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Subject: Re: [PATCH v5 5/5] remoteproc: Add initial zynqmp R5 remoteproc
 driver
To:     Mathieu Poirier <mathieu.poirier@linaro.org>,
        Ben Levinsky <ben.levinsky@xilinx.com>
CC:     <ohad@wizery.com>, <bjorn.andersson@linaro.org>,
        <michals@xilinx.com>, <jollys@xilinx.com>, <rajanv@xilinx.com>,
        <robh+dt@kernel.org>, <mark.rutland@arm.com>,
        <linux-remoteproc@vger.kernel.org>,
        <linux-arm-kernell@lists.infradead.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Wendy Liang <wendy.liang@xilinx.com>,
        Michal Simek <michal.simek@xilinx.com>,
        Ed Mooring <ed.mooring@xilinx.com>, Jason Wu <j.wu@xilinx.com>
References: <1591195783-10290-1-git-send-email-ben.levinsky@xilinx.com>
 <1591195783-10290-6-git-send-email-ben.levinsky@xilinx.com>
 <20200608234935.GA4268@xps15>
From:   Suman Anna <s-anna@ti.com>
Message-ID: <b4217e0f-b14e-3ea1-e531-3b0962516690@ti.com>
Date:   Mon, 8 Jun 2020 19:00:03 -0500
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On 6/8/20 6:49 PM, Mathieu Poirier wrote:
> On Wed, Jun 03, 2020 at 07:49:43AM -0700, Ben Levinsky wrote:
>> R5 is included in Xilinx Zynq UltraScale MPSoC so by adding this
>> remotproc driver, we can boot the R5 sub-system in different
>> configurations.
>>
>> Acked-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
>> Acked-by: Ben Levinsky <ben.levinsky@xilinx.com>
>> Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
>> Signed-off-by: Ben Levinsky <ben.levinsky@xilinx.com>
>> Signed-off-by: Wendy Liang <wendy.liang@xilinx.com>
>> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
>> Signed-off-by: Ed Mooring <ed.mooring@xilinx.com>
>> Signed-off-by: Jason Wu <j.wu@xilinx.com>
>> Tested-by: Ben Levinsky <ben.levinsky@xilinx.com>
>> ---
>> v2:
>> - remove domain struct as per review from Mathieu
>> v3:
>> - add xilinx-related platform mgmt fn's instead of wrapping around
>>    function pointer in xilinx eemi ops struct
>> v4:
>> - add default values for enums
>> - fix formatting as per checkpatch.pl --strict. Note that 1 warning and 1 check
>>    are still raised as each is due to fixing the warning results in that
>> particular line going over 80 characters.
>> v5:
>> - parse_fw change from use of rproc_of_resm_mem_entry_init to rproc_mem_entry_init and use of alloc/release
>> - var's of type zynqmp_r5_pdata all have same local variable name
>> - use dev_dbg instead of dev_info
>>
>> ---
>>   drivers/remoteproc/Kconfig                |  10 +
>>   drivers/remoteproc/Makefile               |   1 +
>>   drivers/remoteproc/zynqmp_r5_remoteproc.c | 898 ++++++++++++++++++++++++++++++
>>   3 files changed, 909 insertions(+)
>>   create mode 100644 drivers/remoteproc/zynqmp_r5_remoteproc.c
>>
>> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
>> index fbaed07..735bd7f 100644
>> --- a/drivers/remoteproc/Kconfig
>> +++ b/drivers/remoteproc/Kconfig
>> @@ -240,6 +240,16 @@ config STM32_RPROC
>>   
>>   	  This can be either built-in or a loadable module.
>>   
>> +config ZYNQMP_R5_REMOTEPROC
>> +	tristate "ZynqMP_R5 remoteproc support"
>> +	depends on ARM64 && PM && ARCH_ZYNQMP
>> +	select RPMSG_VIRTIO
>> +	select MAILBOX
>> +	select ZYNQMP_IPI_MBOX
>> +	help
>> +	  Say y here to support ZynqMP R5 remote processors via the remote
>> +	  processor framework.
>> +
>>   endif # REMOTEPROC
>>   
>>   endmenu
>> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
>> index 0effd38..806ac3f 100644
>> --- a/drivers/remoteproc/Makefile
>> +++ b/drivers/remoteproc/Makefile
>> @@ -27,5 +27,6 @@ obj-$(CONFIG_QCOM_WCNSS_PIL)		+= qcom_wcnss_pil.o
>>   qcom_wcnss_pil-y			+= qcom_wcnss.o
>>   qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
>>   obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
>> +obj-$(CONFIG_ZYNQMP_R5_REMOTEPROC)	+= zynqmp_r5_remoteproc.o
>>   obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
>>   obj-$(CONFIG_STM32_RPROC)		+= stm32_rproc.o
>> diff --git a/drivers/remoteproc/zynqmp_r5_remoteproc.c b/drivers/remoteproc/zynqmp_r5_remoteproc.c
>> new file mode 100644
>> index 0000000..0e4f3ad
>> --- /dev/null
>> +++ b/drivers/remoteproc/zynqmp_r5_remoteproc.c
>> @@ -0,0 +1,898 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Zynq R5 Remote Processor driver
>> + *
>> + * Copyright (C) 2019, 2020 Xilinx Inc. Ben Levinsky <ben.levinsky@xilinx.com>
>> + * Copyright (C) 2015 - 2018 Xilinx Inc.
