swiotlb: add checks for the return value of memblock_alloc*()

Add panic() calls if memblock_alloc() returns NULL.

The panic() format duplicates the one used by memblock itself and in
order to avoid explosion with long parameters list replace open coded
allocation size calculations with a local variable.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Guan Xuetao <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Guo Ren <[email protected]>				[c-sky]
Cc: Heiko Carstens <[email protected]>
Cc: Juergen Gross <[email protected]>			[Xen]
Cc: Mark Salter <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Paul Burton <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Russell King <[email protected]>
Cc: Stafford Horne <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

kernel/dma/swiotlb.c

@@ -199,6 +199,7 @@ void __init swiotlb_update_mem_attributes(void)
 int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
 {
 	unsigned long i, bytes;
+	size_t alloc_size;
 
 	bytes = nslabs << IO_TLB_SHIFT;
 
@@ -211,12 +212,18 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
 	 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
 	 * between io_tlb_start and io_tlb_end.
 	 */
-	io_tlb_list = memblock_alloc(
-				PAGE_ALIGN(io_tlb_nslabs * sizeof(int)),
-				PAGE_SIZE);
-	io_tlb_orig_addr = memblock_alloc(
-				PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)),
-				PAGE_SIZE);
+	alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(int));
+	io_tlb_list = memblock_alloc(alloc_size, PAGE_SIZE);
+	if (!io_tlb_list)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+		      __func__, alloc_size, PAGE_SIZE);
+
+	alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t));
+	io_tlb_orig_addr = memblock_alloc(alloc_size, PAGE_SIZE);
+	if (!io_tlb_orig_addr)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+		      __func__, alloc_size, PAGE_SIZE);
+
 	for (i = 0; i < io_tlb_nslabs; i++) {
 		io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
 		io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;