[IA64] make IOMMU respect the segment boundary limits

IA64's IOMMU implementation allocates memory areas spanning LLD's segment
boundary limit.  It forces low level drivers to have a workaround to adjust
scatter lists that the IOMMU builds.

We are in the process of making all the IOMMUs respect the segment boundary
limits to remove such work around in LLDs.  This patch is for IA64's IOMMU.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 8fa3faf..1b73ffe 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -611,6 +611,9 @@
 	bool
 	default y
 
+config IOMMU_HELPER
+	def_bool (IA64_HP_ZX1 || IA64_HP_ZX1_SWIOTLB || IA64_GENERIC)
+
 source "arch/ia64/hp/sim/Kconfig"
 
 source "arch/ia64/Kconfig.debug"
diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
index 523eae6..9409de5 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -35,6 +35,7 @@
 #include <linux/nodemask.h>
 #include <linux/bitops.h>         /* hweight64() */
 #include <linux/crash_dump.h>
+#include <linux/iommu-helper.h>
 
 #include <asm/delay.h>		/* ia64_get_itc() */
 #include <asm/io.h>
@@ -460,6 +461,13 @@
 	return order;
 }
 
+static unsigned long ptr_to_pide(struct ioc *ioc, unsigned long *res_ptr,
+				 unsigned int bitshiftcnt)
+{
+	return (((unsigned long)res_ptr - (unsigned long)ioc->res_map) << 3)
+		+ bitshiftcnt;
+}
+
 /**
  * sba_search_bitmap - find free space in IO PDIR resource bitmap
  * @ioc: IO MMU structure which owns the pdir we are interested in.
@@ -471,15 +479,25 @@
  * Cool perf optimization: search for log2(size) bits at a time.
  */
 static SBA_INLINE unsigned long
-sba_search_bitmap(struct ioc *ioc, unsigned long bits_wanted, int use_hint)
+sba_search_bitmap(struct ioc *ioc, struct device *dev,
+		  unsigned long bits_wanted, int use_hint)
 {
 	unsigned long *res_ptr;
 	unsigned long *res_end = (unsigned long *) &(ioc->res_map[ioc->res_size]);
-	unsigned long flags, pide = ~0UL;
+	unsigned long flags, pide = ~0UL, tpide;
+	unsigned long boundary_size;
+	unsigned long shift;
+	int ret;
 
 	ASSERT(((unsigned long) ioc->res_hint & (sizeof(unsigned long) - 1UL)) == 0);
 	ASSERT(res_ptr < res_end);
 
+	boundary_size = (unsigned long long)dma_get_seg_boundary(dev) + 1;
+	boundary_size = ALIGN(boundary_size, 1ULL << iovp_shift) >> iovp_shift;
+
+	BUG_ON(ioc->ibase & ~iovp_mask);
+	shift = ioc->ibase >> iovp_shift;
+
 	spin_lock_irqsave(&ioc->res_lock, flags);
 
 	/* Allow caller to force a search through the entire resource space */
@@ -504,9 +522,7 @@
 			if (likely(*res_ptr != ~0UL)) {
 				bitshiftcnt = ffz(*res_ptr);
 				*res_ptr |= (1UL << bitshiftcnt);
-				pide = ((unsigned long)res_ptr - (unsigned long)ioc->res_map);
-				pide <<= 3;	/* convert to bit address */
-				pide += bitshiftcnt;
+				pide = ptr_to_pide(ioc, res_ptr, bitshiftcnt);
 				ioc->res_bitshift = bitshiftcnt + bits_wanted;
 				goto found_it;
 			}
@@ -535,11 +551,13 @@
 			DBG_RES("    %p %lx %lx\n", res_ptr, mask, *res_ptr);
 			ASSERT(0 != mask);
 			for (; mask ; mask <<= o, bitshiftcnt += o) {
-				if(0 == ((*res_ptr) & mask)) {
+				tpide = ptr_to_pide(ioc, res_ptr, bitshiftcnt);
+				ret = iommu_is_span_boundary(tpide, bits_wanted,
+							     shift,
+							     boundary_size);
+				if ((0 == ((*res_ptr) & mask)) && !ret) {
 					*res_ptr |= mask;     /* mark resources busy! */
-					pide = ((unsigned long)res_ptr - (unsigned long)ioc->res_map);
-					pide <<= 3;	/* convert to bit address */
-					pide += bitshiftcnt;
+					pide = tpide;
 					ioc->res_bitshift = bitshiftcnt + bits_wanted;
 					goto found_it;
 				}
@@ -560,6 +578,11 @@
 		end = res_end - qwords;
 
