.../admin-guide/kernel-parameters.txt | 10 +++++++--- arch/arm64/kernel/acpi.c | 18 +++++++++++++++++- 2 files changed, 24 insertions(+), 4 deletions(-)
For varying privacy and security reasons, sometimes we would like to
completely silence the _serial_ console, and only enable it when needed.
But there are many existing systems that depend on this _serial_ console,
so add acpi=nospcr to disable console in ACPI SPCR table as default
_serial_ console.
Signed-off-by: Liu Wei <liuwei09@cestc.cn>
Suggested-by: Prarit Bhargava <prarit@redhat.com>
Suggested-by: Will Deacon <will@kernel.org>
Suggested-by: Andrew Lunn <andrew@lunn.ch>
---
v2: Add a config option suggested by Prarit
v3: Use cmdline acpi=nospcr instead of config
v4: Some description in comment or document
---
.../admin-guide/kernel-parameters.txt | 10 +++++++---
arch/arm64/kernel/acpi.c | 18 +++++++++++++++++-
2 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 11e57ba2985c..6814ff7ae446 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -12,7 +12,7 @@
acpi= [HW,ACPI,X86,ARM64,RISCV64,EARLY]
Advanced Configuration and Power Interface
Format: { force | on | off | strict | noirq | rsdt |
- copy_dsdt }
+ copy_dsdt | nospcr }
force -- enable ACPI if default was off
on -- enable ACPI but allow fallback to DT [arm64,riscv64]
off -- disable ACPI if default was on
@@ -21,8 +21,12 @@
strictly ACPI specification compliant.
rsdt -- prefer RSDT over (default) XSDT
copy_dsdt -- copy DSDT to memory
- For ARM64 and RISCV64, ONLY "acpi=off", "acpi=on" or
- "acpi=force" are available
+ nospcr -- disable console in ACPI SPCR table as
+ default _serial_ console on ARM64
+ For ARM64, ONLY "acpi=off", "acpi=on", "acpi=force" or
+ "acpi=nospcr" are available
+ For RISCV64, ONLY "acpi=off", "acpi=on" or "acpi=force"
+ are available
See also Documentation/power/runtime_pm.rst, pci=noacpi
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index e0e7b93c16cc..55757d8884d4 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -45,6 +45,7 @@ EXPORT_SYMBOL(acpi_pci_disabled);
static bool param_acpi_off __initdata;
static bool param_acpi_on __initdata;
static bool param_acpi_force __initdata;
+static bool param_acpi_nospcr __initdata;
static int __init parse_acpi(char *arg)
{
@@ -58,6 +59,8 @@ static int __init parse_acpi(char *arg)
param_acpi_on = true;
else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
param_acpi_force = true;
+ else if (strcmp(arg, "nospcr") == 0) /* disable SPCR as default console */
+ param_acpi_nospcr = true;
else
return -EINVAL; /* Core will print when we return error */
@@ -237,7 +240,20 @@ void __init acpi_boot_table_init(void)
acpi_put_table(facs);
}
#endif
- acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
+
+ /*
+ * For varying privacy and security reasons, sometimes need
+ * to completely silence the serial console output, and only
+ * enable it when needed.
+ * But there are many existing systems that depend on this
+ * behavior, use acpi=nospcr to disable console in ACPI SPCR
+ * table as default serial console.
+ */
+ acpi_parse_spcr(earlycon_acpi_spcr_enable,
+ !param_acpi_nospcr);
+ pr_info("Use ACPI SPCR as default console: %s\n",
+ param_acpi_nospcr ? "No" : "Yes");
+
if (IS_ENABLED(CONFIG_ACPI_BGRT))
acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
}
--
2.42.1On Tue, 25 Jun 2024 11:05:04 +0800, Liu Wei wrote:
> For varying privacy and security reasons, sometimes we would like to
> completely silence the _serial_ console, and only enable it when needed.
>
> But there are many existing systems that depend on this _serial_ console,
> so add acpi=nospcr to disable console in ACPI SPCR table as default
> _serial_ console.
>
> [...]
Applied to arm64 (for-next/acpi), thanks!
[1/1] ACPI: Add acpi=nospcr to disable ACPI SPCR as default console on ARM64
https://git.kernel.org/arm64/c/f5a4af3c7527
--
Catalin
On 2024/6/25 11:05, Liu Wei wrote:
> For varying privacy and security reasons, sometimes we would like to
> completely silence the _serial_ console, and only enable it when needed.
