[IA64] Paravirtualize swiotlb

Paravirtualize our copy of swiotlb.  A lot of the s/virt_to_phys/virt_to_bus
converstions have already been done in upstream, so I won't special case
them here.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>

diff --git a/linux-2.6-xen-sparse/arch/ia64/xen/swiotlb.c b/linux-2.6-xen-sparse/arch/ia64/xen/swiotlb.c
index 10625785eefd90d412668fce760190b122569bb9..fbc4664bbd299cb3c23a348bc1191c9fcb166c38 100644 (file)
--- a/linux-2.6-xen-sparse/arch/ia64/xen/swiotlb.c
+++ b/linux-2.6-xen-sparse/arch/ia64/xen/swiotlb.c
@@ -32,11 +32,22 @@
 #include <linux/init.h>
 #include <linux/bootmem.h>
 
+#ifdef CONFIG_XEN
+/*
+ * What DMA mask should Xen use to remap the bounce buffer pool?  Most
+ * reports seem to indicate 30 bits is sufficient, except maybe for old
+ * sound cards that we probably don't care about anyway.  If we need to,
+ * we could put in some smarts to try to lower, but hopefully it's not
+ * necessary.
+ */
+#define DMA_BITS       (30)
+#endif
+
 #define OFFSET(val,align) ((unsigned long)     \
                           ( (val) & ( (align) - 1)))
 
 #define SG_ENT_VIRT_ADDRESS(sg)        (page_address((sg)->page) + (sg)->offset)
-#define SG_ENT_PHYS_ADDRESS(SG)        virt_to_phys(SG_ENT_VIRT_ADDRESS(SG))
+#define SG_ENT_PHYS_ADDRESS(SG)        virt_to_bus(SG_ENT_VIRT_ADDRESS(SG))
 
 /*
  * Maximum allowable number of contiguous slabs to map,
@@ -139,6 +150,10 @@ swiotlb_init_with_default_size (size_t default_size)
                io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
        }
 
+#ifdef CONFIG_XEN
+       if (is_running_on_xen())
+               io_tlb_nslabs = roundup_pow_of_two(io_tlb_nslabs);
+#endif
        /*
         * Get IO TLB memory from the low pages
         */
@@ -147,6 +162,17 @@ swiotlb_init_with_default_size (size_t default_size)
                panic("Cannot allocate SWIOTLB buffer");
        io_tlb_end = io_tlb_start + io_tlb_nslabs * (1 << IO_TLB_SHIFT);
 
+#ifdef CONFIG_XEN
+       for (i = 0 ; i < io_tlb_nslabs ; i += IO_TLB_SEGSIZE) {
+               if (xen_create_contiguous_region(
+                               (unsigned long)io_tlb_start +
+                               (i << IO_TLB_SHIFT),
+                               get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT),
+                               DMA_BITS))
+                       panic("Failed to setup Xen contiguous region");
+       }
+#endif
+
        /*
         * Allocate and initialize the free list array.  This array is used
         * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
@@ -162,6 +188,11 @@ swiotlb_init_with_default_size (size_t default_size)
         * Get the overflow emergency buffer
         */
        io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
+#ifdef CONFIG_XEN
+       if (xen_create_contiguous_region((unsigned long)io_tlb_overflow_buffer,
+                                        get_order(io_tlb_overflow), DMA_BITS))
+               panic("Failed to setup Xen contiguous region for overflow");
+#endif
        printk(KERN_INFO "Placing software IO TLB between 0x%lx - 0x%lx\n",
               virt_to_phys(io_tlb_start), virt_to_phys(io_tlb_end));
 }
@@ -188,6 +219,10 @@ swiotlb_late_init_with_default_size (size_t default_size)
                io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
        }
 
