Re: [PATCH v4 3/4] remoteproc: imx_dsp_rproc: Add remoteproc driver for DSP on i.MX

Shengjiu Wang
2021-09-15T03:09:17Z

On Wed, Sep 15, 2021 at 1:56 AM Mathieu Poirier
<mathieu.poirier@linaro.org> wrote:
>
> On Wed, Sep 08, 2021 at 05:10:54PM +0800, Shengjiu Wang wrote:
> > Provide a basic driver to control DSP processor found on NXP i.MX8QM,
> > i.MX8QXP, i.MX8MP and i.MX8ULP.
> >
> > Currently it is able to resolve addresses between DSP and main CPU,
> > start and stop the processor, suspend and resume.
> >
> > The communication between DSP and main CPU is based on mailbox, there
> > are three mailbox channels (tx, rx, rxdb).
> >
> > This driver was tested on NXP i.MX8QM, i.MX8QXP, i.MX8MP and i.MX8ULP.
> >
> > Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> > ---
> > drivers/remoteproc/Kconfig | 11 +
> > drivers/remoteproc/Makefile | 1 +
> > drivers/remoteproc/imx_dsp_rproc.c | 1178 ++++++++++++++++++++++++++++
> > 3 files changed, 1190 insertions(+)
> > create mode 100644 drivers/remoteproc/imx_dsp_rproc.c
> >
> > diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> > index 9a6eedc3994a..890a14e6f3f9 100644
> > --- a/drivers/remoteproc/Kconfig
> > +++ b/drivers/remoteproc/Kconfig
> > @@ -34,6 +34,17 @@ config IMX_REMOTEPROC
> >
> > It's safe to say N here.
> >
> > +config IMX_DSP_REMOTEPROC
> > + tristate "i.MX DSP remoteproc support"
> > + depends on ARCH_MXC
> > + depends on HAVE_ARM_SMCCC
> > + select MAILBOX
> > + help
> > + Say y here to support iMX's DSP remote processors via the remote
> > + processor framework.
> > +
> > + It's safe to say N here.
> > +
> > config INGENIC_VPU_RPROC
> > tristate "Ingenic JZ47xx VPU remoteproc support"
> > depends on MIPS || COMPILE_TEST
> > diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> > index bb26c9e4ef9c..37d5cb1c04bf 100644
> > --- a/drivers/remoteproc/Makefile
> > +++ b/drivers/remoteproc/Makefile
> > @@ -12,6 +12,7 @@ remoteproc-y += remoteproc_virtio.o
> > remoteproc-y += remoteproc_elf_loader.o
> > obj-$(CONFIG_REMOTEPROC_CDEV) += remoteproc_cdev.o
> > obj-$(CONFIG_IMX_REMOTEPROC) += imx_rproc.o
> > +obj-$(CONFIG_IMX_DSP_REMOTEPROC) += imx_dsp_rproc.o
> > obj-$(CONFIG_INGENIC_VPU_RPROC) += ingenic_rproc.o
> > obj-$(CONFIG_MTK_SCP) += mtk_scp.o mtk_scp_ipi.o
> > obj-$(CONFIG_OMAP_REMOTEPROC) += omap_remoteproc.o
> > diff --git a/drivers/remoteproc/imx_dsp_rproc.c b/drivers/remoteproc/imx_dsp_rproc.c
> > new file mode 100644
> > index 000000000000..a12e306b06bd
> > --- /dev/null
> > +++ b/drivers/remoteproc/imx_dsp_rproc.c
> > @@ -0,0 +1,1178 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +// Copyright 2021 NXP
> > +
> > +#include <dt-bindings/firmware/imx/rsrc.h>
> > +#include <linux/arm-smccc.h>
> > +#include <linux/clk.h>
> > +#include <linux/err.h>
> > +#include <linux/firmware.h>
> > +#include <linux/firmware/imx/sci.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/kernel.h>
> > +#include <linux/mailbox_client.h>
> > +#include <linux/mfd/syscon.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of_reserved_mem.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/pm_domain.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/regmap.h>
> > +#include <linux/remoteproc.h>
> > +#include <linux/slab.h>
> > +#include <linux/workqueue.h>
> > +
> > +#include "imx_rproc.h"