>
> But there are many existing systems that depend on this _serial_ console,
> so add acpi=nospcr to disable console in ACPI SPCR table as default
> _serial_ console.
I think this is reasonable, with ACPI SPCR on in default is compatible
with old systems.
>
> Signed-off-by: Liu Wei <liuwei09@cestc.cn>
> Suggested-by: Prarit Bhargava <prarit@redhat.com>
> Suggested-by: Will Deacon <will@kernel.org>
> Suggested-by: Andrew Lunn <andrew@lunn.ch>
> ---
>
> v2: Add a config option suggested by Prarit
>
> v3: Use cmdline acpi=nospcr instead of config
>
> v4: Some description in comment or document
> ---
> .../admin-guide/kernel-parameters.txt | 10 +++++++---
> arch/arm64/kernel/acpi.c | 18 +++++++++++++++++-
> 2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 11e57ba2985c..6814ff7ae446 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -12,7 +12,7 @@
> acpi= [HW,ACPI,X86,ARM64,RISCV64,EARLY]
> Advanced Configuration and Power Interface
> Format: { force | on | off | strict | noirq | rsdt |
> - copy_dsdt }
> + copy_dsdt | nospcr }
> force -- enable ACPI if default was off
> on -- enable ACPI but allow fallback to DT [arm64,riscv64]
> off -- disable ACPI if default was on
> @@ -21,8 +21,12 @@
> strictly ACPI specification compliant.
> rsdt -- prefer RSDT over (default) XSDT
> copy_dsdt -- copy DSDT to memory
> - For ARM64 and RISCV64, ONLY "acpi=off", "acpi=on" or
> - "acpi=force" are available
> + nospcr -- disable console in ACPI SPCR table as
> + default _serial_ console on ARM64
> + For ARM64, ONLY "acpi=off", "acpi=on", "acpi=force" or
> + "acpi=nospcr" are available
> + For RISCV64, ONLY "acpi=off", "acpi=on" or "acpi=force"
> + are available
>
> See also Documentation/power/runtime_pm.rst, pci=noacpi
>
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index e0e7b93c16cc..55757d8884d4 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -45,6 +45,7 @@ EXPORT_SYMBOL(acpi_pci_disabled);
> static bool param_acpi_off __initdata;
> static bool param_acpi_on __initdata;
> static bool param_acpi_force __initdata;
> +static bool param_acpi_nospcr __initdata;
>
> static int __init parse_acpi(char *arg)
> {
> @@ -58,6 +59,8 @@ static int __init parse_acpi(char *arg)
> param_acpi_on = true;
> else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
> param_acpi_force = true;
> + else if (strcmp(arg, "nospcr") == 0) /* disable SPCR as default console */
> + param_acpi_nospcr = true;
> else
> return -EINVAL; /* Core will print when we return error */
>
> @@ -237,7 +240,20 @@ void __init acpi_boot_table_init(void)
> acpi_put_table(facs);
> }
> #endif
> - acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
> +
> + /*
> + * For varying privacy and security reasons, sometimes need
> + * to completely silence the serial console output, and only
> + * enable it when needed.
> + * But there are many existing systems that depend on this
> + * behavior, use acpi=nospcr to disable console in ACPI SPCR
Nit: s/behavior/behaviour
> + * table as default serial console.
> + */
> + acpi_parse_spcr(earlycon_acpi_spcr_enable,
> + !param_acpi_nospcr);
> + pr_info("Use ACPI SPCR as default console: %s\n",
> + param_acpi_nospcr ? "No" : "Yes");
> +
> if (IS_ENABLED(CONFIG_ACPI_BGRT))
> acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
> }
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Thanks
Hanjun
On 6/24/24 23:05, Liu Wei wrote:
> For varying privacy and security reasons, sometimes we would like to
> completely silence the _serial_ console, and only enable it when needed.
>
> But there are many existing systems that depend on this _serial_ console,
> so add acpi=nospcr to disable console in ACPI SPCR table as default
> _serial_ console.
