mfd: intel-peci-client: Add Intel PECI client driver

This commit adds Intel PECI client driver.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>

1 files changed, 119 insertions, 0 deletions

diff --git a/include/linux/mfd/intel-peci-client.h b/include/linux/mfd/intel-peci-client.h
new file mode 100644
index 000000000000..46a8f006ad0e
--- /dev/null
+++ b/include/linux/mfd/intel-peci-client.h
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018-2019 Intel Corporation */
+
+#ifndef __LINUX_MFD_INTEL_PECI_CLIENT_H
+#define __LINUX_MFD_INTEL_PECI_CLIENT_H
+
+#include <linux/peci.h>
+
+#if IS_ENABLED(CONFIG_X86)
+#include <asm/intel-family.h>
+#else
+/*
+ * Architectures other than x86 cannot include the header file so define these
+ * at here. These are needed for detecting type of client x86 CPUs behind a PECI
+ * connection.
+ */
+#define INTEL_FAM6_HASWELL_X		0x3F
+#define INTEL_FAM6_BROADWELL_X		0x4F
+#define INTEL_FAM6_SKYLAKE_X		0x55
+#define INTEL_FAM6_SKYLAKE_XD		0x56
+#endif
+
+#define INTEL_FAM6             6 /* P6 (Pentium Pro and later) */
+
+#define CORE_MASK_BITS_ON_HSX  18
+#define CHAN_RANK_MAX_ON_HSX   8  /* Max number of channel ranks on Haswell */
+#define DIMM_IDX_MAX_ON_HSX    3  /* Max DIMM index per channel on Haswell */
+
+#define CORE_MASK_BITS_ON_BDX  24
+#define CHAN_RANK_MAX_ON_BDX   4  /* Max number of channel ranks on Broadwell */
+#define DIMM_IDX_MAX_ON_BDX    3  /* Max DIMM index per channel on Broadwell */
+
+#define CORE_MASK_BITS_ON_SKX  28
+#define CHAN_RANK_MAX_ON_SKX   6  /* Max number of channel ranks on Skylake */
+#define DIMM_IDX_MAX_ON_SKX    2  /* Max DIMM index per channel on Skylake */
+
+#define CORE_MASK_BITS_ON_SKXD 28
+#define CHAN_RANK_MAX_ON_SKXD  2  /* Max number of channel ranks on Skylake D */
+#define DIMM_IDX_MAX_ON_SKXD   2  /* Max DIMM index per channel on Skylake D */
+
+#define CORE_MASK_BITS_MAX     CORE_MASK_BITS_ON_SKX
+#define CHAN_RANK_MAX          CHAN_RANK_MAX_ON_HSX
+#define DIMM_IDX_MAX           DIMM_IDX_MAX_ON_HSX
+#define DIMM_NUMS_MAX          (CHAN_RANK_MAX * DIMM_IDX_MAX)
+
+/**
+ * struct cpu_gen_info - CPU generation specific information
+ * @family: CPU family ID
+ * @model: CPU model
+ * @core_mask_bits: number of resolved core bits
+ * @chan_rank_max: max number of channel ranks
+ * @dimm_idx_max: max number of DIMM indices
+ *
+ * CPU generation specific information to identify maximum number of cores and
+ * DIMM slots.
+ */
+struct cpu_gen_info {
+	u16  family;
+	u8   model;
+	uint core_mask_bits;
+	uint chan_rank_max;
+	uint dimm_idx_max;
+};
+
+/**
+ * struct peci_client_manager - PECI client manager information
+ * @client; pointer to the PECI client
+ * @name: PECI client manager name
+ * @gen_info: CPU generation info of the detected CPU
+ *
+ * PECI client manager information for managing PECI sideband functions on a CPU
+ * client.
+ */
+struct peci_client_manager {
+	struct peci_client *client;
+	char name[PECI_NAME_SIZE];
+	const struct cpu_gen_info *gen_info;
+};
+
+/**
+ * peci_client_read_package_config - read from the Package Configuration Space
+ * @priv: driver private data structure
+ * @index: encoding index for the requested service
+ * @param: parameter to specify the exact data being requested
+ * @data: data buffer to store the result
+ * Context: can sleep
+ *
+ * A generic PECI command that provides read access to the
+ * "Package Configuration Space" that is maintained by the PCU, including
+ * various power and thermal management functions. Typical PCS read services
+ * supported by the processor may include access to temperature data, energy
+ * status, run time information, DIMM temperatures and so on.
+ *
+ * Return: zero on success, else a negative error code.
+ */
+static inline int
+peci_client_read_package_config(struct peci_client_manager *priv,
+				u8 index, u16 param, u8 *data)
+{
+	struct peci_rd_pkg_cfg_msg msg;
+	int ret;
+
+	msg.addr = priv->client->addr;
+	msg.index = index;
+	msg.param = param;
+	msg.rx_len = 4;
+
+	ret = peci_command(priv->client->adapter, PECI_CMD_RD_PKG_CFG, &msg);
+	if (msg.cc != PECI_DEV_CC_SUCCESS)
+		ret = -EAGAIN;
+	if (ret)
+		return ret;
+
+	memcpy(data, msg.pkg_config, 4);
+
+	return 0;
+}
+
+#endif /* __LINUX_MFD_INTEL_PECI_CLIENT_H */