> > +#include "remoteproc_elf_helpers.h"
> > +#include "remoteproc_internal.h"
> > +
> > +#define DSP_RPROC_CLK_MAX 5
> > +
> > +#define REMOTE_IS_READY BIT(0)
> > +#define REMOTE_READY_WAIT_MAX_RETRIES 500
> > +
> > +/* att flags */
> > +/* DSP own area */
> > +#define ATT_OWN BIT(31)
> > +/* DSP instruction area */
> > +#define ATT_IRAM BIT(30)
> > +
> > +/* Definitions for i.MX8MP */
> > +/* DAP registers */
> > +#define IMX8M_DAP_DEBUG 0x28800000
> > +#define IMX8M_DAP_DEBUG_SIZE (64 * 1024)
> > +#define IMX8M_DAP_PWRCTL (0x4000 + 0x3020)
> > +#define IMX8M_PWRCTL_CORERESET BIT(16)
> > +
> > +/* DSP audio mix registers */
> > +#define IMX8M_AudioDSP_REG0 0x100
> > +#define IMX8M_AudioDSP_REG1 0x104
> > +#define IMX8M_AudioDSP_REG2 0x108
> > +#define IMX8M_AudioDSP_REG3 0x10c
> > +
> > +#define IMX8M_AudioDSP_REG2_RUNSTALL BIT(5)
> > +#define IMX8M_AudioDSP_REG2_PWAITMODE BIT(1)
> > +
> > +/* Definitions for i.MX8ULP */
> > +#define IMX8ULP_SIM_LPAV_REG_SYSCTRL0 0x8
> > +#define IMX8ULP_SYSCTRL0_DSP_DBG_RST BIT(25)
> > +#define IMX8ULP_SYSCTRL0_DSP_PLAT_CLK_EN BIT(19)
> > +#define IMX8ULP_SYSCTRL0_DSP_PBCLK_EN BIT(18)
> > +#define IMX8ULP_SYSCTRL0_DSP_CLK_EN BIT(17)
> > +#define IMX8ULP_SYSCTRL0_DSP_RST BIT(16)
> > +#define IMX8ULP_SYSCTRL0_DSP_OCD_HALT BIT(14)
> > +#define IMX8ULP_SYSCTRL0_DSP_STALL BIT(13)
> > +
> > +#define IMX8ULP_SIP_HIFI_XRDC 0xc200000e
> > +
> > +/*
> > + * enum - Predefined Mailbox Messages
> > + *
> > + * @RP_MBOX_SUSPEND_SYSTEM: system suspend request for the remote processor
> > + *
> > + * @RP_MBOX_SUSPEND_ACK: successful response from remote processor for a
> > + * suspend request
> > + *
> > + * @RP_MBOX_RESUME_SYSTEM: system resume request for the remote processor
> > + *
> > + * @RP_MBOX_RESUME_ACK: successful response from remote processor for a
> > + * resume request
> > + */
> > +enum imx_dsp_rp_mbox_messages {
> > + RP_MBOX_SUSPEND_SYSTEM = 0xFF11,
> > + RP_MBOX_SUSPEND_ACK = 0xFF12,
> > + RP_MBOX_RESUME_SYSTEM = 0xFF13,
> > + RP_MBOX_RESUME_ACK = 0xFF14,
> > +};
> > +
> > +/**
> > + * struct imx_dsp_rproc - DSP remote processor state
> > + * @regmap: regmap handler
> > + * @rproc: rproc handler
> > + * @dsp_dcfg: device configuration pointer
> > + * @clks: clocks needed by this device
> > + * @cl: mailbox client to request the mailbox channel
> > + * @cl_rxdb: mailbox client to request the mailbox channel for doorbell
> > + * @tx_ch: mailbox tx channel handle
> > + * @rx_ch: mailbox rx channel handle
> > + * @rxdb_ch: mailbox rx doorbell channel handle
> > + * @pd_dev: power domain device
> > + * @pd_dev_link: power domain device link
> > + * @ipc_handle: System Control Unit ipc handle
> > + * @rproc_work: work for processing virtio interrupts
> > + * @workqueue: workqueue for processing virtio interrupts
> > + * @pm_comp: completion primitive to sync for suspend response
> > + * @num_domains: power domain number
> > + * @flags: control flags
> > + */
> > +struct imx_dsp_rproc {
> > + struct regmap *regmap;
> > + struct rproc *rproc;
> > + const struct imx_dsp_rproc_dcfg *dsp_dcfg;
> > + struct clk_bulk_data clks[DSP_RPROC_CLK_MAX];
> > + struct mbox_client cl;
> > + struct mbox_client cl_rxdb;
> > + struct mbox_chan *tx_ch;
> > + struct mbox_chan *rx_ch;
> > + struct mbox_chan *rxdb_ch;
> > + struct device **pd_dev;
> > + struct device_link **pd_dev_link;
