Subject: Re: [RFC next-next v2 2/5] net: marvell: prestera: Add PCI interface support

From: Jiri Pirko <[email-masked]>
Date: Mon, 11 May 2020 13:23:46 +0200

Fri, May 01, 2020 at 01:20:49AM CEST, [email-masked] wrote:
>Add PCI interface driver for Prestera Switch ASICs family devices, which
>provides:
>
>    - Firmware loading mechanism
>    - Requests & events handling to/from the firmware
>    - Access to the firmware on the bus level
>
>The firmware has to be loaded each time device is reset. The driver is
>loading it from:
>
>    /lib/firmware/marvell/prestera_fw-v{MAJOR}.{MINOR}.img
>
>The full firmware image version is located within internal header and
>consists of 3 numbers - MAJOR.MINOR.PATCH. Additionally, driver has
>hard-coded minimum supported firmware version which it can work with:
>
>    MAJOR - reflects the support on ABI level between driver and loaded
>            firmware, this number should be the same for driver and loaded
>            firmware.
>
>    MINOR - this is the minimum supported version between driver and the
>            firmware.
>
>    PATCH - indicates only fixes, firmware ABI is not changed.
>
>Firmware image file name contains only MAJOR and MINOR numbers to make
>driver be compatible with any PATCH version.
>
>Signed-off-by: Oleksandr Mazur <[email-masked]>
>Signed-off-by: Vadym Kochan <[email-masked]>
>---
> drivers/net/ethernet/marvell/prestera/Kconfig |  11 +
> .../net/ethernet/marvell/prestera/Makefile    |   2 +
> .../ethernet/marvell/prestera/prestera_pci.c  | 829 ++++++++++++++++++
> 3 files changed, 842 insertions(+)
> create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_pci.c
>
>diff --git a/drivers/net/ethernet/marvell/prestera/Kconfig b/drivers/net/ethernet/marvell/prestera/Kconfig
>index 0eddbc2e5901..087c0abae489 100644
>--- a/drivers/net/ethernet/marvell/prestera/Kconfig
>+++ b/drivers/net/ethernet/marvell/prestera/Kconfig
>@@ -11,3 +11,14 @@ config PRESTERA
> 
> 	  To compile this driver as a module, choose M here: the
> 	  module will be called prestera_sw.
>+
>+config PRESTERA_PCI
>+	tristate "PCI interface driver for Marvell Prestera Switch ASICs family"
>+	depends on PCI && HAS_IOMEM && PRESTERA
>+	default m
>+	---help---
>+	  This is implementation of PCI interface support for Marvell Prestera
>+	  Switch ASICs family.
>+
>+	  To compile this driver as a module, choose M here: the
>+	  module will be called prestera_pci.
>diff --git a/drivers/net/ethernet/marvell/prestera/Makefile b/drivers/net/ethernet/marvell/prestera/Makefile
>index 2c35c498339e..aa99b1348ac4 100644
>--- a/drivers/net/ethernet/marvell/prestera/Makefile
>+++ b/drivers/net/ethernet/marvell/prestera/Makefile
>@@ -2,3 +2,5 @@
> obj-$(CONFIG_PRESTERA)	+= prestera_sw.o
> prestera_sw-objs	:= prestera.o prestera_hw.o prestera_dsa.o \
> 			   prestera_rxtx.o
>+
>+obj-$(CONFIG_PRESTERA_PCI)	+= prestera_pci.o
