[PATCH v4 06/16] riscv: Add Ziccamoa, Ziccif, Ziccrse, and Za64rs to cpufeature and hwprobe

From: Andrew Jones <[email protected]>

Add Ziccamoa, Ziccif, and Za64rs to riscv_isa_ext[] so they can be
parsed from devicetree/ACPI ISA strings. Ziccrse is already present
in cpufeature; this patch only adds its hwprobe exposure.

Expose all four extensions via hwprobe through new bits in
RISCV_HWPROBE_KEY_IMA_EXT_1 (RISCV_HWPROBE_EXT_ZICCAMOA, _ZICCIF,
_ZICCRSE, _ZA64RS), so userspace can probe each of these
RVA23U64-mandatory extensions individually.

Rationale for the validation dependencies added for Ziccamoa and Za64rs:

1) Ziccamoa depends on Zaamo.  The RVA23 profile prose was updated
post-ratification to spell out the Zaamo reference: commit
2b218613752d in riscv/riscv-profiles ("Improve description of
Ziccamoa (#224)") reworded the rva23-profile.adoc (and other profiles
that include Ziccamoa) text from "must support all atomics in A" to
"must support all atomics in the Zaamo extension" [1].

2) Za64rs depends on Zalrsc. The unprivileged ISA manual src/zars.adoc,
integrated in commit ebe06adc22cd ("Integrate profiles as Volume III
(#2771)"), defines Za64rs as: "The Za64rs extension requires that the
reservation sets used by the instructions in the Zalrsc extension be
contiguous, naturally aligned, and at most 64 bytes in size" [2].

Link: https://github.com/riscv/riscv-profiles/commit/2b218613752d63287286b5ae801b820cbd8cc10c [1]
Link: https://github.com/riscv/riscv-isa-manual/blob/main/src/unpriv/zars.adoc [2]
Signed-off-by: Andrew Jones <[email protected]>
Signed-off-by: Guodong Xu <[email protected]>
---
v4: No change.
v3: Indent the added hwprobe.rst entries to match the normalized style; no other change.
v2:
- Rebased to v7.1-rc2.
- Reworded subject and expanded commit message.
- Validation added for Ziccamoa depending on Zaamo and Za64rs depending
  on Zalrsc.
---
 Documentation/arch/riscv/hwprobe.rst  | 16 ++++++++++++++++
 arch/riscv/include/asm/hwcap.h        |  3 +++
 arch/riscv/include/uapi/asm/hwprobe.h |  4 ++++
 arch/riscv/kernel/cpufeature.c        | 21 +++++++++++++++++++++
 arch/riscv/kernel/sys_hwprobe.c       |  4 ++++
 5 files changed, 48 insertions(+)

diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index 49d9fb68632d0..893e1a1215d23 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -405,3 +405,19 @@ The following keys are defined:
   * :c:macro:`RISCV_HWPROBE_EXT_ZICCLSM`: The Zicclsm extension is supported,
     as defined in the RISC-V Profiles specification starting from commit
     b1d80660 ("Updated to ratified state.")
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZICCAMOA`: The Ziccamoa extension is supported,
+    as defined in the RISC-V Profiles specification starting from commit
+    b1d80660 ("Updated to ratified state.")
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZICCIF`: The Ziccif extension is supported,
+    as defined in the RISC-V Profiles specification starting from commit
+    b1d80660 ("Updated to ratified state.")
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZICCRSE`: The Ziccrse extension is supported,
+    as defined in the RISC-V Profiles specification starting from commit
+    b1d80660 ("Updated to ratified state.")
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZA64RS`: The Za64rs extension is supported,
+    as defined in the RISC-V Profiles specification starting from commit
+    b1d80660 ("Updated to ratified state.")
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index e8f4a7dd96a93..0acb7a01ecc0f 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -113,6 +113,9 @@
 #define RISCV_ISA_EXT_ZICFILP		104
 #define RISCV_ISA_EXT_ZICFISS		105
 #define RISCV_ISA_EXT_ZICCLSM		106
+#define RISCV_ISA_EXT_ZICCAMOA		107
+#define RISCV_ISA_EXT_ZICCIF		108
+#define RISCV_ISA_EXT_ZA64RS		109
 