> > + struct imx_sc_ipc *ipc_handle;
> > + struct work_struct rproc_work;
> > + struct workqueue_struct *workqueue;
> > + struct completion pm_comp;
> > + int num_domains;
> > + u32 flags;
> > +};
> > +
> > +/**
> > + * struct imx_dsp_rproc_dcfg - DSP remote processor configuration
> > + * @dcfg: imx_rproc_dcfg handler
> > + * @reset: reset callback function
> > + */
> > +struct imx_dsp_rproc_dcfg {
> > + const struct imx_rproc_dcfg *dcfg;
> > + int (*reset)(struct imx_dsp_rproc *priv);
> > +};
> > +
> > +static const struct imx_rproc_att imx_dsp_rproc_att_imx8qm[] = {
> > + /* dev addr , sys addr , size , flags */
> > + { 0x596e8000, 0x556e8000, 0x00008000, ATT_OWN },
> > + { 0x596f0000, 0x556f0000, 0x00008000, ATT_OWN },
> > + { 0x596f8000, 0x556f8000, 0x00000800, ATT_OWN | ATT_IRAM},
> > + { 0x55700000, 0x55700000, 0x00070000, ATT_OWN },
> > + /* DDR (Data) */
> > + { 0x80000000, 0x80000000, 0x60000000, 0},
> > +};
> > +
> > +static const struct imx_rproc_att imx_dsp_rproc_att_imx8qxp[] = {
> > + /* dev addr , sys addr , size , flags */
> > + { 0x596e8000, 0x596e8000, 0x00008000, ATT_OWN },
> > + { 0x596f0000, 0x596f0000, 0x00008000, ATT_OWN },
> > + { 0x596f8000, 0x596f8000, 0x00000800, ATT_OWN | ATT_IRAM},
> > + { 0x59700000, 0x59700000, 0x00070000, ATT_OWN },
> > + /* DDR (Data) */
> > + { 0x80000000, 0x80000000, 0x60000000, 0},
> > +};
> > +
> > +static const struct imx_rproc_att imx_dsp_rproc_att_imx8mp[] = {
> > + /* dev addr , sys addr , size , flags */
> > + { 0x3b6e8000, 0x3b6e8000, 0x00008000, ATT_OWN },
> > + { 0x3b6f0000, 0x3b6f0000, 0x00008000, ATT_OWN },
> > + { 0x3b6f8000, 0x3b6f8000, 0x00000800, ATT_OWN | ATT_IRAM},
> > + { 0x3b700000, 0x3b700000, 0x00040000, ATT_OWN },
> > + /* DDR (Data) */
> > + { 0x40000000, 0x40000000, 0x80000000, 0},
> > +};
> > +
> > +static const struct imx_rproc_att imx_dsp_rproc_att_imx8ulp[] = {
> > + /* dev addr , sys addr , size , flags */
> > + { 0x21170000, 0x21170000, 0x00010000, ATT_OWN | ATT_IRAM},
> > + { 0x21180000, 0x21180000, 0x00010000, ATT_OWN },
> > + /* DDR (Data) */
> > + { 0x0c000000, 0x80000000, 0x10000000, 0},
> > + { 0x30000000, 0x90000000, 0x10000000, 0},
> > +};
> > +
> > +/* Reset function for DSP on i.MX8MP */
> > +static int imx8mp_dsp_reset(struct imx_dsp_rproc *priv)
> > +{
> > + void __iomem *dap = ioremap_wc(IMX8M_DAP_DEBUG, IMX8M_DAP_DEBUG_SIZE);
> > + int pwrctl;
> > +
> > + /* Put DSP into reset and stall */
> > + pwrctl = readl(dap + IMX8M_DAP_PWRCTL);
> > + pwrctl |= IMX8M_PWRCTL_CORERESET;
> > + writel(pwrctl, dap + IMX8M_DAP_PWRCTL);
> > +
> > + /* Keep reset asserted for 10 cycles */
> > + usleep_range(1, 2);
> > +
> > + regmap_update_bits(priv->regmap, IMX8M_AudioDSP_REG2,
> > + IMX8M_AudioDSP_REG2_RUNSTALL,
> > + IMX8M_AudioDSP_REG2_RUNSTALL);
> > +
> > + /* Take the DSP out of reset and keep stalled for FW loading */
> > + pwrctl = readl(dap + IMX8M_DAP_PWRCTL);
> > + pwrctl &= ~IMX8M_PWRCTL_CORERESET;
> > + writel(pwrctl, dap + IMX8M_DAP_PWRCTL);
> > +
> > + iounmap(dap);
> > + return 0;
> > +}
> > +
> > +/* Reset function for DSP on i.MX8ULP */
> > +static int imx8ulp_dsp_reset(struct imx_dsp_rproc *priv)
> > +{
> > + struct arm_smccc_res res;
> > +
> > + /* Put DSP into reset and stall */
> > + regmap_update_bits(priv->regmap, IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
