swiotlb: Add CONFIG_HAS_IOMEM check around swiotlb_mem_remap()

HAS_IOMEM option may not be selected on some platforms (e.g, s390) and
this will cause compilation failure due to missing memremap()
implementation.

Fix it by stubbing out swiotlb_mem_remap when CONFIG_HAS_IOMEM is not
set.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index b36c1cdd0c4fd185b131f5d529660e0aebc12710..f1e7ea160b43399c89e0e026270f0791796bafaf 100644 (file)
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -163,6 +163,7 @@ static inline unsigned long nr_slots(u64 val)
  * when swiotlb_unencrypted_base is set. (e.g. for Hyper-V AMD SEV-SNP
  * Isolation VMs).
  */
+#ifdef CONFIG_HAS_IOMEM
 static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes)
 {
        void *vaddr = NULL;
@@ -178,6 +179,12 @@ static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes)
 
        return vaddr;
 }
+#else
+static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes)
+{
+       return NULL;
+}
+#endif
 
 /*
  * Early SWIOTLB allocation may be too early to allow an architecture to