powerpc/kexec_file: Add appropriate regions for memory reserve map

While initrd, elfcorehdr and backup regions are already added to the
reserve map, there are a few missing regions that need to be added to
the memory reserve map. Add them here. And now that all the changes to
load panic kernel are in place, claim likewise.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602300473.575379.4218568032039284448.stgit@hbathini

arch/powerpc/kexec/file_load_64.c

@@ -205,6 +205,34 @@ static int get_crash_memory_ranges(struct crash_mem **mem_ranges)
 	return ret;
 }
 
+/**
+ * get_reserved_memory_ranges - Get reserve memory ranges. This list includes
+ *                              memory regions that should be added to the
+ *                              memory reserve map to ensure the region is
+ *                              protected from any mischief.
+ * @mem_ranges:                 Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int get_reserved_memory_ranges(struct crash_mem **mem_ranges)
+{
+	int ret;
+
+	ret = add_rtas_mem_range(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_tce_mem_ranges(mem_ranges);
+	if (ret)
+		goto out;
+
+	ret = add_reserved_mem_ranges(mem_ranges);
+out:
+	if (ret)
+		pr_err("Failed to setup reserved memory ranges\n");
+	return ret;
+}
+
 /**
  * __locate_mem_hole_top_down - Looks top down for a large enough memory hole
  *                              in the memory regions between buf_min & buf_max
@@ -897,8 +925,8 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
 			unsigned long initrd_load_addr,
 			unsigned long initrd_len, const char *cmdline)
 {
-	struct crash_mem *umem = NULL;
-	int ret;
+	struct crash_mem *umem = NULL, *rmem = NULL;
+	int i, nr_ranges, ret;
 
 	ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline);
 	if (ret)
@@ -941,7 +969,27 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
 		}
 	}
 
+	/* Update memory reserve map */
+	ret = get_reserved_memory_ranges(&rmem);
+	if (ret)
+		goto out;
+
+	nr_ranges = rmem ? rmem->nr_ranges : 0;
+	for (i = 0; i < nr_ranges; i++) {
+		u64 base, size;
+
+		base = rmem->ranges[i].start;
+		size = rmem->ranges[i].end - base + 1;
+		ret = fdt_add_mem_rsv(fdt, base, size);
+		if (ret) {
+			pr_err("Error updating memory reserve map: %s\n",
+			       fdt_strerror(ret));
+			goto out;
+		}
+	}
+
 out:
+	kfree(rmem);
 	kfree(umem);
 	return ret;
 }
@@ -1024,10 +1072,10 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 
 		/* Get exclude memory ranges needed for setting up kdump segments */
 		ret = get_exclude_memory_ranges(&(image->arch.exclude_ranges));
-		if (ret)
+		if (ret) {
 			pr_err("Failed to setup exclude memory ranges for buffer lookup\n");
-		/* Return this until all changes for panic kernel are in */
-		return -EOPNOTSUPP;
+			return ret;
+		}
 	}
 
 	return kexec_image_probe_default(image, buf, buf_len);