> > + IMX8ULP_SYSCTRL0_DSP_RST, IMX8ULP_SYSCTRL0_DSP_RST);
> > + regmap_update_bits(priv->regmap, IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
> > + IMX8ULP_SYSCTRL0_DSP_STALL,
> > + IMX8ULP_SYSCTRL0_DSP_STALL);
> > +
> > + /* Configure resources of DSP through TFA */
> > + arm_smccc_smc(IMX8ULP_SIP_HIFI_XRDC, 0, 0, 0, 0, 0, 0, 0, &res);
> > +
> > + /* Take the DSP out of reset and keep stalled for FW loading */
> > + regmap_update_bits(priv->regmap, IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
> > + IMX8ULP_SYSCTRL0_DSP_RST, 0);
> > + regmap_update_bits(priv->regmap, IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
> > + IMX8ULP_SYSCTRL0_DSP_DBG_RST, 0);
> > +
> > + return 0;
> > +}
> > +
> > +/* Specific configuration for i.MX8MP */
> > +static const struct imx_rproc_dcfg dsp_rproc_cfg_imx8mp = {
> > + .src_reg = IMX8M_AudioDSP_REG2,
> > + .src_mask = IMX8M_AudioDSP_REG2_RUNSTALL,
> > + .src_start = 0,
> > + .src_stop = IMX8M_AudioDSP_REG2_RUNSTALL,
> > + .att = imx_dsp_rproc_att_imx8mp,
> > + .att_size = ARRAY_SIZE(imx_dsp_rproc_att_imx8mp),
> > + .method = IMX_RPROC_MMIO,
> > +};
> > +
> > +static const struct imx_dsp_rproc_dcfg imx_dsp_rproc_cfg_imx8mp = {
> > + .dcfg = &dsp_rproc_cfg_imx8mp,
> > + .reset = imx8mp_dsp_reset,
> > +};
> > +
> > +/* Specific configuration for i.MX8ULP */
> > +static const struct imx_rproc_dcfg dsp_rproc_cfg_imx8ulp = {
> > + .src_reg = IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
> > + .src_mask = IMX8ULP_SYSCTRL0_DSP_STALL,
> > + .src_start = 0,
> > + .src_stop = IMX8ULP_SYSCTRL0_DSP_STALL,
> > + .att = imx_dsp_rproc_att_imx8ulp,
> > + .att_size = ARRAY_SIZE(imx_dsp_rproc_att_imx8ulp),
> > + .method = IMX_RPROC_MMIO,
> > +};
> > +
> > +static const struct imx_dsp_rproc_dcfg imx_dsp_rproc_cfg_imx8ulp = {
> > + .dcfg = &dsp_rproc_cfg_imx8ulp,
> > + .reset = imx8ulp_dsp_reset,
> > +};
> > +
> > +/* Specific configuration for i.MX8QXP */
> > +static const struct imx_rproc_dcfg dsp_rproc_cfg_imx8qxp = {
> > + .att = imx_dsp_rproc_att_imx8qxp,
> > + .att_size = ARRAY_SIZE(imx_dsp_rproc_att_imx8qxp),
> > + .method = IMX_RPROC_SCU_API,
> > +};
> > +
> > +static const struct imx_dsp_rproc_dcfg imx_dsp_rproc_cfg_imx8qxp = {
> > + .dcfg = &dsp_rproc_cfg_imx8qxp,
> > +};
> > +
> > +/* Specific configuration for i.MX8QM */
> > +static const struct imx_rproc_dcfg dsp_rproc_cfg_imx8qm = {
> > + .att = imx_dsp_rproc_att_imx8qm,
> > + .att_size = ARRAY_SIZE(imx_dsp_rproc_att_imx8qm),
> > + .method = IMX_RPROC_SCU_API,
> > +};
> > +
> > +static const struct imx_dsp_rproc_dcfg imx_dsp_rproc_cfg_imx8qm = {
> > + .dcfg = &dsp_rproc_cfg_imx8qm,
> > +};
> > +
> > +static int imx_dsp_rproc_ready(struct rproc *rproc)
> > +{
> > + struct imx_dsp_rproc *priv = rproc->priv;
> > + int i;
> > +
> > + if (!priv->rxdb_ch)
> > + return 0;
> > +
> > + for (i = 0; i < REMOTE_READY_WAIT_MAX_RETRIES; i++) {
> > + if (priv->flags & REMOTE_IS_READY)
> > + return 0;
> > + usleep_range(100, 200);
> > + }
> > +
> > + return -ETIMEDOUT;
> > +}
> > +
> > +/*
> > + * Start function for rproc_ops
> > + *
> > + * There is a handshake for start procedure: when DSP starts, it
> > + * will send a doorbell message to this driver, then the
> > + * REMOTE_IS_READY flags is set, then driver will kick
> > + * a message to DSP.