>> + * Copyright (C) 2015 Jason Wu <j.wu@xilinx.com>
>> + *
>> + * Based on origin OMAP and Zynq Remote Processor driver
>> + *
>> + * Copyright (C) 2012 Michal Simek <monstr@monstr.eu>
>> + * Copyright (C) 2012 PetaLogix
>> + * Copyright (C) 2011 Texas Instruments, Inc.
>> + * Copyright (C) 2011 Google, Inc.
>> + */
>> +
>> +#include <linux/atomic.h>
>> +#include <linux/cpu.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/delay.h>
>> +#include <linux/err.h>
>> +#include <linux/firmware/xlnx-zynqmp.h>
>> +#include <linux/genalloc.h>
>> +#include <linux/idr.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/kernel.h>
>> +#include <linux/list.h>
>> +#include <linux/mailbox_client.h>
>> +#include <linux/mailbox/zynqmp-ipi-message.h>
>> +#include <linux/module.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/of_reserved_mem.h>
>> +#include <linux/pfn.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/remoteproc.h>
>> +#include <linux/skbuff.h>
>> +#include <linux/slab.h>
>> +#include <linux/sysfs.h>
>> +
>> +#include "remoteproc_internal.h"
>> +
>> +#define MAX_RPROCS	2 /* Support up to 2 RPU */
>> +#define MAX_MEM_PNODES	4 /* Max power nodes for one RPU memory instance */
>> +
>> +#define DEFAULT_FIRMWARE_NAME	"rproc-rpu-fw"
>> +
>> +/* PM proc states */
>> +#define PM_PROC_STATE_ACTIVE 1U
>> +
>> +/* IPI buffer MAX length */
>> +#define IPI_BUF_LEN_MAX	32U
>> +/* RX mailbox client buffer max length */
>> +#define RX_MBOX_CLIENT_BUF_MAX	(IPI_BUF_LEN_MAX + \
>> +				 sizeof(struct zynqmp_ipi_message))
>> +
>> +static bool autoboot __read_mostly;
>> +
>> +/**
>> + * struct zynqmp_r5_mem - zynqmp rpu memory data
>> + * @pnode_id: TCM power domain ids
>> + * @res: memory resource
>> + * @node: list node
>> + */
>> +struct zynqmp_r5_mem {
>> +	u32 pnode_id[MAX_MEM_PNODES];
>> +	struct resource res;
>> +	struct list_head node;
>> +};
>> +
>> +/**
>> + * struct zynqmp_r5_pdata - zynqmp rpu remote processor private data
>> + * @dev: device of RPU instance
>> + * @rproc: rproc handle
>> + * @pnode_id: RPU CPU power domain id
>> + * @mems: memory resources
>> + * @is_r5_mode_set: indicate if r5 operation mode is set
>> + * @tx_mc: tx mailbox client
>> + * @rx_mc: rx mailbox client
>> + * @tx_chan: tx mailbox channel
>> + * @rx_chan: rx mailbox channel
>> + * @mbox_work: mbox_work for the RPU remoteproc
>> + * @tx_mc_skbs: socket buffers for tx mailbox client
>> + * @rx_mc_buf: rx mailbox client buffer to save the rx message
>> + */
>> +struct zynqmp_r5_pdata {
>> +	struct device dev;
>> +	struct rproc *rproc;
>> +	u32 pnode_id;
>> +	struct list_head mems;
>> +	bool is_r5_mode_set;
>> +	struct mbox_client tx_mc;
>> +	struct mbox_client rx_mc;
>> +	struct mbox_chan *tx_chan;
>> +	struct mbox_chan *rx_chan;
>> +	struct work_struct mbox_work;
>> +	struct sk_buff_head tx_mc_skbs;
>> +	unsigned char rx_mc_buf[RX_MBOX_CLIENT_BUF_MAX];
>> +};
>> +
>> +/**
>> + * table of RPUs
>> + */
>> +struct zynqmp_r5_pdata rpus[MAX_RPROCS];
>> +/**
>> + *  RPU core configuration
>> + */
>> +enum rpu_oper_mode rpu_mode;
>> +
>> +/*
>> + * r5_set_mode - set RPU operation mode
>> + * @pdata: Remote processor private data
>> + *
>> + * set RPU oepration mode
>> + *
>> + * Return: 0 for success, negative value for failure
>> + */
>> +static int r5_set_mode(struct zynqmp_r5_pdata *pdata)
>> +{
>> +	u32 val[PAYLOAD_ARG_CNT] = {0}, expect, tcm_mode;
>> +	struct device *dev = &pdata->dev;
>> +	int ret;
>> +
>> +	expect = (u32)rpu_mode;
>> +	ret = zynqmp_pm_get_rpu_mode(pdata->pnode_id, 0, 0, val);
>> +	if (ret < 0) {
>> +		dev_err(dev, "failed to get RPU oper mode.\n");
>> +		return ret;
>> +	}
>> +	if (val[0] == expect) {
>> +		dev_dbg(dev, "RPU mode matches: %x\n", val[0]);
>> +	} else {
>> +		ret = zynqmp_pm_set_rpu_mode(pdata->pnode_id,
>> +					     expect, 0, val);
>> +		if (ret < 0) {
>> +			dev_err(dev,
>> +				"failed to set RPU oper mode.\n");
>> +			return ret;
>> +		}
>> +	}
>> +
>> +	tcm_mode = (expect == (u32)PM_RPU_MODE_LOCKSTEP) ?
