s390/crypto: Display Query and Query Authentication Information in sysfs

Displays the query (fc=0) and query authentication information (fc=127)
as binary in sysfs per CPACF instruction. Files are located in
/sys/devices/system/cpu/cpacf/. These information can be fetched via
asm already except for PCKMO because this instruction is privileged. To
offer a unified interface all CPACF instructions will have this
information displayed in sysfs in files <instruction>_query_raw and
<instruction>_query_auth_info_raw.

A new tool introduced into s390-tools called cpacfinfo will use this
information to convert and display in human readable form.

Suggested-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Finn Callies <fcallies@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

2 files changed, 120 insertions, 0 deletions

diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 5ceb08b338d3..48caae8c7e10 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -50,6 +50,7 @@ extra-y				+= vmlinux.lds
 obj-$(CONFIG_SYSFS)		+= nospec-sysfs.o
 CFLAGS_REMOVE_nospec-branch.o	+= $(CC_FLAGS_EXPOLINE)
 
+obj-$(CONFIG_SYSFS)		+= cpacf.o
 obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_SCHED_TOPOLOGY)	+= topology.o hiperdispatch.o
 obj-$(CONFIG_NUMA)		+= numa.o
diff --git a/arch/s390/kernel/cpacf.c b/arch/s390/kernel/cpacf.c
new file mode 100644
index 000000000000..c8575dbc890d
--- /dev/null
+++ b/arch/s390/kernel/cpacf.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2024
+ */
+
+#define KMSG_COMPONENT "cpacf"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/cpu.h>
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <asm/cpacf.h>
+
+#define CPACF_QUERY(name, instruction)						\
+static ssize_t name##_query_raw_read(struct file *fp,				\
+				     struct kobject *kobj,			\
+				     struct bin_attribute *attr,		\
+				     char *buf, loff_t offs,			\
+				     size_t count)				\
+{										\
+	cpacf_mask_t mask;							\
+										\
+	if (!cpacf_query(CPACF_##instruction, &mask))				\
+		return -EOPNOTSUPP;						\
+	return memory_read_from_buffer(buf, count, &offs, &mask, sizeof(mask));	\
+}										\
+static BIN_ATTR_RO(name##_query_raw, sizeof(cpacf_mask_t))
+
+CPACF_QUERY(km, KM);
+CPACF_QUERY(kmc, KMC);
+CPACF_QUERY(kimd, KIMD);
+CPACF_QUERY(klmd, KLMD);
+CPACF_QUERY(kmac, KMAC);
+CPACF_QUERY(pckmo, PCKMO);
+CPACF_QUERY(kmf, KMF);
+CPACF_QUERY(kmctr, KMCTR);
+CPACF_QUERY(kmo, KMO);
+CPACF_QUERY(pcc, PCC);
+CPACF_QUERY(prno, PRNO);
+CPACF_QUERY(kma, KMA);
+CPACF_QUERY(kdsa, KDSA);
+
+#define CPACF_QAI(name, instruction)				\
+static ssize_t name##_query_auth_info_raw_read(			\
+	struct file *fp, struct kobject *kobj,			\
+	struct bin_attribute *attr, char *buf, loff_t offs,	\
+	size_t count)						\
+{								\
+	cpacf_qai_t qai;					\
+								\
+	if (!cpacf_qai(CPACF_##instruction, &qai))		\
+		return -EOPNOTSUPP;				\
+	return memory_read_from_buffer(buf, count, &offs, &qai, \
+					sizeof(qai));		\
+}								\
+static BIN_ATTR_RO(name##_query_auth_info_raw, sizeof(cpacf_qai_t))
+
+CPACF_QAI(km, KM);
+CPACF_QAI(kmc, KMC);
+CPACF_QAI(kimd, KIMD);
+CPACF_QAI(klmd, KLMD);
+CPACF_QAI(kmac, KMAC);
+CPACF_QAI(pckmo, PCKMO);
+CPACF_QAI(kmf, KMF);
+CPACF_QAI(kmctr, KMCTR);
+CPACF_QAI(kmo, KMO);
+CPACF_QAI(pcc, PCC);
+CPACF_QAI(prno, PRNO);
+CPACF_QAI(kma, KMA);
+CPACF_QAI(kdsa, KDSA);
+
+static struct bin_attribute *cpacf_attrs[] = {
+	&bin_attr_km_query_raw,
+	&bin_attr_kmc_query_raw,
+	&bin_attr_kimd_query_raw,
+	&bin_attr_klmd_query_raw,
+	&bin_attr_kmac_query_raw,
+	&bin_attr_pckmo_query_raw,
+	&bin_attr_kmf_query_raw,
+	&bin_attr_kmctr_query_raw,
+	&bin_attr_kmo_query_raw,
+	&bin_attr_pcc_query_raw,
+	&bin_attr_prno_query_raw,
+	&bin_attr_kma_query_raw,
+	&bin_attr_kdsa_query_raw,
+	&bin_attr_km_query_auth_info_raw,
+	&bin_attr_kmc_query_auth_info_raw,
+	&bin_attr_kimd_query_auth_info_raw,
+	&bin_attr_klmd_query_auth_info_raw,
+	&bin_attr_kmac_query_auth_info_raw,
+	&bin_attr_pckmo_query_auth_info_raw,
+	&bin_attr_kmf_query_auth_info_raw,
+	&bin_attr_kmctr_query_auth_info_raw,
+	&bin_attr_kmo_query_auth_info_raw,
+	&bin_attr_pcc_query_auth_info_raw,
+	&bin_attr_prno_query_auth_info_raw,
+	&bin_attr_kma_query_auth_info_raw,
+	&bin_attr_kdsa_query_auth_info_raw,
+	NULL,
+};
+
+static const struct attribute_group cpacf_attr_grp = {
+	.name = "cpacf",
+	.bin_attrs = cpacf_attrs,
+};
+
+static int __init cpacf_init(void)
+{
+	struct device *cpu_root;
+	int rc = 0;
+
+	cpu_root = bus_get_dev_root(&cpu_subsys);
+	if (cpu_root) {
+		rc = sysfs_create_group(&cpu_root->kobj, &cpacf_attr_grp);
+		put_device(cpu_root);
+	}
+	return rc;
+}
+device_initcall(cpacf_init);