drivers/firmware/smccc/soc_id.c | 79 +++++++++++++++++++++++++++++++++ include/linux/arm-smccc.h | 37 +++++++++++++++ 2 files changed, 116 insertions(+)
Issue Number 1.6 of the Arm SMC Calling Convention introduces an
optional SOC_ID name string. If available, point the 'machine' field of
the SoC Device Attributes at this string so that it will appear under
/sys/bus/soc/devices/soc0/machine. On Arm SMC compliant SoCs, this will
allow things like 'lscpu' to eventually get a SoC provider model name
from there rather than each tool/utility needing to get a possibly
inconsistent, obsolete, or incorrect model/machine name from its own
hardcoded model/machine name table.
Signed-off-by: Paul Benoit <paul@os.amperecomputing.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
---
v2->v3: Add conditionalization to exclude SOC_ID Name from 32-bit builds.
v1->v2: Address code review identified issues.
drivers/firmware/smccc/soc_id.c | 79 +++++++++++++++++++++++++++++++++
include/linux/arm-smccc.h | 37 +++++++++++++++
2 files changed, 116 insertions(+)
diff --git a/drivers/firmware/smccc/soc_id.c b/drivers/firmware/smccc/soc_id.c
index 1990263fbba0..3b50ff5d2cbd 100644
--- a/drivers/firmware/smccc/soc_id.c
+++ b/drivers/firmware/smccc/soc_id.c
@@ -32,6 +32,12 @@
static struct soc_device *soc_dev;
static struct soc_device_attribute *soc_dev_attr;
+static char __init *smccc_soc_name_init(void);
+
+#ifdef CONFIG_ARM64
+static char __ro_after_init smccc_soc_id_name[136] = "";
+#endif
+
static int __init smccc_soc_init(void)
{
int soc_id_rev, soc_id_version;
@@ -72,6 +78,7 @@ static int __init smccc_soc_init(void)
soc_dev_attr->soc_id = soc_id_str;
soc_dev_attr->revision = soc_id_rev_str;
soc_dev_attr->family = soc_id_jep106_id_str;
+ soc_dev_attr->machine = smccc_soc_name_init();
soc_dev = soc_device_register(soc_dev_attr);
if (IS_ERR(soc_dev)) {
@@ -93,3 +100,75 @@ static void __exit smccc_soc_exit(void)
kfree(soc_dev_attr);
}
module_exit(smccc_soc_exit);
+
+
+#ifdef CONFIG_ARM64
+static inline void str_fragment_from_reg(char *dst, unsigned long reg)
+{
+ dst[0] = (reg >> 0) & 0xff;
+ dst[1] = (reg >> 8) & 0xff;
+ dst[2] = (reg >> 16) & 0xff;
+ dst[3] = (reg >> 24) & 0xff;
+ dst[4] = (reg >> 32) & 0xff;
+ dst[5] = (reg >> 40) & 0xff;
+ dst[6] = (reg >> 48) & 0xff;
+ dst[7] = (reg >> 56) & 0xff;
+}
+#endif
+
+static char __init *smccc_soc_name_init(void)
+{
+#ifdef CONFIG_ARM64
+ struct arm_smccc_1_2_regs args;
+ struct arm_smccc_1_2_regs res;
+ size_t len;
+
+ /*
+ * Issue Number 1.6 of the Arm SMC Calling Convention
+ * specification introduces an optional "name" string
+ * to the ARM_SMCCC_ARCH_SOC_ID function. Fetch it if
+ * available.
+ */
+ args.a0 = ARM_SMCCC_ARCH_SOC_ID;
+ args.a1 = 2; /* SOC_ID name */
+ arm_smccc_1_2_invoke(&args, &res);
+ if ((u32)res.a0 == 0) {
+ const unsigned int regsize = sizeof(res.a1);
+
+ /*
+ * Copy res.a1..res.a17 to the smccc_soc_id_name string
+ * 8 bytes at a time. As per Issue 1.6 of the Arm SMC
+ * Calling Convention, the string will be NUL terminated
+ * and padded, from the end of the string to the end of the
+ * 136 byte buffer, with NULs.
