xen/swiotlb: Move the error strings to its own function.

That way we can more easily reuse those errors when using the
late SWIOTLB init.

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index a2aad6e..701b103 100644 (file)
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -154,11 +154,33 @@ static unsigned long xen_set_nslabs(unsigned long nr_tbl)
 
        return xen_io_tlb_nslabs << IO_TLB_SHIFT;
 }
+
+enum xen_swiotlb_err {
+       XEN_SWIOTLB_UNKNOWN = 0,
+       XEN_SWIOTLB_ENOMEM,
+       XEN_SWIOTLB_EFIXUP
+};
+
+static const char *xen_swiotlb_error(enum xen_swiotlb_err err)
+{
+       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 "";
+}
 void __init xen_swiotlb_init(int verbose)
 {
        unsigned long bytes;
        int rc = -ENOMEM;
-       char *m = NULL;
+       enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN;
        unsigned int repeat = 3;
 
        xen_io_tlb_nslabs = swiotlb_nr_tbl();
@@ -169,7 +191,7 @@ retry:
         */
        xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
        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;
@@ -181,10 +203,7 @@ retry:
                               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!";
+               m_ret = XEN_SWIOTLB_EFIXUP;
                goto error;
        }
        start_dma_addr = xen_virt_to_bus(xen_io_tlb_start);
@@ -199,8 +218,8 @@ 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);
+       xen_raw_printk("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
+       panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
 }
 
 void *