>diff --git a/drivers/net/ethernet/marvell/prestera/prestera_pci.c b/drivers/net/ethernet/marvell/prestera/prestera_pci.c
>new file mode 100644
>index 000000000000..a3b1bcd4fc73
>--- /dev/null
>+++ b/drivers/net/ethernet/marvell/prestera/prestera_pci.c
>@@ -0,0 +1,829 @@
>+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
>+/* Copyright (c) 2019-2020 Marvell International Ltd. All rights reserved */
>+
>+#include <linux/module.h>
>+#include <linux/kernel.h>
>+#include <linux/device.h>
>+#include <linux/pci.h>
>+#include <linux/circ_buf.h>
>+#include <linux/firmware.h>
>+#include <linux/iopoll.h>
>+
>+#include "prestera.h"
>+
>+#define PRESTERA_MSG_MAX_SIZE 1500
>+
>+#define PRESTERA_SUPP_FW_MAJ_VER	2
>+#define PRESTERA_SUPP_FW_MIN_VER	0
>+
>+#define PRESTERA_FW_PATH \
>+	"marvell/mvsw_prestera_fw-v" __stringify(PRESTERA_SUPP_FW_MAJ_VER) \
>+	"." __stringify(PRESTERA_SUPP_FW_MIN_VER) ".img"
>+
>+#define PRESTERA_FW_HDR_MAGIC	0x351D9D06
>+#define PRESTERA_FW_DL_TIMEOUT	50000
>+#define PRESTERA_FW_BLK_SZ	1024
>+
>+#define PRESTERA_FW_VER_MAJ_MUL 1000000
>+#define PRESTERA_FW_VER_MIN_MUL 1000
>+
>+#define PRESTERA_FW_VER_MAJ(v)	((v) / PRESTERA_FW_VER_MAJ_MUL)
>+
>+#define PRESTERA_FW_VER_MIN(v) \
>+	(((v) - (PRESTERA_FW_VER_MAJ(v) * PRESTERA_FW_VER_MAJ_MUL)) / \
>+			PRESTERA_FW_VER_MIN_MUL)
>+
>+#define PRESTERA_FW_VER_PATCH(v) \
>+	((v) - (PRESTERA_FW_VER_MAJ(v) * PRESTERA_FW_VER_MAJ_MUL) - \
>+			(PRESTERA_FW_VER_MIN(v) * PRESTERA_FW_VER_MIN_MUL))
>+
>+struct prestera_fw_header {
>+	__be32 magic_number;
>+	__be32 version_value;
>+	u8 reserved[8];
>+} __packed;
>+
>+struct prestera_ldr_regs {
>+	u32 ldr_ready;
>+	u32 pad1;
>+
>+	u32 ldr_img_size;
>+	u32 ldr_ctl_flags;
>+
>+	u32 ldr_buf_offs;
>+	u32 ldr_buf_size;
>+
>+	u32 ldr_buf_rd;
>+	u32 pad2;
>+	u32 ldr_buf_wr;
>+
>+	u32 ldr_status;
>+} __packed __aligned(4);
>+
>+#define PRESTERA_LDR_REG_OFFSET(f)	offsetof(struct prestera_ldr_regs, f)
>+
>+#define PRESTERA_LDR_READY_MAGIC	0xf00dfeed
>+
>+#define PRESTERA_LDR_STATUS_IMG_DL	BIT(0)
>+#define PRESTERA_LDR_STATUS_START_FW	BIT(1)
>+#define PRESTERA_LDR_STATUS_INVALID_IMG	BIT(2)
>+#define PRESTERA_LDR_STATUS_NOMEM	BIT(3)
>+
>+#define PRESTERA_LDR_REG_BASE(fw)	((fw)->ldr_regs)
>+#define PRESTERA_LDR_REG_ADDR(fw, reg)	(PRESTERA_LDR_REG_BASE(fw) + (reg))
>+
>+#define prestera_ldr_write(fw, reg, val) \
>+	writel(val, PRESTERA_LDR_REG_ADDR(fw, reg))
>+#define prestera_ldr_read(fw, reg)	\
>+	readl(PRESTERA_LDR_REG_ADDR(fw, reg))
>+
>+/* fw loader registers */
>+#define PRESTERA_LDR_READY_REG		PRESTERA_LDR_REG_OFFSET(ldr_ready)
>+#define PRESTERA_LDR_IMG_SIZE_REG	PRESTERA_LDR_REG_OFFSET(ldr_img_size)
>+#define PRESTERA_LDR_CTL_REG		PRESTERA_LDR_REG_OFFSET(ldr_ctl_flags)
>+#define PRESTERA_LDR_BUF_SIZE_REG	PRESTERA_LDR_REG_OFFSET(ldr_buf_size)
>+#define PRESTERA_LDR_BUF_OFFS_REG	PRESTERA_LDR_REG_OFFSET(ldr_buf_offs)