+ */
+ str_fragment_from_reg(smccc_soc_id_name + 0*regsize, res.a1);
+ str_fragment_from_reg(smccc_soc_id_name + 1*regsize, res.a2);
+ str_fragment_from_reg(smccc_soc_id_name + 2*regsize, res.a3);
+ str_fragment_from_reg(smccc_soc_id_name + 3*regsize, res.a4);
+ str_fragment_from_reg(smccc_soc_id_name + 4*regsize, res.a5);
+ str_fragment_from_reg(smccc_soc_id_name + 5*regsize, res.a6);
+ str_fragment_from_reg(smccc_soc_id_name + 6*regsize, res.a7);
+ str_fragment_from_reg(smccc_soc_id_name + 7*regsize, res.a8);
+ str_fragment_from_reg(smccc_soc_id_name + 8*regsize, res.a9);
+ str_fragment_from_reg(smccc_soc_id_name + 9*regsize, res.a10);
+ str_fragment_from_reg(smccc_soc_id_name + 10*regsize, res.a11);
+ str_fragment_from_reg(smccc_soc_id_name + 11*regsize, res.a12);
+ str_fragment_from_reg(smccc_soc_id_name + 12*regsize, res.a13);
+ str_fragment_from_reg(smccc_soc_id_name + 13*regsize, res.a14);
+ str_fragment_from_reg(smccc_soc_id_name + 14*regsize, res.a15);
+ str_fragment_from_reg(smccc_soc_id_name + 15*regsize, res.a16);
+ str_fragment_from_reg(smccc_soc_id_name + 16*regsize, res.a17);
+
+ len = strnlen(smccc_soc_id_name, sizeof(smccc_soc_id_name));
+ if (len) {
+ if (len == sizeof(smccc_soc_id_name))
+ pr_warn(FW_BUG "Ignoring improperly formatted Name\n");
+ else
+ return smccc_soc_id_name;
+ }
+ }
+#endif
+
+ return NULL;
+}
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 67f6fdf2e7cd..9d444e5862fe 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -607,6 +607,12 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
___res->a0 = SMCCC_RET_NOT_SUPPORTED; \
} while (0)
+#define __fail_smccc_1_2(___res) \
+ do { \
+ if (___res) \
+ ___res->a0 = SMCCC_RET_NOT_SUPPORTED; \
+ } while (0)
+
/*
* arm_smccc_1_1_invoke() - make an SMCCC v1.1 compliant call
*
@@ -639,5 +645,36 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
method; \
})
+/*
+ * arm_smccc_1_2_invoke() - make an SMCCC v1.2 compliant call
+ *
+ * @args: SMC args are in the a0..a17 fields of the arm_smcc_1_2_regs structure
+ * @res: result values from registers 0 to 17
+ *
+ * This macro will make either an HVC call or an SMC call depending on the
+ * current SMCCC conduit. If no valid conduit is available then -1
+ * (SMCCC_RET_NOT_SUPPORTED) is returned in @res.a0 (if supplied).
+ *
+ * The return value also provides the conduit that was used.
+ */
+#define arm_smccc_1_2_invoke(args, res) ({ \
+ struct arm_smccc_1_2_regs *__args = args; \
+ struct arm_smccc_1_2_regs *__res = res; \
+ int method = arm_smccc_1_1_get_conduit(); \
+ switch (method) { \
+ case SMCCC_CONDUIT_HVC: \
+ arm_smccc_1_2_hvc(__args, __res); \
+ break; \
+ case SMCCC_CONDUIT_SMC: \
+ arm_smccc_1_2_smc(__args, __res); \
+ break; \
+ default: \
+ __fail_smccc_1_2(__res); \
+ method = SMCCC_CONDUIT_NONE; \
+ break; \
+ } \
+ method; \
+ })
+
#endif /*__ASSEMBLY__*/
#endif /*__LINUX_ARM_SMCCC_H*/
--
2.47.0Mostly minor coding style comments from me, otherwise LGTM.
On Tue, Dec 17, 2024 at 04:13:38PM -0800, Paul Benoit wrote:
Split the commit into multiple paragraphs, it looks too crowded 😄.
> Issue Number 1.6 of the Arm SMC Calling Convention introduces an
> optional SOC_ID name string.
> If available, point the 'machine' field of
^^^^ I prefer implemented instead of available.
> the SoC Device Attributes at this string so that it will appear under
> /sys/bus/soc/devices/soc0/machine.
Break into new paragraph here.
> On Arm SMC compliant SoCs, this will
> allow things like 'lscpu' to eventually get a SoC provider model name
> from there rather than each tool/utility needing to get a possibly
> inconsistent, obsolete, or incorrect model/machine name from its own
> hardcoded model/machine name table.