>> +		    PM_RPU_TCM_COMB : PM_RPU_TCM_SPLIT;
>> +	ret = zynqmp_pm_set_tcm_config(pdata->pnode_id, tcm_mode, 0, val);
>> +	if (ret < 0) {
>> +		dev_err(dev, "failed to config TCM to %x.\n",
>> +			expect);
>> +		return ret;
>> +	}
>> +	pdata->is_r5_mode_set = true;
>> +	return 0;
>> +}
>> +
>> +/**
>> + * r5_is_running - check if r5 is running
>> + * @pdata: Remote processor private data
>> + *
>> + * check if R5 is running
>> + *
>> + * Return: true if r5 is running, false otherwise
>> + */
>> +static bool r5_is_running(struct zynqmp_r5_pdata *pdata)
>> +{
>> +	u32 status, requirements, usage;
>> +	struct device *dev = &pdata->dev;
>> +
>> +	if (zynqmp_pm_get_node_status(pdata->pnode_id,
>> +				      &status, &requirements, &usage)) {
>> +		dev_err(dev, "Failed to get RPU node %d status.\n",
>> +			pdata->pnode_id);
>> +		return false;
>> +	} else if (status != PM_PROC_STATE_ACTIVE) {
>> +		dev_dbg(dev, "RPU is not running.\n");
>> +		return false;
>> +	}
>> +
>> +	dev_dbg(dev, "RPU is running.\n");
>> +	return true;
>> +}
>> +
>> +/*
>> + * ZynqMP R5 remoteproc memory release function
>> + */
>> +static int zynqmp_r5_mem_release(struct rproc *rproc,
>> +				 struct rproc_mem_entry *mem)
>> +{
>> +	struct zynqmp_r5_mem *priv;
>> +	int i, ret;
>> +	struct device *dev = &rproc->dev;
>> +
>> +	priv = mem->priv;
>> +	if (!priv)
>> +		return 0;
>> +	for (i = 0; i < MAX_MEM_PNODES; i++) {
>> +		if (priv->pnode_id[i]) {
>> +			dev_dbg(dev, "%s, pnode %d\n",
>> +				__func__, priv->pnode_id[i]);
>> +			ret = zynqmp_pm_release_node(priv->pnode_id[i]);
>> +			if (ret < 0) {
>> +				dev_err(dev,
>> +					"failed to release power node: %u\n",
>> +					priv->pnode_id[i]);
>> +				return ret;
>> +			}
>> +		} else {
>> +			break;
>> +		}
>> +	}
>> +	return 0;
>> +}
>> +
>> +/*
>> + * ZynqMP R5 remoteproc operations
>> + */
>> +static int zynqmp_r5_rproc_start(struct rproc *rproc)
>> +{
>> +	struct device *dev = rproc->dev.parent;
>> +	struct zynqmp_r5_pdata *pdata = rproc->priv;
>> +	enum rpu_boot_mem bootmem;
>> +	int ret;
>> +	/* Set up R5 if not already setup */
>> +	ret = pdata->is_r5_mode_set ? 0 : r5_set_mode(pdata);
> 
> Is there any reason why r5_set_mode() has to be done as part of the start()
> function rather than at probe() time?
> 
>> +	if (ret) {
>> +		dev_err(dev, "failed to set R5 operation mode.\n");
>> +		return ret;
>> +	}
>> +	if ((rproc->bootaddr & 0xF0000000) == 0xF0000000)
>> +		bootmem = PM_RPU_BOOTMEM_HIVEC;
>> +	else
>> +		bootmem = PM_RPU_BOOTMEM_LOVEC;
>> +	dev_dbg(dev, "RPU boot from %s.",
>> +		bootmem == PM_RPU_BOOTMEM_HIVEC ? "OCM" : "TCM");
>> +	ret = zynqmp_pm_request_wakeup(pdata->pnode_id, 1,
>> +				       bootmem, ZYNQMP_PM_REQUEST_ACK_NO);
>> +	if (ret < 0) {
>> +		dev_err(dev, "failed to boot R5.\n");
>> +		return ret;
>> +	}
>> +	return 0;
>> +}
>> +
>> +static int zynqmp_r5_rproc_stop(struct rproc *rproc)
>> +{
>> +	struct zynqmp_r5_pdata *pdata = rproc->priv;
>> +	int ret;
>> +
>> +	ret = zynqmp_pm_force_powerdown(pdata->pnode_id,
>> +					ZYNQMP_PM_REQUEST_ACK_BLOCKING);
>> +	if (ret < 0) {
>> +		dev_err(&pdata->dev, "failed to shutdown R5.\n");
>> +		return ret;
>> +	}
>> +	pdata->is_r5_mode_set = false;
> 
> Why resetting this to false?  If r5_set_mode() needs to be called every time the
> remote processor is booted, why carrying an extra variable (pdata->is_r5_mode_set)?
