[PATCH 1/3] s390/cpufeature: rework to allow more than only hwcap bits

Steffen Eiden
2022-07-12T10:52:35Z

Rework cpufeature implementation to allow for various cpu feature
indications, which is not only limited to hwcap bits. This is achieved
by adding a sequential list of cpu feature numbers, where each of them
is mapped to an entry which indicates what this number is about.

Each entry contains a type member, which indicates what feature
name space to look into (e.g. hwcap, or cpu facility). If wanted this
allows also to automatically load modules only in e.g. z/VM
configurations.

Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
arch/s390/crypto/aes_s390.c | 2 +-
arch/s390/crypto/chacha-glue.c | 2 +-
arch/s390/crypto/crc32-vx.c | 2 +-
arch/s390/crypto/des_s390.c | 2 +-
arch/s390/crypto/ghash_s390.c | 2 +-
arch/s390/crypto/prng.c | 2 +-
arch/s390/crypto/sha1_s390.c | 2 +-
arch/s390/crypto/sha256_s390.c | 2 +-
arch/s390/crypto/sha3_256_s390.c | 2 +-
arch/s390/crypto/sha3_512_s390.c | 2 +-
arch/s390/crypto/sha512_s390.c | 2 +-
arch/s390/include/asm/cpufeature.h | 43 +++++++++++++--------
arch/s390/kernel/Makefile | 2 +-
arch/s390/kernel/cpufeature.c | 62 ++++++++++++++++++++++++++++++
arch/s390/kernel/processor.c | 10 -----
drivers/char/hw_random/s390-trng.c | 2 +-
drivers/s390/crypto/pkey_api.c | 2 +-
17 files changed, 104 insertions(+), 39 deletions(-)
create mode 100644 arch/s390/kernel/cpufeature.c

diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index 1023e9d43d44..526c3f40f6a2 100644
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -1049,7 +1049,7 @@ static int __init aes_s390_init(void)
return ret;
}

-module_cpu_feature_match(MSA, aes_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init);
module_exit(aes_s390_fini);

MODULE_ALIAS_CRYPTO("aes-all");
diff --git a/arch/s390/crypto/chacha-glue.c b/arch/s390/crypto/chacha-glue.c
index 2ec51f339cec..7752bd314558 100644
--- a/arch/s390/crypto/chacha-glue.c
+++ b/arch/s390/crypto/chacha-glue.c
@@ -121,7 +121,7 @@ static void __exit chacha_mod_fini(void)
crypto_unregister_skciphers(chacha_algs, ARRAY_SIZE(chacha_algs));
}

-module_cpu_feature_match(VXRS, chacha_mod_init);
+module_cpu_feature_match(S390_CPU_FEATURE_VXRS, chacha_mod_init);
module_exit(chacha_mod_fini);

MODULE_DESCRIPTION("ChaCha20 stream cipher");
diff --git a/arch/s390/crypto/crc32-vx.c b/arch/s390/crypto/crc32-vx.c
index fafecad20752..017143e9cef7 100644
--- a/arch/s390/crypto/crc32-vx.c
+++ b/arch/s390/crypto/crc32-vx.c
@@ -298,7 +298,7 @@ static void __exit crc_vx_mod_exit(void)
crypto_unregister_shashes(crc32_vx_algs, ARRAY_SIZE(crc32_vx_algs));
}

-module_cpu_feature_match(VXRS, crc_vx_mod_init);
+module_cpu_feature_match(S390_CPU_FEATURE_VXRS, crc_vx_mod_init);
module_exit(crc_vx_mod_exit);

MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>");
diff --git a/arch/s390/crypto/des_s390.c b/arch/s390/crypto/des_s390.c
index e013088b5115..8e75b83a5ddc 100644
--- a/arch/s390/crypto/des_s390.c
+++ b/arch/s390/crypto/des_s390.c
@@ -492,7 +492,7 @@ static int __init des_s390_init(void)
return ret;
}

-module_cpu_feature_match(MSA, des_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, des_s390_init);
module_exit(des_s390_exit);

MODULE_ALIAS_CRYPTO("des");
diff --git a/arch/s390/crypto/ghash_s390.c b/arch/s390/crypto/ghash_s390.c
index 6b07a2f1ce8a..0800a2a5799f 100644
--- a/arch/s390/crypto/ghash_s390.c
+++ b/arch/s390/crypto/ghash_s390.c
@@ -145,7 +145,7 @@ static void __exit ghash_mod_exit(void)
crypto_unregister_shash(&ghash_alg);
}

