powerpc/fadump: improve fadump_reserve_mem()

Some code clean-up like using minimal assignments and updating printk
messages. Also, add an 'error_out' label for handling error cleanup
at one place.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821343485.5656.10202857091553646948.stgit@hbathini.in.ibm.com

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index b17673d..7d47d4b 100644 (file)
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -338,16 +338,15 @@ static void __init fadump_reserve_crash_area(unsigned long base,
 
 int __init fadump_reserve_mem(void)
 {
-       unsigned long base, size, memory_boundary;
+       u64 base, size, mem_boundary;
+       int ret = 1;
 
        if (!fw_dump.fadump_enabled)
                return 0;
 
        if (!fw_dump.fadump_supported) {
-               printk(KERN_INFO "Firmware-assisted dump is not supported on"
-                               " this hardware\n");
-               fw_dump.fadump_enabled = 0;
-               return 0;
+               pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
+               goto error_out;
        }
        /*
         * Initialize boot memory size
@@ -355,7 +354,8 @@ int __init fadump_reserve_mem(void)
         * first kernel.
         */
        if (!fw_dump.dump_active) {
-               fw_dump.boot_memory_size = fadump_calculate_reserve_size();
+               fw_dump.boot_memory_size =
+                       PAGE_ALIGN(fadump_calculate_reserve_size());
 #ifdef CONFIG_CMA
                if (!fw_dump.nocma)
                        fw_dump.boot_memory_size =
@@ -381,10 +381,11 @@ int __init fadump_reserve_mem(void)
                                " dump, now %#016llx\n", memory_limit);
        }
        if (memory_limit)
-               memory_boundary = memory_limit;
+               mem_boundary = memory_limit;
        else
-               memory_boundary = memblock_end_of_DRAM();
+               mem_boundary = memblock_end_of_DRAM();
 
+       base = fw_dump.boot_memory_size;
        size = get_fadump_area_size();
        fw_dump.reserve_dump_area_size = size;
        if (fw_dump.dump_active) {
@@ -404,8 +405,7 @@ int __init fadump_reserve_mem(void)
                 * dump is written to disk by userspace tool. This memory
                 * will be released for general use once the dump is saved.
                 */
-               base = fw_dump.boot_memory_size;
-               size = memory_boundary - base;
+               size = mem_boundary - base;
                fadump_reserve_crash_area(base, size);
 
                pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
@@ -418,29 +418,31 @@ int __init fadump_reserve_mem(void)
                 * use memblock_find_in_range() here since it doesn't allocate
                 * from bottom to top.
                 */
-               for (base = fw_dump.boot_memory_size;
-                    base <= (memory_boundary - size);
-                    base += size) {
+               while (base <= (mem_boundary - size)) {
                        if (memblock_is_region_memory(base, size) &&
                            !memblock_is_region_reserved(base, size))
                                break;
+
+                       base += size;
                }
-               if ((base > (memory_boundary - size)) ||
+
+               if ((base > (mem_boundary - size)) ||
                    memblock_reserve(base, size)) {
-                       pr_err("Failed to reserve memory\n");
-                       return 0;
+                       pr_err("Failed to reserve memory!\n");
+                       goto error_out;
                }
 
-               pr_info("Reserved %ldMB of memory at %ldMB for firmware-"
-                       "assisted dump (System RAM: %ldMB)\n",
-                       (unsigned long)(size >> 20),
-                       (unsigned long)(base >> 20),
-                       (unsigned long)(memblock_phys_mem_size() >> 20));
+               pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
+                       (size >> 20), base, (memblock_phys_mem_size() >> 20));
 
                fw_dump.reserve_dump_area_start = base;
-               return fadump_cma_init();
+               ret = fadump_cma_init();
        }
-       return 1;
+
+       return ret;
+error_out:
+       fw_dump.fadump_enabled = 0;
+       return 0;
 }
 
 unsigned long __init arch_reserved_kernel_pages(void)