[IA64] Add Variable Page Size and IA64 Support in Intel IOMMU

The patch contains Intel IOMMU IA64 specific code. It defines new
machvec dig_vtd, hooks for IOMMU, DMAR table detection, cache line flush
function, etc.

For a generic kernel with CONFIG_DMAR=y, if Intel IOMMU is detected,
dig_vtd is used for machinve vector. Otherwise, kernel falls back to
dig machine vector. Kernel parameter "machvec=dig" or "intel_iommu=off"
can be used to force kernel to boot dig machine vector.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/lib/flush.S b/arch/ia64/lib/flush.S
index 2a0d27f..1d8c888 100644
--- a/arch/ia64/lib/flush.S
+++ b/arch/ia64/lib/flush.S
@@ -60,3 +60,58 @@
 	mov	ar.lc=r3		// restore ar.lc
 	br.ret.sptk.many rp
 END(flush_icache_range)
+
+	/*
+	 * clflush_cache_range(start,size)
+	 *
+	 *	Flush cache lines from start to start+size-1.
+	 *
+	 *	Must deal with range from start to start+size-1 but nothing else
+	 *	(need to be careful not to touch addresses that may be
+	 *	unmapped).
+	 *
+	 *	Note: "in0" and "in1" are preserved for debugging purposes.
+	 */
+	.section .kprobes.text,"ax"
+GLOBAL_ENTRY(clflush_cache_range)
+
+	.prologue
+	alloc	r2=ar.pfs,2,0,0,0
+	movl	r3=ia64_cache_stride_shift
+	mov	r21=1
+	add     r22=in1,in0
+	;;
+	ld8	r20=[r3]		// r20: stride shift
+	sub	r22=r22,r0,1		// last byte address
+	;;
+	shr.u	r23=in0,r20		// start / (stride size)
+	shr.u	r22=r22,r20		// (last byte address) / (stride size)
+	shl	r21=r21,r20		// r21: stride size of the i-cache(s)
+	;;
+	sub	r8=r22,r23		// number of strides - 1
+	shl	r24=r23,r20		// r24: addresses for "fc" =
+					//	"start" rounded down to stride
+					//	boundary
+	.save	ar.lc,r3
+	mov	r3=ar.lc		// save ar.lc
+	;;
+
+	.body
+	mov	ar.lc=r8
+	;;
+	/*
+	 * 32 byte aligned loop, even number of (actually 2) bundles
+	 */
+.Loop_fc:
+	fc	r24		// issuable on M0 only
+	add	r24=r21,r24	// we flush "stride size" bytes per iteration
+	nop.i	0
+	br.cloop.sptk.few .Loop_fc
+	;;
+	sync.i
+	;;
+	srlz.i
+	;;
+	mov	ar.lc=r3		// restore ar.lc
+	br.ret.sptk.many rp
+END(clflush_cache_range)