Re: [PATCH v5 1/5] powerpc/kexec: make update_cpus_node non-static

[Laurent Dufour <ldufour@linux.ibm.com>]

On 20/06/2022, 09:01:02, Sourabh Jain wrote:
> Make the update_cpus_node function non-static and export it for
> usage in other kexec components.
> 
> The update_cpus_node definition is moved to core_64.c so that it
> can be used with both kexec_load and kexec_file_load system calls.
> 
> No functional change intended.

And FWIW
Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com>
> 
> Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> ---
>  arch/powerpc/include/asm/kexec.h  |  1 +
>  arch/powerpc/kexec/core_64.c      | 88 +++++++++++++++++++++++++++++++
>  arch/powerpc/kexec/file_load_64.c | 87 ------------------------------
>  3 files changed, 89 insertions(+), 87 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
> index 2aefe14e1442..c8040c93b15a 100644
> --- a/arch/powerpc/include/asm/kexec.h
> +++ b/arch/powerpc/include/asm/kexec.h
> @@ -129,6 +129,7 @@ unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image);
>  int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
>  			unsigned long initrd_load_addr,
>  			unsigned long initrd_len, const char *cmdline);
> +int update_cpus_node(void *fdt);
>  #endif /* CONFIG_PPC64 */
>  
>  #endif /* CONFIG_KEXEC_FILE */
> diff --git a/arch/powerpc/kexec/core_64.c b/arch/powerpc/kexec/core_64.c
> index 6cc7793b8420..65b3afb2169a 100644
> --- a/arch/powerpc/kexec/core_64.c
> +++ b/arch/powerpc/kexec/core_64.c
> @@ -16,6 +16,7 @@
>  #include <linux/kernel.h>
>  #include <linux/cpu.h>
>  #include <linux/hardirq.h>
> +#include <linux/libfdt.h>
>  
>  #include <asm/page.h>
>  #include <asm/current.h>
> @@ -377,6 +378,93 @@ void default_machine_kexec(struct kimage *image)
>  	/* NOTREACHED */
>  }
>  
> +/**
> + * add_node_props - Reads node properties from device node structure and add
> + *                  them to fdt.
> + * @fdt:            Flattened device tree of the kernel
> + * @node_offset:    offset of the node to add a property at
> + * @dn:             device node pointer
> + *
> + * Returns 0 on success, negative errno on error.
> + */
> +static int add_node_props(void *fdt, int node_offset, const struct device_node *dn)
> +{
> +	int ret = 0;
> +	struct property *pp;
> +
> +	if (!dn)
> +		return -EINVAL;
> +
> +	for_each_property_of_node(dn, pp) {
> +		ret = fdt_setprop(fdt, node_offset, pp->name, pp->value, pp->length);
> +		if (ret < 0) {
> +			pr_err("Unable to add %s property: %s\n", pp->name, fdt_strerror(ret));
> +			return ret;
> +		}
> +	}
> +	return ret;
> +}
> +
> +/**
> + * update_cpus_node - Update cpus node of flattened device tree using of_root
> + *                    device node.
> + * @fdt:              Flattened device tree of the kernel.
> + *
> + * Returns 0 on success, negative errno on error.
> + */
> +int update_cpus_node(void *fdt)
> +{
> +	struct device_node *cpus_node, *dn;
> +	int cpus_offset, cpus_subnode_offset, ret = 0;
> +
> +	cpus_offset = fdt_path_offset(fdt, "/cpus");
> +	if (cpus_offset < 0 && cpus_offset != -FDT_ERR_NOTFOUND) {
> +		pr_err("Malformed device tree: error reading /cpus node: %s\n",
> +		       fdt_strerror(cpus_offset));
> +		return cpus_offset;
> +	}
> +
> +	if (cpus_offset > 0) {
> +		ret = fdt_del_node(fdt, cpus_offset);
> +		if (ret < 0) {
> +			pr_err("Error deleting /cpus node: %s\n", fdt_strerror(ret));
> +			return -EINVAL;
> +		}
> +	}
> +
> +	/* Add cpus node to fdt */
> +	cpus_offset = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"), "cpus");
> +	if (cpus_offset < 0) {
> +		pr_err("Error creating /cpus node: %s\n", fdt_strerror(cpus_offset));
> +		return -EINVAL;
> +	}
> +
> +	/* Add cpus node properties */
> +	cpus_node = of_find_node_by_path("/cpus");
> +	ret = add_node_props(fdt, cpus_offset, cpus_node);
