Change in coreboot[master]: drivers/intel/dptf: Add OEM variables support

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/50127 )

Change subject: drivers/intel/dptf: Add OEM variables support
......................................................................

drivers/intel/dptf: Add OEM variables support

This adds OEM variables feature under DPTF as per BWG doc #541817. Using
this, platform vendors can expose an array of OEM-specific values as OEM
variables to be used in determining DPTF policy. These are obtained via
the ODVP method, and then simply exposed under sysfs. In addition, these
gets updated when a notification is received or when the DPTF policy is
changed by userspace.

BRANCH=None
BUG=b:187253038
TEST=Built and tested on dedede board

Change-Id: Iaf3cf7b40e9a441b41d0c659d76895a58669c2fb
Signed-off-by: Sumeet R Pawnikar 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50127
Tested-by: build bot (Jenkins) 
Reviewed-by: Tim Wawrzynczak 
Reviewed-by: Karthik Ramasubramanian 
---
M src/drivers/intel/dptf/chip.h
M src/drivers/intel/dptf/dptf.c
2 files changed, 56 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Karthik Ramasubramanian: Looks good to me, approved
  Tim Wawrzynczak: Looks good to me, approved

diff --git a/src/drivers/intel/dptf/chip.h b/src/drivers/intel/dptf/chip.h
index 5408d9e..59b1e25 100644
--- a/src/drivers/intel/dptf/chip.h
+++ b/src/drivers/intel/dptf/chip.h
@@ -12,6 +12,9 @@
    {.source = DPTF_##src, .temp = (tmp), .type = DPTF_CRITICAL_##typ}
 #define TEMP_PCT(t, p) {.temp = (t), .fan_pct = (p)}

+/* Total number of OEM variables */
+#define DPTF_OEM_VARIABLE_COUNT		6
+
 struct drivers_intel_dptf_config {
    struct {
    	struct dptf_active_policy active[DPTF_MAX_ACTIVE_POLICIES];
@@ -51,6 +54,11 @@
    		const char *desc;
    	} tsr[DPTF_MAX_TSR];
    } options;
+
+	/* OEM variables */
+	struct {
+		uint32_t oem_variables[DPTF_OEM_VARIABLE_COUNT];
+	} oem_data;
 };

#endif /* _DRIVERS_INTEL_DPTF_CHIP_H_ */
diff --git a/src/drivers/intel/dptf/dptf.c b/src/drivers/intel/dptf/dptf.c
index 7d19df5..f9b4dee 100644
--- a/src/drivers/intel/dptf/dptf.c
+++ b/src/drivers/intel/dptf/dptf.c
@@ -117,6 +117,53 @@
    acpigen_pop_len(); /* Device */
 }

+/* _SB.DPTF */
+static void write_oem_variables(const struct drivers_intel_dptf_config *config)
+{
+	int i;
+
+	acpigen_write_name("ODVX");
+	acpigen_write_package(DPTF_OEM_VARIABLE_COUNT);
+	for (i = 0; i < DPTF_OEM_VARIABLE_COUNT; i++)
+		acpigen_write_dword(config->oem_data.oem_variables[i]);
+	acpigen_write_package_end();
+
+	/*
+	 * Method (ODUP, 2)
+	 * Arg0 = Index of ODVX to update
+	 * Arg1 = Value to place in ODVX[Arg0]
+	 */
+	acpigen_write_method_serialized("ODUP", 2);
+	/* ODVX[Arg0] = Arg1 */
+	acpigen_write_store();
+	acpigen_emit_byte(ARG1_OP);
+	acpigen_emit_byte(INDEX_OP);
+	acpigen_emit_namestring("ODVX");
+	acpigen_emit_byte(ARG0_OP);
+	acpigen_emit_byte(ZERO_OP); /* Ignore Index() Destination */
+	acpigen_write_method_end();
+
+	/*
+	 * Method (ODGT, 1)
+	 * Arg0 = Index of ODVX to get
+	 */
+	acpigen_write_method_serialized("ODGT", 1);
+	 /* Return (ODVX[Arg0]) */
+	acpigen_emit_byte(RETURN_OP);
+	acpigen_emit_byte(DEREF_OP);
+	acpigen_emit_byte(INDEX_OP);
+	acpigen_emit_namestring("ODVX");
+	acpigen_emit_byte(ARG0_OP);
+	acpigen_emit_byte(ZERO_OP); /* Ignore Index() Destination */
+	acpigen_write_method_end();
+
+	/* Method (ODVP) { Return (ODVX) } */
+	acpigen_write_method_serialized("ODVP", 0);
+	acpigen_emit_byte(RETURN_OP);
+	acpigen_emit_namestring("ODVX");
+	acpigen_write_method_end();
+}
+
 /* _SB.DPTF.xxxx */
 static void write_generic_devices(const struct drivers_intel_dptf_config *config,
    			  const struct dptf_platform_info *platform_info)
@@ -169,6 +216,7 @@
    write_tcpu(parent, config);
    write_open_dptf_device(dev, platform_info);
    write_fan(config, platform_info);
+	write_oem_variables(config);
    write_generic_devices(config, platform_info);

acpigen_pop_len(); /* DPTF Device (write_open_dptf_device) */