-module_cpu_feature_match(MSA, ghash_mod_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, ghash_mod_init);
module_exit(ghash_mod_exit);

MODULE_ALIAS_CRYPTO("ghash");
diff --git a/arch/s390/crypto/prng.c b/arch/s390/crypto/prng.c
index ae382bafc772..a077087bc6cc 100644
--- a/arch/s390/crypto/prng.c
+++ b/arch/s390/crypto/prng.c
@@ -907,5 +907,5 @@ static void __exit prng_exit(void)
}
}

-module_cpu_feature_match(MSA, prng_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, prng_init);
module_exit(prng_exit);
diff --git a/arch/s390/crypto/sha1_s390.c b/arch/s390/crypto/sha1_s390.c
index a3fabf310a38..bc3a22704e09 100644
--- a/arch/s390/crypto/sha1_s390.c
+++ b/arch/s390/crypto/sha1_s390.c
@@ -95,7 +95,7 @@ static void __exit sha1_s390_fini(void)
crypto_unregister_shash(&alg);
}

-module_cpu_feature_match(MSA, sha1_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, sha1_s390_init);
module_exit(sha1_s390_fini);

MODULE_ALIAS_CRYPTO("sha1");
diff --git a/arch/s390/crypto/sha256_s390.c b/arch/s390/crypto/sha256_s390.c
index 24983f175676..6f1ccdf93d3e 100644
--- a/arch/s390/crypto/sha256_s390.c
+++ b/arch/s390/crypto/sha256_s390.c
@@ -134,7 +134,7 @@ static void __exit sha256_s390_fini(void)
crypto_unregister_shash(&sha256_alg);
}

-module_cpu_feature_match(MSA, sha256_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, sha256_s390_init);
module_exit(sha256_s390_fini);

MODULE_ALIAS_CRYPTO("sha256");
diff --git a/arch/s390/crypto/sha3_256_s390.c b/arch/s390/crypto/sha3_256_s390.c
index 30ac49b635bf..e1350e033a32 100644
--- a/arch/s390/crypto/sha3_256_s390.c
+++ b/arch/s390/crypto/sha3_256_s390.c
@@ -137,7 +137,7 @@ static void __exit sha3_256_s390_fini(void)
crypto_unregister_shash(&sha3_256_alg);
}

-module_cpu_feature_match(MSA, sha3_256_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, sha3_256_s390_init);
module_exit(sha3_256_s390_fini);

MODULE_ALIAS_CRYPTO("sha3-256");
diff --git a/arch/s390/crypto/sha3_512_s390.c b/arch/s390/crypto/sha3_512_s390.c
index e70d50f7620f..06c142ed9bb1 100644
--- a/arch/s390/crypto/sha3_512_s390.c
+++ b/arch/s390/crypto/sha3_512_s390.c
@@ -147,7 +147,7 @@ static void __exit fini(void)
crypto_unregister_shash(&sha3_384_alg);
}

-module_cpu_feature_match(MSA, init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, init);
module_exit(fini);

MODULE_LICENSE("GPL");
diff --git a/arch/s390/crypto/sha512_s390.c b/arch/s390/crypto/sha512_s390.c
index 43ce4956df73..04f11c407763 100644
--- a/arch/s390/crypto/sha512_s390.c
+++ b/arch/s390/crypto/sha512_s390.c
@@ -142,7 +142,7 @@ static void __exit fini(void)
crypto_unregister_shash(&sha384_alg);
}

-module_cpu_feature_match(MSA, init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, init);
module_exit(fini);

MODULE_LICENSE("GPL");
diff --git a/arch/s390/include/asm/cpufeature.h b/arch/s390/include/asm/cpufeature.h
index 14cfd48d598e..aa8081dad411 100644
--- a/arch/s390/include/asm/cpufeature.h
+++ b/arch/s390/include/asm/cpufeature.h
@@ -2,28 +2,41 @@
/*
* Module interface for CPU features
*
- * Copyright IBM Corp. 2015
+ * Copyright IBM Corp. 2015, 2022
* Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
*/

