Attached patch adds a DMA zone to xen, also modifies xen_contig_memory()

to ask for DMA pages.
Signed-off-by: srparish@us.ibm.com

linux-2.6-xen-sparse/arch/xen/i386/mm/hypervisor.c

@@ -296,7 +296,7 @@ void xen_contig_memory(unsigned long vstart, unsigned int order)
 
     /* 2. Get a new contiguous memory extent. */
     BUG_ON(HYPERVISOR_dom_mem_op(
-        MEMOP_increase_reservation, &mfn, 1, order) != 1);
+	       MEMOP_increase_reservation, &mfn, 1, order | (32<<8)) != 1);
 
     /* 3. Map the new extent in place of old pages. */
     for (i = 0; i < (1<<order); i++) {

xen/arch/x86/domain_build.c

@@ -63,7 +63,7 @@ static struct pfn_info *alloc_largest(struct domain *d, unsigned long max)
     unsigned int order = get_order(max * PAGE_SIZE);
     if ( (max & (max-1)) != 0 )
         order--;
-    while ( (page = alloc_domheap_pages(d, order)) == NULL )
+    while ( (page = alloc_domheap_pages(d, order, 0)) == NULL )
         if ( order-- == 0 )
             break;
     return page;

xen/arch/x86/x86_32/mm.c

@@ -102,7 +102,7 @@ void __init paging_init(void)
         mpt_size = 4*1024*1024;
     for ( i = 0; i < (mpt_size >> L2_PAGETABLE_SHIFT); i++ )
     {
-        if ( (pg = alloc_domheap_pages(NULL, PAGETABLE_ORDER)) == NULL )
+        if ( (pg = alloc_domheap_pages(NULL, PAGETABLE_ORDER, 0) == NULL )
             panic("Not enough memory to bootstrap Xen.\n");
         idle_pg_table_l2[l2_linear_offset(RDWR_MPT_VIRT_START) + i] =
             l2e_from_page(pg, PAGE_HYPERVISOR | _PAGE_PSE);

xen/arch/x86/x86_64/mm.c

@@ -100,7 +100,7 @@ void __init paging_init(void)
      */
     for ( i = 0; i < max_page; i += ((1UL << L2_PAGETABLE_SHIFT) / 8) )
     {
-        pg = alloc_domheap_pages(NULL, PAGETABLE_ORDER);
+        pg = alloc_domheap_pages(NULL, PAGETABLE_ORDER, 0);
         if ( pg == NULL )
             panic("Not enough memory for m2p table\n");
         map_pages_to_xen(

xen/common/dom_mem_ops.c

@@ -37,7 +37,8 @@ alloc_dom_mem(struct domain *d,
               unsigned long *extent_list, 
               unsigned long  start_extent,
               unsigned int   nr_extents,
-              unsigned int   extent_order)
+              unsigned int   extent_order,
+    		  unsigned int   flags)
 {
     struct pfn_info *page;
     unsigned long    i;
@@ -56,7 +57,8 @@ alloc_dom_mem(struct domain *d,
     {
         PREEMPT_CHECK(MEMOP_increase_reservation);
 
-        if ( unlikely((page = alloc_domheap_pages(d, extent_order)) == NULL) )
+        if ( unlikely((page = alloc_domheap_pages(d, extent_order,
+                                                  flags)) == NULL) )
         {
             DPRINTK("Could not allocate a frame\n");
             return i;
@@ -131,11 +133,16 @@ do_dom_mem_op(unsigned long  op,
 {
     struct domain *d;
     unsigned long  rc, start_extent;
+    unsigned int   address_bits_order;
 
     /* Extract @start_extent from @op. */
     start_extent  = op >> START_EXTENT_SHIFT;
     op           &= (1 << START_EXTENT_SHIFT) - 1;
 
+    /* seperate extent_order and address_bits_order */
+    address_bits_order = (extent_order >> 1) & 0xff;
+    extent_order &= 0xff;
+
     if ( unlikely(start_extent > nr_extents) )
         return -EINVAL;
 
@@ -150,7 +157,8 @@ do_dom_mem_op(unsigned long  op,
     {
     case MEMOP_increase_reservation:
         rc = alloc_dom_mem(
-            d, extent_list, start_extent, nr_extents, extent_order);
+            d, extent_list, start_extent, nr_extents, extent_order,
+            (address_bits_order <= 32) ? ALLOC_DOM_DMA : 0);
         break;
     case MEMOP_decrease_reservation:
         rc = free_dom_mem(

xen/common/page_alloc.c

@@ -207,7 +207,13 @@ unsigned long alloc_boot_pages(unsigned long nr_pfns, unsigned long pfn_align)
 
 #define MEMZONE_XEN 0
 #define MEMZONE_DOM 1
-#define NR_ZONES    2
+#define MEMZONE_DMADOM 2
+#define NR_ZONES    3
+
+
+#define MAX_DMADOM_PFN 0xFFFFF
+#define pfn_dom_zone_type(_pfn)                                 \
+    (((_pfn) <= MAX_DMADOM_PFN) ? MEMZONE_DMADOM : MEMZONE_DOM)
 
 /* Up to 2^20 pages can be allocated at once. */
 #define MAX_ORDER 20
@@ -236,7 +242,7 @@ void end_boot_allocator(void)
         if ( next_free )
             map_alloc(i+1, 1); /* prevent merging in free_heap_pages() */
         if ( curr_free )
-            free_heap_pages(MEMZONE_DOM, pfn_to_page(i), 0);
+            free_heap_pages(pfn_dom_zone_type(i), pfn_to_page(i), 0);
     }
 }
 