> 
>> +	return 0;
>> +}
>> +
>> +static int zynqmp_r5_rproc_mem_alloc(struct rproc *rproc,
>> +				      struct rproc_mem_entry *mem)
>> +{
>> +	struct device *dev = rproc->dev.parent;
>> +	void *va;
>> +
>> +	dev_dbg(rproc->dev.parent, "map memory: %pa\n", &mem->dma);
>> +	va = ioremap_wc(mem->dma, mem->len);
>> +	if (IS_ERR_OR_NULL(va)) {
>> +		dev_err(dev, "Unable to map memory region: %pa+%x\n",
>> +			&mem->dma, mem->len);
>> +		return -ENOMEM;
>> +	}
>> +
>> +	/* Update memory entry va */
>> +	mem->va = va;
>> +
>> +	return 0;
>> +}
>> +static int zynqmp_r5_rproc_mem_release(struct rproc *rproc,
>> +				       struct rproc_mem_entry *mem)
>> +{
>> +	dev_dbg(rproc->dev.parent, "unmap memory: %pa\n", &mem->dma);
>> +	iounmap(mem->va);
>> +
>> +	return 0;
>> +}
>> +
>> +static int zynqmp_r5_parse_fw(struct rproc *rproc, const struct firmware *fw)
>> +{
>> +	int num_mems, i, ret;
>> +	struct zynqmp_r5_pdata *pdata = rproc->priv;
>> +	struct device *dev = &pdata->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct rproc_mem_entry *mem;
>> +	struct device_node *child;
>> +	struct resource rsc;
>> +
>> +	num_mems = of_count_phandle_with_args(np, "memory-region", NULL);
>> +	if (num_mems <= 0)
>> +		return 0;
>> +	for (i = 0; i < num_mems; i++) {
>> +		struct device_node *node;
>> +		struct zynqmp_r5_mem *zynqmp_mem;
>> +		struct reserved_mem *rmem;
>> +		char rproc_name[20];
>> +
>> +		node = of_parse_phandle(np, "memory-region", i);
>> +		rmem = of_reserved_mem_lookup(node);
>> +		if (!rmem) {
>> +			dev_err(dev, "unable to acquire memory-region\n");
>> +			return -EINVAL;
>> +		}
>> +
>> +		if (strstr(node->name, "vdev0buffer")) {
>> +			/* Register DMA region */
>> +			mem = rproc_mem_entry_init(dev, NULL,
>> +						   (dma_addr_t)rmem->base,
>> +						   rmem->size, rmem->base,
>> +						   NULL, NULL,
>> +						   "vdev0buffer");
> 
> Out of sheer curiosity, why did you choose to use rproc_mem_entry_init() rather
> than rproc_of_resm_mem_entry_init()?  After all the vdev0buffer is part of a
> reserved memory...
> 
> There is more comments further below.  I'm out of time for today, I'll continue
> with the rest of zynmp_r5_parse_fw() tomorrow.
> 
> Thanks,
> Mathieu
> 
>> +			if (!mem) {
>> +				dev_err(dev, "unable to initialize memory-region %s\n",
>> +					node->name);
>> +				return -ENOMEM;
>> +			}
>> +			dev_dbg(dev, "parsed %s at  %llx\r\n", mem->name,
>> +				mem->dma);
>> +			rproc_add_carveout(rproc, mem);
>> +			continue;
>> +		} else if (strstr(node->name, "vdev") &&
>> +				    strstr(node->name, "vring")) {
>> +			int id, vring_id;
>> +			char name[16];
>> +
>> +			id = node->name[8] - '0';
>> +			vring_id = node->name[14] - '0';
>> +			snprintf(name, sizeof(name), "vdev%dvring%d", id,
>> +				 vring_id);
>> +			/* Register vring */
>> +			mem = rproc_mem_entry_init(dev, NULL,
>> +						   (dma_addr_t)rmem->base,
>> +						   rmem->size, rmem->base,
>> +						   zynqmp_r5_rproc_mem_alloc,
>> +						   zynqmp_r5_rproc_mem_release,
>> +						   name);
>> +			dev_dbg(dev, "parsed %s at %llx\r\n", mem->name,
>> +				mem->dma);
>> +			rproc_add_carveout(rproc, mem);
>> +			continue;
>> +		} else {
>> +			mem = rproc_mem_entry_init(dev, NULL,
>> +						   (dma_addr_t)rmem->base,
>> +						   rmem->size, rmem->base,
>> +						   zynqmp_r5_rproc_mem_alloc,
>> +						   zynqmp_r5_rproc_mem_release,
>> +						   node->name);
>> +
>> +			if (!mem) {
>> +				dev_err(dev,
>> +					"unable to init memory-region %s\n",
>> +					node->name);
>> +				return -ENOMEM;
>> +			}
>> +			mem->of_resm_idx = i;
>> +
>> +			rproc_add_carveout(rproc, mem);
>> +		}
>> +	}
>> +
>> +	/* map TCM */
>> +	for_each_available_child_of_node(np, child) {
>> +		struct property *prop;
>> +		const __be32 *cur;
>> +		u32 pnode_id;
>> +		void *va;
>> +		dma_addr_t dma;
>> +		resource_size_t size;
>> +
>> +		ret = of_address_to_resource(child, 0, &rsc);
>> +
>> +		i = 0;
>> +		of_property_for_each_u32(child, "pnode-id", prop, cur,
>> +					 pnode_id) {
>> +			ret = zynqmp_pm_request_node(pnode_id,
>> +				ZYNQMP_PM_CAPABILITY_ACCESS, 0,
>> +				ZYNQMP_PM_REQUEST_ACK_BLOCKING);
>> +			if (ret < 0) {
>> +				dev_err(dev, "failed to request power node: %u\n",
>> +					pnode_id);
>> +				return ret;
>> +			}
