[PATCH v6 15/37] acpi: Add processor device

Patrick Rudolph
2024-10-02T09:54:28Z

Add a new method to write the processor device identified by _HID
ACPI0007, that is preferred over the Processor OpCode since ACPI 6.0.

Fixes booting arm using ACPI only since the Processor OpCode isn't
found valid by the Linux kernel.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Simon Glass <sjg@chromium.org>
---
include/acpi/acpigen.h | 12 ++++++++++++
lib/acpi/acpigen.c | 11 +++++++++++
2 files changed, 23 insertions(+)

diff --git a/include/acpi/acpigen.h b/include/acpi/acpigen.h
index 3aa94d70b9..16df85b9c1 100644
--- a/include/acpi/acpigen.h
+++ b/include/acpi/acpigen.h
@@ -833,6 +833,7 @@ void acpigen_write_dsm_end(struct acpi_ctx *ctx);
*
* This emits a Processor package header with the required information. The
* caller must complete the information and call acpigen_pop_len() at the end
+ * Deprecated since ACPI 6.0.
*
* @ctx: ACPI context pointer
* @cpuindex: CPU number
@@ -842,6 +843,17 @@ void acpigen_write_dsm_end(struct acpi_ctx *ctx);
void acpigen_write_processor(struct acpi_ctx *ctx, uint cpuindex,
u32 pblock_addr, uint pblock_len);

+/**
+ * acpigen_write_processor_device() - Write a Processor device
+ *
+ * Write a device with _HID ACPI0007 identifying a processor.
+ * Replacement for the Processor OpCode.
+ *
+ * @ctx: ACPI context pointer
+ * @cpuindex: CPU number
+ */
+void acpigen_write_processor_device(struct acpi_ctx *ctx, uint cpuindex);
+
/**
* acpigen_write_processor_package() - Write a package containing the processors
*
diff --git a/lib/acpi/acpigen.c b/lib/acpi/acpigen.c
index b95cabb914..427ebc2104 100644
--- a/lib/acpi/acpigen.c
+++ b/lib/acpi/acpigen.c
@@ -361,6 +361,17 @@ void acpigen_write_processor(struct acpi_ctx *ctx, uint cpuindex,
acpigen_emit_byte(ctx, pblock_len);
}

+void acpigen_write_processor_device(struct acpi_ctx *ctx, uint cpuindex)
+{
+ char pscope[16];
+
+ snprintf(pscope, sizeof(pscope), ACPI_CPU_STRING, cpuindex);
+ acpigen_write_device(ctx, pscope);
+ acpigen_write_name_string(ctx, "_HID", "ACPI0007");
+ acpigen_write_name_integer(ctx, "_UID", cpuindex);
+ acpigen_pop_len(ctx); /* Device */
+}
+
void acpigen_write_processor_package(struct acpi_ctx *ctx,
const char *const name,
const uint first_core,
--
2.46.2