Subject: Re: [PATCH v17 04/10] powerpc: Use common of_kexec_alloc_and_setup_fdt()

From: Lakshmi Ramasubramanian <[email-masked]>
Date: Wed, 10 Feb 2021 17:50:31 -0800

On 2/10/21 5:42 PM, Thiago Jung Bauermann wrote:
> 
> Lakshmi Ramasubramanian <[email-masked]> writes:
> 
>> From: Rob Herring <[email-masked]>
>>
>> The code for setting up the /chosen node in the device tree
>> and updating the memory reservation for the next kernel has been
>> moved to of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".
>>
>> Use the common of_kexec_alloc_and_setup_fdt() to setup the device tree
>> and update the memory reservation for kexec for powerpc.
>>
>> Signed-off-by: Rob Herring <[email-masked]>
>> Signed-off-by: Lakshmi Ramasubramanian <[email-masked]>
>> ---
>>   arch/powerpc/include/asm/kexec.h  |   1 +
>>   arch/powerpc/kexec/elf_64.c       |  29 ++++---
>>   arch/powerpc/kexec/file_load.c    | 132 +-----------------------------
>>   arch/powerpc/kexec/file_load_64.c |   3 +
>>   4 files changed, 25 insertions(+), 140 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
>> index dbf09d2f36d0..bdd0ddb9ac4d 100644
>> --- a/arch/powerpc/include/asm/kexec.h
>> +++ b/arch/powerpc/include/asm/kexec.h
>> @@ -111,6 +111,7 @@ struct kimage_arch {
>>   	unsigned long elf_headers_mem;
>>   	unsigned long elf_headers_sz;
>>   	void *elf_headers;
>> +	void *fdt;
>>   
>>   #ifdef CONFIG_IMA_KEXEC
>>   	phys_addr_t ima_buffer_addr;
>> diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
>> index d0e459bb2f05..bfabd06f99b1 100644
>> --- a/arch/powerpc/kexec/elf_64.c
>> +++ b/arch/powerpc/kexec/elf_64.c
>> @@ -19,6 +19,7 @@
>>   #include <linux/kexec.h>
>>   #include <linux/libfdt.h>
>>   #include <linux/module.h>
>> +#include <linux/of.h>
>>   #include <linux/of_fdt.h>
>>   #include <linux/slab.h>
>>   #include <linux/types.h>
>> @@ -29,7 +30,6 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
>>   			unsigned long cmdline_len)
>>   {
>>   	int ret;
>> -	unsigned int fdt_size;
>>   	unsigned long kernel_load_addr;
>>   	unsigned long initrd_load_addr = 0, fdt_load_addr;
>>   	void *fdt;
>> @@ -102,19 +102,13 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
>>   		pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
>>   	}
>>   
>> -	fdt_size = fdt_totalsize(initial_boot_params) * 2;
>> -	fdt = kmalloc(fdt_size, GFP_KERNEL);
>> +	fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
>> +					   initrd_len, cmdline);
>>   	if (!fdt) {
>>   		pr_err("Not enough memory for the device tree.\n");
> 
> This error string can be a bit misleading now, since
> of_kexec_alloc_and_setup_fdt() can fail for reasons other than lack of
> memory. I suggest changing it to the error string from fdt_open_into()
> below:
> 
> 		pr_err("Error setting up the new device tree.\n");
> 
> With this change:
Agreed - I will make this change.

> 
> Reviewed-by: Thiago Jung Bauermann <[email-masked]>
> 
> And also:
> 
> Tested-by: Thiago Jung Bauermann <[email-masked]>
> 

Thanks a lot for your help Thiago.

  -lakshmi