linux-kernel - Re: [PATCH 08/33] ACPI: Define acpi_put_table cleanup handler and acpi_get_table

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Message-ID: <20251110161100.000039f3@huawei.com>
Date: Mon, 10 Nov 2025 16:11:00 +0000
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: Ben Horgan <ben.horgan@....com>
CC: <james.morse@....com>, <amitsinght@...vell.com>,
	<baisheng.gao@...soc.com>, <baolin.wang@...ux.alibaba.com>,
	<bobo.shaobowang@...wei.com>, <carl@...amperecomputing.com>,
	<catalin.marinas@....com>, <dakr@...nel.org>, <dave.martin@....com>,
	<david@...hat.com>, <dfustini@...libre.com>, <fenghuay@...dia.com>,
	<gregkh@...uxfoundation.org>, <gshan@...hat.com>, <guohanjun@...wei.com>,
	<jeremy.linton@....com>, <kobak@...dia.com>, <lcherian@...vell.com>,
	<lenb@...nel.org>, <linux-acpi@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>, <linux-kernel@...r.kernel.org>,
	<lpieralisi@...nel.org>, <peternewman@...gle.com>, <quic_jiles@...cinc.com>,
	<rafael@...nel.org>, <robh@...nel.org>, <rohit.mathew@....com>,
	<scott@...amperecomputing.com>, <sdonthineni@...dia.com>,
	<sudeep.holla@....com>, <tan.shaopeng@...itsu.com>, <will@...nel.org>,
	<xhao@...ux.alibaba.com>
Subject: Re: [PATCH 08/33] ACPI: Define acpi_put_table cleanup handler and
 acpi_get_table_ret() helper

On Fri, 7 Nov 2025 12:34:25 +0000
Ben Horgan <ben.horgan@....com> wrote:

> Define a cleanup helper for use with __free to release the acpi table when
> the pointer goes out of scope. Also, introduce the helper
> acpi_get_table_ret() to simplify a commonly used pattern involving
> acpi_get_table().
> 
> These are first used in a subsequent commit.
> 
> Signed-off-by: Ben Horgan <ben.horgan@....com>

Seems useful enough to be to be worth having. Needs input from
Rafael.

Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>

> ---
>  include/linux/acpi.h | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index a9dbacabdf89..1124b7dc79fd 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -8,6 +8,7 @@
>  #ifndef _LINUX_ACPI_H
>  #define _LINUX_ACPI_H
>  
> +#include <linux/cleanup.h>
>  #include <linux/errno.h>
>  #include <linux/ioport.h>	/* for struct resource */
>  #include <linux/resource_ext.h>
> @@ -221,6 +222,17 @@ void acpi_reserve_initial_tables (void);
>  void acpi_table_init_complete (void);
>  int acpi_table_init (void);
>  
> +static inline struct acpi_table_header *acpi_get_table_ret(char *signature, u32 instance)
> +{
> +	struct acpi_table_header *table;
> +	int status = acpi_get_table(signature, instance, &table);
> +
> +	if (ACPI_FAILURE(status))
> +		return ERR_PTR(-ENOENT);
> +	return table;
> +}
> +DEFINE_FREE(acpi_put_table, struct acpi_table_header *, if (!IS_ERR_OR_NULL(_T)) acpi_put_table(_T))
> +
>  int acpi_table_parse(char *id, acpi_tbl_table_handler handler);
>  int __init_or_acpilib acpi_table_parse_entries(char *id,
>  		unsigned long table_size, int entry_id,