>> +		}
>> +		size = resource_size(&rsc);
>> +		va = devm_ioremap_wc(dev, rsc.start, size);
>> +		if (!va)
>> +			return -ENOMEM;
>> +
>> +		/* zero out tcm base address */
>> +		if (rsc.start & 0xffe00000) {
>> +			rsc.start &= 0x000fffff;
>> +			/* handle tcm banks 1 a and b
>> +			 * (0xffe9000 and oxffeb0000)
>> +			 */
>> +				if (rsc.start & 0x80000)
>> +					rsc.start -= 0x90000;
>> +		}
>> +
>> +		dma = (dma_addr_t)rsc.start;
>> +		mem = rproc_mem_entry_init(dev, va, dma, (int)size, rsc.start,
>> +					   NULL, zynqmp_r5_mem_release,
>> +					   rsc.name);
>> +		if (!mem)
>> +			return -ENOMEM;
>> +
>> +		rproc_add_carveout(rproc, mem);
>> +	}
>> +
>> +	ret = rproc_elf_load_rsc_table(rproc, fw);
>> +	if (ret == -EINVAL)
>> +		ret = 0;
>> +	return ret;
>> +}
>> +
>> +/* kick a firmware */
>> +static void zynqmp_r5_rproc_kick(struct rproc *rproc, int vqid)
>> +{
>> +	struct device *dev = rproc->dev.parent;
>> +	struct zynqmp_r5_pdata *pdata = rproc->priv;
>> +
>> +	dev_dbg(dev, "KICK Firmware to start send messages vqid %d\n", vqid);
>> +
>> +	if (vqid < 0) {
>> +		/* If vqid is negative, does not pass the vqid to
>> +		 * mailbox. As vqid is supposed to be 0 or possive.
>> +		 * It also gives a way to just kick instead but
>> +		 * not use the IPI buffer. It is better to provide
>> +		 * a proper way to pass the short message, which will
>> +		 * need to sync to upstream first, for now,
>> +		 * use negative vqid to assume no message will be
>> +		 * passed with IPI buffer, but just raise interrupt.
>> +		 * This will be faster as it doesn't need to copy the
>> +		 * message to the IPI buffer.
>> +		 *
>> +		 * It will ignore the return, as failure is due to
>> +		 * there already kicks in the mailbox queue.
>> +		 */
>> +		(void)mbox_send_message(pdata->tx_chan, NULL);
>> +	} else {
>> +		struct sk_buff *skb;
>> +		unsigned int skb_len;
>> +		struct zynqmp_ipi_message *mb_msg;
>> +		int ret;
>> +
>> +		skb_len = (unsigned int)(sizeof(vqid) + sizeof(mb_msg));
>> +		skb = alloc_skb(skb_len, GFP_ATOMIC);
>> +		if (!skb) {
>> +			dev_err(dev,
>> +				"Failed to allocate skb to kick remote.\n");
>> +			return;
>> +		}
>> +		mb_msg = (struct zynqmp_ipi_message *)skb_put(skb, skb_len);
>> +		mb_msg->len = sizeof(vqid);
>> +		memcpy(mb_msg->data, &vqid, sizeof(vqid));
>> +		skb_queue_tail(&pdata->tx_mc_skbs, skb);
>> +		ret = mbox_send_message(pdata->tx_chan, mb_msg);
>> +		if (ret < 0) {
>> +			dev_warn(dev, "Failed to kick remote.\n");
>> +			skb_dequeue_tail(&pdata->tx_mc_skbs);
>> +			kfree_skb(skb);
>> +		}
>> +	}
>> +}
>> +
>> +static struct rproc_ops zynqmp_r5_rproc_ops = {
>> +	.start		= zynqmp_r5_rproc_start,
>> +	.stop		= zynqmp_r5_rproc_stop,
>> +	.load		= rproc_elf_load_segments,
>> +	.parse_fw	= zynqmp_r5_parse_fw,
>> +	.find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
>> +	.sanity_check	= rproc_elf_sanity_check,
>> +	.get_boot_addr	= rproc_elf_get_boot_addr,
>> +	.kick		= zynqmp_r5_rproc_kick,
>> +};
>> +
>> +/* zynqmp_r5_mem_probe() - probes RPU TCM memory device
>> + * @pdata: pointer to the RPU remoteproc private data
>> + * @node: pointer to the memory node
>> + *
>> + * Function to retrieve resources for RPU TCM memory device.
>> + */
>> +static int zynqmp_r5_mem_probe(struct zynqmp_r5_pdata *pdata,
>> +			       struct device_node *node)
>> +{
>> +	struct device *dev;
>> +	struct zynqmp_r5_mem *mem;
>> +	int ret;
>> +	struct property *prop;
>> +	const __be32 *cur;
>> +	u32 val;
>> +	int i = 0;
>> +
>> +	dev = &pdata->dev;
>> +	mem = devm_kzalloc(dev, sizeof(*mem), GFP_KERNEL);
>> +	if (!mem)
>> +		return -ENOMEM;
>> +	ret = of_address_to_resource(node, 0, &mem->res);
>> +	if (ret < 0) {
>> +		dev_err(dev, "failed to get resource of memory %s",
>> +			of_node_full_name(node));
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* Get the power domain id */
>> +	if (of_find_property(node, "pnode-id", NULL)) {
>> +		of_property_for_each_u32(node, "pnode-id", prop, cur, val)
>> +			mem->pnode_id[i++] = val;
>> +	}
>> +	list_add_tail(&mem->node, &pdata->mems);
>> +	return 0;
>> +}
>> +
>> +/**
>> + * zynqmp_r5_release() - ZynqMP R5 device release function
>> + * @dev: pointer to the device struct of ZynqMP R5
>> + *
>> + * Function to release ZynqMP R5 device.