> > + */
> > +static int imx_dsp_rproc_start(struct rproc *rproc)
> > +{
> > + struct imx_dsp_rproc *priv = rproc->priv;
> > + const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
> > + const struct imx_rproc_dcfg *dcfg = dsp_dcfg->dcfg;
> > + struct device *dev = rproc->dev.parent;
> > + int ret;
> > +
> > + switch (dcfg->method) {
> > + case IMX_RPROC_MMIO:
> > + ret = regmap_update_bits(priv->regmap,
> > + dcfg->src_reg,
> > + dcfg->src_mask,
> > + dcfg->src_start);
> > + break;
> > + case IMX_RPROC_SCU_API:
> > + ret = imx_sc_pm_cpu_start(priv->ipc_handle,
> > + IMX_SC_R_DSP,
> > + true,
> > + rproc->bootaddr);
> > + break;
> > + default:
> > + return -EOPNOTSUPP;
> > + }
> > +
> > + if (ret)
> > + dev_err(dev, "Failed to enable remote core!\n");
> > + else
> > + ret = imx_dsp_rproc_ready(rproc);
> > +
> > + return ret;
> > +}
> > +
> > +/*
> > + * Stop function for rproc_ops
> > + * It clears the REMOTE_IS_READY flags
> > + */
> > +static int imx_dsp_rproc_stop(struct rproc *rproc)
> > +{
> > + struct imx_dsp_rproc *priv = rproc->priv;
> > + const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
> > + const struct imx_rproc_dcfg *dcfg = dsp_dcfg->dcfg;
> > + struct device *dev = rproc->dev.parent;
> > + int ret = 0;
> > +
> > + if (rproc->state == RPROC_CRASHED) {
> > + priv->flags &= ~REMOTE_IS_READY;
> > + return 0;
> > + }
> > +
> > + switch (dcfg->method) {
> > + case IMX_RPROC_MMIO:
> > + ret = regmap_update_bits(priv->regmap, dcfg->src_reg, dcfg->src_mask,
> > + dcfg->src_stop);
> > + break;
> > + case IMX_RPROC_SCU_API:
> > + ret = imx_sc_pm_cpu_start(priv->ipc_handle,
> > + IMX_SC_R_DSP,
> > + false,
> > + rproc->bootaddr);
> > + break;
> > + default:
> > + return -EOPNOTSUPP;
> > + }
> > +
> > + if (ret)
> > + dev_err(dev, "Failed to stop remote core\n");
> > + else
> > + priv->flags &= ~REMOTE_IS_READY;
> > +
> > + return ret;
> > +}
> > +
> > +/**
> > + * imx_dsp_rproc_sys_to_da() - internal memory translation helper
> > + * @priv: private data pointer
> > + * @sys: system address (DDR address)
> > + * @len: length of the memory buffer
> > + * @da: device address to translate
> > + *
> > + * Convert system address (DDR address) to device address (DSP)
> > + * for there may be memory remap for device.
> > + */
> > +static int imx_dsp_rproc_sys_to_da(struct imx_dsp_rproc *priv, u64 sys,
> > + size_t len, u64 *da)
> > +{
> > + const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
> > + const struct imx_rproc_dcfg *dcfg = dsp_dcfg->dcfg;
> > + int i;
> > +
> > + /* Parse address translation table */
> > + for (i = 0; i < dcfg->att_size; i++) {
> > + const struct imx_rproc_att *att = &dcfg->att[i];
> > +
> > + if (sys >= att->sa && sys + len <= att->sa + att->size) {
> > + unsigned int offset = sys - att->sa;
> > +
> > + *da = att->da + offset;
> > + return 0;
> > + }
> > + }
> > +
> > + return -ENOENT;
> > +}
> > +
> > +static void imx_dsp_rproc_vq_work(struct work_struct *work)
> > +{
> > + struct imx_dsp_rproc *priv = container_of(work, struct imx_dsp_rproc,
> > + rproc_work);
> > +
> > + rproc_vq_interrupt(priv->rproc, 0);
> > + rproc_vq_interrupt(priv->rproc, 1);
> > +}
> > +
> > +/**
> > + * imx_dsp_rproc_rx_callback() - inbound mailbox message handler
> > + * @cl: mailbox client pointer used for requesting the mailbox channel
> > + * @data: mailbox payload
> > + *
> > + * This handler is invoked by mailbox driver whenever a mailbox
> > + * message is received. Usually, the SUSPEND and RESUME related messages
> > + * are handled in this function, other messages are handled by remoteproc core
> > + */
> > +static void imx_dsp_rproc_rx_callback(struct mbox_client *cl, void *data)
> > +{
> > + struct rproc *rproc = dev_get_drvdata(cl->dev);
> > + struct imx_dsp_rproc *priv = rproc->priv;
> > + struct device *dev = rproc->dev.parent;
> > + u32 message = (u32)(*(u32 *)data);
> > +
> > + dev_dbg(dev, "mbox msg: 0x%x\n", message);
> > +
> > + switch (message) {
> > + case RP_MBOX_SUSPEND_ACK:
> > + complete(&priv->pm_comp);
> > + break;
> > + case RP_MBOX_RESUME_ACK:
> > + complete(&priv->pm_comp);
> > + break;
> > + default:
> > + queue_work(priv->workqueue, &priv->rproc_work);
> > + break;
> > + }
> > +}
> > +
> > +/**
> > + * imx_dsp_rproc_rxdb_callback() - inbound mailbox message handler
> > + * @cl: mailbox client pointer used for requesting the mailbox channel
> > + * @data: mailbox payload
> > + *
> > + * For doorbell, there is no message specified, just set REMOTE_IS_READY
> > + * flag.