>+#define PRESTERA_LDR_BUF_RD_REG		PRESTERA_LDR_REG_OFFSET(ldr_buf_rd)
>+#define PRESTERA_LDR_BUF_WR_REG		PRESTERA_LDR_REG_OFFSET(ldr_buf_wr)
>+#define PRESTERA_LDR_STATUS_REG		PRESTERA_LDR_REG_OFFSET(ldr_status)
>+
>+#define PRESTERA_LDR_CTL_DL_START	BIT(0)
>+
>+#define PRESTERA_EVT_QNUM_MAX	4
>+
>+struct prestera_fw_evtq_regs {
>+	u32 rd_idx;
>+	u32 pad1;
>+	u32 wr_idx;
>+	u32 pad2;
>+	u32 offs;
>+	u32 len;
>+};
>+
>+struct prestera_fw_regs {
>+	u32 fw_ready;
>+	u32 pad;
>+	u32 cmd_offs;
>+	u32 cmd_len;
>+	u32 evt_offs;
>+	u32 evt_qnum;
>+
>+	u32 cmd_req_ctl;
>+	u32 cmd_req_len;
>+	u32 cmd_rcv_ctl;
>+	u32 cmd_rcv_len;
>+
>+	u32 fw_status;
>+	u32 rx_status;
>+
>+	struct prestera_fw_evtq_regs evtq_list[PRESTERA_EVT_QNUM_MAX];
>+};
>+
>+#define PRESTERA_FW_REG_OFFSET(f)	offsetof(struct prestera_fw_regs, f)
>+
>+#define PRESTERA_FW_READY_MAGIC	0xcafebabe
>+
>+/* fw registers */
>+#define PRESTERA_FW_READY_REG		PRESTERA_FW_REG_OFFSET(fw_ready)
>+
>+#define PRESTERA_CMD_BUF_OFFS_REG	PRESTERA_FW_REG_OFFSET(cmd_offs)
>+#define PRESTERA_CMD_BUF_LEN_REG	PRESTERA_FW_REG_OFFSET(cmd_len)
>+#define PRESTERA_EVT_BUF_OFFS_REG	PRESTERA_FW_REG_OFFSET(evt_offs)
>+#define PRESTERA_EVT_QNUM_REG		PRESTERA_FW_REG_OFFSET(evt_qnum)
>+
>+#define PRESTERA_CMD_REQ_CTL_REG	PRESTERA_FW_REG_OFFSET(cmd_req_ctl)
>+#define PRESTERA_CMD_REQ_LEN_REG	PRESTERA_FW_REG_OFFSET(cmd_req_len)
>+
>+#define PRESTERA_CMD_RCV_CTL_REG	PRESTERA_FW_REG_OFFSET(cmd_rcv_ctl)
>+#define PRESTERA_CMD_RCV_LEN_REG	PRESTERA_FW_REG_OFFSET(cmd_rcv_len)
>+#define PRESTERA_FW_STATUS_REG		PRESTERA_FW_REG_OFFSET(fw_status)
>+#define PRESTERA_RX_STATUS_REG		PRESTERA_FW_REG_OFFSET(rx_status)
>+
>+/* PRESTERA_CMD_REQ_CTL_REG flags */
>+#define PRESTERA_CMD_F_REQ_SENT		BIT(0)
>+#define PRESTERA_CMD_F_REPL_RCVD	BIT(1)
>+
>+/* PRESTERA_CMD_RCV_CTL_REG flags */
>+#define PRESTERA_CMD_F_REPL_SENT	BIT(0)
>+
>+#define PRESTERA_EVTQ_REG_OFFSET(q, f)			\
>+	(PRESTERA_FW_REG_OFFSET(evtq_list) +		\
>+	 (q) * sizeof(struct prestera_fw_evtq_regs) +	\
>+	 offsetof(struct prestera_fw_evtq_regs, f))
>+
>+#define PRESTERA_EVTQ_RD_IDX_REG(q)	PRESTERA_EVTQ_REG_OFFSET(q, rd_idx)
>+#define PRESTERA_EVTQ_WR_IDX_REG(q)	PRESTERA_EVTQ_REG_OFFSET(q, wr_idx)
>+#define PRESTERA_EVTQ_OFFS_REG(q)	PRESTERA_EVTQ_REG_OFFSET(q, offs)
>+#define PRESTERA_EVTQ_LEN_REG(q)	PRESTERA_EVTQ_REG_OFFSET(q, len)
>+
>+#define PRESTERA_FW_REG_BASE(fw)	((fw)->dev.ctl_regs)
>+#define PRESTERA_FW_REG_ADDR(fw, reg)	PRESTERA_FW_REG_BASE(fw) + (reg)
>+
>+#define prestera_fw_write(fw, reg, val)	\
>+	writel(val, PRESTERA_FW_REG_ADDR(fw, reg))
>+#define prestera_fw_read(fw, reg) \
>+	readl(PRESTERA_FW_REG_ADDR(fw, reg))
>+
>+struct prestera_fw_evtq {
>+	u8 __iomem *addr;
>+	size_t len;
>+};
>+
>+struct prestera_fw {
>+	struct workqueue_struct *wq;
>+	struct prestera_device dev;
>+	struct pci_dev *pci_dev;
>+
>+	u8 __iomem *ldr_regs;
>+