#ifndef __ASM_S390_CPUFEATURE_H
#define __ASM_S390_CPUFEATURE_H

-#include <asm/elf.h>
+enum {
+ S390_CPU_FEATURE_ESAN3,
+ S390_CPU_FEATURE_ZARCH,
+ S390_CPU_FEATURE_STFLE,
+ S390_CPU_FEATURE_MSA,
+ S390_CPU_FEATURE_LDISP,
+ S390_CPU_FEATURE_EIMM,
+ S390_CPU_FEATURE_DFP,
+ S390_CPU_FEATURE_HPAGE,
+ S390_CPU_FEATURE_ETF3EH,
+ S390_CPU_FEATURE_HIGH_GPRS,
+ S390_CPU_FEATURE_TE,
+ S390_CPU_FEATURE_VXRS,
+ S390_CPU_FEATURE_VXRS_BCD,
+ S390_CPU_FEATURE_VXRS_EXT,
+ S390_CPU_FEATURE_GS,
+ S390_CPU_FEATURE_VXRS_EXT2,
+ S390_CPU_FEATURE_VXRS_PDE,
+ S390_CPU_FEATURE_SORT,
+ S390_CPU_FEATURE_DFLT,
+ S390_CPU_FEATURE_VXRS_PDE2,
+ S390_CPU_FEATURE_NNPA,
+ S390_CPU_FEATURE_PCI_MIO,
+ S390_CPU_FEATURE_SIE,
+ MAX_CPU_FEATURES
+};

-/* Hardware features on Linux on z Systems are indicated by facility bits that
- * are mapped to the so-called machine flags. Particular machine flags are
- * then used to define ELF hardware capabilities; most notably hardware flags
- * that are essential for user space / glibc.
- *
- * Restrict the set of exposed CPU features to ELF hardware capabilities for
- * now. Additional machine flags can be indicated by values larger than
- * MAX_ELF_HWCAP_FEATURES.
- */
-#define MAX_ELF_HWCAP_FEATURES (8 * sizeof(elf_hwcap))
-#define MAX_CPU_FEATURES MAX_ELF_HWCAP_FEATURES
-
-#define cpu_feature(feat) ilog2(HWCAP_ ## feat)
+#define cpu_feature(feature) (feature)

int cpu_have_feature(unsigned int nr);

diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 27d6b3c7aa06..3cbfa9fddd9a 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -35,7 +35,7 @@ CFLAGS_unwind_bc.o += -fno-optimize-sibling-calls

