drivers/firmware/smccc/soc_id.c | 75 +++++++++++++++++++++++++++++++++ include/linux/arm-smccc.h | 37 ++++++++++++++++ 2 files changed, 112 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
---
v1->v2: Address code review identified issues.
drivers/firmware/smccc/soc_id.c | 75 +++++++++++++++++++++++++++++++++
include/linux/arm-smccc.h | 37 ++++++++++++++++
2 files changed, 112 insertions(+)
diff --git a/drivers/firmware/smccc/soc_id.c b/drivers/firmware/smccc/soc_id.c
index 1990263fbba0..b72d100bdf31 100644
--- a/drivers/firmware/smccc/soc_id.c
+++ b/drivers/firmware/smccc/soc_id.c
@@ -32,6 +32,10 @@
static struct soc_device *soc_dev;
static struct soc_device_attribute *soc_dev_attr;
+static char __init *smccc_soc_name_init(void);
+
+static char __ro_after_init smccc_soc_id_name[136] = "";
+
static int __init smccc_soc_init(void)
{
int soc_id_rev, soc_id_version;
@@ -72,6 +76,7 @@ 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 +98,73 @@ static void __exit smccc_soc_exit(void)
kfree(soc_dev_attr);
}
module_exit(smccc_soc_exit);
+
+
+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;
+}
+
+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*/
--
2.46.2Hi Paul,
kernel test robot noticed the following build warnings:
[auto build test WARNING on soc/for-next]
[also build test WARNING on linus/master v6.13-rc1 next-20241203]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Paul-Benoit/firmware-smccc-Support-optional-Arm-SMC-SOC_ID-name/20241204-124243
base: https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git for-next
patch link: https://lore.kernel.org/r/20241203212854.5565-1-paul%40os.amperecomputing.com
patch subject: [PATCH v2] firmware: smccc: Support optional Arm SMC SOC_ID name
config: arm-qcom_defconfig (https://download.01.org/0day-ci/archive/20241204/202412042020.U9EEV8mE-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 592c0fe55f6d9a811028b5f3507be91458ab2713)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241204/202412042020.U9EEV8mE-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202412042020.U9EEV8mE-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/firmware/smccc/soc_id.c:109:16: warning: shift count >= width of type [-Wshift-count-overflow]
109 | dst[4] = (reg >> 32) & 0xff;
| ^ ~~
drivers/firmware/smccc/soc_id.c:110:16: warning: shift count >= width of type [-Wshift-count-overflow]
110 | dst[5] = (reg >> 40) & 0xff;
| ^ ~~
drivers/firmware/smccc/soc_id.c:111:16: warning: shift count >= width of type [-Wshift-count-overflow]
111 | dst[6] = (reg >> 48) & 0xff;
| ^ ~~
drivers/firmware/smccc/soc_id.c:112:16: warning: shift count >= width of type [-Wshift-count-overflow]
112 | dst[7] = (reg >> 56) & 0xff;
| ^ ~~
>> drivers/firmware/smccc/soc_id.c:37:29: warning: unused variable 'smccc_soc_id_name' [-Wunused-variable]
37 | static char __ro_after_init smccc_soc_id_name[136] = "";
| ^~~~~~~~~~~~~~~~~
drivers/firmware/smccc/soc_id.c:103:20: warning: unused function 'str_fragment_from_reg' [-Wunused-function]
103 | static inline void str_fragment_from_reg(char *dst, unsigned long reg)
| ^~~~~~~~~~~~~~~~~~~~~
6 warnings generated.