 		for (; res_ptr < end; res_ptr++) {
+			tpide = ptr_to_pide(ioc, res_ptr, 0);
+			ret = iommu_is_span_boundary(tpide, bits_wanted,
+						     shift, boundary_size);
+			if (ret)
+				goto next_ptr;
 			for (i = 0 ; i < qwords ; i++) {
 				if (res_ptr[i] != 0)
 					goto next_ptr;
@@ -572,8 +595,7 @@
 				res_ptr[i] = ~0UL;
 			res_ptr[i] |= RESMAP_MASK(bits);
 
-			pide = ((unsigned long)res_ptr - (unsigned long)ioc->res_map);
-			pide <<= 3;	/* convert to bit address */
+			pide = tpide;
 			res_ptr += qwords;
 			ioc->res_bitshift = bits;
 			goto found_it;
@@ -605,7 +627,7 @@
  * resource bit map.
  */
 static int
-sba_alloc_range(struct ioc *ioc, size_t size)
+sba_alloc_range(struct ioc *ioc, struct device *dev, size_t size)
 {
 	unsigned int pages_needed = size >> iovp_shift;
 #ifdef PDIR_SEARCH_TIMING
@@ -622,9 +644,9 @@
 	/*
 	** "seek and ye shall find"...praying never hurts either...
 	*/
-	pide = sba_search_bitmap(ioc, pages_needed, 1);
+	pide = sba_search_bitmap(ioc, dev, pages_needed, 1);
 	if (unlikely(pide >= (ioc->res_size << 3))) {
-		pide = sba_search_bitmap(ioc, pages_needed, 0);
+		pide = sba_search_bitmap(ioc, dev, pages_needed, 0);
 		if (unlikely(pide >= (ioc->res_size << 3))) {
 #if DELAYED_RESOURCE_CNT > 0
 			unsigned long flags;
@@ -653,7 +675,7 @@
 			}
 			spin_unlock_irqrestore(&ioc->saved_lock, flags);
 
-			pide = sba_search_bitmap(ioc, pages_needed, 0);
+			pide = sba_search_bitmap(ioc, dev, pages_needed, 0);
 			if (unlikely(pide >= (ioc->res_size << 3)))
 				panic(__FILE__ ": I/O MMU @ %p is out of mapping resources\n",
 				      ioc->ioc_hpa);
@@ -936,7 +958,7 @@
 	spin_unlock_irqrestore(&ioc->res_lock, flags);
 #endif
 
-	pide = sba_alloc_range(ioc, size);
+	pide = sba_alloc_range(ioc, dev, size);
 
 	iovp = (dma_addr_t) pide << iovp_shift;
 
@@ -1373,7 +1395,7 @@
 		dma_len = (dma_len + dma_offset + ~iovp_mask) & iovp_mask;
 		ASSERT(dma_len <= DMA_CHUNK_SIZE);
 		dma_sg->dma_address = (dma_addr_t) (PIDE_FLAG
-			| (sba_alloc_range(ioc, dma_len) << iovp_shift)
+			| (sba_alloc_range(ioc, dev, dma_len) << iovp_shift)
 			| dma_offset);
 		n_mappings++;
 	}