obj-y := traps.o time.o process.o earlypgm.o early.o setup.o idle.o vtime.o
obj-y += processor.o syscall.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
-obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o
+obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o cpufeature.o
obj-y += sysinfo.o lgr.o os_info.o machine_kexec.o
obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o
diff --git a/arch/s390/kernel/cpufeature.c b/arch/s390/kernel/cpufeature.c
new file mode 100644
index 000000000000..ea4bbfd855db
--- /dev/null
+++ b/arch/s390/kernel/cpufeature.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2022
+ * Author(s): Steffen Eiden <seiden@linux.ibm.com>
+ * Heiko Carstens <hca@linux.ibm.com>
+ */
+#include <linux/cpufeature.h>
+#include <linux/bug.h>
+#include <asm/elf.h>
+
+enum {
+ TYPE_HWCAP,
+};
+
+struct s390_cpu_feature {
+ unsigned int type : 4;
+ unsigned int num : 28;
+};
+
+static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = {
+ [S390_CPU_FEATURE_ESAN3] = {.type = TYPE_HWCAP, .num = HWCAP_NR_ESAN3},
+ [S390_CPU_FEATURE_ZARCH] = {.type = TYPE_HWCAP, .num = HWCAP_NR_ZARCH},
+ [S390_CPU_FEATURE_STFLE] = {.type = TYPE_HWCAP, .num = HWCAP_NR_STFLE},
+ [S390_CPU_FEATURE_MSA] = {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA},
+ [S390_CPU_FEATURE_LDISP] = {.type = TYPE_HWCAP, .num = HWCAP_NR_LDISP},
+ [S390_CPU_FEATURE_EIMM] = {.type = TYPE_HWCAP, .num = HWCAP_NR_EIMM},
+ [S390_CPU_FEATURE_DFP] = {.type = TYPE_HWCAP, .num = HWCAP_NR_DFP},
+ [S390_CPU_FEATURE_HPAGE] = {.type = TYPE_HWCAP, .num = HWCAP_NR_HPAGE},
+ [S390_CPU_FEATURE_ETF3EH] = {.type = TYPE_HWCAP, .num = HWCAP_NR_ETF3EH},
+ [S390_CPU_FEATURE_HIGH_GPRS] = {.type = TYPE_HWCAP, .num = HWCAP_NR_HIGH_GPRS},
+ [S390_CPU_FEATURE_TE] = {.type = TYPE_HWCAP, .num = HWCAP_NR_TE},
+ [S390_CPU_FEATURE_VXRS] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS},
+ [S390_CPU_FEATURE_VXRS_BCD] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS_BCD},
+ [S390_CPU_FEATURE_VXRS_EXT] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS_EXT},
+ [S390_CPU_FEATURE_GS] = {.type = TYPE_HWCAP, .num = HWCAP_NR_GS},
+ [S390_CPU_FEATURE_VXRS_EXT2] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS_EXT2},
+ [S390_CPU_FEATURE_VXRS_PDE] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS_PDE},
+ [S390_CPU_FEATURE_SORT] = {.type = TYPE_HWCAP, .num = HWCAP_NR_SORT},
+ [S390_CPU_FEATURE_DFLT] = {.type = TYPE_HWCAP, .num = HWCAP_NR_DFLT},
+ [S390_CPU_FEATURE_VXRS_PDE2] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS_PDE2},
+ [S390_CPU_FEATURE_NNPA] = {.type = TYPE_HWCAP, .num = HWCAP_NR_NNPA},
+ [S390_CPU_FEATURE_PCI_MIO] = {.type = TYPE_HWCAP, .num = HWCAP_NR_PCI_MIO},
+ [S390_CPU_FEATURE_SIE] = {.type = TYPE_HWCAP, .num = HWCAP_NR_SIE},
+};
+
+/*
+ * cpu_have_feature - Test CPU features on module initialization
+ */
+int cpu_have_feature(unsigned int num)
+{
+ struct s390_cpu_feature *feature;
+
+ feature = &s390_cpu_features[num];
+ switch (feature->type) {
+ case TYPE_HWCAP:
+ return !!(elf_hwcap & (1UL << feature->num));
+ default:
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+}
+EXPORT_SYMBOL(cpu_have_feature);
diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c
index aa0e0e7fc773..a194611ba88c 100644
--- a/arch/s390/kernel/processor.c
+++ b/arch/s390/kernel/processor.c
@@ -8,7 +8,6 @@
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/stop_machine.h>
-#include <linux/cpufeature.h>
#include <linux/bitops.h>
#include <linux/kernel.h>
#include <linux/random.h>
@@ -96,15 +95,6 @@ void cpu_init(void)
enter_lazy_tlb(&init_mm, current);
}

-/*
- * cpu_have_feature - Test CPU features on module initialization
- */
-int cpu_have_feature(unsigned int num)
-{
- return elf_hwcap & (1UL << num);
-}
-EXPORT_SYMBOL(cpu_have_feature);
-
static void show_facilities(struct seq_file *m)
{
unsigned int bit;
diff --git a/drivers/char/hw_random/s390-trng.c b/drivers/char/hw_random/s390-trng.c
index 2beaa35c0d74..12fbac0ed8ca 100644
--- a/drivers/char/hw_random/s390-trng.c
+++ b/drivers/char/hw_random/s390-trng.c
@@ -261,5 +261,5 @@ static void __exit trng_exit(void)
trng_debug_exit();
}

-module_cpu_feature_match(MSA, trng_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, trng_init);
module_exit(trng_exit);
diff --git a/drivers/s390/crypto/pkey_api.c b/drivers/s390/crypto/pkey_api.c
index 7329caa7d467..5a05d1cdfec2 100644
--- a/drivers/s390/crypto/pkey_api.c
+++ b/drivers/s390/crypto/pkey_api.c
@@ -2115,5 +2115,5 @@ static void __exit pkey_exit(void)
pkey_debug_exit();
}

-module_cpu_feature_match(MSA, pkey_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, pkey_init);
module_exit(pkey_exit);
--
2.35.3