1 files changed, 75 insertions, 26 deletions

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 2e74dba6a04d..58db6df866ef 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -144,31 +144,72 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
         } while (i < nslabs);
         return 0;
 }
+static unsigned long xen_set_nslabs(unsigned long nr_tbl)
+{
+        if (!nr_tbl) {
+                xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
+                xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
+        } else
+                xen_io_tlb_nslabs = nr_tbl;
+
+        return xen_io_tlb_nslabs << IO_TLB_SHIFT;
+}
+
+enum xen_swiotlb_err {
+        XEN_SWIOTLB_UNKNOWN = 0,
+        XEN_SWIOTLB_ENOMEM,
+        XEN_SWIOTLB_EFIXUP
+};
 
-void __init xen_swiotlb_init(int verbose)
+static const char *xen_swiotlb_error(enum xen_swiotlb_err err)
 {
-        unsigned long bytes;
+        switch (err) {
+        case XEN_SWIOTLB_ENOMEM:
+                return "Cannot allocate Xen-SWIOTLB buffer\n";
+        case XEN_SWIOTLB_EFIXUP:
+                return "Failed to get contiguous memory for DMA from Xen!\n"\
+                    "You either: don't have the permissions, do not have"\
+                    " enough free memory under 4GB, or the hypervisor memory"\
+                    " is too fragmented!";
+        default:
+                break;
+        }
+        return "";
+}
+int __ref xen_swiotlb_init(int verbose, bool early)
+{
+        unsigned long bytes, order;
         int rc = -ENOMEM;
-        unsigned long nr_tbl;
-        char *m = NULL;
+        enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN;
         unsigned int repeat = 3;
 
-        nr_tbl = swiotlb_nr_tbl();
-        if (nr_tbl)
-                xen_io_tlb_nslabs = nr_tbl;
-        else {
-                xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
-                xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
-        }
+        xen_io_tlb_nslabs = swiotlb_nr_tbl();
 retry:
-        bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
-
+        bytes = xen_set_nslabs(xen_io_tlb_nslabs);
+        order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT);
         /*
          * Get IO TLB memory from any location.
          */
-        xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
+        if (early)
+                xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
+        else {
+#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
+#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
+                while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
+                        xen_io_tlb_start = (void *)__get_free_pages(__GFP_NOWARN, order);
+                        if (xen_io_tlb_start)
+                                break;
+                        order--;
+                }
+                if (order != get_order(bytes)) {
+                        pr_warn("Warning: only able to allocate %ld MB "
+                                "for software IO TLB\n", (PAGE_SIZE << order) >> 20);
+                        xen_io_tlb_nslabs = SLABS_PER_PAGE << order;
+                        bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
+                }
+        }
         if (!xen_io_tlb_start) {
-                m = "Cannot allocate Xen-SWIOTLB buffer!\n";
+                m_ret = XEN_SWIOTLB_ENOMEM;
                 goto error;
         }
         xen_io_tlb_end = xen_io_tlb_start + bytes;
@@ -179,17 +220,22 @@ retry:
                                bytes,
                                xen_io_tlb_nslabs);
         if (rc) {
-                free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
-                m = "Failed to get contiguous memory for DMA from Xen!\n"\
-                    "You either: don't have the permissions, do not have"\
-                    " enough free memory under 4GB, or the hypervisor memory"\
-                    "is too fragmented!";
+                if (early)
+                        free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
+                else {
+                        free_pages((unsigned long)xen_io_tlb_start, order);
+                        xen_io_tlb_start = NULL;
+                }
+                m_ret = XEN_SWIOTLB_EFIXUP;
                 goto error;
         }
         start_dma_addr = xen_virt_to_bus(xen_io_tlb_start);
-        swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose);
-
-        return;
+        if (early) {
+                swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose);
+                rc = 0;
+        } else
+                rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs);
+        return rc;
 error:
         if (repeat--) {
                 xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */
@@ -198,10 +244,13 @@ error:
                       (xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20);
                 goto retry;
         }
-        xen_raw_printk("%s (rc:%d)", m, rc);
-        panic("%s (rc:%d)", m, rc);
+        pr_err("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
+        if (early)
+                panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
+        else
+                free_pages((unsigned long)xen_io_tlb_start, order);
+        return rc;
 }
-
 void *
 xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                            dma_addr_t *dma_handle, gfp_t flags,