> > + */
> > +static void imx_dsp_rproc_rxdb_callback(struct mbox_client *cl, void *data)
> > +{
> > + struct rproc *rproc = dev_get_drvdata(cl->dev);
> > + struct imx_dsp_rproc *priv = rproc->priv;
> > +
> > + /* Remote is ready after firmware is loaded and running */
> > + priv->flags |= REMOTE_IS_READY;
> > +}
> > +
> > +/**
> > + * imx_dsp_rproc_mbox_init() - request mailbox channels
> > + * @priv: private data pointer
> > + *
> > + * Request three mailbox channels (tx, rx, rxdb).
> > + */
> > +static int imx_dsp_rproc_mbox_init(struct imx_dsp_rproc *priv)
> > +{
> > + struct device *dev = priv->rproc->dev.parent;
> > + struct mbox_client *cl;
> > + int ret;
> > +
> > + if (!of_get_property(dev->of_node, "mbox-names", NULL))
> > + return 0;
> > +
> > + cl = &priv->cl;
> > + cl->dev = dev;
> > + cl->tx_block = true;
> > + cl->tx_tout = 100;
> > + cl->knows_txdone = false;
> > + cl->rx_callback = imx_dsp_rproc_rx_callback;
> > +
> > + /* Channel for sending message */
> > + priv->tx_ch = mbox_request_channel_byname(cl, "tx");
> > + if (IS_ERR(priv->tx_ch)) {
> > + ret = PTR_ERR(priv->tx_ch);
> > + dev_dbg(cl->dev, "failed to request tx mailbox channel: %d\n",
> > + ret);
> > + goto err_out;
> > + }
> > +
> > + /* Channel for receiving message */
> > + priv->rx_ch = mbox_request_channel_byname(cl, "rx");
> > + if (IS_ERR(priv->rx_ch)) {
> > + ret = PTR_ERR(priv->rx_ch);
> > + dev_dbg(cl->dev, "failed to request rx mailbox channel: %d\n",
> > + ret);
> > + goto err_out;
> > + }
> > +
> > + cl = &priv->cl_rxdb;
> > + cl->dev = dev;
> > + cl->rx_callback = imx_dsp_rproc_rxdb_callback;
> > +
> > + /*
> > + * RX door bell is used to receive the ready signal from remote
> > + * after firmware loaded.
> > + */
> > + priv->rxdb_ch = mbox_request_channel_byname(cl, "rxdb");
> > + if (IS_ERR(priv->rxdb_ch)) {
> > + ret = PTR_ERR(priv->rxdb_ch);
> > + dev_dbg(cl->dev, "failed to request mbox chan rxdb, ret %d\n",
> > + ret);
> > + goto err_out;
> > + }
> > +
> > + return 0;
> > +
> > +err_out:
> > + if (!IS_ERR(priv->tx_ch))
> > + mbox_free_channel(priv->tx_ch);
> > + if (!IS_ERR(priv->rx_ch))
> > + mbox_free_channel(priv->rx_ch);
> > + if (!IS_ERR(priv->rxdb_ch))
> > + mbox_free_channel(priv->rxdb_ch);
> > +
> > + return ret;
> > +}
> > +
> > +static void imx_dsp_rproc_free_mbox(struct imx_dsp_rproc *priv)
> > +{
> > + mbox_free_channel(priv->tx_ch);
> > + mbox_free_channel(priv->rx_ch);
> > + mbox_free_channel(priv->rxdb_ch);
> > +}
> > +
> > +/**
> > + * imx_dsp_rproc_add_carveout() - request mailbox channels
> > + * @priv: private data pointer
> > + *
> > + * This function registers specified memory entry in @rproc carveouts list
> > + * The carveouts can help to mapping the memory address for DSP.
> > + */
> > +static int imx_dsp_rproc_add_carveout(struct imx_dsp_rproc *priv)
> > +{
> > + const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
> > + const struct imx_rproc_dcfg *dcfg = dsp_dcfg->dcfg;
> > + struct rproc *rproc = priv->rproc;
> > + struct device *dev = rproc->dev.parent;
> > + struct device_node *np = dev->of_node;
> > + struct of_phandle_iterator it;
> > + struct rproc_mem_entry *mem;
> > + struct reserved_mem *rmem;
> > + void __iomem *cpu_addr;
> > + int a;
> > + u64 da;
> > +
> > + /* Remap required addresses */
> > + for (a = 0; a < dcfg->att_size; a++) {
> > + const struct imx_rproc_att *att = &dcfg->att[a];
> > +
> > + if (!(att->flags & ATT_OWN))
> > + continue;
> > +
> > + if (imx_dsp_rproc_sys_to_da(priv, att->sa, att->size, &da))
> > + return -EINVAL;
> > +
> > + cpu_addr = devm_ioremap_wc(dev, att->sa, att->size);
> > +
> > + /* Register memory region */
> > + mem = rproc_mem_entry_init(dev, cpu_addr, (dma_addr_t)att->sa,
> > + att->size, da, NULL, NULL, "dsp_mem");
> > +
> > + if (mem)
> > + rproc_coredump_add_segment(rproc, da, att->size);
> > + else
> > + return -ENOMEM;
> > +
> > + rproc_add_carveout(rproc, mem);
> > + }
> > +
> > + of_phandle_iterator_init(&it, np, "memory-region", NULL, 0);
> > + while (of_phandle_iterator_next(&it) == 0) {
> > + /*
> > + * Ignore the first memory region which will be used vdev buffer.
