This commit parses Zb/Zk related string from DT and
output them in cpuinfo

One thing worth noting is that if DT provides zk,
all zbkb, zbkc, zbkx and zkn, zkr, zkt would be enabled.

Note that zk is a valid extension name and the current
DT binding spec allows this.

There currently lacks a mechanism to merge them when
producing cpuinfo. Namely if you provide a riscv,isa
"rv64imafdc_zk_zks", the cpuinfo output would be
"rv64imafdc_zbkb_zbkc_zbkx_zknd_zkne_zknh_zkr_zksed
_zksh_zkt"

Tested-by: Jiatai He <redacted>
Signed-off-by: Hongren (Zenithal) Zheng <i@zenithal.me>
---
 arch/riscv/include/asm/hwcap.h | 14 ++++++++++++++
 arch/riscv/kernel/cpu.c        | 14 ++++++++++++++
 arch/riscv/kernel/cpufeature.c | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+)

diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 0734e42f74f2..199eda39e0b8 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h

@@ -52,6 +52,20 @@ extern unsigned long elf_hwcap;
  */
 enum riscv_isa_ext_id {
 	RISCV_ISA_EXT_SSCOFPMF = RISCV_ISA_EXT_BASE,
+	RISCV_ISA_EXT_ZBA,
+	RISCV_ISA_EXT_ZBB,
+	RISCV_ISA_EXT_ZBC,
+	RISCV_ISA_EXT_ZBS,
+	RISCV_ISA_EXT_ZBKB,
+	RISCV_ISA_EXT_ZBKC,
+	RISCV_ISA_EXT_ZBKX,
+	RISCV_ISA_EXT_ZKNE,
+	RISCV_ISA_EXT_ZKND,
+	RISCV_ISA_EXT_ZKNH,
+	RISCV_ISA_EXT_ZKSED,
+	RISCV_ISA_EXT_ZKSH,
+	RISCV_ISA_EXT_ZKR,
+	RISCV_ISA_EXT_ZKT,
 	RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX,
 };
 

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index ccb617791e56..7251336969c1 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c

@@ -87,6 +87,20 @@ int riscv_of_parent_hartid(struct device_node *node)
  *    extensions by an underscore.
  */
 static struct riscv_isa_ext_data isa_ext_arr[] = {
+	__RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA),
+	__RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
+	__RISCV_ISA_EXT_DATA(zbc, RISCV_ISA_EXT_ZBC),
+	__RISCV_ISA_EXT_DATA(zbkb, RISCV_ISA_EXT_ZBKB),
+	__RISCV_ISA_EXT_DATA(zbkc, RISCV_ISA_EXT_ZBKC),
+	__RISCV_ISA_EXT_DATA(zbkx, RISCV_ISA_EXT_ZBKX),
+	__RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS),
+	__RISCV_ISA_EXT_DATA(zknd, RISCV_ISA_EXT_ZKND),
+	__RISCV_ISA_EXT_DATA(zkne, RISCV_ISA_EXT_ZKNE),
+	__RISCV_ISA_EXT_DATA(zknh, RISCV_ISA_EXT_ZKNH),
+	__RISCV_ISA_EXT_DATA(zkr, RISCV_ISA_EXT_ZKR),
+	__RISCV_ISA_EXT_DATA(zksed, RISCV_ISA_EXT_ZKSED),
+	__RISCV_ISA_EXT_DATA(zksh, RISCV_ISA_EXT_ZKSH),
+	__RISCV_ISA_EXT_DATA(zkt, RISCV_ISA_EXT_ZKT),
 	__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),

 	__RISCV_ISA_EXT_DATA("", RISCV_ISA_EXT_MAX),
 };

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 1b2d42d7f589..10f9daf3734e 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c

@@ -192,6 +192,39 @@ void __init riscv_fill_hwcap(void)
 				set_bit(*ext - 'a', this_isa);
 			} else {
 				SET_ISA_EXT_MAP("sscofpmf", RISCV_ISA_EXT_SSCOFPMF);
+				SET_ISA_EXT_MAP("zba"     , RISCV_ISA_EXT_ZBA     );