[PATCH 5/8] xen-swiotlb: remove xen_io_tlb_start and xen_io_tlb_nslabs

[Christoph Hellwig <hch@xxxxxx>]

The xen_io_tlb_start and xen_io_tlb_nslabs variables ar now only used in
xen_swiotlb_init, so replace them with local variables.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 drivers/xen/swiotlb-xen.c | 57 +++++++++++++++++----------------------
 1 file changed, 25 insertions(+), 32 deletions(-)

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 57f8d5fadc1fcd..6e0f2c5ecd1a2f 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -40,14 +40,7 @@
 
 #include <trace/events/swiotlb.h>
 #define MAX_DMA_BITS 32
-/*
- * Used to do a quick range check in swiotlb_tbl_unmap_single and
- * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by 
this
- * API.
- */
 
-static char *xen_io_tlb_start;
-static unsigned long xen_io_tlb_nslabs;
 /*
  * Quick lookup value of the bus address of the IOTLB.
  */
@@ -169,75 +162,75 @@ int __ref xen_swiotlb_init(int verbose, bool early)
        int rc = -ENOMEM;
        enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN;
        unsigned int repeat = 3;
+       char *start;
+       unsigned long nslabs;
 
-       xen_io_tlb_nslabs = swiotlb_nr_tbl();
+       nslabs = swiotlb_nr_tbl();
 retry:
-       if (!xen_io_tlb_nslabs)
-               xen_io_tlb_nslabs = DEFAULT_NSLABS;
-       bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
+       if (!nslabs)
+               nslabs = DEFAULT_NSLABS;
+       bytes = nslabs << IO_TLB_SHIFT;
        order = get_order(bytes);
 
        /*
         * IO TLB memory already allocated. Just use it.
         */
-       if (io_tlb_start != 0) {
-               xen_io_tlb_start = phys_to_virt(io_tlb_start);
+       if (io_tlb_start != 0)
                goto end;
-       }
 
        /*
         * Get IO TLB memory from any location.
         */
        if (early) {
-               xen_io_tlb_start = memblock_alloc(PAGE_ALIGN(bytes),
+               start = memblock_alloc(PAGE_ALIGN(bytes),
                                                  PAGE_SIZE);
-               if (!xen_io_tlb_start)
+               if (!start)
                        panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
                              __func__, PAGE_ALIGN(bytes), PAGE_SIZE);
        } 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 
*)xen_get_swiotlb_free_pages(order);
-                       if (xen_io_tlb_start)
+                       start = (void *)xen_get_swiotlb_free_pages(order);
+                       if (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;
+                       nslabs = SLABS_PER_PAGE << order;
+                       bytes = nslabs << IO_TLB_SHIFT;
                }
        }
-       if (!xen_io_tlb_start) {
+       if (!start) {
                m_ret = XEN_SWIOTLB_ENOMEM;
                goto error;
        }
        /*
         * And replace that memory with pages under 4GB.
         */
-       rc = xen_swiotlb_fixup(xen_io_tlb_start,
+       rc = xen_swiotlb_fixup(start,
                               bytes,
-                              xen_io_tlb_nslabs);
+                              nslabs);
        if (rc) {
                if (early)
-                       memblock_free(__pa(xen_io_tlb_start),
+                       memblock_free(__pa(start),
                                      PAGE_ALIGN(bytes));
                else {
-                       free_pages((unsigned long)xen_io_tlb_start, order);
-                       xen_io_tlb_start = NULL;
+                       free_pages((unsigned long)start, order);
+                       start = NULL;
                }
                m_ret = XEN_SWIOTLB_EFIXUP;
                goto error;
        }
        if (early) {
-               if (swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs,
+               if (swiotlb_init_with_tbl(start, nslabs,
                         verbose))
                        panic("Cannot allocate SWIOTLB buffer");
                rc = 0;
        } else
-               rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, 
xen_io_tlb_nslabs);
+               rc = swiotlb_late_init_with_tbl(start, nslabs);
 
 end:
        if (!rc)
@@ -246,17 +239,17 @@ int __ref xen_swiotlb_init(int verbose, bool early)
        return rc;
 error:
        if (repeat--) {
-               xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */
-                                       (xen_io_tlb_nslabs >> 1));
+               nslabs = max(1024UL, /* Min is 2MB */
+                                       (nslabs >> 1));
                pr_info("Lowering to %luMB\n",
-                       (xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20);
+                       (nslabs << IO_TLB_SHIFT) >> 20);
                goto retry;
        }
        pr_err("%s (rc:%d)\n", 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);
+               free_pages((unsigned long)start, order);
        return rc;
 }
 
-- 
2.29.2