add	%g3, %g7, %g3
+
+	/* Get RES mondo queue base phys address into %g5.  */
+	ldx	[%g3 + TRAP_PER_CPU_RESUM_MONDO_PA], %g5
+
+	/* Get RES kernel buffer base phys address into %g7.  */
+	ldx	[%g3 + TRAP_PER_CPU_RESUM_KBUF_PA], %g7
+
+	/* If the first word is non-zero, queue is full.  */
+	ldxa	[%g7 + %g2] ASI_PHYS_USE_EC, %g1
+	brnz,pn	%g1, sun4v_res_mondo_queue_full
+	 nop
+
+	/* Remember this entry's offset in %g1.  */
+	mov	%g2, %g1
+
+	/* Copy 64-byte queue entry into kernel buffer.  */
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+
+	/* Update queue head pointer.  */
+	sethi	%hi(8192 - 1), %g4
+	or	%g4, %lo(8192 - 1), %g4
+	and	%g2, %g4, %g2
+
+	mov	INTRQ_RESUM_MONDO_HEAD, %g4
+	stxa	%g2, [%g4] ASI_QUEUE
+	membar	#Sync
+
+	/* Disable interrupts and save register state so we can call
+	 * C code.  The etrap handling will leave %g4 in %l4 for us
+	 * when it's done.
+	 */
+	rdpr	%pil, %g2
+	wrpr	%g0, 15, %pil
+	mov	%g1, %g4
+	ba,pt	%xcc, etrap_irq
+	 rd	%pc, %g7
+
+	/* Log the event.  */
+	add	%sp, PTREGS_OFF, %o0
+	call	sun4v_resum_error
+	 mov	%l4, %o1
+
+	/* Return from trap.  */
+	ba,pt	%xcc, rtrap_irq
+	 nop
+
+sun4v_res_mondo_queue_empty:
+	retry
+
+sun4v_res_mondo_queue_full:
+	/* The queue is full, consolidate our damage by setting
+	 * the head equal to the tail.  We'll just trap again otherwise.
+	 * Call C code to log the event.
+	 */
+	mov	INTRQ_RESUM_MONDO_HEAD, %g2
+	stxa	%g4, [%g2] ASI_QUEUE
+	membar	#Sync
+
+	rdpr	%pil, %g2
+	wrpr	%g0, 15, %pil
+	ba,pt	%xcc, etrap_irq
+	 rd	%pc, %g7
+
+	call	sun4v_resum_overflow
+	 add	%sp, PTREGS_OFF, %o0
+
+	ba,pt	%xcc, rtrap_irq
+	 nop
+
+sun4v_nonres_mondo:
+	/* Head offset in %g2, tail offset in %g4.  */
+	mov	INTRQ_NONRESUM_MONDO_HEAD, %g2
+	ldxa	[%g2] ASI_QUEUE, %g2
+	mov	INTRQ_NONRESUM_MONDO_TAIL, %g4
+	ldxa	[%g4] ASI_QUEUE, %g4
+	cmp	%g2, %g4
+	be,pn	%xcc, sun4v_nonres_mondo_queue_empty
+	 nop
+
+	/* Get &trap_block[smp_processor_id()] into %g3.  */
+	__GET_CPUID(%g1)
+	sethi	%hi(trap_block), %g3
+	sllx	%g1, TRAP_BLOCK_SZ_SHIFT, %g7
+	or	%g3, %lo(trap_block), %g3
+	add	%g3, %g7, %g3
+
+	/* Get RES mondo queue base phys address into %g5.  */
+	ldx	[%g3 + TRAP_PER_CPU_NONRESUM_MONDO_PA], %g5
+
+	/* Get RES kernel buffer base phys address into %g7.  */
+	ldx	[%g3 + TRAP_PER_CPU_NONRESUM_KBUF_PA], %g7
+
+	/* If the first word is non-zero, queue is full.  */
+	ldxa	[%g7 + %g2] ASI_PHYS_USE_EC, %g1
+	brnz,pn	%g1, sun4v_nonres_mondo_queue_full
+	 nop
+
+	/* Remember this entry's offset in %g1.  */
+	mov	%g2, %g1
+
+	/* Copy 64-byte queue entry into kernel buffer.  */
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+	ldxa	[%g5 + %g2] ASI_PHYS_USE_EC, %g3
+	stxa	%g3, [%g7 + %g2] ASI_PHYS_USE_EC
+	add	%g2, 0x08, %g2
+
+	/* Update queue head pointer.  */
+	sethi	%hi(8192 - 1), %g4
+	or	%g4, %lo(8192 - 1), %g4
+	and	%g2, %g4, %g2
+
+	mov	INTRQ_NONRESUM_MONDO_HEAD, %g4
+	stxa	%g2, [%g4] ASI_QUEUE
+	membar	#Sync
+
+	/* Disable interrupts and save register state so we can call
+	 * C code.  The etrap handling will leave %g4 in %l4 for us
+	 * when it's done.
+	 */
+	rdpr	%pil, %g2
+	wrpr	%g0, 15, %pil
+	mov	%g1, %g4
+	ba,pt	%xcc, etrap_irq
+	 rd	%pc, %g7
+
+	/* Log the event.  */
+	add	%sp, PTREGS_OFF, %o0
+	call	sun4v_nonresum_error
+	 mov	%l4, %o1
+
+	/* Return from trap.  */
+	ba,pt	%xcc, rtrap_irq
+	 nop
+
+sun4v_nonres_mondo_queue_empty:
+	retry
+
+sun4v_nonres_mondo_queue_full:
+	/* The queue is full, consolidate our damage by setting
+	 * the head equal to the tail.  We'll just trap again otherwise.
+	 * Call C code to log the event.
+	 */
+	mov	INTRQ_NONRESUM_MONDO_HEAD, %g2
+	stxa	%g4, [%g2] ASI_QUEUE
+	membar	#Sync
+
+	rdpr	%pil, %g2
+	wrpr	%g0, 15, %pil
+	ba,pt	%xcc, etrap_irq
+	 rd	%pc, %g7
+
+	call	sun4v_nonresum_overflow
+	 add	%sp, PTREGS_OFF, %o0
+
+	ba,pt	%xcc, rtrap_irq
+	 nop