James,

On Tue, May 15, 2018 at 05:15:52PM +0100, James Morse wrote:

Hi Akashi,

On 15/05/18 05:45, AKASHI Takahiro wrote:

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On Fri, May 11, 2018 at 06:03:49PM +0100, James Morse wrote:

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On 07/05/18 06:22, AKASHI Takahiro wrote:

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On Tue, May 01, 2018 at 06:46:06PM +0100, James Morse wrote:

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On 25/04/18 07:26, AKASHI Takahiro wrote:

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diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index f76ea92dff91..f7dbba00be10 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c

@@ -205,10 +205,17 @@ void machine_kexec(struct kimage *kimage)

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 	cpu_soft_restart(kimage != kexec_crash_image,
-		reboot_code_buffer_phys, kimage->head, kimage->start, 0);
+		reboot_code_buffer_phys, kimage->head, kimage->start,
+#ifdef CONFIG_KEXEC_FILE
+				kimage->purgatory_info.purgatory_buf ?
+						0 : kimage->arch.dtb_mem);
+#else
+				0);
+#endif

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purgatory_buf seems to only be set in kexec_purgatory_setup_kbuf(), called from
kexec_load_purgatory(), which we don't use. How does this get a value?

Would it be better to always use kimage->arch.dtb_mem, and ensure that is 0 for
regular kexec (as we can't know where the dtb is)? (image_arg may then be a
better name).

The problem is arch.dtb_mem is currently defined only if CONFIG_KEXEC_FILE.

I thought it was ARCH_HAS_KIMAGE_ARCH, which we can define all the time if
that's what we want.

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So I would like to
- merge this patch with patch#8
- change the condition
        #ifdef CONFIG_KEXEC_FILE
       				kimage->file_mode ? kimage->arch.dtb_mem : 0);

We don't need "kimage->file_mode ?" since arch.dtb_mem is 0 if !file_mode.

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        #else
        			0);
        #endif

If we can avoid even this #ifdef by always having kimage->arch, I'd prefer that.
If we do that 'dtb_mem' would need some thing that indicates its for kexec_file,
as kexec has a DTB too, we just don't know where it is...

OK, but I want to have a minimum of kexec.arch always exist.

I'm curious, why? Its 32bytes that is allocated a maximum of twice.

I believe that I'm a stingy minimalist :)

(my questions on what needs to go in there were because it looked like a third
user was missing...)

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How about this?

| struct kimage_arch {
| 	phys_addr_t dtb_mem;
| #ifdef CONFIG_KEXEC_FILE

#ifdef in structs just breeds more #ifdefs, as the code that accesses those
members has to be behind the same set of conditions.

Given this, I prefer the #ifdefs around cpu_soft_restart() as it doesn't force
us to add more #ifdefs later.

OK

For either option without purgatory_info:
Reviewed-by: James Morse <james.morse@arm.com>

Thanks,
-Takahiro AKASHI

Thanks,

James