iommu/riscv: Command and fault queue support

Introduce device command submission and fault reporting queues,
as described in Chapter 3.1 and 3.2 of the RISC-V IOMMU Architecture
Specification.

Command and fault queues are instantiated in contiguous system memory
local to IOMMU device domain, or mapped from fixed I/O space provided
by the hardware implementation. Detection of the location and maximum
allowed size of the queue utilize WARL properties of queue base control
register. Driver implementation will try to allocate up to 128KB of
system memory, while respecting hardware supported maximum queue size.

Interrupts allocation is based on interrupt vectors availability and
distributed to all queues in simple round-robin fashion. For hardware
Implementation with fixed event type to interrupt vector assignment
IVEC WARL property is used to discover such mappings.

Address translation, command and queue fault handling in this change
is limited to simple fault reporting without taking any action.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Tomasz Jeznach <tjeznach@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/c4735fb6829053eff37ce1bcca4906192afd743c.1729059707.git.tjeznach@rivosinc.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/riscv/iommu-bits.h

@@ -706,4 +706,79 @@ struct riscv_iommu_msipte {
 #define RISCV_IOMMU_MSIPTE_MRIF_NPPN	RISCV_IOMMU_PPN_FIELD
 #define RISCV_IOMMU_MSIPTE_MRIF_NID_MSB	BIT_ULL(60)
 
+/* Helper functions: command structure builders. */
+
+static inline void riscv_iommu_cmd_inval_vma(struct riscv_iommu_command *cmd)
+{
+	cmd->dword0 = FIELD_PREP(RISCV_IOMMU_CMD_OPCODE, RISCV_IOMMU_CMD_IOTINVAL_OPCODE) |
+		      FIELD_PREP(RISCV_IOMMU_CMD_FUNC, RISCV_IOMMU_CMD_IOTINVAL_FUNC_VMA);
+	cmd->dword1 = 0;
+}
+
+static inline void riscv_iommu_cmd_inval_set_addr(struct riscv_iommu_command *cmd,
+						  u64 addr)
+{
+	cmd->dword1 = FIELD_PREP(RISCV_IOMMU_CMD_IOTINVAL_ADDR, phys_to_pfn(addr));
+	cmd->dword0 |= RISCV_IOMMU_CMD_IOTINVAL_AV;
+}
+
+static inline void riscv_iommu_cmd_inval_set_pscid(struct riscv_iommu_command *cmd,
+						   int pscid)
+{
+	cmd->dword0 |= FIELD_PREP(RISCV_IOMMU_CMD_IOTINVAL_PSCID, pscid) |
+		       RISCV_IOMMU_CMD_IOTINVAL_PSCV;
+}
+
+static inline void riscv_iommu_cmd_inval_set_gscid(struct riscv_iommu_command *cmd,
+						   int gscid)
+{
+	cmd->dword0 |= FIELD_PREP(RISCV_IOMMU_CMD_IOTINVAL_GSCID, gscid) |
+		       RISCV_IOMMU_CMD_IOTINVAL_GV;
+}
+
+static inline void riscv_iommu_cmd_iofence(struct riscv_iommu_command *cmd)
+{
+	cmd->dword0 = FIELD_PREP(RISCV_IOMMU_CMD_OPCODE, RISCV_IOMMU_CMD_IOFENCE_OPCODE) |
+		      FIELD_PREP(RISCV_IOMMU_CMD_FUNC, RISCV_IOMMU_CMD_IOFENCE_FUNC_C) |
+		      RISCV_IOMMU_CMD_IOFENCE_PR | RISCV_IOMMU_CMD_IOFENCE_PW;
+	cmd->dword1 = 0;
+}
+
+static inline void riscv_iommu_cmd_iofence_set_av(struct riscv_iommu_command *cmd,
+						  u64 addr, u32 data)
+{
+	cmd->dword0 = FIELD_PREP(RISCV_IOMMU_CMD_OPCODE, RISCV_IOMMU_CMD_IOFENCE_OPCODE) |
+		      FIELD_PREP(RISCV_IOMMU_CMD_FUNC, RISCV_IOMMU_CMD_IOFENCE_FUNC_C) |
+		      FIELD_PREP(RISCV_IOMMU_CMD_IOFENCE_DATA, data) |
+		      RISCV_IOMMU_CMD_IOFENCE_AV;
+	cmd->dword1 = addr >> 2;
+}
+
+static inline void riscv_iommu_cmd_iodir_inval_ddt(struct riscv_iommu_command *cmd)
+{
+	cmd->dword0 = FIELD_PREP(RISCV_IOMMU_CMD_OPCODE, RISCV_IOMMU_CMD_IODIR_OPCODE) |
+		      FIELD_PREP(RISCV_IOMMU_CMD_FUNC, RISCV_IOMMU_CMD_IODIR_FUNC_INVAL_DDT);
+	cmd->dword1 = 0;
+}
+
+static inline void riscv_iommu_cmd_iodir_inval_pdt(struct riscv_iommu_command *cmd)
+{
+	cmd->dword0 = FIELD_PREP(RISCV_IOMMU_CMD_OPCODE, RISCV_IOMMU_CMD_IODIR_OPCODE) |
+		      FIELD_PREP(RISCV_IOMMU_CMD_FUNC, RISCV_IOMMU_CMD_IODIR_FUNC_INVAL_PDT);
+	cmd->dword1 = 0;
+}
+
+static inline void riscv_iommu_cmd_iodir_set_did(struct riscv_iommu_command *cmd,
+						 unsigned int devid)
+{
+	cmd->dword0 |= FIELD_PREP(RISCV_IOMMU_CMD_IODIR_DID, devid) |
+		       RISCV_IOMMU_CMD_IODIR_DV;
+}
+
+static inline void riscv_iommu_cmd_iodir_set_pid(struct riscv_iommu_command *cmd,
+						 unsigned int pasid)
+{
+	cmd->dword0 |= FIELD_PREP(RISCV_IOMMU_CMD_IODIR_PID, pasid);
+}
+
 #endif /* _RISCV_IOMMU_BITS_H_ */