Re: [net-next 2/6] net: marvell: prestera: Add PCI interface support

From: Ido Schimmel
Date: Wed Jun 03 2020 - 05:59:50 EST


On Thu, May 28, 2020 at 06:12:41PM +0300, Vadym Kochan wrote:
> drivers/net/ethernet/marvell/prestera/Kconfig | 11 +
> .../net/ethernet/marvell/prestera/Makefile | 2 +
> .../ethernet/marvell/prestera/prestera_pci.c | 825 ++++++++++++++++++
> 3 files changed, 838 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 76b68613ea7a..0848edb272a5 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.
> +
> +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 610d75032b78..2146714eab21 100644
> --- a/drivers/net/ethernet/marvell/prestera/Makefile
> +++ b/drivers/net/ethernet/marvell/prestera/Makefile
> @@ -2,3 +2,5 @@
> obj-$(CONFIG_PRESTERA) += prestera.o
> prestera-objs := prestera_main.o prestera_hw.o prestera_dsa.o \
> prestera_rxtx.o
> +
> +obj-$(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..0ec07732b12e
> --- /dev/null
> +++ b/drivers/net/ethernet/marvell/prestera/prestera_pci.c
> @@ -0,0 +1,825 @@
> +// 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 \
> + "mrvl/prestera/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_DL_TIMEOUT_MS (50 * 1000)

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

The convention in the networking subsystem is to use reverse xmas tree
for local variables:

---
--
-

> + 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;

Use a define instead of a magic number

> +
> + 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);

Likewise

> + if (err) {
> + dev_err(fw->dev.dev, "FW is failed to start\n");

FW failed to start

> + 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 directly

> +
> + 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 int waitus = PRESTERA_FW_DL_TIMEOUT * 1000;
> + unsigned long mask = ~(PRESTERA_LDR_STATUS_IMG_DL);
> + 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");
> + 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;
> + u16 maj_supp = PRESTERA_SUPP_FW_MAJ_VER;
> + u16 min_supp = PRESTERA_SUPP_FW_MIN_VER;
> +
> + if (rev->maj == maj_supp && rev->min >= min_supp)
> + 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 hdr magic is invalid");
> + 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;

Reverse xmas tree

> + int err;
> +
> + err = pci_enable_device(pdev);
> + if (err) {
> + dev_err(&pdev->dev, "pci_enable_device failed\n");
> + goto err_pci_enable_device;

Why the goto? You have nothing to rollback.

> + }
> +
> + 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);

I believe you don't need to call flush_workqueue() before
destroy_workqueue()

> + prestera_fw_uninit(fw);
> + iounmap(fw->dev.pp_regs);
> + iounmap(fw->dev.ctl_regs);
> + pci_release_regions(pdev);
> + pci_disable_device(pdev);
> + kfree(fw);

Not symmetric with the error path above

> +}
> +
> +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 DX",
> + .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_LICENSE("Dual BSD/GPL");
> +MODULE_DESCRIPTION("Marvell Prestera switch PCI interface");
> --
> 2.17.1
>