+#ifdef CONFIG_XEN
+       if (is_running_on_xen())
+               io_tlb_nslabs = roundup_pow_of_two(io_tlb_nslabs);
+#endif
        /*
         * Get IO TLB memory from the low pages
         */
@@ -213,6 +248,16 @@ swiotlb_late_init_with_default_size (size_t default_size)
        io_tlb_end = io_tlb_start + io_tlb_nslabs * (1 << IO_TLB_SHIFT);
        memset(io_tlb_start, 0, io_tlb_nslabs * (1 << IO_TLB_SHIFT));
 
+#ifdef CONFIG_XEN
+       for (i = 0 ; i < io_tlb_nslabs ; i += IO_TLB_SEGSIZE) {
+               if (xen_create_contiguous_region(
+                               (unsigned long)io_tlb_start +
+                               (i << IO_TLB_SHIFT),
+                               get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT),
+                               DMA_BITS))
+                       panic("Failed to setup Xen contiguous region");
+       }
+#endif
        /*
         * Allocate and initialize the free list array.  This array is used
         * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
@@ -242,6 +287,11 @@ swiotlb_late_init_with_default_size (size_t default_size)
        if (!io_tlb_overflow_buffer)
                goto cleanup4;
 
+#ifdef CONFIG_XEN
+       if (xen_create_contiguous_region((unsigned long)io_tlb_overflow_buffer,
+                                        get_order(io_tlb_overflow), DMA_BITS))
+               panic("Failed to setup Xen contiguous region for overflow");
+#endif
        printk(KERN_INFO "Placing %ldMB software IO TLB between 0x%lx - "
               "0x%lx\n", (io_tlb_nslabs * (1 << IO_TLB_SHIFT)) >> 20,
               virt_to_phys(io_tlb_start), virt_to_phys(io_tlb_end));
@@ -445,7 +495,25 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
        flags |= GFP_DMA;
 
        ret = (void *)__get_free_pages(flags, order);
-       if (ret && address_needs_mapping(hwdev, virt_to_phys(ret))) {
+#ifdef CONFIG_XEN
+       if (ret && is_running_on_xen()) {
+               if (xen_create_contiguous_region((unsigned long)ret, order,
+                                       fls64(hwdev->coherent_dma_mask))) {
+                       free_pages((unsigned long)ret, order);
+                       ret = NULL;
+               } else {
+                       /*
+                        * Short circuit the rest, xen_create_contiguous_region
+                        * should fail if it didn't give us an address within
+                        * the mask requested.  
+                        */
+                       memset(ret, 0, size);
+                       *dma_handle = virt_to_bus(ret);
+                       return ret;
+               }
+       }
+#endif
+       if (ret && address_needs_mapping(hwdev, virt_to_bus(ret))) {
                /*
                 * The allocated memory isn't reachable by the device.
                 * Fall back on swiotlb_map_single().
@@ -465,11 +533,11 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                if (swiotlb_dma_mapping_error(handle))
                        return NULL;
 
-               ret = phys_to_virt(handle);
+               ret = bus_to_virt(handle);
        }
 
        memset(ret, 0, size);
-       dev_addr = virt_to_phys(ret);
+       dev_addr = virt_to_bus(ret);
 
        /* Confirm address can be DMA'd by device */
        if (address_needs_mapping(hwdev, dev_addr)) {
@@ -487,9 +555,13 @@ swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
                      dma_addr_t dma_handle)
 {
        if (!(vaddr >= (void *)io_tlb_start
-                    && vaddr < (void *)io_tlb_end))
+                    && vaddr < (void *)io_tlb_end)) {
+#ifdef CONFIG_XEN
+               xen_destroy_contiguous_region((unsigned long)vaddr,
+                                             get_order(size));
+#endif
                free_pages((unsigned long) vaddr, get_order(size));
-       else
+       } else
                /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
                swiotlb_unmap_single (hwdev, dma_handle, size, DMA_TO_DEVICE);
 }
@@ -525,7 +597,7 @@ swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
 dma_addr_t
 swiotlb_map_single(struct device *hwdev, void *ptr, size_t size, int dir)
 {
-       unsigned long dev_addr = virt_to_phys(ptr);
+       unsigned long dev_addr = virt_to_bus(ptr);
        void *map;
 