Empty lines not needed here.

>+	u8 __iomem *ldr_ring_buf;
>+	u32 ldr_buf_len;
>+	u32 ldr_wr_idx;
>+
>+	/* serialize access to dev->send_req */

You can put the comment on the same line

>+	struct mutex cmd_mtx;
>+	size_t cmd_mbox_len;
>+	u8 __iomem *cmd_mbox;
>+	struct prestera_fw_evtq evt_queue[PRESTERA_EVT_QNUM_MAX];
>+	u8 evt_qnum;
>+	struct work_struct evt_work;
>+	u8 __iomem *evt_buf;
>+	u8 *evt_msg;
>+};
>+
>+static int prestera_fw_load(struct prestera_fw *fw);
>+
>+static u32 prestera_fw_evtq_len(struct prestera_fw *fw, u8 qid)
>+{
>+	return fw->evt_queue[qid].len;
>+}
>+
>+static u32 prestera_fw_evtq_avail(struct prestera_fw *fw, u8 qid)
>+{
>+	u32 wr_idx = prestera_fw_read(fw, PRESTERA_EVTQ_WR_IDX_REG(qid));
>+	u32 rd_idx = prestera_fw_read(fw, PRESTERA_EVTQ_RD_IDX_REG(qid));
>+
>+	return CIRC_CNT(wr_idx, rd_idx, prestera_fw_evtq_len(fw, qid));
>+}
>+
>+static void prestera_fw_evtq_rd_set(struct prestera_fw *fw,
>+				    u8 qid, u32 idx)
>+{
>+	u32 rd_idx = idx & (prestera_fw_evtq_len(fw, qid) - 1);
>+
>+	prestera_fw_write(fw, PRESTERA_EVTQ_RD_IDX_REG(qid), rd_idx);
>+}
>+
>+static u8 __iomem *prestera_fw_evtq_buf(struct prestera_fw *fw, u8 qid)
>+{
>+	return fw->evt_queue[qid].addr;
>+}
>+
>+static u32 prestera_fw_evtq_read32(struct prestera_fw *fw, u8 qid)
>+{
>+	u32 rd_idx = prestera_fw_read(fw, PRESTERA_EVTQ_RD_IDX_REG(qid));
>+	u32 val;
>+
>+	val = readl(prestera_fw_evtq_buf(fw, qid) + rd_idx);
>+	prestera_fw_evtq_rd_set(fw, qid, rd_idx + 4);
>+	return val;
>+}
>+
>+static ssize_t prestera_fw_evtq_read_buf(struct prestera_fw *fw,
>+					 u8 qid, u8 *buf, size_t len)
>+{
>+	u32 idx = prestera_fw_read(fw, PRESTERA_EVTQ_RD_IDX_REG(qid));
>+	u8 __iomem *evtq_addr = prestera_fw_evtq_buf(fw, qid);
>+	u32 *buf32 = (u32 *)buf;
>+	int i;
>+
>+	for (i = 0; i < len / 4; buf32++, i++) {
>+		*buf32 = readl_relaxed(evtq_addr + idx);
>+		idx = (idx + 4) & (prestera_fw_evtq_len(fw, qid) - 1);
>+	}
>+
>+	prestera_fw_evtq_rd_set(fw, qid, idx);
>+
>+	return i;
>+}
>+
>+static u8 prestera_fw_evtq_pick(struct prestera_fw *fw)
>+{
>+	int qid;
>+
>+	for (qid = 0; qid < fw->evt_qnum; qid++) {
>+		if (prestera_fw_evtq_avail(fw, qid) >= 4)
>+			return qid;
>+	}
>+
>+	return PRESTERA_EVT_QNUM_MAX;
>+}
>+
>+static void prestera_fw_evt_work_fn(struct work_struct *work)
>+{
>+	struct prestera_fw *fw;
>+	u8 *msg;
>+	u8 qid;
>+
>+	fw = container_of(work, struct prestera_fw, evt_work);
>+	msg = fw->evt_msg;
>+
>+	while ((qid = prestera_fw_evtq_pick(fw)) < PRESTERA_EVT_QNUM_MAX) {
>+		u32 idx;
>+		u32 len;
>+
>+		len = prestera_fw_evtq_read32(fw, qid);
>+		idx = prestera_fw_read(fw, PRESTERA_EVTQ_RD_IDX_REG(qid));
>+
>+		WARN_ON(prestera_fw_evtq_avail(fw, qid) < len);
>+
>+		if (WARN_ON(len > PRESTERA_MSG_MAX_SIZE)) {
>+			prestera_fw_evtq_rd_set(fw, qid, idx + len);
>+			continue;
>+		}
>+
>+		prestera_fw_evtq_read_buf(fw, qid, msg, len);
>+
>+		if (fw->dev.recv_msg)
>+			fw->dev.recv_msg(&fw->dev, msg, len);
>+	}
>+}
>+
>+static int prestera_fw_wait_reg32(struct prestera_fw *fw, u32 reg, u32 cmp,
>+				  unsigned int waitms)
>+{
>+	u8 __iomem *addr = PRESTERA_FW_REG_ADDR(fw, reg);
>+	u32 val = 0;
>+
>+	return readl_poll_timeout(addr, val, cmp == val, 1000 * 10, waitms * 1000);
>+}
>+
>+static void prestera_pci_copy_to(u8 __iomem *dst, u8 *src, size_t len)
>+{
>+	u32 __iomem *dst32 = (u32 __iomem *)dst;
>+	u32 *src32 = (u32 *)src;
>+	int i;
>+
>+	for (i = 0; i < (len / 4); dst32++, src32++, i++)
>+		writel_relaxed(*src32, dst32);
>+}
>+
>+static void prestera_pci_copy_from(u8 *dst, u8 __iomem *src, size_t len)
>+{
>+	u32 *dst32 = (u32 *)dst;
>+	u32 __iomem *src32 = (u32 __iomem *)src;
>+	int i;
>+
>+	for (i = 0; i < (len / 4); dst32++, src32++, i++)
>+		*dst32 = readl_relaxed(src32);
>+}
>+
>+static int prestera_fw_cmd_send(struct prestera_fw *fw,
>+				u8 *in_msg, size_t in_size,
>+				u8 *out_msg, size_t out_size,
>+				unsigned int waitms)
>+{
>+	u32 ret_size = 0;
>+	int err = 0;
>+
>+	if (!waitms)
>+		waitms = 30000;
>+
>+	if (ALIGN(in_size, 4) > fw->cmd_mbox_len)
>+		return -EMSGSIZE;
>+
>+	/* wait for finish previous reply from FW */
