[PATCH RFC v3 11/11] ACPI: RISC-V: Add support for RISC-V Quality of Service Controller (RQSC)

Call acpi_parse_rqsc() from acpi_arch_init() to discover CBQRI
controllers when an RQSC table is present. The RQSC table is optional;
AE_NOT_FOUND is silenced since many systems will not have QoS
controllers. Other ACPI failures are reported as errors.

Link: https://github.com/riscv-non-isa/riscv-cbqri/releases/tag/v1.0
Link: https://github.com/riscv-non-isa/riscv-rqsc/blob/main/src/
Signed-off-by: Drew Fustini <[email protected]>
---
 drivers/acpi/riscv/init.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/acpi/riscv/init.c b/drivers/acpi/riscv/init.c
index 7c00f7995e86..8a74dff42dce 100644
--- a/drivers/acpi/riscv/init.c
+++ b/drivers/acpi/riscv/init.c
@@ -4,12 +4,35 @@
  *	Author: Sunil V L <[email protected]>
  */
 
+#define pr_fmt(fmt) "ACPI: RQSC: " fmt
+
 #include <linux/acpi.h>
 #include "init.h"
 
 void __init acpi_arch_init(void)
 {
+	struct acpi_table_header *rqsc;
+	acpi_status status;
+	int rc;
+
 	riscv_acpi_init_gsi_mapping();
+
 	if (IS_ENABLED(CONFIG_ACPI_RIMT))
 		riscv_acpi_rimt_init();
+
+	if (IS_ENABLED(CONFIG_RISCV_ISA_SSQOSID) && !acpi_disabled) {
+		status = acpi_get_table(ACPI_SIG_RQSC, 0, &rqsc);
+		if (status == AE_NOT_FOUND) {
+			/* RQSC is optional; silence on systems without it */
+		} else if (ACPI_FAILURE(status)) {
+			pr_err("failed to get ACPI RQSC table: %s\n",
+			       acpi_format_exception(status));
+		} else {
+			rc = acpi_parse_rqsc(rqsc);
+			if (rc < 0)
+				pr_err("failed to parse ACPI RQSC table: %d\n",
+				       rc);
+			acpi_put_table(rqsc);
+		}
+	}
 }

-- 
2.43.0