>
> Signed-off-by: Paul Benoit <paul@os.amperecomputing.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: linux-arm-kernel@lists.infradead.org
> ---
>
> v2->v3: Add conditionalization to exclude SOC_ID Name from 32-bit builds.
> v1->v2: Address code review identified issues.
>
> drivers/firmware/smccc/soc_id.c | 79 +++++++++++++++++++++++++++++++++
> include/linux/arm-smccc.h | 37 +++++++++++++++
> 2 files changed, 116 insertions(+)
>
> diff --git a/drivers/firmware/smccc/soc_id.c b/drivers/firmware/smccc/soc_id.c
> index 1990263fbba0..3b50ff5d2cbd 100644
> --- a/drivers/firmware/smccc/soc_id.c
> +++ b/drivers/firmware/smccc/soc_id.c
> @@ -32,6 +32,12 @@
> static struct soc_device *soc_dev;
> static struct soc_device_attribute *soc_dev_attr;
>
> +static char __init *smccc_soc_name_init(void);
> +
Not really needed if you move you code before smccc_soc_init()
> +#ifdef CONFIG_ARM64
> +static char __ro_after_init smccc_soc_id_name[136] = "";
Move all in one block under #ifdef, details below.
> +#endif
> +
> static int __init smccc_soc_init(void)
> {
> int soc_id_rev, soc_id_version;
> @@ -72,6 +78,7 @@ static int __init smccc_soc_init(void)
> soc_dev_attr->soc_id = soc_id_str;
> soc_dev_attr->revision = soc_id_rev_str;
> soc_dev_attr->family = soc_id_jep106_id_str;
> + soc_dev_attr->machine = smccc_soc_name_init();
>
> soc_dev = soc_device_register(soc_dev_attr);
> if (IS_ERR(soc_dev)) {
> @@ -93,3 +100,75 @@ static void __exit smccc_soc_exit(void)
> kfree(soc_dev_attr);
> }
> module_exit(smccc_soc_exit);
Generally it good to have module_{init,exit} at the end of the file.
Move you additions above these.
> +
> +
> +#ifdef CONFIG_ARM64
> +static inline void str_fragment_from_reg(char *dst, unsigned long reg)
> +{
> + dst[0] = (reg >> 0) & 0xff;
> + dst[1] = (reg >> 8) & 0xff;
> + dst[2] = (reg >> 16) & 0xff;
> + dst[3] = (reg >> 24) & 0xff;
> + dst[4] = (reg >> 32) & 0xff;
> + dst[5] = (reg >> 40) & 0xff;
> + dst[6] = (reg >> 48) & 0xff;
> + dst[7] = (reg >> 56) & 0xff;
> +}
> +#endif
> +
> +static char __init *smccc_soc_name_init(void)
> +{
> +#ifdef CONFIG_ARM64
> + struct arm_smccc_1_2_regs args;
> + struct arm_smccc_1_2_regs res;
> + size_t len;
> +
> + /*
> + * Issue Number 1.6 of the Arm SMC Calling Convention
> + * specification introduces an optional "name" string
> + * to the ARM_SMCCC_ARCH_SOC_ID function. Fetch it if
> + * available.
> + */
> + args.a0 = ARM_SMCCC_ARCH_SOC_ID;
> + args.a1 = 2; /* SOC_ID name */
> + arm_smccc_1_2_invoke(&args, &res);
> + if ((u32)res.a0 == 0) {
> + const unsigned int regsize = sizeof(res.a1);
> +
> + /*
> + * Copy res.a1..res.a17 to the smccc_soc_id_name string
> + * 8 bytes at a time. As per Issue 1.6 of the Arm SMC
> + * Calling Convention, the string will be NUL terminated
> + * and padded, from the end of the string to the end of the
> + * 136 byte buffer, with NULs.