        BUG_ON(dir == DMA_NONE);
@@ -534,7 +606,8 @@ swiotlb_map_single(struct device *hwdev, void *ptr, size_t size, int dir)
         * we can safely return the device addr and not worry about bounce
         * buffering it.
         */
-       if (!address_needs_mapping(hwdev, dev_addr) && !swiotlb_force)
+       if (!range_straddles_page_boundary(ptr, size) &&
+           !address_needs_mapping(hwdev, dev_addr) && !swiotlb_force)
                return dev_addr;
 
        /*
@@ -546,7 +619,7 @@ swiotlb_map_single(struct device *hwdev, void *ptr, size_t size, int dir)
                map = io_tlb_overflow_buffer;
        }
 
-       dev_addr = virt_to_phys(map);
+       dev_addr = virt_to_bus(map);
 
        /*
         * Ensure that the address returned is DMA'ble
@@ -567,6 +640,12 @@ mark_clean(void *addr, size_t size)
 {
        unsigned long pg_addr, end;
 
+#ifdef CONFIG_XEN
+       /* XXX: Bad things happen when starting domUs if this is enabled. */
+       if (is_running_on_xen())
+               return;
+#endif
+
        pg_addr = PAGE_ALIGN((unsigned long) addr);
        end = (unsigned long) addr + size;
        while (pg_addr + PAGE_SIZE <= end) {
@@ -588,7 +667,7 @@ void
 swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size,
                     int dir)
 {
-       char *dma_addr = phys_to_virt(dev_addr);
+       char *dma_addr = bus_to_virt(dev_addr);
 
        BUG_ON(dir == DMA_NONE);
        if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
@@ -611,7 +690,7 @@ static inline void
 swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
                    size_t size, int dir, int target)
 {
-       char *dma_addr = phys_to_virt(dev_addr);
+       char *dma_addr = bus_to_virt(dev_addr);
 
        BUG_ON(dir == DMA_NONE);
        if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
@@ -642,7 +721,7 @@ swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr,
                          unsigned long offset, size_t size,
                          int dir, int target)
 {
-       char *dma_addr = phys_to_virt(dev_addr) + offset;
+       char *dma_addr = bus_to_virt(dev_addr) + offset;
 
        BUG_ON(dir == DMA_NONE);
        if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
@@ -695,7 +774,7 @@ swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
 
        for (i = 0; i < nelems; i++, sg++) {
                addr = SG_ENT_VIRT_ADDRESS(sg);
-               dev_addr = virt_to_phys(addr);
+               dev_addr = virt_to_bus(addr);
                if (swiotlb_force || address_needs_mapping(hwdev, dev_addr)) {
                        void *map = map_single(hwdev, addr, sg->length, dir);
                        sg->dma_address = virt_to_bus(map);
@@ -728,7 +807,7 @@ swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
 
        for (i = 0; i < nelems; i++, sg++)
                if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
-                       unmap_single(hwdev, (void *) phys_to_virt(sg->dma_address), sg->dma_length, dir);
+                       unmap_single(hwdev, (void *) bus_to_virt(sg->dma_address), sg->dma_length, dir);
                else if (dir == DMA_FROM_DEVICE)
                        mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
 }
@@ -771,7 +850,7 @@ swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
 int
 swiotlb_dma_mapping_error(dma_addr_t dma_addr)
 {
-       return (dma_addr == virt_to_phys(io_tlb_overflow_buffer));
+       return (dma_addr == virt_to_bus(io_tlb_overflow_buffer));
 }
 
 /*
@@ -783,7 +862,7 @@ swiotlb_dma_mapping_error(dma_addr_t dma_addr)
 int
 swiotlb_dma_supported (struct device *hwdev, u64 mask)
 {
-       return (virt_to_phys (io_tlb_end) - 1) <= mask;
+       return (virt_to_bus(io_tlb_end) - 1) <= mask;
 }
 
 EXPORT_SYMBOL(swiotlb_init);