x86/platform/uv/BAU: Add generic function pointers

Many BAU functions have different implementations depending on the UV
version. Rather than switching on the uvhub_version throughout the driver,
we can define a set of operations for each version. This is especially
beneficial for UV4, which will require many new MMR read/write functions.

Currently, the set of abstracted functions are the same for UV1, UV2, and
UV3. The functions were chosen because each one will have a different
implementation for UV4. Other functions will be added as needed to handle
new implementations or to cleanup the existing differences between UV1,
UV2, and UV3, i.e. read_status and wait_completion.

Signed-off-by: Andrew Banman <abanman@sgi.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mike Travis <travis@sgi.com>
Acked-by: Dimitri Sivanich <sivanich@sgi.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: akpm@linux-foundation.org
Cc: rja@sgi.com
Link: http://lkml.kernel.org/r/1474474161-265604-6-git-send-email-abanman@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/uv/uv_bau.h

@@ -385,6 +385,17 @@ struct uv2_3_bau_msg_header {
 	/* bits 127:120 */
 };
 
+/* Abstracted BAU functions */
+struct bau_operations {
+	unsigned long (*read_l_sw_ack)(void);
+	unsigned long (*read_g_sw_ack)(int pnode);
+	unsigned long (*bau_gpa_to_offset)(unsigned long vaddr);
+	void (*write_l_sw_ack)(unsigned long mmr);
+	void (*write_g_sw_ack)(int pnode, unsigned long mmr);
+	void (*write_payload_first)(int pnode, unsigned long mmr);
+	void (*write_payload_last)(int pnode, unsigned long mmr);
+};
+
 /*
  * The activation descriptor:
  * The format of the message to send, plus all accompanying control

arch/x86/platform/uv/tlb_uv.c

@@ -24,6 +24,18 @@
 #include <asm/irq_vectors.h>
 #include <asm/timer.h>
 
+static struct bau_operations ops;
+
+static struct bau_operations uv123_bau_ops = {
+	.bau_gpa_to_offset       = uv_gpa_to_offset,
+	.read_l_sw_ack           = read_mmr_sw_ack,
+	.read_g_sw_ack           = read_gmmr_sw_ack,
+	.write_l_sw_ack          = write_mmr_sw_ack,
+	.write_g_sw_ack          = write_gmmr_sw_ack,
+	.write_payload_first     = write_mmr_payload_first,
+	.write_payload_last      = write_mmr_payload_last,
+};
+
 /* timeouts in nanoseconds (indexed by UVH_AGING_PRESCALE_SEL urgency7 30:28) */
 static int timeout_base_ns[] = {
 		20,
@@ -2135,6 +2147,13 @@ static int __init uv_bau_init(void)
 	if (!is_uv_system())
 		return 0;
 
+	if (is_uv3_hub())
+		ops = uv123_bau_ops;
+	else if (is_uv2_hub())
+		ops = uv123_bau_ops;
+	else if (is_uv1_hub())
+		ops = uv123_bau_ops;
+
 	for_each_possible_cpu(cur_cpu) {
 		mask = &per_cpu(uv_flush_tlb_mask, cur_cpu);
 		zalloc_cpumask_var_node(mask, GFP_KERNEL, cpu_to_node(cur_cpu));