>
> Signed-off-by: Liu Wei <liuwei09@cestc.cn>
> Suggested-by: Prarit Bhargava <prarit@redhat.com>
> Suggested-by: Will Deacon <will@kernel.org>
> Suggested-by: Andrew Lunn <andrew@lunn.ch>
> ---
>
> v2: Add a config option suggested by Prarit
>
> v3: Use cmdline acpi=nospcr instead of config
>
> v4: Some description in comment or document
> ---
> .../admin-guide/kernel-parameters.txt | 10 +++++++---
> arch/arm64/kernel/acpi.c | 18 +++++++++++++++++-
> 2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 11e57ba2985c..6814ff7ae446 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -12,7 +12,7 @@
> acpi= [HW,ACPI,X86,ARM64,RISCV64,EARLY]
> Advanced Configuration and Power Interface
> Format: { force | on | off | strict | noirq | rsdt |
> - copy_dsdt }
> + copy_dsdt | nospcr }
> force -- enable ACPI if default was off
> on -- enable ACPI but allow fallback to DT [arm64,riscv64]
> off -- disable ACPI if default was on
> @@ -21,8 +21,12 @@
> strictly ACPI specification compliant.
> rsdt -- prefer RSDT over (default) XSDT
> copy_dsdt -- copy DSDT to memory
> - For ARM64 and RISCV64, ONLY "acpi=off", "acpi=on" or
> - "acpi=force" are available
> + nospcr -- disable console in ACPI SPCR table as
> + default _serial_ console on ARM64
> + For ARM64, ONLY "acpi=off", "acpi=on", "acpi=force" or
> + "acpi=nospcr" are available
> + For RISCV64, ONLY "acpi=off", "acpi=on" or "acpi=force"
> + are available
>
> See also Documentation/power/runtime_pm.rst, pci=noacpi
>
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index e0e7b93c16cc..55757d8884d4 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -45,6 +45,7 @@ EXPORT_SYMBOL(acpi_pci_disabled);
> static bool param_acpi_off __initdata;
> static bool param_acpi_on __initdata;
> static bool param_acpi_force __initdata;
> +static bool param_acpi_nospcr __initdata;
>
> static int __init parse_acpi(char *arg)
> {
> @@ -58,6 +59,8 @@ static int __init parse_acpi(char *arg)
> param_acpi_on = true;
> else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
> param_acpi_force = true;
> + else if (strcmp(arg, "nospcr") == 0) /* disable SPCR as default console */
> + param_acpi_nospcr = true;
> else
> return -EINVAL; /* Core will print when we return error */
>
> @@ -237,7 +240,20 @@ void __init acpi_boot_table_init(void)
> acpi_put_table(facs);
> }
> #endif
> - acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
> +
> + /*
> + * For varying privacy and security reasons, sometimes need
> + * to completely silence the serial console output, and only
> + * enable it when needed.
> + * But there are many existing systems that depend on this
> + * behavior, use acpi=nospcr to disable console in ACPI SPCR
> + * table as default serial console.
> + */
> + acpi_parse_spcr(earlycon_acpi_spcr_enable,
> + !param_acpi_nospcr);
> + pr_info("Use ACPI SPCR as default console: %s\n",
> + param_acpi_nospcr ? "No" : "Yes");
> +
> if (IS_ENABLED(CONFIG_ACPI_BGRT))
> acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
> }
This looks good to me. Sorry that this took so long Liu.
Reviewed-by: Prarit Bhargava <prarit@redhat.com>
P.
From: Prarit Bhargava <prarit@redhat.com> > On 6/24/24 23:05, Liu Wei wrote: > > For varying privacy and security reasons, sometimes we would like to > > completely silence the _serial_ console, and only enable it when needed. > > > > But there are many existing systems that depend on this _serial_ console, > > so add acpi=nospcr to disable console in ACPI SPCR table as default > > _serial_ console. > > > > Signed-off-by: Liu Wei <liuwei09@cestc.cn> > > Suggested-by: Prarit Bhargava <prarit@redhat.com> > > Suggested-by: Will Deacon <will@kernel.org> > > Suggested-by: Andrew Lunn <andrew@lunn.ch> > > --- > > > > v2: Add a config option suggested by Prarit > > > > v3: Use cmdline acpi=nospcr instead of config > > > > v4: Some description in comment or document > > --- > > .../admin-guide/kernel-parameters.txt | 10 +++++++--- > > arch/arm64/kernel/acpi.c | 18 +++++++++++++++++- > > 2 files changed, 24 insertions(+), 4 deletions(-) > > > > ... > > > > This looks good to me. Sorry that this took so long Liu. > > Reviewed-by: Prarit Bhargava <prarit@redhat.com> > Thanks, my pleasure. Liu Wei > > P.
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