[PATCH v15 14/20] arm64/kexec: Add pr_debug output

Geoff Levand
2016-03-14T17:48:01Z

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>
---
arch/arm64/kernel/machine_kexec.c | 67 +++++++++++++++++++++++++++++++++++++--
1 file changed, 65 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index 6fd0f0c..75f6696 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -11,6 +11,7 @@

#include <linux/highmem.h>
#include <linux/kexec.h>
+#include <linux/libfdt_env.h>
#include <linux/of_fdt.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
@@ -26,6 +27,47 @@ extern const unsigned long arm64_relocate_new_kernel_size;

static unsigned long kimage_start;

+/**
+ * kexec_is_dtb - Helper routine to check the device tree header signature.
+ */
+static bool kexec_is_dtb(const void *dtb)
+{
+ __be32 magic;
+
+ if (get_user(magic, (__be32 *)dtb))
+ return false;
+
+ return fdt32_to_cpu(magic) == OF_DT_HEADER;
+}
+
+/**
+ * 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%s\n",
+ i,
+ kimage->segment[i].mem,
+ kimage->segment[i].mem + kimage->segment[i].memsz,
+ kimage->segment[i].memsz,
+ kimage->segment[i].memsz / PAGE_SIZE,
+ (kexec_is_dtb(kimage->segment[i].buf) ?
+ ", dtb segment" : ""));
+ }
+}
+
void machine_kexec_cleanup(struct kimage *kimage)
{
/* Empty routine needed to avoid build errors. */
@@ -39,6 +81,8 @@ void machine_kexec_cleanup(struct kimage *kimage)
int machine_kexec_prepare(struct kimage *kimage)
{
kimage_start = kimage->start;
+ kexec_image_info(kimage);
+
return 0;
}

@@ -81,10 +125,10 @@ static void kexec_segment_flush(const struct kimage *kimage)
{
unsigned long i;

- pr_devel("%s:\n", __func__);
+ pr_debug("%s:\n", __func__);

for (i = 0; i < kimage->nr_segments; i++) {
- pr_devel(" segment[%lu]: %016lx - %016lx, %lx bytes, %lu pages\n",
+ 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,
@@ -111,6 +155,25 @@ void machine_kexec(struct kimage *kimage)
reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
reboot_code_buffer = kmap(kimage->control_code_page);

+ 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);
+
+ pr_debug("%s:%d: kimage_head: %lx\n", __func__, __LINE__,
+ kimage->head);
+ pr_debug("%s:%d: kimage_start: %lx\n", __func__, __LINE__,
+ kimage_start);
+
/*
* Copy arm64_relocate_new_kernel to the reboot_code_buffer for use
* after the kernel is shut down.
--
2.5.0