> + */
> + str_fragment_from_reg(smccc_soc_id_name + 0*regsize, res.a1);
> + str_fragment_from_reg(smccc_soc_id_name + 1*regsize, res.a2);
> + str_fragment_from_reg(smccc_soc_id_name + 2*regsize, res.a3);
> + str_fragment_from_reg(smccc_soc_id_name + 3*regsize, res.a4);
> + str_fragment_from_reg(smccc_soc_id_name + 4*regsize, res.a5);
> + str_fragment_from_reg(smccc_soc_id_name + 5*regsize, res.a6);
> + str_fragment_from_reg(smccc_soc_id_name + 6*regsize, res.a7);
> + str_fragment_from_reg(smccc_soc_id_name + 7*regsize, res.a8);
> + str_fragment_from_reg(smccc_soc_id_name + 8*regsize, res.a9);
> + str_fragment_from_reg(smccc_soc_id_name + 9*regsize, res.a10);
> + str_fragment_from_reg(smccc_soc_id_name + 10*regsize, res.a11);
> + str_fragment_from_reg(smccc_soc_id_name + 11*regsize, res.a12);
> + str_fragment_from_reg(smccc_soc_id_name + 12*regsize, res.a13);
> + str_fragment_from_reg(smccc_soc_id_name + 13*regsize, res.a14);
> + str_fragment_from_reg(smccc_soc_id_name + 14*regsize, res.a15);
> + str_fragment_from_reg(smccc_soc_id_name + 15*regsize, res.a16);
> + str_fragment_from_reg(smccc_soc_id_name + 16*regsize, res.a17);
> +
> + len = strnlen(smccc_soc_id_name, sizeof(smccc_soc_id_name));
> + if (len) {
> + if (len == sizeof(smccc_soc_id_name))
> + pr_warn(FW_BUG "Ignoring improperly formatted Name\n");
> + else
> + return smccc_soc_id_name;
> + }
> + }
> +#endif
> +
> + return NULL;
> +}
Can we improve readability with
#ifdef CONFIG_ARM64
static char __ro_after_init smccc_soc_id_name[136] = "";
<both str_fragment_from_reg and smccc_soc_name_init here>
#else
static char __init *smccc_soc_name_init(void)
{
return NULL;
}
#endif
> diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
> index 67f6fdf2e7cd..9d444e5862fe 100644
> --- a/include/linux/arm-smccc.h
> +++ b/include/linux/arm-smccc.h
> @@ -607,6 +607,12 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
> ___res->a0 = SMCCC_RET_NOT_SUPPORTED; \
> } while (0)
>
> +#define __fail_smccc_1_2(___res) \
> + do { \
> + if (___res) \
> + ___res->a0 = SMCCC_RET_NOT_SUPPORTED; \
> + } while (0)
> +
> /*
> * arm_smccc_1_1_invoke() - make an SMCCC v1.1 compliant call
> *
> @@ -639,5 +645,36 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
> method; \
> })
>
> +/*
> + * arm_smccc_1_2_invoke() - make an SMCCC v1.2 compliant call
> + *
> + * @args: SMC args are in the a0..a17 fields of the arm_smcc_1_2_regs structure
> + * @res: result values from registers 0 to 17
> + *
> + * This macro will make either an HVC call or an SMC call depending on the
> + * current SMCCC conduit. If no valid conduit is available then -1
> + * (SMCCC_RET_NOT_SUPPORTED) is returned in @res.a0 (if supplied).
> + *
> + * The return value also provides the conduit that was used.
> + */
> +#define arm_smccc_1_2_invoke(args, res) ({ \
> + struct arm_smccc_1_2_regs *__args = args; \
I think we can move this macro and the above under CONFIG_ARM64 as
arm_smccc_1_2_regs is defined only for ARM64 for now. Otherwise one
could use this macro and get undefined compiler errors for the structure.
--
Regards,
Sudeep
Hi Sudeep,
Thank you for your feedback.
I hope to submit the suggested changes as v4 of the patch early next week.
On 2/10/2025 7:13 AM, Sudeep Holla wrote:
> Mostly minor coding style comments from me, otherwise LGTM.
>
> On Tue, Dec 17, 2024 at 04:13:38PM -0800, Paul Benoit wrote:
>
> Split the commit into multiple paragraphs, it looks too crowded 😄 >
>> Issue Number 1.6 of the Arm SMC Calling Convention introduces an
>> optional SOC_ID name string.
>
>> If available, point the 'machine' field of
>
> ^^^^ I prefer implemented instead of available.
I changed the wording to use "implemented" rather than "available".
>
>> the SoC Device Attributes at this string so that it will appear under
>> /sys/bus/soc/devices/soc0/machine.
>
> Break into new paragraph here.
I made the split, and adjusted the line lengths/breaks so as to not
exceed 75 columns/characters.
>
>> On Arm SMC compliant SoCs, this will
>> allow things like 'lscpu' to eventually get a SoC provider model name
>> from there rather than each tool/utility needing to get a possibly
>> inconsistent, obsolete, or incorrect model/machine name from its own
>> hardcoded model/machine name table.
