arm64/kexec: Add pr_debug output

To aid in debugging kexec problems or when adding new functionality to
kexec add a new routine kexec_image_info() and several inline pr_debug
statements.

Signed-off-by: Geoff Levand <geoff@infradead.org>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index c40e646..bc96c8a 100644 (file)
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -24,6 +24,32 @@ extern const unsigned long arm64_relocate_new_kernel_size;
 
 static unsigned long kimage_start;
 
+/**
+ * kexec_image_info - For debugging output.
+ */
+#define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i)
+static void _kexec_image_info(const char *func, int line,
+       const struct kimage *kimage)
+{
+       unsigned long i;
+
+       pr_debug("%s:%d:\n", func, line);
+       pr_debug("  kexec kimage info:\n");
+       pr_debug("    type:        %d\n", kimage->type);
+       pr_debug("    start:       %lx\n", kimage->start);
+       pr_debug("    head:        %lx\n", kimage->head);
+       pr_debug("    nr_segments: %lu\n", kimage->nr_segments);
+
+       for (i = 0; i < kimage->nr_segments; i++) {
+               pr_debug("      segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
+                       i,
+                       kimage->segment[i].mem,
+                       kimage->segment[i].mem + kimage->segment[i].memsz,
+                       kimage->segment[i].memsz,
+                       kimage->segment[i].memsz /  PAGE_SIZE);
+       }
+}
+
 void machine_kexec_cleanup(struct kimage *kimage)
 {
        /* Empty routine needed to avoid build errors. */
@@ -40,6 +66,8 @@ int machine_kexec_prepare(struct kimage *kimage)
 {
        kimage_start = kimage->start;
 
+       kexec_image_info(kimage);
+
        if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
                pr_err("Can't kexec: CPUs are stuck in the kernel.\n");
                return -EBUSY;
@@ -125,6 +153,20 @@ void machine_kexec(struct kimage *kimage)
        reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
        reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys);
 
+       kexec_image_info(kimage);
+
+       pr_debug("%s:%d: control_code_page:        %p\n", __func__, __LINE__,
+               kimage->control_code_page);
+       pr_debug("%s:%d: reboot_code_buffer_phys:  %pa\n", __func__, __LINE__,
+               &reboot_code_buffer_phys);
+       pr_debug("%s:%d: reboot_code_buffer:       %p\n", __func__, __LINE__,
+               reboot_code_buffer);
+       pr_debug("%s:%d: relocate_new_kernel:      %p\n", __func__, __LINE__,
+               arm64_relocate_new_kernel);
+       pr_debug("%s:%d: relocate_new_kernel_size: 0x%lx(%lu) bytes\n",
+               __func__, __LINE__, arm64_relocate_new_kernel_size,
+               arm64_relocate_new_kernel_size);
+
        /*
         * Copy arm64_relocate_new_kernel to the reboot_code_buffer for use
         * after the kernel is shut down.