>+	err = prestera_fw_wait_reg32(fw, PRESTERA_CMD_RCV_CTL_REG, 0, 30);
>+	if (err) {
>+		dev_err(fw->dev.dev, "finish reply from FW is timed out\n");
>+		return err;
>+	}
>+
>+	prestera_fw_write(fw, PRESTERA_CMD_REQ_LEN_REG, in_size);
>+	prestera_pci_copy_to(fw->cmd_mbox, in_msg, in_size);
>+
>+	prestera_fw_write(fw, PRESTERA_CMD_REQ_CTL_REG, PRESTERA_CMD_F_REQ_SENT);
>+
>+	/* wait for reply from FW */
>+	err = prestera_fw_wait_reg32(fw, PRESTERA_CMD_RCV_CTL_REG,
>+				     PRESTERA_CMD_F_REPL_SENT, waitms);
>+	if (err) {
>+		dev_err(fw->dev.dev, "reply from FW is timed out\n");
>+		goto cmd_exit;
>+	}
>+
>+	ret_size = prestera_fw_read(fw, PRESTERA_CMD_RCV_LEN_REG);
>+	if (ret_size > out_size) {
>+		dev_err(fw->dev.dev, "ret_size (%u) > out_len(%zu)\n",
>+			ret_size, out_size);
>+		err = -EMSGSIZE;
>+		goto cmd_exit;
>+	}
>+
>+	prestera_pci_copy_from(out_msg, fw->cmd_mbox + in_size, ret_size);
>+
>+cmd_exit:
>+	prestera_fw_write(fw, PRESTERA_CMD_REQ_CTL_REG, PRESTERA_CMD_F_REPL_RCVD);
>+	return err;
>+}
>+
>+static int prestera_fw_send_req(struct prestera_device *dev,
>+				u8 *in_msg, size_t in_size, u8 *out_msg,
>+				size_t out_size, unsigned int waitms)
>+{
>+	struct prestera_fw *fw;
>+	ssize_t ret;
>+
>+	fw = container_of(dev, struct prestera_fw, dev);
>+
>+	mutex_lock(&fw->cmd_mtx);
>+	ret = prestera_fw_cmd_send(fw, in_msg, in_size, out_msg, out_size, waitms);
>+	mutex_unlock(&fw->cmd_mtx);
>+
>+	return ret;
>+}
>+
>+static int prestera_fw_init(struct prestera_fw *fw)
>+{
>+	u8 __iomem *base;
>+	int err;
>+	u8 qid;
>+
>+	fw->dev.send_req = prestera_fw_send_req;
>+	fw->ldr_regs = fw->dev.ctl_regs;
>+
>+	err = prestera_fw_load(fw);
>+	if (err && err != -ETIMEDOUT)
>+		return err;
>+
>+	err = prestera_fw_wait_reg32(fw, PRESTERA_FW_READY_REG,
>+				     PRESTERA_FW_READY_MAGIC, 20000);
>+	if (err) {
>+		dev_err(fw->dev.dev, "FW is failed to start\n");
>+		return err;
>+	}
>+
>+	base = fw->dev.ctl_regs;
>+
>+	fw->cmd_mbox = base + prestera_fw_read(fw, PRESTERA_CMD_BUF_OFFS_REG);
>+	fw->cmd_mbox_len = prestera_fw_read(fw, PRESTERA_CMD_BUF_LEN_REG);
>+	mutex_init(&fw->cmd_mtx);
>+
>+	fw->evt_buf = base + prestera_fw_read(fw, PRESTERA_EVT_BUF_OFFS_REG);
>+	fw->evt_qnum = prestera_fw_read(fw, PRESTERA_EVT_QNUM_REG);
>+	fw->evt_msg = kmalloc(PRESTERA_MSG_MAX_SIZE, GFP_KERNEL);
>+	if (!fw->evt_msg)
>+		return -ENOMEM;
>+
>+	for (qid = 0; qid < fw->evt_qnum; qid++) {
>+		u32 offs = prestera_fw_read(fw, PRESTERA_EVTQ_OFFS_REG(qid));
>+		struct prestera_fw_evtq *evtq = &fw->evt_queue[qid];
>+
>+		evtq->len = prestera_fw_read(fw, PRESTERA_EVTQ_LEN_REG(qid));
>+		evtq->addr = fw->evt_buf + offs;
>+	}
>+
>+	return 0;
>+}
>+
>+static void prestera_fw_uninit(struct prestera_fw *fw)
>+{
>+	kfree(fw->evt_msg);
>+}
>+
>+static irqreturn_t prestera_pci_irq_handler(int irq, void *dev_id)
>+{
>+	struct prestera_fw *fw = dev_id;
>+
>+	if (prestera_fw_read(fw, PRESTERA_RX_STATUS_REG)) {
>+		prestera_fw_write(fw, PRESTERA_RX_STATUS_REG, 0);
>+
>+		if (fw->dev.recv_pkt)
>+			fw->dev.recv_pkt(&fw->dev);
>+	}
>+
>+	queue_work(fw->wq, &fw->evt_work);
>+
>+	return IRQ_HANDLED;
>+}
>+
>+static int prestera_ldr_wait_reg32(struct prestera_fw *fw,
>+				   u32 reg, u32 cmp, unsigned int waitms)
>+{
>+	u8 __iomem *addr = PRESTERA_LDR_REG_ADDR(fw, reg);
>+	u32 val = 0;
>+
>+	return readl_poll_timeout(addr, val, cmp == val, 1000 * 10, waitms * 1000);
>+}
>+
>+static u32 prestera_ldr_wait_buf(struct prestera_fw *fw, size_t len)
>+{
>+	u8 __iomem *addr = PRESTERA_LDR_REG_ADDR(fw, PRESTERA_LDR_BUF_RD_REG);
>+	u32 buf_len = fw->ldr_buf_len;
>+	u32 wr_idx = fw->ldr_wr_idx;
>+	u32 rd_idx = 0;
>+	int err;
>+
>+	err = readl_poll_timeout(addr, rd_idx,
>+				 CIRC_SPACE(wr_idx, rd_idx, buf_len) >= len,
>+				 1000, 100 * 1000);
>+	if (err)
>+		return err;
>+
>+	return 0;
>+}
>+
>+static int prestera_ldr_wait_dl_finish(struct prestera_fw *fw)
>+{
>+	u8 __iomem *addr = PRESTERA_LDR_REG_ADDR(fw, PRESTERA_LDR_STATUS_REG);
>+	unsigned long mask = ~(PRESTERA_LDR_STATUS_IMG_DL);
>+	unsigned int waitus = PRESTERA_FW_DL_TIMEOUT * 1000;