@@ -474,14 +480,21 @@ void init_domheap_pages(physaddr_t ps, physaddr_t pe)
 {
     ASSERT(!in_irq());
 
-    ps = round_pgup(ps);
-    pe = round_pgdown(pe);
+    ps = round_pgup(ps) >> PAGE_SHIFT;
+    pe = round_pgdown(pe) >> PAGE_SHIFT;
 
-    init_heap_pages(MEMZONE_DOM, phys_to_page(ps), (pe - ps) >> PAGE_SHIFT);
+    if (ps < MAX_DMADOM_PFN && pe > MAX_DMADOM_PFN) {
+        init_heap_pages(MEMZONE_DMADOM, pfn_to_page(ps), MAX_DMADOM_PFN - ps);
+        init_heap_pages(MEMZONE_DOM, pfn_to_page(MAX_DMADOM_PFN),
+                        pe - MAX_DMADOM_PFN);
+    }
+    else
+        init_heap_pages(pfn_dom_zone_type(ps), pfn_to_page(ps), pe - ps);
 }
 
 
-struct pfn_info *alloc_domheap_pages(struct domain *d, unsigned int order)
+struct pfn_info *alloc_domheap_pages(struct domain *d, unsigned int order,
+                                     unsigned int flags)
 {
     struct pfn_info *pg;
     cpumask_t mask;
@@ -489,8 +502,13 @@ struct pfn_info *alloc_domheap_pages(struct domain *d, unsigned int order)
 
     ASSERT(!in_irq());
 
-    if ( unlikely((pg = alloc_heap_pages(MEMZONE_DOM, order)) == NULL) )
-        return NULL;
+    pg = NULL;
+    if (! (flags & ALLOC_DOM_DMA))
+        pg = alloc_heap_pages(MEMZONE_DOM, order);
+    if (pg == NULL) {
+        if ( unlikely((pg = alloc_heap_pages(MEMZONE_DMADOM, order)) == NULL) )
+            return NULL;
+    }
 
     mask = pg->u.free.cpumask;
     tlbflush_filter(mask, pg->tlbflush_timestamp);
@@ -531,7 +549,7 @@ struct pfn_info *alloc_domheap_pages(struct domain *d, unsigned int order)
         DPRINTK("...or the domain is dying (%d)\n", 
                 !!test_bit(_DOMF_dying, &d->domain_flags));
         spin_unlock(&d->page_alloc_lock);
-        free_heap_pages(MEMZONE_DOM, pg, order);
+        free_heap_pages(pfn_dom_zone_type(page_to_pfn(pg)), pg, order);
         return NULL;
     }
 
@@ -596,7 +614,7 @@ void free_domheap_pages(struct pfn_info *pg, unsigned int order)
 
         if ( likely(!test_bit(_DOMF_dying, &d->domain_flags)) )
         {
-            free_heap_pages(MEMZONE_DOM, pg, order);
+            free_heap_pages(pfn_dom_zone_type(page_to_pfn(pg)), pg, order);
         }
         else
         {
@@ -616,7 +634,7 @@ void free_domheap_pages(struct pfn_info *pg, unsigned int order)
     else
     {
         /* Freeing an anonymous domain-heap page. */
-        free_heap_pages(MEMZONE_DOM, pg, order);
+        free_heap_pages(pfn_dom_zone_type(page_to_pfn(pg)), pg, order);
         drop_dom_ref = 0;
     }
 
@@ -627,7 +645,7 @@ void free_domheap_pages(struct pfn_info *pg, unsigned int order)
 
 unsigned long avail_domheap_pages(void)
 {
-    return avail[MEMZONE_DOM];
+    return avail[MEMZONE_DOM] + avail[MEMZONE_DMADOM];
 }
 
 
@@ -676,7 +694,7 @@ static void page_scrub_softirq(void)
             p = map_domain_page(page_to_pfn(pg));
             clear_page(p);
             unmap_domain_page(p);
-            free_heap_pages(MEMZONE_DOM, pg, 0);
+            free_heap_pages(pfn_dom_zone_type(page_to_pfn(pg)), pg, 0);
         }
     } while ( (NOW() - start) < MILLISECS(1) );
 }

xen/include/xen/mm.h

@@ -33,12 +33,15 @@ void free_xenheap_pages(void *v, unsigned int order);
 
 /* Domain suballocator. These functions are *not* interrupt-safe.*/
 void init_domheap_pages(physaddr_t ps, physaddr_t pe);
-struct pfn_info *alloc_domheap_pages(struct domain *d, unsigned int order);
+struct pfn_info *alloc_domheap_pages(
+    struct domain *d, unsigned int order, unsigned int flags);
 void free_domheap_pages(struct pfn_info *pg, unsigned int order);
 unsigned long avail_domheap_pages(void);
-#define alloc_domheap_page(d) (alloc_domheap_pages(d,0))
+#define alloc_domheap_page(d) (alloc_domheap_pages(d,0,0))
 #define free_domheap_page(p)  (free_domheap_pages(p,0))
 
+#define ALLOC_DOM_DMA 1
+
 /* Automatic page scrubbing for dead domains. */
 extern struct list_head page_scrub_list;
 #define page_scrub_schedule_work()              \