>>
>> Signed-off-by: Paul Benoit <paul@os.amperecomputing.com>
>> Cc: Mark Rutland <mark.rutland@arm.com>
>> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
>> Cc: Sudeep Holla <sudeep.holla@arm.com>
>> Cc: linux-arm-kernel@lists.infradead.org
>> ---
>>
>> v2->v3: Add conditionalization to exclude SOC_ID Name from 32-bit builds.
>> v1->v2: Address code review identified issues.
>>
>> drivers/firmware/smccc/soc_id.c | 79 +++++++++++++++++++++++++++++++++
>> include/linux/arm-smccc.h | 37 +++++++++++++++
>> 2 files changed, 116 insertions(+)
>>
>> diff --git a/drivers/firmware/smccc/soc_id.c b/drivers/firmware/smccc/soc_id.c
>> index 1990263fbba0..3b50ff5d2cbd 100644
>> --- a/drivers/firmware/smccc/soc_id.c
>> +++ b/drivers/firmware/smccc/soc_id.c
>> @@ -32,6 +32,12 @@
>> static struct soc_device *soc_dev;
>> static struct soc_device_attribute *soc_dev_attr;
>>
>> +static char __init *smccc_soc_name_init(void);
>> +
>
> Not really needed if you move you code before smccc_soc_init()
>
It has been eliminated.
>> +#ifdef CONFIG_ARM64
>> +static char __ro_after_init smccc_soc_id_name[136] = "";
>
> Move all in one block under #ifdef, details below.
>
I have made that change.
>> +#endif
>> +
>> static int __init smccc_soc_init(void)
>> {
>> int soc_id_rev, soc_id_version;
>> @@ -72,6 +78,7 @@ static int __init smccc_soc_init(void)
>> soc_dev_attr->soc_id = soc_id_str;
>> soc_dev_attr->revision = soc_id_rev_str;
>> soc_dev_attr->family = soc_id_jep106_id_str;
>> + soc_dev_attr->machine = smccc_soc_name_init();
>>
>> soc_dev = soc_device_register(soc_dev_attr);
>> if (IS_ERR(soc_dev)) {
>> @@ -93,3 +100,75 @@ static void __exit smccc_soc_exit(void)
>> kfree(soc_dev_attr);
>> }
>> module_exit(smccc_soc_exit);
>
> Generally it good to have module_{init,exit} at the end of the file.
> Move you additions above these.
>
Agreed. I have made that change as part of your suggestion to "Move all
in one block under #ifdef".
>> +
>> +
>> +#ifdef CONFIG_ARM64
>> +static inline void str_fragment_from_reg(char *dst, unsigned long reg)
>> +{
>> + dst[0] = (reg >> 0) & 0xff;
>> + dst[1] = (reg >> 8) & 0xff;
>> + dst[2] = (reg >> 16) & 0xff;
>> + dst[3] = (reg >> 24) & 0xff;
>> + dst[4] = (reg >> 32) & 0xff;
>> + dst[5] = (reg >> 40) & 0xff;
>> + dst[6] = (reg >> 48) & 0xff;
>> + dst[7] = (reg >> 56) & 0xff;
>> +}
>> +#endif
>> +
>> +static char __init *smccc_soc_name_init(void)
>> +{
>> +#ifdef CONFIG_ARM64
>> + struct arm_smccc_1_2_regs args;
>> + struct arm_smccc_1_2_regs res;
>> + size_t len;
>> +
>> + /*
>> + * Issue Number 1.6 of the Arm SMC Calling Convention
>> + * specification introduces an optional "name" string
>> + * to the ARM_SMCCC_ARCH_SOC_ID function. Fetch it if
>> + * available.
>> + */
>> + args.a0 = ARM_SMCCC_ARCH_SOC_ID;
>> + args.a1 = 2; /* SOC_ID name */
>> + arm_smccc_1_2_invoke(&args, &res);
>> + if ((u32)res.a0 == 0) {
>> + const unsigned int regsize = sizeof(res.a1);
>> +
>> + /*
>> + * Copy res.a1..res.a17 to the smccc_soc_id_name string
>> + * 8 bytes at a time. As per Issue 1.6 of the Arm SMC
>> + * Calling Convention, the string will be NUL terminated
>> + * and padded, from the end of the string to the end of the
>> + * 136 byte buffer, with NULs.