reverse christmas tree.

>+	u32 val = 0;
>+	int err;
>+
>+	err = readl_poll_timeout(addr, val, val & mask, 1000 * 10, waitus);
>+	if (err) {
>+		dev_err(fw->dev.dev, "Timeout to load FW img [state=%d]",
>+			prestera_ldr_read(fw, PRESTERA_LDR_STATUS_REG));
>+		return err;
>+	}
>+
>+	return 0;
>+}
>+
>+static void prestera_ldr_wr_idx_move(struct prestera_fw *fw, unsigned int n)
>+{
>+	fw->ldr_wr_idx = (fw->ldr_wr_idx + (n)) & (fw->ldr_buf_len - 1);
>+}
>+
>+static void prestera_ldr_wr_idx_commit(struct prestera_fw *fw)
>+{
>+	prestera_ldr_write(fw, PRESTERA_LDR_BUF_WR_REG, fw->ldr_wr_idx);
>+}
>+
>+static u8 __iomem *prestera_ldr_wr_ptr(struct prestera_fw *fw)
>+{
>+	return fw->ldr_ring_buf + fw->ldr_wr_idx;
>+}
>+
>+static int prestera_ldr_send(struct prestera_fw *fw, const u8 *buf, size_t len)
>+{
>+	int err;
>+	int i;
>+
>+	err = prestera_ldr_wait_buf(fw, len);
>+	if (err) {
>+		dev_err(fw->dev.dev, "failed wait for sending firmware\n");
>+		return err;
>+	}
>+
>+	for (i = 0; i < len; i += 4) {
>+		writel_relaxed(*(u32 *)(buf + i), prestera_ldr_wr_ptr(fw));
>+		prestera_ldr_wr_idx_move(fw, 4);
>+	}
>+
>+	prestera_ldr_wr_idx_commit(fw);
>+	return 0;
>+}
>+
>+static int prestera_ldr_fw_send(struct prestera_fw *fw,
>+				const char *img, u32 fw_size)
>+{
>+	u32 status;
>+	u32 pos;
>+	int err;
>+
>+	err = prestera_ldr_wait_reg32(fw, PRESTERA_LDR_STATUS_REG,
>+				      PRESTERA_LDR_STATUS_IMG_DL, 5 * 1000);
>+	if (err) {
>+		dev_err(fw->dev.dev, "Loader is not ready to load image\n");
>+		return err;
>+	}
>+
>+	for (pos = 0; pos < fw_size; pos += PRESTERA_FW_BLK_SZ) {
>+		if (pos + PRESTERA_FW_BLK_SZ > fw_size)
>+			break;
>+
>+		err = prestera_ldr_send(fw, img + pos, PRESTERA_FW_BLK_SZ);
>+		if (err)
>+			return err;
>+	}
>+
>+	if (pos < fw_size) {
>+		err = prestera_ldr_send(fw, img + pos, fw_size - pos);
>+		if (err)
>+			return err;
>+	}
>+
>+	err = prestera_ldr_wait_dl_finish(fw);
>+	if (err)
>+		return err;
>+
>+	status = prestera_ldr_read(fw, PRESTERA_LDR_STATUS_REG);
>+	if (status != PRESTERA_LDR_STATUS_START_FW) {
>+		switch (status) {
>+		case PRESTERA_LDR_STATUS_INVALID_IMG:
>+			dev_err(fw->dev.dev, "FW img has bad crc\n");

