Re: [RFC PATCH 4/4] powerpc: Use common of_kexec_setup_new_fdt()

[Lakshmi Ramasubramanian <nramas@linux.microsoft.com>]

On 12/11/20 2:10 PM, Rob Herring wrote:
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
> 
> After the IMA changes, delete_fdt_mem_rsv() can also be removed.
> 
>   arch/powerpc/kexec/file_load.c | 125 ++-------------------------------
>   1 file changed, 6 insertions(+), 119 deletions(-)
> 

This change looks good to me.

Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>

  -lakshmi

> diff --git a/arch/powerpc/kexec/file_load.c b/arch/powerpc/kexec/file_load.c
> index e452b11df631..956bcb2d1ec2 100644
> --- a/arch/powerpc/kexec/file_load.c
> +++ b/arch/powerpc/kexec/file_load.c
> @@ -16,6 +16,7 @@
> 
>   #include <linux/slab.h>
>   #include <linux/kexec.h>
> +#include <linux/of.h>
>   #include <linux/of_fdt.h>
>   #include <linux/libfdt.h>
>   #include <asm/setup.h>
> @@ -156,132 +157,18 @@ int setup_new_fdt(const struct kimage *image, void *fdt,
>   		  unsigned long initrd_load_addr, unsigned long initrd_len,
>   		  const char *cmdline)
>   {
> -	int ret, chosen_node;
> -	const void *prop;
> -
> -	/* Remove memory reservation for the current device tree. */
> -	ret = delete_fdt_mem_rsv(fdt, __pa(initial_boot_params),
> -				 fdt_totalsize(initial_boot_params));
> -	if (ret == 0)
> -		pr_debug("Removed old device tree reservation.\n");
> -	else if (ret != -ENOENT)
> -		return ret;
> -
> -	chosen_node = fdt_path_offset(fdt, "/chosen");
> -	if (chosen_node == -FDT_ERR_NOTFOUND) {
> -		chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
> -					      "chosen");
> -		if (chosen_node < 0) {
> -			pr_err("Error creating /chosen.\n");
> -			return -EINVAL;
> -		}
> -	} else if (chosen_node < 0) {
> -		pr_err("Malformed device tree: error reading /chosen.\n");
> -		return -EINVAL;
> -	}
> -
> -	/* Did we boot using an initrd? */
> -	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
> -	if (prop) {
> -		uint64_t tmp_start, tmp_end, tmp_size;
> -
> -		tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));
> -
> -		prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
> -		if (!prop) {
> -			pr_err("Malformed device tree.\n");
> -			return -EINVAL;
> -		}
> -		tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));
> -
> -		/*
> -		 * kexec reserves exact initrd size, while firmware may
> -		 * reserve a multiple of PAGE_SIZE, so check for both.
> -		 */
> -		tmp_size = tmp_end - tmp_start;
> -		ret = delete_fdt_mem_rsv(fdt, tmp_start, tmp_size);
> -		if (ret == -ENOENT)
> -			ret = delete_fdt_mem_rsv(fdt, tmp_start,
> -						 round_up(tmp_size, PAGE_SIZE));
> -		if (ret == 0)
> -			pr_debug("Removed old initrd reservation.\n");
> -		else if (ret != -ENOENT)
> -			return ret;
> -
> -		/* If there's no new initrd, delete the old initrd's info. */
> -		if (initrd_len == 0) {
> -			ret = fdt_delprop(fdt, chosen_node,
> -					  "linux,initrd-start");
> -			if (ret) {
> -				pr_err("Error deleting linux,initrd-start.\n");
> -				return -EINVAL;
> -			}
> -
> -			ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
> -			if (ret) {
> -				pr_err("Error deleting linux,initrd-end.\n");
> -				return -EINVAL;
> -			}
> -		}
> -	}
> -
> -	if (initrd_len) {
> -		ret = fdt_setprop_u64(fdt, chosen_node,
> -				      "linux,initrd-start",
> -				      initrd_load_addr);
> -		if (ret < 0)
> -			goto err;
> -
> -		/* initrd-end is the first address after the initrd image. */
> -		ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
> -				      initrd_load_addr + initrd_len);
> -		if (ret < 0)
> -			goto err;
> -
> -		ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
> -		if (ret) {
> -			pr_err("Error reserving initrd memory: %s\n",
> -			       fdt_strerror(ret));
> -			return -EINVAL;
> -		}
> -	}
> -
> -	if (cmdline != NULL) {
> -		ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
> -		if (ret < 0)
> -			goto err;
> -	} else {
> -		ret = fdt_delprop(fdt, chosen_node, "bootargs");
> -		if (ret && ret != -FDT_ERR_NOTFOUND) {
> -			pr_err("Error deleting bootargs.\n");
> -			return -EINVAL;
> -		}
> -	}
> +	int ret;
> 
> -	if (image->type == KEXEC_TYPE_CRASH) {
> -		/*
> -		 * Avoid elfcorehdr from being stomped on in kdump kernel by
> -		 * setting up memory reserve map.
> -		 */
> -		ret = fdt_add_mem_rsv(fdt, image->arch.elf_headers_mem,
> -				      image->arch.elf_headers_sz);
> -		if (ret) {
> -			pr_err("Error reserving elfcorehdr memory: %s\n",
> -			       fdt_strerror(ret));
> -			goto err;
> -		}
> -	}
> +	ret = of_kexec_setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline);
> +	if (ret)
> +		goto err;
> 
> -	ret = setup_ima_buffer(image, fdt, chosen_node);
> +	ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen"));
>   	if (ret) {
>   		pr_err("Error setting up the new device tree.\n");
>   		return ret;
>   	}
> 
> -	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
> -	if (ret)
> -		goto err;
> -
>   	return 0;
> 
>   err:
> --
> 2.25.1
>