vim +109 drivers/firmware/smccc/soc_id.c
36
> 37 static char __ro_after_init smccc_soc_id_name[136] = "";
38
39 static int __init smccc_soc_init(void)
40 {
41 int soc_id_rev, soc_id_version;
42 static char soc_id_str[20], soc_id_rev_str[12];
43 static char soc_id_jep106_id_str[12];
44
45 if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
46 return 0;
47
48 soc_id_version = arm_smccc_get_soc_id_version();
49 if (soc_id_version == SMCCC_RET_NOT_SUPPORTED) {
50 pr_info("ARCH_SOC_ID not implemented, skipping ....\n");
51 return 0;
52 }
53
54 if (soc_id_version < 0) {
55 pr_err("Invalid SoC Version: %x\n", soc_id_version);
56 return -EINVAL;
57 }
58
59 soc_id_rev = arm_smccc_get_soc_id_revision();
60 if (soc_id_rev < 0) {
61 pr_err("Invalid SoC Revision: %x\n", soc_id_rev);
62 return -EINVAL;
63 }
64
65 soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
66 if (!soc_dev_attr)
67 return -ENOMEM;
68
69 sprintf(soc_id_rev_str, "0x%08x", soc_id_rev);
70 sprintf(soc_id_jep106_id_str, "jep106:%02x%02x",
71 JEP106_BANK_CONT_CODE(soc_id_version),
72 JEP106_ID_CODE(soc_id_version));
73 sprintf(soc_id_str, "%s:%04x", soc_id_jep106_id_str,
74 IMP_DEF_SOC_ID(soc_id_version));
75
76 soc_dev_attr->soc_id = soc_id_str;
77 soc_dev_attr->revision = soc_id_rev_str;
78 soc_dev_attr->family = soc_id_jep106_id_str;
79 soc_dev_attr->machine = smccc_soc_name_init();
80
81 soc_dev = soc_device_register(soc_dev_attr);
82 if (IS_ERR(soc_dev)) {
83 kfree(soc_dev_attr);
84 return PTR_ERR(soc_dev);
85 }
86
87 pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id,
88 soc_dev_attr->revision);
89
90 return 0;
91 }
92 module_init(smccc_soc_init);
93
94 static void __exit smccc_soc_exit(void)
95 {
96 if (soc_dev)
97 soc_device_unregister(soc_dev);
98 kfree(soc_dev_attr);
99 }
100 module_exit(smccc_soc_exit);
101
102
103 static inline void str_fragment_from_reg(char *dst, unsigned long reg)
104 {
105 dst[0] = (reg >> 0) & 0xff;
106 dst[1] = (reg >> 8) & 0xff;
107 dst[2] = (reg >> 16) & 0xff;
108 dst[3] = (reg >> 24) & 0xff;
> 109 dst[4] = (reg >> 32) & 0xff;
> 110 dst[5] = (reg >> 40) & 0xff;
111 dst[6] = (reg >> 48) & 0xff;
112 dst[7] = (reg >> 56) & 0xff;
113 }
114
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Paul,
kernel test robot noticed the following build warnings:
[auto build test WARNING on soc/for-next]
[also build test WARNING on linus/master v6.13-rc1 next-20241203]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Paul-Benoit/firmware-smccc-Support-optional-Arm-SMC-SOC_ID-name/20241204-124243
base: https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git for-next
patch link: https://lore.kernel.org/r/20241203212854.5565-1-paul%40os.amperecomputing.com
patch subject: [PATCH v2] firmware: smccc: Support optional Arm SMC SOC_ID name
config: arm-sp7021_defconfig (https://download.01.org/0day-ci/archive/20241204/202412041926.d2p2hcQe-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241204/202412041926.d2p2hcQe-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202412041926.d2p2hcQe-lkp@intel.com/
All warnings (new ones prefixed by >>):
drivers/firmware/smccc/soc_id.c: In function 'str_fragment_from_reg':