s/crc/CRC/

>+			return -EINVAL;
>+		case PRESTERA_LDR_STATUS_NOMEM:
>+			dev_err(fw->dev.dev, "Loader has no enough mem\n");
>+			return -ENOMEM;
>+		default:
>+			break;
>+		}
>+	}
>+
>+	return 0;
>+}
>+
>+static void prestera_fw_rev_parse(const struct prestera_fw_header *hdr,
>+				  struct prestera_fw_rev *rev)
>+{
>+	u32 version = be32_to_cpu(hdr->version_value);
>+
>+	rev->maj = PRESTERA_FW_VER_MAJ(version);
>+	rev->min = PRESTERA_FW_VER_MIN(version);
>+	rev->sub = PRESTERA_FW_VER_PATCH(version);
>+}
>+
>+static int prestera_fw_rev_check(struct prestera_fw *fw)
>+{
>+	struct prestera_fw_rev *rev = &fw->dev.fw_rev;
>+
>+	if (rev->maj == PRESTERA_SUPP_FW_MAJ_VER &&
>+	    rev->min >= PRESTERA_SUPP_FW_MIN_VER) {
>+		return 0;
>+	}
>+
>+	dev_err(fw->dev.dev, "Driver supports FW version only '%u.%u.x'",
>+		PRESTERA_SUPP_FW_MAJ_VER, PRESTERA_SUPP_FW_MIN_VER);
>+
>+	return -EINVAL;
>+}
>+
>+static int prestera_fw_hdr_parse(struct prestera_fw *fw,
>+				 const struct firmware *img)
>+{
>+	struct prestera_fw_header *hdr = (struct prestera_fw_header *)img->data;
>+	struct prestera_fw_rev *rev = &fw->dev.fw_rev;
>+	u32 magic;
>+
>+	magic = be32_to_cpu(hdr->magic_number);
>+	if (magic != PRESTERA_FW_HDR_MAGIC) {
>+		dev_err(fw->dev.dev, "FW img type is invalid");

Type? Isn't it "magic"?