>> + */
>> +static void zynqmp_r5_release(struct device *dev)
>> +{
>> +	struct zynqmp_r5_pdata *pdata;
>> +	struct rproc *rproc;
>> +	struct sk_buff *skb;
>> +
>> +	pdata = dev_get_drvdata(dev);
>> +	rproc = pdata->rproc;
>> +	if (rproc) {
>> +		rproc_del(rproc);
>> +		rproc_free(rproc);
>> +	}
>> +	if (pdata->tx_chan)
>> +		mbox_free_channel(pdata->tx_chan);
>> +	if (pdata->rx_chan)
>> +		mbox_free_channel(pdata->rx_chan);
>> +	/* Discard all SKBs */
>> +	while (!skb_queue_empty(&pdata->tx_mc_skbs)) {
>> +		skb = skb_dequeue(&pdata->tx_mc_skbs);
>> +		kfree_skb(skb);
>> +	}
>> +
>> +	put_device(dev->parent);
>> +}
>> +
>> +/**
>> + * event_notified_idr_cb() - event notified idr callback
>> + * @id: idr id
>> + * @ptr: pointer to idr private data
>> + * @data: data passed to idr_for_each callback
>> + *
>> + * Pass notification to remoteproc virtio
>> + *
>> + * Return: 0. having return is to satisfy the idr_for_each() function
>> + *          pointer input argument requirement.
>> + **/
>> +static int event_notified_idr_cb(int id, void *ptr, void *data)
>> +{
>> +	struct rproc *rproc = data;
>> +
>> +	(void)rproc_vq_interrupt(rproc, id);
>> +	return 0;
>> +}
>> +
>> +/**
>> + * handle_event_notified() - remoteproc notification work funciton
>> + * @work: pointer to the work structure
>> + *
>> + * It checks each registered remoteproc notify IDs.
>> + */
>> +static void handle_event_notified(struct work_struct *work)
>> +{
>> +	struct rproc *rproc;
>> +	struct zynqmp_r5_pdata *pdata;
>> +
>> +	pdata = container_of(work, struct zynqmp_r5_pdata, mbox_work);
>> +
>> +	(void)mbox_send_message(pdata->rx_chan, NULL);
>> +	rproc = pdata->rproc;
>> +	/*
>> +	 * We only use IPI for interrupt. The firmware side may or may
>> +	 * not write the notifyid when it trigger IPI.
>> +	 * And thus, we scan through all the registered notifyids.
>> +	 */
>> +	idr_for_each(&rproc->notifyids, event_notified_idr_cb, rproc);
>> +}
>> +
>> +/**
>> + * zynqmp_r5_mb_rx_cb() - Receive channel mailbox callback
>> + * @cl: mailbox client
>> + * @mssg: message pointer
>> + *
>> + * It will schedule the R5 notification work.
>> + */
>> +static void zynqmp_r5_mb_rx_cb(struct mbox_client *cl, void *mssg)
>> +{
>> +	struct zynqmp_r5_pdata *pdata;
>> +
>> +	pdata = container_of(cl, struct zynqmp_r5_pdata, rx_mc);
>> +	if (mssg) {
>> +		struct zynqmp_ipi_message *ipi_msg, *buf_msg;
>> +		size_t len;
>> +
>> +		ipi_msg = (struct zynqmp_ipi_message *)mssg;
>> +		buf_msg = (struct zynqmp_ipi_message *)pdata->rx_mc_buf;
>> +		len = (ipi_msg->len >= IPI_BUF_LEN_MAX) ?
>> +		      IPI_BUF_LEN_MAX : ipi_msg->len;
>> +		buf_msg->len = len;
>> +		memcpy(buf_msg->data, ipi_msg->data, len);
>> +	}
>> +	schedule_work(&pdata->mbox_work);
>> +}
>> +
>> +/**
>> + * zynqmp_r5_mb_tx_done() - Request has been sent to the remote
>> + * @cl: mailbox client
>> + * @mssg: pointer to the message which has been sent
>> + * @r: status of last TX - OK or error
>> + *
>> + * It will be called by the mailbox framework when the last TX has done.
>> + */
>> +static void zynqmp_r5_mb_tx_done(struct mbox_client *cl, void *mssg, int r)
>> +{
>> +	struct zynqmp_r5_pdata *pdata;
>> +	struct sk_buff *skb;
>> +
>> +	if (!mssg)
>> +		return;
>> +	pdata = container_of(cl, struct zynqmp_r5_pdata, tx_mc);
>> +	skb = skb_dequeue(&pdata->tx_mc_skbs);
>> +	kfree_skb(skb);
>> +}
>> +
>> +/**
>> + * zynqmp_r5_setup_mbox() - Setup mailboxes
>> + *
>> + * @pdata: pointer to the ZynqMP R5 processor platform data
>> + * @node: pointer of the device node
>> + *
>> + * Function to setup mailboxes to talk to RPU.
>> + *
>> + * Return: 0 for success, negative value for failure.
