[PATCH v2 2/6] x86/platform/uv/BAU: Add payload descriptor qualifier

[Andrew Banman]

On UV4, the destination agent verifies each message by checking the
descriptor qualifier field of the message payload. Messages without this
field set to 0x534749 will cause a hub error to assert.

Split bau_message_payload into uv1_2_3 and uv4 versions to account for the
different payload formats. Enforce the size of each field by using the
appropriate integer type. Replace extraneous comments with a kernel-doc
comment for each struct.

Populate the descriptor qualifier field before the INTD broadcast is
initiated by the sender. This ensures each message sent by with the BAU
driver is verified.

Signed-off-by: Andrew Banman <abanman@xxxxxxx>
Acked-by: Mike Travis <mike.travis@xxxxxxx>
---
 arch/x86/include/asm/uv/uv_bau.h | 40 ++++++++++++++++++++++++++++------------
 arch/x86/platform/uv/tlb_uv.c    | 27 +++++++++++++++++++--------
 2 files changed, 47 insertions(+), 20 deletions(-)

diff --git a/arch/x86/include/asm/uv/uv_bau.h b/arch/x86/include/asm/uv/uv_bau.h
index 768093f..1ed0574 100644
--- a/arch/x86/include/asm/uv/uv_bau.h
+++ b/arch/x86/include/asm/uv/uv_bau.h
@@ -185,6 +185,8 @@
 #define MSG_REGULAR			1
 #define MSG_RETRY			2
 
+#define BAU_DESC_QUALIFIER		0x534749
+
 enum uv_bau_version {
 	UV_BAU_V1 = 1,
 	UV_BAU_V2,
@@ -229,20 +231,31 @@ struct bau_local_cpumask {
  *   the s/w ack bit vector  ]
  */
 
-/*
- * The payload is software-defined for INTD transactions
+/**
+ * struct uv1_2_3_bau_msg_payload - defines payload for INTD transactions
+ * @address: signifies a page or all TLB's of the cpu
+ * @acknowledge_count: CPUs on the destination Hub that received the interrupt
  */
-struct bau_msg_payload {
-	unsigned long	address;		/* signifies a page or all
-						   TLB's of the cpu */
-	/* 64 bits */
-	unsigned short	sending_cpu;		/* filled in by sender */
-	/* 16 bits */
-	unsigned short	acknowledge_count;	/* filled in by destination */
-	/* 16 bits */
-	unsigned int	reserved1:32;		/* not usable */
+struct uv1_2_3_bau_msg_payload {
+	u64 address;
+	u16 sending_cpu;
+	u16 acknowledge_count;
+	u32 reserved1;
 };
 
+/**
+ * struct uv4_bau_msg_payload - defines payload for INTD transactions
+ * @address: signifies a page or all TLB's of the cpu
+ * @acknowledge_count: CPUs on the destination Hub that received the interrupt
+ * @qualifier: set by source to verify origin of INTD broadcast
+ */
+struct uv4_bau_msg_payload {
+	u64 address;
+	u16 sending_cpu;
+	u16 acknowledge_count;
+	u32 reserved1:8;
+	u32 qualifier:24;
+};
 
 /*
  * UV1 Message header:  16 bytes (128 bits) (bytes 0x30-0x3f of descriptor)
@@ -418,7 +431,10 @@ struct bau_desc {
 		struct uv2_3_bau_msg_header	uv2_3_hdr;
 	} header;
 
-	struct bau_msg_payload			payload;
+	union bau_payload_header {
+		struct uv1_2_3_bau_msg_payload	uv1_2_3;
+		struct uv4_bau_msg_payload	uv4;
+	} payload;
 };
 /* UV1:
  *   -payload--    ---------header------
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
index f4f5aa6..70721c4 100644
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -1114,15 +1114,12 @@ const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
 						unsigned long end,
 						unsigned int cpu)
 {
-	int locals = 0;
-	int remotes = 0;
-	int hubs = 0;
+	int locals = 0, remotes = 0, hubs = 0;
 	struct bau_desc *bau_desc;
 	struct cpumask *flush_mask;
 	struct ptc_stats *stat;
 	struct bau_control *bcp;
-	unsigned long descriptor_status;
-	unsigned long status;
+	unsigned long descriptor_status, status, address;
 
 	bcp = &per_cpu(bau_control, cpu);
 
@@ -1171,10 +1168,24 @@ const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
 	record_send_statistics(stat, locals, hubs, remotes, bau_desc);
 
 	if (!end || (end - start) <= PAGE_SIZE)
-		bau_desc->payload.address = start;
+		address = start;
 	else
-		bau_desc->payload.address = TLB_FLUSH_ALL;
-	bau_desc->payload.sending_cpu = cpu;
+		address = TLB_FLUSH_ALL;
+
+	switch (bcp->uvhub_version) {
+	case UV_BAU_V1:
+	case UV_BAU_V2:
+	case UV_BAU_V3:
+		bau_desc->payload.uv1_2_3.address = address;
+		bau_desc->payload.uv1_2_3.sending_cpu = cpu;
+		break;
+	case UV_BAU_V4:
+		bau_desc->payload.uv4.address = address;
+		bau_desc->payload.uv4.sending_cpu = cpu;
+		bau_desc->payload.uv4.qualifier = BAU_DESC_QUALIFIER;
+		break;
+	}
+
 	/*
 	 * uv_flush_send_and_wait returns 0 if all cpu's were messaged,
 	 * or 1 if it gave up and the original cpumask should be returned.
-- 
1.8.2.1