> +	of_node_put(cpus_node);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Loop through all subnodes of cpus and add them to fdt */
> +	for_each_node_by_type(dn, "cpu") {
> +		cpus_subnode_offset = fdt_add_subnode(fdt, cpus_offset, dn->full_name);
> +		if (cpus_subnode_offset < 0) {
> +			pr_err("Unable to add %s subnode: %s\n", dn->full_name,
> +			       fdt_strerror(cpus_subnode_offset));
> +			ret = cpus_subnode_offset;
> +			goto out;
> +		}
> +
> +		ret = add_node_props(fdt, cpus_subnode_offset, dn);
> +		if (ret < 0)
> +			goto out;
> +	}
> +out:
> +	of_node_put(dn);
> +	return ret;
> +}
> +
>  #ifdef CONFIG_PPC_64S_HASH_MMU
>  /* Values we need to export to the second kernel via the device tree. */
>  static unsigned long htab_base;
> diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
> index 07da6bf1cf24..57f991b0a9da 100644
> --- a/arch/powerpc/kexec/file_load_64.c
> +++ b/arch/powerpc/kexec/file_load_64.c
> @@ -951,93 +951,6 @@ unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image)
>  	return (unsigned int)(usm_entries * sizeof(u64));
>  }
>  
> -/**
> - * add_node_props - Reads node properties from device node structure and add
> - *                  them to fdt.
> - * @fdt:            Flattened device tree of the kernel
> - * @node_offset:    offset of the node to add a property at
> - * @dn:             device node pointer
> - *
> - * Returns 0 on success, negative errno on error.
> - */
> -static int add_node_props(void *fdt, int node_offset, const struct device_node *dn)
> -{
> -	int ret = 0;
> -	struct property *pp;
> -
> -	if (!dn)
> -		return -EINVAL;
> -
> -	for_each_property_of_node(dn, pp) {
> -		ret = fdt_setprop(fdt, node_offset, pp->name, pp->value, pp->length);
> -		if (ret < 0) {
> -			pr_err("Unable to add %s property: %s\n", pp->name, fdt_strerror(ret));
> -			return ret;
> -		}
> -	}
> -	return ret;
> -}
> -
> -/**
> - * update_cpus_node - Update cpus node of flattened device tree using of_root
> - *                    device node.
> - * @fdt:              Flattened device tree of the kernel.
> - *
> - * Returns 0 on success, negative errno on error.
> - */
> -static int update_cpus_node(void *fdt)
> -{
> -	struct device_node *cpus_node, *dn;
> -	int cpus_offset, cpus_subnode_offset, ret = 0;
> -
> -	cpus_offset = fdt_path_offset(fdt, "/cpus");
> -	if (cpus_offset < 0 && cpus_offset != -FDT_ERR_NOTFOUND) {
> -		pr_err("Malformed device tree: error reading /cpus node: %s\n",
> -		       fdt_strerror(cpus_offset));
> -		return cpus_offset;
> -	}
> -
> -	if (cpus_offset > 0) {
> -		ret = fdt_del_node(fdt, cpus_offset);
> -		if (ret < 0) {
> -			pr_err("Error deleting /cpus node: %s\n", fdt_strerror(ret));
> -			return -EINVAL;
> -		}
> -	}
> -
> -	/* Add cpus node to fdt */
> -	cpus_offset = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"), "cpus");
> -	if (cpus_offset < 0) {
> -		pr_err("Error creating /cpus node: %s\n", fdt_strerror(cpus_offset));
> -		return -EINVAL;
> -	}
> -
> -	/* Add cpus node properties */
> -	cpus_node = of_find_node_by_path("/cpus");
> -	ret = add_node_props(fdt, cpus_offset, cpus_node);
> -	of_node_put(cpus_node);
> -	if (ret < 0)
> -		return ret;
> -
> -	/* Loop through all subnodes of cpus and add them to fdt */
> -	for_each_node_by_type(dn, "cpu") {
> -		cpus_subnode_offset = fdt_add_subnode(fdt, cpus_offset, dn->full_name);
> -		if (cpus_subnode_offset < 0) {
> -			pr_err("Unable to add %s subnode: %s\n", dn->full_name,
> -			       fdt_strerror(cpus_subnode_offset));
> -			ret = cpus_subnode_offset;
> -			goto out;
> -		}
> -
> -		ret = add_node_props(fdt, cpus_subnode_offset, dn);
> -		if (ret < 0)
> -			goto out;
> -	}
> -out:
> -	of_node_put(dn);
> -	return ret;
> -}
> -
>  /**
>   * setup_new_fdt_ppc64 - Update the flattend device-tree of the kernel
>   *                       being loaded.