Some minor nits below.
eric
On 3/21/22 03:04, Sourabh Jain wrote:
The kernel changes needed to add support for crash hotplug support for
kexec_load system calls are similar to kexec_file_load (which has already
been implemented in earlier patches). Since kexec segment array is
prepared by kexec tool in the userspace, the kernel does aware of which
s/kernel does aware/ kernel is not aware/ ?
index FDT segment is present.
The only change was done to enabled crash hotplug support for kexec_load is
s/was done to enabled/to enable/ ?
updated the crash hotplug handler to identify the FDT segment from kexec
s/updated/ to update/ ?
segment array.
Signed-off-by: Sourabh Jain <sourabhj...@linux.ibm.com>
---
arch/powerpc/kexec/core_64.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kexec/core_64.c b/arch/powerpc/kexec/core_64.c
index a470fe6904e3..2c248dfb169b 100644
--- a/arch/powerpc/kexec/core_64.c
+++ b/arch/powerpc/kexec/core_64.c
@@ -480,7 +480,9 @@ int update_cpus_node(void *fdt)
void arch_crash_hotplug_handler(struct kimage *image, unsigned int hp_action,
unsigned long a, unsigned long b)
{
- void *fdt;
+ void *fdt, *ptr;
+ unsigned int n;
+ unsigned long mem, memsz;
/* No action needed for CPU hot-unplug */
if (hp_action == KEXEC_CRASH_HP_REMOVE_CPU)
@@ -492,6 +494,23 @@ void arch_crash_hotplug_handler(struct kimage *image,
unsigned int hp_action,
return;
}
+ /* Sine kexec segments for kexec_load system call is prepred by
s/Sine/Since/
s/is prepred/are prepared/
+ * kexec tool in userspace we need loop through all the segments
+ * to find out segment index corresponds FDT segment. In case of
+ * kexec_file_load it is discovered during the load itself.
+ */
+ if (!image->arch.fdt_index_valid) {
+ for (n = 0; n < image->nr_segments; n++) {
+ mem = image->segment[n].mem;
+ memsz = image->segment[n].memsz;
+ ptr = __va(mem);
+ if (ptr && fdt_magic(ptr) == FDT_MAGIC) {
+ image->arch.fdt_index = n;
+ image->arch.fdt_index_valid = true;
How about adding a break; statement to early exit?
+ }
+ }
+ }
+
/* Must have valid FDT index */
if (!image->arch.fdt_index_valid) {
pr_err("crash hp: unable to locate FDT segment");