>+		return -EINVAL;
>+	}
>+
>+	prestera_fw_rev_parse(hdr, rev);
>+
>+	dev_info(fw->dev.dev, "FW version '%u.%u.%u'\n",
>+		 rev->maj, rev->min, rev->sub);
>+
>+	return prestera_fw_rev_check(fw);
>+}
>+
>+static int prestera_fw_load(struct prestera_fw *fw)
>+{
>+	size_t hlen = sizeof(struct prestera_fw_header);
>+	const struct firmware *f;
>+	int err;
>+
>+	err = prestera_ldr_wait_reg32(fw, PRESTERA_LDR_READY_REG,
>+				      PRESTERA_LDR_READY_MAGIC, 5 * 1000);
>+	if (err) {
>+		dev_err(fw->dev.dev, "waiting for FW loader is timed out");
>+		return err;
>+	}
>+
>+	fw->ldr_ring_buf = fw->ldr_regs +
>+		prestera_ldr_read(fw, PRESTERA_LDR_BUF_OFFS_REG);
>+
>+	fw->ldr_buf_len =
>+		prestera_ldr_read(fw, PRESTERA_LDR_BUF_SIZE_REG);
>+
>+	fw->ldr_wr_idx = 0;
>+
>+	err = request_firmware_direct(&f, PRESTERA_FW_PATH, &fw->pci_dev->dev);
>+	if (err) {
>+		dev_err(fw->dev.dev, "failed to request firmware file\n");
>+		return err;
>+	}
>+
>+	if (!IS_ALIGNED(f->size, 4)) {
>+		dev_err(fw->dev.dev, "FW image file is not aligned");
>+		release_firmware(f);
>+		return -EINVAL;
>+	}
>+
>+	err = prestera_fw_hdr_parse(fw, f);
>+	if (err) {
>+		dev_err(fw->dev.dev, "FW image header is invalid\n");
>+		release_firmware(f);
>+		return err;
>+	}
>+
>+	prestera_ldr_write(fw, PRESTERA_LDR_IMG_SIZE_REG, f->size - hlen);
>+	prestera_ldr_write(fw, PRESTERA_LDR_CTL_REG, PRESTERA_LDR_CTL_DL_START);
>+
>+	dev_info(fw->dev.dev, "Loading prestera FW image ...");
>+
>+	err = prestera_ldr_fw_send(fw, f->data + hlen, f->size - hlen);
>+
>+	release_firmware(f);
>+	return err;
>+}
>+
>+static int prestera_pci_probe(struct pci_dev *pdev,
>+			      const struct pci_device_id *id)
>+{
>+	const char *driver_name = pdev->driver->name;
>+	struct prestera_fw *fw;
>+	u8 __iomem *ctl_addr, *pp_addr;
>+	int err;
>+
>+	err = pci_enable_device(pdev);
>+	if (err) {
>+		dev_err(&pdev->dev, "pci_enable_device failed\n");
>+		goto err_pci_enable_device;
>+	}
>+
>+	err = pci_request_regions(pdev, driver_name);
>+	if (err) {
>+		dev_err(&pdev->dev, "pci_request_regions failed\n");
>+		goto err_pci_request_regions;
>+	}
>+
>+	if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(30))) {
>+		dev_err(&pdev->dev, "fail to set DMA mask\n");
>+		goto err_dma_mask;
>+	}
>+
>+	ctl_addr = pci_ioremap_bar(pdev, 2);
>+	if (!ctl_addr) {
>+		dev_err(&pdev->dev, "ioremap failed\n");
>+		err = -EIO;
>+		goto err_ctl_ioremap;
>+	}
>+
>+	pp_addr = pci_ioremap_bar(pdev, 4);
>+	if (!pp_addr) {
>+		dev_err(&pdev->dev, "ioremap failed\n");
>+		err = -EIO;
>+		goto err_pp_ioremap;
>+	}
>+
>+	pci_set_master(pdev);
>+
>+	fw = kzalloc(sizeof(*fw), GFP_KERNEL);
>+	if (!fw) {
>+		err = -ENOMEM;
>+		goto err_pci_dev_alloc;
>+	}
>+
>+	fw->pci_dev = pdev;
>+	fw->dev.dev = &pdev->dev;
>+	fw->dev.ctl_regs = ctl_addr;
>+	fw->dev.pp_regs = pp_addr;
>+
>+	fw->wq = alloc_workqueue("prestera_fw_wq", WQ_HIGHPRI, 1);
>+	if (!fw->wq)
>+		goto err_wq_alloc;
>+
>+	INIT_WORK(&fw->evt_work, prestera_fw_evt_work_fn);
>+
>+	err = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
>+	if (err < 0) {
>+		dev_err(&pdev->dev, "MSI IRQ init failed\n");
>+		goto err_irq_alloc;
>+	}
>+
>+	err = request_irq(pci_irq_vector(pdev, 0), prestera_pci_irq_handler,
>+			  0, driver_name, fw);
>+	if (err) {
>+		dev_err(&pdev->dev, "fail to request IRQ\n");
>+		goto err_request_irq;
>+	}
>+
>+	pci_set_drvdata(pdev, fw);
>+
>+	err = prestera_fw_init(fw);
>+	if (err)
>+		goto err_prestera_fw_init;
>+
>+	dev_info(fw->dev.dev, "Switch FW is ready\n");
>+
>+	err = prestera_device_register(&fw->dev);
>+	if (err)
>+		goto err_prestera_dev_register;
>+
>+	return 0;
>+
>+err_prestera_dev_register:
>+	prestera_fw_uninit(fw);
>+err_prestera_fw_init:
>+	free_irq(pci_irq_vector(pdev, 0), fw);
>+err_request_irq:
>+	pci_free_irq_vectors(pdev);
>+err_irq_alloc:
>+	destroy_workqueue(fw->wq);
>+err_wq_alloc:
>+	kfree(fw);
>+err_pci_dev_alloc:
>+	iounmap(pp_addr);
>+err_pp_ioremap:
>+	iounmap(ctl_addr);
>+err_ctl_ioremap:
>+err_dma_mask:
>+	pci_release_regions(pdev);
>+err_pci_request_regions:
>+	pci_disable_device(pdev);
>+err_pci_enable_device:
>+	return err;
>+}
>+
>+static void prestera_pci_remove(struct pci_dev *pdev)
>+{
>+	struct prestera_fw *fw = pci_get_drvdata(pdev);
>+
>+	free_irq(pci_irq_vector(pdev, 0), fw);
>+	pci_free_irq_vectors(pdev);
>+	prestera_device_unregister(&fw->dev);
>+	flush_workqueue(fw->wq);
>+	destroy_workqueue(fw->wq);
>+	prestera_fw_uninit(fw);
>+	iounmap(fw->dev.pp_regs);
>+	iounmap(fw->dev.ctl_regs);
>+	pci_release_regions(pdev);
>+	pci_disable_device(pdev);
>+	kfree(fw);
>+}
>+
>+static const struct pci_device_id prestera_pci_devices[] = {
>+	{ PCI_DEVICE(PCI_VENDOR_ID_MARVELL, 0xC804) },
>+	{ }
>+};
>+MODULE_DEVICE_TABLE(pci, prestera_pci_devices);
>+
>+static struct pci_driver prestera_pci_driver = {
>+	.name     = "Prestera AC3x 98DX326x",

This looks very specific. Is is related to 0xC804?

>+	.id_table = prestera_pci_devices,
>+	.probe    = prestera_pci_probe,
>+	.remove   = prestera_pci_remove,
>+};
>+
>+static int __init prestera_pci_init(void)
>+{
>+	return pci_register_driver(&prestera_pci_driver);
>+}
>+
>+static void __exit prestera_pci_exit(void)
>+{
>+	pci_unregister_driver(&prestera_pci_driver);
>+}
>+
>+module_init(prestera_pci_init);
>+module_exit(prestera_pci_exit);
>+
>+MODULE_AUTHOR("Marvell Semi.");

Author is you, not a company.

>+MODULE_LICENSE("Dual BSD/GPL");
>+MODULE_DESCRIPTION("Marvell Prestera switch PCI interface");
>-- 
>2.17.1
>