> > + * No need to do extra handlings, rproc_add_virtio_dev will handle it.
> > + */
> > + if (!strcmp(it.node->name, "vdev0buffer"))
> > + continue;
> > +
> > + rmem = of_reserved_mem_lookup(it.node);
> > + if (!rmem) {
> > + dev_err(dev, "unable to acquire memory-region\n");
> > + return -EINVAL;
> > + }
> > +
> > + if (imx_dsp_rproc_sys_to_da(priv, rmem->base, rmem->size, &da))
> > + return -EINVAL;
> > +
> > + cpu_addr = devm_ioremap_wc(dev, rmem->base, rmem->size);
> > +
> > + /* Register memory region */
> > + mem = rproc_mem_entry_init(dev, cpu_addr, (dma_addr_t)rmem->base,
> > + rmem->size, da, NULL, NULL, it.node->name);
> > +
> > + if (mem)
> > + rproc_coredump_add_segment(rproc, da, rmem->size);
> > + else
> > + return -ENOMEM;
> > +
> > + rproc_add_carveout(rproc, mem);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * imx_dsp_rproc_elf_load_segments() - load firmware segments to memory
> > + * @rproc: remote processor which will be booted using these fw segments
> > + * @fw: the ELF firmware image
> > + *
> > + * This function specially checks if memsz is zero or not, otherwise it
> > + * is mostly same as rproc_elf_load_segments().
> > + */
> > +static int imx_dsp_rproc_elf_load_segments(struct rproc *rproc,
> > + const struct firmware *fw)
> > +{
> > + struct device *dev = &rproc->dev;
> > + u8 class = fw_elf_get_class(fw);
> > + u32 elf_phdr_get_size = elf_size_of_phdr(class);
> > + const u8 *elf_data = fw->data;
> > + const void *ehdr, *phdr;
> > + int i, ret = 0;
> > + u16 phnum;
> > +
> > + ehdr = elf_data;
> > + phnum = elf_hdr_get_e_phnum(class, ehdr);
> > + phdr = elf_data + elf_hdr_get_e_phoff(class, ehdr);
> > +
> > + /* go through the available ELF segments */
> > + for (i = 0; i < phnum; i++, phdr += elf_phdr_get_size) {
> > + u64 da = elf_phdr_get_p_paddr(class, phdr);
> > + u64 memsz = elf_phdr_get_p_memsz(class, phdr);
> > + u64 filesz = elf_phdr_get_p_filesz(class, phdr);
> > + u64 offset = elf_phdr_get_p_offset(class, phdr);
> > + u32 type = elf_phdr_get_p_type(class, phdr);
> > + void *ptr;
> > + bool is_iomem;
> > +
> > + if (type != PT_LOAD || !memsz)
> > + continue;
> > +
> > + dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n",
> > + type, da, memsz, filesz);
> > +
> > + if (filesz > memsz) {
> > + dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n",
> > + filesz, memsz);
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + if (offset + filesz > fw->size) {
> > + dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
> > + offset + filesz, fw->size);
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + if (!rproc_u64_fit_in_size_t(memsz)) {
> > + dev_err(dev, "size (%llx) does not fit in size_t type\n",
> > + memsz);
> > + ret = -EOVERFLOW;
> > + break;
> > + }
> > +
> > + /* grab the kernel address for this device address */
> > + ptr = rproc_da_to_va(rproc, da, memsz, &is_iomem);
> > + if (!ptr) {
> > + dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
> > + memsz);
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + /* put the segment where the remote processor expects it */
> > + if (filesz)
> > + memcpy(ptr, elf_data + offset, filesz);
> > +
> > + /*
> > + * Zero out remaining memory for this segment.
> > + *
> > + * This isn't strictly required since dma_alloc_coherent already
> > + * did this for us. albeit harmless, we may consider removing
> > + * this.
> > + */
> > + if (memsz > filesz)
> > + memset(ptr + filesz, 0, memsz - filesz);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +/* Prepare function for rproc_ops */
> > +static int imx_dsp_rproc_prepare(struct rproc *rproc)
> > +{
> > + struct imx_dsp_rproc *priv = rproc->priv;
> > + struct device *dev = rproc->dev.parent;
> > + struct rproc_mem_entry *carveout;
> > + int ret;
> > +
> > + ret = imx_dsp_rproc_add_carveout(priv);
> > + if (ret) {
> > + dev_err(dev, "failed on imx_dsp_rproc_add_carveout\n");
> > + return ret;
> > + }
> > +
> > + pm_runtime_get_sync(dev);
> > +
> > + /*
> > + * Clear buffers after pm rumtime for internal ocram is not
> > + * accessible if power and clock are not enabled.