>> + */
>> +static int zynqmp_r5_setup_mbox(struct zynqmp_r5_pdata *pdata,
>> +				struct device_node *node)
>> +{
>> +	struct device *dev = &pdata->dev;
>> +	struct mbox_client *mclient;
>> +
>> +	/* Setup TX mailbox channel client */
>> +	mclient = &pdata->tx_mc;
>> +	mclient->dev = dev;
>> +	mclient->rx_callback = NULL;
>> +	mclient->tx_block = false;
>> +	mclient->knows_txdone = false;
>> +	mclient->tx_done = zynqmp_r5_mb_tx_done;
>> +
>> +	/* Setup TX mailbox channel client */
>> +	mclient = &pdata->rx_mc;
>> +	mclient->dev = dev;
>> +	mclient->rx_callback = zynqmp_r5_mb_rx_cb;
>> +	mclient->tx_block = false;
>> +	mclient->knows_txdone = false;
>> +
>> +	INIT_WORK(&pdata->mbox_work, handle_event_notified);
>> +
>> +	/* Request TX and RX channels */
>> +	pdata->tx_chan = mbox_request_channel_byname(&pdata->tx_mc, "tx");
>> +	if (IS_ERR(pdata->tx_chan)) {
>> +		dev_err(dev, "failed to request mbox tx channel.\n");
>> +		pdata->tx_chan = NULL;
>> +		return -EINVAL;
>> +	}
>> +	pdata->rx_chan = mbox_request_channel_byname(&pdata->rx_mc, "rx");
>> +	if (IS_ERR(pdata->rx_chan)) {
>> +		dev_err(dev, "failed to request mbox rx channel.\n");
>> +		pdata->rx_chan = NULL;
>> +		return -EINVAL;
>> +	}
>> +	skb_queue_head_init(&pdata->tx_mc_skbs);
>> +	return 0;
>> +}
>> +
>> +/**
>> + * zynqmp_r5_probe() - Probes ZynqMP R5 processor device node
>> + * @pdata: pointer to the ZynqMP R5 processor platform data
>> + * @pdev: parent RPU domain platform device
>> + * @node: pointer of the device node
>> + *
>> + * Function to retrieve the information of the ZynqMP R5 device node.
>> + *
>> + * Return: 0 for success, negative value for failure.
>> + */
>> +static int zynqmp_r5_probe(struct zynqmp_r5_pdata *pdata,
>> +			   struct platform_device *pdev,
>> +			   struct device_node *node)
>> +{
>> +	struct device *dev = &pdata->dev;
>> +	struct rproc *rproc;
>> +	struct device_node *nc;
>> +	int ret;
>> +
>> +	/* Create device for ZynqMP R5 device */
>> +	dev->parent = &pdev->dev;
>> +	dev->release = zynqmp_r5_release;
>> +	dev->of_node = node;
>> +	dev_set_name(dev, "%s", of_node_full_name(node));
>> +	dev_set_drvdata(dev, pdata);
>> +	ret = device_register(dev);
>> +	if (ret) {
>> +		dev_err(dev, "failed to register device.\n");
>> +		return ret;
>> +	}
>> +	get_device(&pdev->dev);
>> +
>> +	/* Allocate remoteproc instance */
>> +	rproc = rproc_alloc(dev, dev_name(dev), &zynqmp_r5_rproc_ops, NULL, 0);
>> +	if (!rproc) {
>> +		dev_err(dev, "rproc allocation failed.\n");
>> +		ret = -ENOMEM;
>> +		goto error;
>> +	}
>> +	rproc->auto_boot = autoboot;
>> +	pdata->rproc = rproc;
>> +	rproc->priv = pdata;
>> +
>> +	/*
>> +	 * The device has not been spawned from a device tree, so
>> +	 * arch_setup_dma_ops has not been called, thus leaving
>> +	 * the device with dummy DMA ops.
>> +	 * Fix this by inheriting the parent's DMA ops and mask.
>> +	 */
>> +	rproc->dev.dma_mask = pdev->dev.dma_mask;
>> +	set_dma_ops(&rproc->dev, get_dma_ops(&pdev->dev));
>> +
>> +	/* Probe R5 memory devices */
>> +	INIT_LIST_HEAD(&pdata->mems);
>> +	for_each_available_child_of_node(node, nc) {
>> +		ret = zynqmp_r5_mem_probe(pdata, nc);
>> +		if (ret) {
>> +			dev_err(dev, "failed to probe memory %s.\n",
>> +				of_node_full_name(nc));
>> +			goto error;
>> +		}
>> +	}
>> +
>> +	/* Set up DMA mask */
>> +	ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
>> +	if (ret) {
>> +		dev_warn(dev, "dma_set_coherent_mask failed: %d\n", ret);
>> +		/* If DMA is not configured yet, try to configure it. */
>> +		ret = of_dma_configure(dev, node, true);
>> +		if (ret) {
>> +			dev_err(dev, "failed to configure DMA.\n");
>> +			goto error;
>> +		}
>> +	}
>> +
>> +	/* Get R5 power domain node */
>> +	ret = of_property_read_u32(node, "pnode-id", &pdata->pnode_id);
>> +	if (ret) {
>> +		dev_err(dev, "failed to get power node id.\n");
>> +		goto error;
>> +	}
>> +
>> +	/* Check if R5 is running */
>> +	if (r5_is_running(pdata)) {
>> +		atomic_inc(&rproc->power);
>> +		rproc->state = RPROC_RUNNING;
>> +	}
> 
> How does this work when state_store() returns an error if rproc->state ==
> RPROC_RUNNING?  As such the remote processor is running but there is no
> way to attach to it.  As I requested during my previous review, please hold off
> on supporting scenarios where the remote processor is already running when the
> driver is probe.  We are working on introducing that in the remoteproc core.
