virtio: vdpa: new SolidNET DPU driver.

This commit includes:
 1) The driver to manage the controlplane over vDPA bus.
 2) A HW monitor device to read health values from the DPU.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230110165638.123745-4-alvaro.karsz@solid-run.com>
Message-Id: <20230209075128.78915-1-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

MAINTAINERS

@@ -22061,6 +22061,10 @@ IFCVF VIRTIO DATA PATH ACCELERATOR
 R:	Zhu Lingshan <lingshan.zhu@intel.com>
 F:	drivers/vdpa/ifcvf/
+SNET DPU VIRTIO DATA PATH ACCELERATOR
+R:	Alvaro Karsz <alvaro.karsz@solid-run.com>
+F:	drivers/vdpa/solidrun/
+
 VIRTIO BALLOON
 M:	"Michael S. Tsirkin" <mst@redhat.com>
 M:	David Hildenbrand <david@redhat.com>

drivers/vdpa/Kconfig

@@ -98,4 +98,22 @@ config ALIBABA_ENI_VDPA
 	  VDPA driver for Alibaba ENI (Elastic Network Interface) which is built upon
 	  virtio 0.9.5 specification.
 
+ config SNET_VDPA
+	tristate "SolidRun's vDPA driver for SolidNET"
+	depends on PCI_MSI && PCI_IOV && (HWMON || HWMON=n)
+
+	# This driver MAY create a HWMON device.
+	# Depending on (HWMON || HWMON=n) ensures that:
+	# If HWMON=n the driver can be compiled either as a module or built-in.
+	# If HWMON=y the driver can be compiled either as a module or built-in.
+	# If HWMON=m the driver is forced to be compiled as a module.
+	# By doing so, IS_ENABLED can be used instead of IS_REACHABLE
+
+	help
+	  vDPA driver for SolidNET DPU.
+	  With this driver, the VirtIO dataplane can be
+	  offloaded to a SolidNET DPU.
+	  This driver includes a HW monitor device that
+	  reads health values from the DPU.
+
 endif # VDPA

drivers/vdpa/Makefile

@@ -6,3 +6,4 @@ obj-$(CONFIG_IFCVF)    += ifcvf/
 obj-$(CONFIG_MLX5_VDPA) += mlx5/
 obj-$(CONFIG_VP_VDPA)    += virtio_pci/
 obj-$(CONFIG_ALIBABA_ENI_VDPA) += alibaba/
+obj-$(CONFIG_SNET_VDPA) += solidrun/

drivers/vdpa/solidrun/Makefile

+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_SNET_VDPA) += snet_vdpa.o
+snet_vdpa-$(CONFIG_SNET_VDPA) += snet_main.o
+ifdef CONFIG_HWMON
+snet_vdpa-$(CONFIG_SNET_VDPA) += snet_hwmon.o
+endif