>> + */
>> + str_fragment_from_reg(smccc_soc_id_name + 0*regsize, res.a1);
>> + str_fragment_from_reg(smccc_soc_id_name + 1*regsize, res.a2);
>> + str_fragment_from_reg(smccc_soc_id_name + 2*regsize, res.a3);
>> + str_fragment_from_reg(smccc_soc_id_name + 3*regsize, res.a4);
>> + str_fragment_from_reg(smccc_soc_id_name + 4*regsize, res.a5);
>> + str_fragment_from_reg(smccc_soc_id_name + 5*regsize, res.a6);
>> + str_fragment_from_reg(smccc_soc_id_name + 6*regsize, res.a7);
>> + str_fragment_from_reg(smccc_soc_id_name + 7*regsize, res.a8);
>> + str_fragment_from_reg(smccc_soc_id_name + 8*regsize, res.a9);
>> + str_fragment_from_reg(smccc_soc_id_name + 9*regsize, res.a10);
>> + str_fragment_from_reg(smccc_soc_id_name + 10*regsize, res.a11);
>> + str_fragment_from_reg(smccc_soc_id_name + 11*regsize, res.a12);
>> + str_fragment_from_reg(smccc_soc_id_name + 12*regsize, res.a13);
>> + str_fragment_from_reg(smccc_soc_id_name + 13*regsize, res.a14);
>> + str_fragment_from_reg(smccc_soc_id_name + 14*regsize, res.a15);
>> + str_fragment_from_reg(smccc_soc_id_name + 15*regsize, res.a16);
>> + str_fragment_from_reg(smccc_soc_id_name + 16*regsize, res.a17);
>> +
>> + len = strnlen(smccc_soc_id_name, sizeof(smccc_soc_id_name));
>> + if (len) {
>> + if (len == sizeof(smccc_soc_id_name))
>> + pr_warn(FW_BUG "Ignoring improperly formatted Name\n");
>> + else
>> + return smccc_soc_id_name;
>> + }
>> + }
>> +#endif
>> +
>> + return NULL;
>> +}
>
> Can we improve readability with
>
> #ifdef CONFIG_ARM64
>
> static char __ro_after_init smccc_soc_id_name[136] = "";
>
> <both str_fragment_from_reg and smccc_soc_name_init here>
>
> #else
> static char __init *smccc_soc_name_init(void)
> {
> return NULL;
> }
>
> #endif
>
I have made the change suggested above.
>> diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
>> index 67f6fdf2e7cd..9d444e5862fe 100644
>> --- a/include/linux/arm-smccc.h
>> +++ b/include/linux/arm-smccc.h
>> @@ -607,6 +607,12 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
>> ___res->a0 = SMCCC_RET_NOT_SUPPORTED; \
>> } while (0)
>>
>> +#define __fail_smccc_1_2(___res) \
>> + do { \
>> + if (___res) \
>> + ___res->a0 = SMCCC_RET_NOT_SUPPORTED; \
>> + } while (0)
>> +
>> /*
>> * arm_smccc_1_1_invoke() - make an SMCCC v1.1 compliant call
>> *
>> @@ -639,5 +645,36 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
>> method; \
>> })
>>
>> +/*
>> + * arm_smccc_1_2_invoke() - make an SMCCC v1.2 compliant call
>> + *
>> + * @args: SMC args are in the a0..a17 fields of the arm_smcc_1_2_regs structure
>> + * @res: result values from registers 0 to 17
>> + *
>> + * This macro will make either an HVC call or an SMC call depending on the
>> + * current SMCCC conduit. If no valid conduit is available then -1
>> + * (SMCCC_RET_NOT_SUPPORTED) is returned in @res.a0 (if supplied).
>> + *
>> + * The return value also provides the conduit that was used.
>> + */
>> +#define arm_smccc_1_2_invoke(args, res) ({ \
>> + struct arm_smccc_1_2_regs *__args = args; \
>
> I think we can move this macro and the above under CONFIG_ARM64 as
> arm_smccc_1_2_regs is defined only for ARM64 for now. Otherwise one
> could use this macro and get undefined compiler errors for the structure.
>
I added another #ifdef CONFIG_ARM64 around arm_smccc_1_2_invoke. It
seemed cleaner to keep arm_smccc_1_2_invoke located right after
arm_smccc_1_1_invoke rather than to move it amongst the other
CONFIG_ARM64 conditionalization for struct definitions, prototypes, etc.
Though, I'm open to moving it if you think that is better than having
it immediately follow arm_smccc_1_1_invoke.
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