>> drivers/firmware/smccc/soc_id.c:109:23: warning: right shift count >= width of type [-Wshift-count-overflow]
109 | dst[4] = (reg >> 32) & 0xff;
| ^~
drivers/firmware/smccc/soc_id.c:110:23: warning: right shift count >= width of type [-Wshift-count-overflow]
110 | dst[5] = (reg >> 40) & 0xff;
| ^~
drivers/firmware/smccc/soc_id.c:111:23: warning: right shift count >= width of type [-Wshift-count-overflow]
111 | dst[6] = (reg >> 48) & 0xff;
| ^~
drivers/firmware/smccc/soc_id.c:112:23: warning: right shift count >= width of type [-Wshift-count-overflow]
112 | dst[7] = (reg >> 56) & 0xff;
| ^~
drivers/firmware/smccc/soc_id.c: At top level:
>> drivers/firmware/smccc/soc_id.c:37:29: warning: 'smccc_soc_id_name' defined but not used [-Wunused-variable]
37 | static char __ro_after_init smccc_soc_id_name[136] = "";
| ^~~~~~~~~~~~~~~~~
vim +109 drivers/firmware/smccc/soc_id.c
36
> 37 static char __ro_after_init smccc_soc_id_name[136] = "";
38
39 static int __init smccc_soc_init(void)
40 {
41 int soc_id_rev, soc_id_version;
42 static char soc_id_str[20], soc_id_rev_str[12];
43 static char soc_id_jep106_id_str[12];
44
45 if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
46 return 0;
47
48 soc_id_version = arm_smccc_get_soc_id_version();
49 if (soc_id_version == SMCCC_RET_NOT_SUPPORTED) {
50 pr_info("ARCH_SOC_ID not implemented, skipping ....\n");
51 return 0;
52 }
53
54 if (soc_id_version < 0) {
55 pr_err("Invalid SoC Version: %x\n", soc_id_version);
56 return -EINVAL;
57 }
58
59 soc_id_rev = arm_smccc_get_soc_id_revision();
60 if (soc_id_rev < 0) {
61 pr_err("Invalid SoC Revision: %x\n", soc_id_rev);
62 return -EINVAL;
63 }
64
65 soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
66 if (!soc_dev_attr)
67 return -ENOMEM;
68
69 sprintf(soc_id_rev_str, "0x%08x", soc_id_rev);
70 sprintf(soc_id_jep106_id_str, "jep106:%02x%02x",
71 JEP106_BANK_CONT_CODE(soc_id_version),
72 JEP106_ID_CODE(soc_id_version));
73 sprintf(soc_id_str, "%s:%04x", soc_id_jep106_id_str,
74 IMP_DEF_SOC_ID(soc_id_version));
75
76 soc_dev_attr->soc_id = soc_id_str;
77 soc_dev_attr->revision = soc_id_rev_str;
78 soc_dev_attr->family = soc_id_jep106_id_str;
79 soc_dev_attr->machine = smccc_soc_name_init();
80
81 soc_dev = soc_device_register(soc_dev_attr);
82 if (IS_ERR(soc_dev)) {
83 kfree(soc_dev_attr);
84 return PTR_ERR(soc_dev);
85 }
86
87 pr_info("ID = %s Revision = %s\n", soc_dev_attr->soc_id,
88 soc_dev_attr->revision);
89
90 return 0;
91 }
92 module_init(smccc_soc_init);
93
94 static void __exit smccc_soc_exit(void)
95 {
96 if (soc_dev)
97 soc_device_unregister(soc_dev);
98 kfree(soc_dev_attr);
99 }
100 module_exit(smccc_soc_exit);
101
102
103 static inline void str_fragment_from_reg(char *dst, unsigned long reg)
104 {
105 dst[0] = (reg >> 0) & 0xff;
106 dst[1] = (reg >> 8) & 0xff;
107 dst[2] = (reg >> 16) & 0xff;
108 dst[3] = (reg >> 24) & 0xff;
> 109 dst[4] = (reg >> 32) & 0xff;
110 dst[5] = (reg >> 40) & 0xff;
111 dst[6] = (reg >> 48) & 0xff;
112 dst[7] = (reg >> 56) & 0xff;
113 }
114
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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