drivers/vdpa/solidrun/snet_hwmon.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SolidRun DPU driver for control plane
+ *
+ * Copyright (C) 2022 SolidRun
+ *
+ * Author: Alvaro Karsz <alvaro.karsz@solid-run.com>
+ *
+ */
+#include <linux/hwmon.h>
+
+#include "snet_vdpa.h"
+
+/* Monitor offsets */
+#define SNET_MON_TMP0_IN_OFF      0x00
+#define SNET_MON_TMP0_MAX_OFF     0x08
+#define SNET_MON_TMP0_CRIT_OFF    0x10
+#define SNET_MON_TMP1_IN_OFF      0x18
+#define SNET_MON_TMP1_CRIT_OFF    0x20
+#define SNET_MON_CURR_IN_OFF      0x28
+#define SNET_MON_CURR_MAX_OFF     0x30
+#define SNET_MON_CURR_CRIT_OFF    0x38
+#define SNET_MON_PWR_IN_OFF       0x40
+#define SNET_MON_VOLT_IN_OFF      0x48
+#define SNET_MON_VOLT_CRIT_OFF    0x50
+#define SNET_MON_VOLT_LCRIT_OFF   0x58
+
+static void snet_hwmon_read_reg(struct psnet *psnet, u32 reg, long *out)
+{
+	*out = psnet_read64(psnet, psnet->cfg.hwmon_off + reg);
+}
+
+static umode_t snet_howmon_is_visible(const void *data,
+				      enum hwmon_sensor_types type,
+				      u32 attr, int channel)
+{
+	return 0444;
+}
+
+static int snet_howmon_read(struct device *dev, enum hwmon_sensor_types type,
+			    u32 attr, int channel, long *val)
+{
+	struct psnet *psnet = dev_get_drvdata(dev);
+	int ret = 0;
+
+	switch (type) {
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_lcrit:
+			snet_hwmon_read_reg(psnet, SNET_MON_VOLT_LCRIT_OFF, val);
+			break;
+		case hwmon_in_crit:
+			snet_hwmon_read_reg(psnet, SNET_MON_VOLT_CRIT_OFF, val);
+			break;
+		case hwmon_in_input:
+			snet_hwmon_read_reg(psnet, SNET_MON_VOLT_IN_OFF, val);
+			break;
+		default:
+			ret = -EOPNOTSUPP;
+			break;
+		}
+		break;
+
+	case hwmon_power:
+		switch (attr) {
+		case hwmon_power_input:
+			snet_hwmon_read_reg(psnet, SNET_MON_PWR_IN_OFF, val);
+			break;
+
+		default:
+			ret = -EOPNOTSUPP;
+			break;
+		}
+		break;
+
+	case hwmon_curr:
+		switch (attr) {
+		case hwmon_curr_input:
+			snet_hwmon_read_reg(psnet, SNET_MON_CURR_IN_OFF, val);
+			break;
+		case hwmon_curr_max:
+			snet_hwmon_read_reg(psnet, SNET_MON_CURR_MAX_OFF, val);
+			break;
+		case hwmon_curr_crit:
+			snet_hwmon_read_reg(psnet, SNET_MON_CURR_CRIT_OFF, val);
+			break;
+		default:
+			ret = -EOPNOTSUPP;
+			break;
+		}
+		break;
+
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+			if (channel == 0)
+				snet_hwmon_read_reg(psnet, SNET_MON_TMP0_IN_OFF, val);
+			else
+				snet_hwmon_read_reg(psnet, SNET_MON_TMP1_IN_OFF, val);
+			break;
+		case hwmon_temp_max:
+			if (channel == 0)
+				snet_hwmon_read_reg(psnet, SNET_MON_TMP0_MAX_OFF, val);
+			else
+				ret = -EOPNOTSUPP;
+			break;
+		case hwmon_temp_crit:
+			if (channel == 0)
+				snet_hwmon_read_reg(psnet, SNET_MON_TMP0_CRIT_OFF, val);
+			else
+				snet_hwmon_read_reg(psnet, SNET_MON_TMP1_CRIT_OFF, val);
+			break;
+
+		default:
+			ret = -EOPNOTSUPP;
+			break;
+		}
+		break;
+
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+	return ret;
+}
+
+static int snet_hwmon_read_string(struct device *dev,
+				  enum hwmon_sensor_types type, u32 attr,
+				  int channel, const char **str)
+{
+	int ret = 0;
+
+	switch (type) {
+	case hwmon_in:
+		*str = "main_vin";
+		break;
+	case hwmon_power:
+		*str = "soc_pin";
+		break;
+	case hwmon_curr:
+		*str = "soc_iin";
+		break;
+	case hwmon_temp:
+		if (channel == 0)
+			*str = "power_stage_temp";
+		else
+			*str = "ic_junction_temp";
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+	return ret;
+}
+
+static const struct hwmon_ops snet_hwmon_ops = {
+	.is_visible = snet_howmon_is_visible,
+	.read = snet_howmon_read,
+	.read_string = snet_hwmon_read_string
+};
+
+static const struct hwmon_channel_info *snet_hwmon_info[] = {
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_LABEL),
+	HWMON_CHANNEL_INFO(power, HWMON_P_INPUT | HWMON_P_LABEL),
+	HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT | HWMON_C_MAX | HWMON_C_CRIT | HWMON_C_LABEL),
+	HWMON_CHANNEL_INFO(in, HWMON_I_INPUT | HWMON_I_CRIT | HWMON_I_LCRIT | HWMON_I_LABEL),
+			   NULL
+};
+
+static const struct hwmon_chip_info snet_hwmono_info = {
+	.ops = &snet_hwmon_ops,
+	.info = snet_hwmon_info,
+};
+
+/* Create an HW monitor device */
+void psnet_create_hwmon(struct pci_dev *pdev)
+{
+	struct device *hwmon;
+	struct psnet *psnet = pci_get_drvdata(pdev);
+
+	snprintf(psnet->hwmon_name, SNET_NAME_SIZE, "snet_%s", pci_name(pdev));
+	hwmon = devm_hwmon_device_register_with_info(&pdev->dev, psnet->hwmon_name, psnet,
+						     &snet_hwmono_info, NULL);
+	/* The monitor is not mandatory, Just alert user in case of an error */
+	if (IS_ERR(hwmon))
+		SNET_WARN(pdev, "Failed to create SNET hwmon, error %ld\n", PTR_ERR(hwmon));
+}