> > + */
> > + list_for_each_entry(carveout, &rproc->carveouts, node) {
> > + if (carveout->va)
> > + memset(carveout->va, 0, carveout->len);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/* Unprepare function for rproc_ops */
> > +static int imx_dsp_rproc_unprepare(struct rproc *rproc)
> > +{
> > + pm_runtime_put_sync(rproc->dev.parent);
> > +
> > + return 0;
> > +}
> > +
> > +/* Kick function for rproc_ops */
> > +static void imx_dsp_rproc_kick(struct rproc *rproc, int vqid)
> > +{
> > + struct imx_dsp_rproc *priv = rproc->priv;
> > + struct device *dev = rproc->dev.parent;
> > + int err;
> > + __u32 mmsg;
> > +
> > + if (!priv->tx_ch) {
> > + dev_err(dev, "No initialized mbox tx channel\n");
> > + return;
> > + }
> > +
> > + /*
> > + * Send the index of the triggered virtqueue as the mu payload.
> > + * Let remote processor know which virtqueue is used.
> > + */
> > + mmsg = vqid;
> > +
> > + err = mbox_send_message(priv->tx_ch, (void *)&mmsg);
> > + if (err < 0)
> > + dev_err(dev, "%s: failed (%d, err:%d)\n", __func__, vqid, err);
> > +}
> > +
> > +static const struct rproc_ops imx_dsp_rproc_ops = {
> > + .prepare = imx_dsp_rproc_prepare,
> > + .unprepare = imx_dsp_rproc_unprepare,
> > + .start = imx_dsp_rproc_start,
> > + .stop = imx_dsp_rproc_stop,
> > + .kick = imx_dsp_rproc_kick,
> > + .load = imx_dsp_rproc_elf_load_segments,
> > + .parse_fw = rproc_elf_load_rsc_table,
> > + .sanity_check = rproc_elf_sanity_check,
> > + .get_boot_addr = rproc_elf_get_boot_addr,
> > +};
> > +
> > +/**
> > + * imx_dsp_attach_pm_domains() - attach the power domains
> > + * @priv: private data pointer
> > + *
> > + * On i.MX8QM and i.MX8QXP there is multiple power domains
> > + * required, so need to link them.
> > + */
> > +static int imx_dsp_attach_pm_domains(struct imx_dsp_rproc *priv)
> > +{
> > + struct device *dev = priv->rproc->dev.parent;
> > + int ret, i;
> > +
> > + priv->num_domains = of_count_phandle_with_args(dev->of_node,
> > + "power-domains",
> > + "#power-domain-cells");
> > +
> > + /* If only one domain, then no need to link the device */
> > + if (priv->num_domains <= 1)
> > + return 0;
> > +
> > + priv->pd_dev = devm_kmalloc_array(dev, priv->num_domains,
> > + sizeof(*priv->pd_dev),
> > + GFP_KERNEL);
> > + if (!priv->pd_dev)
> > + return -ENOMEM;
> > +
> > + priv->pd_dev_link = devm_kmalloc_array(dev, priv->num_domains,
> > + sizeof(*priv->pd_dev_link),
> > + GFP_KERNEL);
> > + if (!priv->pd_dev_link)
> > + return -ENOMEM;
> > +
> > + for (i = 0; i < priv->num_domains; i++) {
> > + priv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
> > + if (IS_ERR(priv->pd_dev[i]))
> > + return PTR_ERR(priv->pd_dev[i]);
> > +
> > + priv->pd_dev_link[i] = device_link_add(dev,
> > + priv->pd_dev[i],
> > + DL_FLAG_STATELESS |
> > + DL_FLAG_PM_RUNTIME);
> > + if (IS_ERR(priv->pd_dev_link[i])) {
> > + dev_pm_domain_detach(priv->pd_dev[i], false);
> > + ret = PTR_ERR(priv->pd_dev_link[i]);
> > + goto detach_pm;
> > + }
>
> The kernel documentation for dev_pm_domain_attach_by_id() and device_link_add()
> cleary mention the possibility to return a NULL value - are you sure those calls
> will never return NULL and as such don't check for it?

Good catch, thank you. It should be update as below

for (i = 0; i < priv->num_domains; i++) {
priv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
if (IS_ERR(priv->pd_dev[i])) {
ret = PTR_ERR(priv->pd_dev[i]);
goto detach_pm;
}

/*
* device_link_add will check priv->pd_dev[i], if it is
* NULL, then will break.
*/
priv->pd_dev_link[i] = device_link_add(dev,
priv->pd_dev[i],
DL_FLAG_STATELESS |
DL_FLAG_PM_RUNTIME);
if (!priv->pd_dev_link[i]) {
dev_pm_domain_detach(priv->pd_dev[i], false);
ret = -EINVAL;
goto detach_pm;
}
}

Best regards
Wang Shengjiu