[PATCH v3 06/13] KVM: arm64: Share the ITS command field accessors with the hypervisor

[Fuad Tabba <fuad.tabba@linux.dev>]

The vgic's ITS emulation reads command fields with its_cmd_mask_field()
and the its_cmd_get_*() accessors. struct its_cmd_block, the block they
decode, is private to the ITS driver, and a later patch has the
protected KVM hypervisor parse the host's commands too.

Move the command block and the accessors to arm-gic-v3.h, which already
holds the GITS_CMD_* encodings, so there is one copy of each. Only KVM
reads commands, but the accessors decode the block the driver writes, so
they sit with it rather than in a KVM header.

No functional change intended.

Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
---
 arch/arm64/kvm/vgic/vgic-its.c     | 15 ---------------
 drivers/irqchip/irq-gic-v3-its.c   | 10 ----------
 include/linux/irqchip/arm-gic-v3.h | 22 ++++++++++++++++++++++
 3 files changed, 22 insertions(+), 25 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 7e9b265b1f521..78e480d112025 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -802,21 +802,6 @@ static bool vgic_its_map_lpi(struct kvm *kvm, struct its_ite *ite,
 	return false;
 }
 
-static u64 its_cmd_mask_field(u64 *its_cmd, int word, int shift, int size)
-{
-	return (le64_to_cpu(its_cmd[word]) >> shift) & (BIT_ULL(size) - 1);
-}
-
-#define its_cmd_get_command(cmd)	its_cmd_mask_field(cmd, 0,  0,  8)
-#define its_cmd_get_deviceid(cmd)	its_cmd_mask_field(cmd, 0, 32, 32)
-#define its_cmd_get_size(cmd)		(its_cmd_mask_field(cmd, 1,  0,  5) + 1)
-#define its_cmd_get_id(cmd)		its_cmd_mask_field(cmd, 1,  0, 32)
-#define its_cmd_get_physical_id(cmd)	its_cmd_mask_field(cmd, 1, 32, 32)
-#define its_cmd_get_collection(cmd)	its_cmd_mask_field(cmd, 2,  0, 16)
-#define its_cmd_get_ittaddr(cmd)	(its_cmd_mask_field(cmd, 2,  8, 44) << 8)
-#define its_cmd_get_target_addr(cmd)	its_cmd_mask_field(cmd, 2, 16, 32)
-#define its_cmd_get_validbit(cmd)	its_cmd_mask_field(cmd, 2, 63,  1)
-
 /*
  * The DISCARD command frees an Interrupt Translation Table Entry (ITTE).
  * Must be called with the its_lock mutex held.
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index f06da58cccf3d..3e27c7d58e024 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -528,16 +528,6 @@ struct its_cmd_desc {
 	};
 };
 
-/*
- * The ITS command block, which is what the ITS actually parses.
- */
-struct its_cmd_block {
-	union {
-		u64	raw_cmd[4];
-		__le64	raw_cmd_le[4];
-	};
-};
-
 #define ITS_CMD_QUEUE_SZ		SZ_64K
 #define ITS_CMD_QUEUE_NR_ENTRIES	(ITS_CMD_QUEUE_SZ / sizeof(struct its_cmd_block))
 
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index ea5fd2374ebe0..e0bec40adf2b7 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -657,6 +657,28 @@ static inline bool gic_enable_sre(void)
 	return !!(val & ICC_SRE_EL1_SRE);
 }
 
+struct its_cmd_block {
+	union {
+		u64	raw_cmd[4];
+		__le64	raw_cmd_le[4];
+	};
+};
+
+static inline u64 its_cmd_mask_field(u64 *its_cmd, int word, int shift, int size)
+{
+	return (le64_to_cpu(its_cmd[word]) >> shift) & (BIT_ULL(size) - 1);
+}
+
+#define its_cmd_get_command(cmd)	its_cmd_mask_field(cmd, 0,  0,  8)
+#define its_cmd_get_deviceid(cmd)	its_cmd_mask_field(cmd, 0, 32, 32)
+#define its_cmd_get_size(cmd)		(its_cmd_mask_field(cmd, 1,  0,  5) + 1)
+#define its_cmd_get_id(cmd)		its_cmd_mask_field(cmd, 1,  0, 32)
+#define its_cmd_get_physical_id(cmd)	its_cmd_mask_field(cmd, 1, 32, 32)
+#define its_cmd_get_collection(cmd)	its_cmd_mask_field(cmd, 2,  0, 16)
+#define its_cmd_get_ittaddr(cmd)	(its_cmd_mask_field(cmd, 2,  8, 44) << 8)
+#define its_cmd_get_target_addr(cmd)	its_cmd_mask_field(cmd, 2, 16, 32)
+#define its_cmd_get_validbit(cmd)	its_cmd_mask_field(cmd, 2, 63,  1)
+
 #endif
 
 #endif
-- 
2.47.3