iommu: dmar: Extend struct irte for VT-d Posted-Interrupts

The IRTE (Interrupt Remapping Table Entry) is either an entry for
remapped or for posted interrupts. The hardware distiguishes between
remapped and posted entries by bit 15 in the low 64 bit of the
IRTE. If cleared the entry is remapped, if set it's posted.

The entries have common fields and dependent on the posted bit fields
with different meanings.

Extend struct irte to handle the differences between remap and posted
mode by having three structs in the unions:

        - Shared
        - Remapped
        - Posted

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Feng Wu <feng.wu@intel.com>
Acked-by: Joerg Roedel <joro@8bytes.org>
Cc: jiang.liu@linux.intel.com
Cc: iommu@lists.linux-foundation.org
Cc: dwmw2@infradead.org
Link: http://lkml.kernel.org/r/1433827237-3382-3-git-send-email-feng.wu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/dmar.h

@@ -185,33 +185,73 @@ static inline int dmar_device_remove(void *handle)
 
 struct irte {
 	union {
+		/* Shared between remapped and posted mode*/
 		struct {
-			__u64	present 	: 1,
-				fpd		: 1,
-				dst_mode	: 1,
-				redir_hint	: 1,
-				trigger_mode	: 1,
-				dlvry_mode	: 3,
-				avail		: 4,
-				__reserved_1	: 4,
-				vector		: 8,
-				__reserved_2	: 8,
-				dest_id		: 32;
+			__u64	present		: 1,  /*  0      */
+				fpd		: 1,  /*  1      */
+				__res0		: 6,  /*  2 -  6 */
+				avail		: 4,  /*  8 - 11 */
+				__res1		: 3,  /* 12 - 14 */
+				pst		: 1,  /* 15      */
+				vector		: 8,  /* 16 - 23 */
+				__res2		: 40; /* 24 - 63 */
+		};
+
+		/* Remapped mode */
+		struct {
+			__u64	r_present	: 1,  /*  0      */
+				r_fpd		: 1,  /*  1      */
+				dst_mode	: 1,  /*  2      */
+				redir_hint	: 1,  /*  3      */
+				trigger_mode	: 1,  /*  4      */
+				dlvry_mode	: 3,  /*  5 -  7 */
+				r_avail		: 4,  /*  8 - 11 */
+				r_res0		: 4,  /* 12 - 15 */
+				r_vector	: 8,  /* 16 - 23 */
+				r_res1		: 8,  /* 24 - 31 */
+				dest_id		: 32; /* 32 - 63 */
+		};
+
+		/* Posted mode */
+		struct {
+			__u64	p_present	: 1,  /*  0      */
+				p_fpd		: 1,  /*  1      */
+				p_res0		: 6,  /*  2 -  7 */
+				p_avail		: 4,  /*  8 - 11 */
+				p_res1		: 2,  /* 12 - 13 */
+				p_urgent	: 1,  /* 14      */
+				p_pst		: 1,  /* 15      */
+				p_vector	: 8,  /* 16 - 23 */
+				p_res2		: 14, /* 24 - 37 */
+				pda_l		: 26; /* 38 - 63 */
 		};
 		__u64 low;
 	};
 
 	union {
+		/* Shared between remapped and posted mode*/
 		struct {
-			__u64	sid		: 16,
-				sq		: 2,
-				svt		: 2,
-				__reserved_3	: 44;
+			__u64	sid		: 16,  /* 64 - 79  */
+				sq		: 2,   /* 80 - 81  */
+				svt		: 2,   /* 82 - 83  */
+				__res3		: 44;  /* 84 - 127 */
+		};
+
+		/* Posted mode*/
+		struct {
+			__u64	p_sid		: 16,  /* 64 - 79  */
+				p_sq		: 2,   /* 80 - 81  */
+				p_svt		: 2,   /* 82 - 83  */
+				p_res3		: 12,  /* 84 - 95  */
+				pda_h		: 32;  /* 96 - 127 */
 		};
 		__u64 high;
 	};
 };
 
+#define PDA_LOW_BIT    26
+#define PDA_HIGH_BIT   32
+
 enum {
 	IRQ_REMAP_XAPIC_MODE,
 	IRQ_REMAP_X2APIC_MODE,