drivers/vdpa/solidrun/snet_vdpa.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * SolidRun DPU driver for control plane
+ *
+ * Copyright (C) 2022 SolidRun
+ *
+ * Author: Alvaro Karsz <alvaro.karsz@solid-run.com>
+ *
+ */
+#ifndef _SNET_VDPA_H_
+#define _SNET_VDPA_H_
+
+#include <linux/vdpa.h>
+#include <linux/pci.h>
+
+#define SNET_NAME_SIZE 256
+
+#define SNET_ERR(pdev, fmt, ...) dev_err(&(pdev)->dev, "%s"fmt, "snet_vdpa: ", ##__VA_ARGS__)
+#define SNET_WARN(pdev, fmt, ...) dev_warn(&(pdev)->dev, "%s"fmt, "snet_vdpa: ", ##__VA_ARGS__)
+#define SNET_INFO(pdev, fmt, ...) dev_info(&(pdev)->dev, "%s"fmt, "snet_vdpa: ", ##__VA_ARGS__)
+#define SNET_DBG(pdev, fmt, ...) dev_dbg(&(pdev)->dev, "%s"fmt, "snet_vdpa: ", ##__VA_ARGS__)
+#define SNET_HAS_FEATURE(s, f) ((s)->negotiated_features & BIT_ULL(f))
+/* VQ struct */
+struct snet_vq {
+	/* VQ callback */
+	struct vdpa_callback cb;
+	/* desc base address */
+	u64 desc_area;
+	/* device base address */
+	u64 device_area;
+	/* driver base address */
+	u64 driver_area;
+	/* Queue size */
+	u32 num;
+	/* Serial ID for VQ */
+	u32 sid;
+	/* is ready flag */
+	bool ready;
+	/* IRQ number */
+	u32 irq;
+	/* IRQ index, DPU uses this to parse data from MSI-X table */
+	u32 irq_idx;
+	/* IRQ name */
+	char irq_name[SNET_NAME_SIZE];
+	/* pointer to mapped PCI BAR register used by this VQ to kick */
+	void __iomem *kick_ptr;
+};
+
+struct snet {
+	/* vdpa device */
+	struct vdpa_device vdpa;
+	/* Config callback */
+	struct vdpa_callback cb;
+	/* array of virqueues */
+	struct snet_vq **vqs;
+	/* Used features */
+	u64 negotiated_features;
+	/* Device serial ID */
+	u32 sid;
+	/* device status */
+	u8 status;
+	/* boolean indicating if snet config was passed to the device */
+	bool dpu_ready;
+	/* IRQ number */
+	u32 cfg_irq;
+	/* IRQ index, DPU uses this to parse data from MSI-X table */
+	u32 cfg_irq_idx;
+	/* IRQ name */
+	char cfg_irq_name[SNET_NAME_SIZE];
+	/* BAR to access the VF */
+	void __iomem *bar;
+	/* PCI device */
+	struct pci_dev *pdev;
+	/* Pointer to snet pdev parent device */
+	struct psnet *psnet;
+	/* Pointer to snet config device */
+	struct snet_dev_cfg *cfg;
+};
+
+struct snet_dev_cfg {
+	/* Device ID following VirtIO spec. */
+	u32 virtio_id;
+	/* Number of VQs for this device */
+	u32 vq_num;
+	/* Size of every VQ */
+	u32 vq_size;
+	/* Virtual Function id */
+	u32 vfid;
+	/* Device features, following VirtIO spec */
+	u64 features;
+	/* Reserved for future usage */
+	u32 rsvd[6];
+	/* VirtIO device specific config size */
+	u32 cfg_size;
+	/* VirtIO device specific config address */
+	void __iomem *virtio_cfg;