> 
>> +
>> +	if (!of_get_property(dev->of_node, "mboxes", NULL)) {
>> +		dev_dbg(dev, "no mailboxes.\n");
>> +		goto error;
>> +	} else {
>> +		ret = zynqmp_r5_setup_mbox(pdata, node);
>> +		if (ret < 0)
>> +			goto error;
>> +	}
>> +
>> +	/* Add R5 remoteproc */
>> +	ret = rproc_add(rproc);
>> +	if (ret) {
>> +		dev_err(dev, "rproc registration failed\n");
>> +		goto error;
>> +	}
>> +	return 0;
>> +error:
>> +	if (pdata->rproc)
>> +		rproc_free(pdata->rproc);
>> +	pdata->rproc = NULL;
>> +	device_unregister(dev);
>> +	put_device(&pdev->dev);
>> +	return ret;
>> +}
>> +
>> +static int zynqmp_r5_remoteproc_probe(struct platform_device *pdev)
>> +{
>> +	const unsigned char *prop;
>> +	int ret, i;
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *nc;
>> +	struct zynqmp_r5_pdata *pdata;
>> +
>> +	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
>> +	if (!pdata)
>> +		return -ENOMEM;
>> +	platform_set_drvdata(pdev, pdata);
>> +
>> +	prop = of_get_property(dev->of_node, "core_conf", NULL);
>> +	if (!prop) {
>> +		dev_err(&pdev->dev, "core_conf is not used.\n");
>> +		return -EINVAL;
>> +	}
> 
> This should be the same as what Texas Instrument is doing, i.e:
>          lockstep-mode = <1>
> 
> That way:
> 
> 1) The wheel is not re-invented.
> 2) An 'enum rpu_oper_mode' can be used directly.
> 3) No need for string comparison.

So, for my next version, I am planning to change this "lockstep-mode" to 
a ti,cluster-mode property (still an enum/integer). We have a new SoC 
family coming up wherein we are supporting a unique mode called "Single 
CPU" mode which is not the same as LockStep, and I will be finding the 
current "lockstep-mode" property limiting there.

regards
Suman

> 
>> +
>> +	dev_dbg(dev, "RPU core_conf: %s\n", prop);
>> +	if (!strcmp(prop, "split")) {
>> +		rpu_mode = PM_RPU_MODE_SPLIT;
>> +	} else if (!strcmp(prop, "lockstep")) {
>> +		rpu_mode = PM_RPU_MODE_LOCKSTEP;
>> +	} else {
>> +		dev_err(dev,
>> +			"Invalid core_conf mode provided - %s , %d\n",
>> +			prop, (int)rpu_mode);
>> +		return -EINVAL;
>> +	}
>> +
>> +	i = 0;
> 
> This can be done when the variable is declared above.
> 
>> +	for_each_available_child_of_node(dev->of_node, nc) {
>> +		ret = zynqmp_r5_probe(&rpus[i], pdev, nc);
>> +		if (ret) {
>> +			dev_err(dev, "failed to probe rpu %s.\n",
>> +				of_node_full_name(nc));
>> +			return ret;
>> +		}
>> +		i++;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int zynqmp_r5_remoteproc_remove(struct platform_device *pdev)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < MAX_RPROCS; i++) {
>> +		struct zynqmp_r5_pdata *pdata = &rpus[i];
>> +		struct rproc *rproc;
>> +
>> +		rproc = pdata->rproc;
>> +		if (rproc) {
>> +			rproc_del(rproc);
>> +			rproc_free(rproc);
>> +			pdata->rproc = NULL;
>> +		}
>> +		if (pdata->tx_chan) {
>> +			mbox_free_channel(pdata->tx_chan);
>> +			pdata->tx_chan = NULL;
>> +		}
>> +		if (pdata->rx_chan) {
>> +			mbox_free_channel(pdata->rx_chan);
>> +			pdata->rx_chan = NULL;
>> +		}
>> +
>> +		device_unregister(&pdata->dev);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +/* Match table for OF platform binding */
>> +static const struct of_device_id zynqmp_r5_remoteproc_match[] = {
>> +	{ .compatible = "xlnx,zynqmp-r5-remoteproc-1.0", },
>> +	{ /* end of list */ },
>> +};
>> +MODULE_DEVICE_TABLE(of, zynqmp_r5_remoteproc_match);
>> +
>> +static struct platform_driver zynqmp_r5_remoteproc_driver = {
>> +	.probe = zynqmp_r5_remoteproc_probe,
>> +	.remove = zynqmp_r5_remoteproc_remove,
>> +	.driver = {
>> +		.name = "zynqmp_r5_remoteproc",
>> +		.of_match_table = zynqmp_r5_remoteproc_match,
>> +	},
>> +};
>> +module_platform_driver(zynqmp_r5_remoteproc_driver);
>> +
>> +module_param_named(autoboot,  autoboot, bool, 0444);
>> +MODULE_PARM_DESC(autoboot,
>> +		 "enable | disable autoboot. (default: true)");
>> +
>> +MODULE_AUTHOR("Ben Levinsky <ben.levinsky@xilinx.com>");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("ZynqMP R5 remote processor control driver");
>> -- 
>> 2.7.4
>>