 #define RISCV_ISA_EXT_XLINUXENVCFG	127
 
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index 6819df159c51e..58d1e86e47ae7 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -117,6 +117,10 @@ struct riscv_hwprobe {
 #define RISCV_HWPROBE_KEY_IMA_EXT_1		16
 #define		RISCV_HWPROBE_EXT_ZICFISS	(1ULL << 0)
 #define		RISCV_HWPROBE_EXT_ZICCLSM	(1ULL << 1)
+#define		RISCV_HWPROBE_EXT_ZICCAMOA	(1ULL << 2)
+#define		RISCV_HWPROBE_EXT_ZICCIF	(1ULL << 3)
+#define		RISCV_HWPROBE_EXT_ZICCRSE	(1ULL << 4)
+#define		RISCV_HWPROBE_EXT_ZA64RS	(1ULL << 5)
 
 /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */
 
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 1fb595581adcf..b9538e69fa1b3 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -90,6 +90,24 @@ static int riscv_ext_f_depends(const struct riscv_isa_ext_data *data,
 	return -EPROBE_DEFER;
 }
 
+static int riscv_ext_zaamo_depends(const struct riscv_isa_ext_data *data,
+				   const unsigned long *isa_bitmap)
+{
+	if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZAAMO))
+		return 0;
+
+	return -EPROBE_DEFER;
+}
+
+static int riscv_ext_zalrsc_depends(const struct riscv_isa_ext_data *data,
+				    const unsigned long *isa_bitmap)
+{
+	if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZALRSC))
+		return 0;
+
+	return -EPROBE_DEFER;
+}
+
 static int riscv_ext_zicbom_validate(const struct riscv_isa_ext_data *data,
 				     const unsigned long *isa_bitmap)
 {
@@ -502,6 +520,8 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_SUPERSET_VALIDATE(zicbom, RISCV_ISA_EXT_ZICBOM, riscv_xlinuxenvcfg_exts, riscv_ext_zicbom_validate),
 	__RISCV_ISA_EXT_DATA_VALIDATE(zicbop, RISCV_ISA_EXT_ZICBOP, riscv_ext_zicbop_validate),
 	__RISCV_ISA_EXT_SUPERSET_VALIDATE(zicboz, RISCV_ISA_EXT_ZICBOZ, riscv_xlinuxenvcfg_exts, riscv_ext_zicboz_validate),
+	__RISCV_ISA_EXT_DATA_VALIDATE(ziccamoa, RISCV_ISA_EXT_ZICCAMOA, riscv_ext_zaamo_depends),
+	__RISCV_ISA_EXT_DATA(ziccif, RISCV_ISA_EXT_ZICCIF),
 	__RISCV_ISA_EXT_DATA(zicclsm, RISCV_ISA_EXT_ZICCLSM),
 	__RISCV_ISA_EXT_DATA(ziccrse, RISCV_ISA_EXT_ZICCRSE),
 	__RISCV_ISA_EXT_SUPERSET_VALIDATE(zicfilp, RISCV_ISA_EXT_ZICFILP, riscv_xlinuxenvcfg_exts,
@@ -516,6 +536,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
 	__RISCV_ISA_EXT_DATA(zihpm, RISCV_ISA_EXT_ZIHPM),
 	__RISCV_ISA_EXT_DATA(zimop, RISCV_ISA_EXT_ZIMOP),
+	__RISCV_ISA_EXT_DATA_VALIDATE(za64rs, RISCV_ISA_EXT_ZA64RS, riscv_ext_zalrsc_depends),
 	__RISCV_ISA_EXT_DATA(zaamo, RISCV_ISA_EXT_ZAAMO),
 	__RISCV_ISA_EXT_DATA(zabha, RISCV_ISA_EXT_ZABHA),
 	__RISCV_ISA_EXT_DATA(zacas, RISCV_ISA_EXT_ZACAS),
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 9cf62266f1890..b15ac9adf7920 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -206,6 +206,10 @@ static void hwprobe_isa_ext1(struct riscv_hwprobe *pair,
 		 */
 		EXT_KEY(isainfo->isa, ZICFISS, pair->value, missing);
 		EXT_KEY(isainfo->isa, ZICCLSM, pair->value, missing);
+		EXT_KEY(isainfo->isa, ZICCAMOA, pair->value, missing);
+		EXT_KEY(isainfo->isa, ZICCIF, pair->value, missing);
+		EXT_KEY(isainfo->isa, ZICCRSE, pair->value, missing);
+		EXT_KEY(isainfo->isa, ZA64RS, pair->value, missing);
 	}
 
 	/* Now turn off reporting features if any CPU is missing it. */

-- 
2.43.0