+} __packed;
+
+struct snet_cfg {
+	/* Magic key */
+	u32 key;
+	/* Size of total config in bytes */
+	u32 cfg_size;
+	/* Config version */
+	u32 cfg_ver;
+	/* Number of Virtual Functions to create */
+	u32 vf_num;
+	/* BAR to use for the VFs */
+	u32 vf_bar;
+	/* Where should we write the SNET's config */
+	u32 host_cfg_off;
+	/* Max. allowed size for a SNET's config */
+	u32 max_size_host_cfg;
+	/* VirtIO config offset in BAR */
+	u32 virtio_cfg_off;
+	/* Offset in PCI BAR for VQ kicks */
+	u32 kick_off;
+	/* Offset in PCI BAR for HW monitoring */
+	u32 hwmon_off;
+	/* Offset in PCI BAR for SNET messages */
+	u32 msg_off;
+	/* Config general flags - enum snet_cfg_flags */
+	u32 flags;
+	/* Reserved for future usage */
+	u32 rsvd[6];
+	/* Number of snet devices */
+	u32 devices_num;
+	/* The actual devices */
+	struct snet_dev_cfg **devs;
+} __packed;
+
+/* SolidNET PCIe device, one device per PCIe physical function */
+struct psnet {
+	/* PCI BARs */
+	void __iomem *bars[PCI_STD_NUM_BARS];
+	/* Negotiated config version */
+	u32 negotiated_cfg_ver;
+	/* Next IRQ index to use in case when the IRQs are allocated from this device */
+	u32 next_irq;
+	/* BAR number used to communicate with the device */
+	u8 barno;
+	/* spinlock to protect data that can be changed by SNET devices */
+	spinlock_t lock;
+	/* Pointer to the device's config read from BAR */
+	struct snet_cfg cfg;
+	/* Name of monitor device */
+	char hwmon_name[SNET_NAME_SIZE];
+};
+
+enum snet_cfg_flags {
+	/* Create a HWMON device */
+	SNET_CFG_FLAG_HWMON = BIT(0),
+	/* USE IRQs from the physical function */
+	SNET_CFG_FLAG_IRQ_PF = BIT(1),
+};
+
+#define PSNET_FLAG_ON(p, f)	((p)->cfg.flags & (f))
+
+static inline u32 psnet_read32(struct psnet *psnet, u32 off)
+{
+	return ioread32(psnet->bars[psnet->barno] + off);
+}
+
+static inline u32 snet_read32(struct snet *snet, u32 off)
+{
+	return ioread32(snet->bar + off);
+}
+
+static inline void snet_write32(struct snet *snet, u32 off, u32 val)
+{
+	iowrite32(val, snet->bar + off);
+}
+
+static inline u64 psnet_read64(struct psnet *psnet, u32 off)
+{
+	u64 val;
+	/* 64bits are written in 2 halves, low part first */
+	val = (u64)psnet_read32(psnet, off);
+	val |= ((u64)psnet_read32(psnet, off + 4) << 32);
+	return val;
+}
+
+static inline void snet_write64(struct snet *snet, u32 off, u64 val)
+{
+	/* The DPU expects a 64bit integer in 2 halves, the low part first */
+	snet_write32(snet, off, (u32)val);
+	snet_write32(snet, off + 4, (u32)(val >> 32));
+}
+
+#if IS_ENABLED(CONFIG_HWMON)
+void psnet_create_hwmon(struct pci_dev *pdev);
+#endif
+
+#endif //_SNET_VDPA_H_