[PATCH v26 5/5] remoteproc: Add initial zynqmp R5 remoteproc driver

Ben Levinsky BLEVINSK at xilinx.com
Thu Mar 11 23:47:15 GMT 2021


Hi Mathieu 

Thanks for the feedback. I responded inline

-----Original Message-----
From: Mathieu Poirier <mathieu.poirier at linaro.org>
Date: Monday, March 8, 2021 at 11:00 AM
To: Ben Levinsky <BLEVINSK at xilinx.com>
Cc: "devicetree at vger.kernel.org" <devicetree at vger.kernel.org>, "linux-remoteproc at vger.kernel.org" <linux-remoteproc at vger.kernel.org>, "linux-kernel at vger.kernel.org" <linux-kernel at vger.kernel.org>, "linux-arm-kernel at lists.infradead.org" <linux-arm-kernel at lists.infradead.org>, Michal Simek <michals at xilinx.com>
Subject: Re: [PATCH v26 5/5] remoteproc: Add initial zynqmp R5 remoteproc driver

    On Tue, Feb 23, 2021 at 07:44:47AM -0800, Ben Levinsky wrote:
    > R5 is included in Xilinx Zynq UltraScale MPSoC so by adding this
    > remoteproc driver, we can boot the R5 sub-system in two different
    > configurations -
    > 	* Split
    > 	* Lockstep
    > 
    > The Xilinx R5 Remoteproc Driver boots the R5's via calls to the Xilinx
    > Platform Management Unit that handles the R5 configuration, memory access
    > and R5 lifecycle management. The interface to this manager is done in this
    > driver via zynqmp_pm_* function calls.
    > 
    > Signed-off-by: Wendy Liang <wendy.liang at xilinx.com>
    > Signed-off-by: Michal Simek <michal.simek at xilinx.com>
    > Signed-off-by: Ed Mooring <ed.mooring at xilinx.com>
    > Signed-off-by: Jason Wu <j.wu at xilinx.com>
    > Signed-off-by: Ben Levinsky <ben.levinsky at xilinx.com>
    > ---
    >  drivers/remoteproc/Kconfig                |   8 +
    >  drivers/remoteproc/Makefile               |   1 +
    >  drivers/remoteproc/zynqmp_r5_remoteproc.c | 954 ++++++++++++++++++++++
    >  3 files changed, 963 insertions(+)
    >  create mode 100644 drivers/remoteproc/zynqmp_r5_remoteproc.c
    > 
    > diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
    > index c6659dfea7c7..c2fe54b1d94f 100644
    > --- a/drivers/remoteproc/Kconfig
    > +++ b/drivers/remoteproc/Kconfig
    > @@ -275,6 +275,14 @@ config TI_K3_DSP_REMOTEPROC
    >  	  It's safe to say N here if you're not interested in utilizing
    >  	  the DSP slave processors.
    >  
    > +config ZYNQMP_R5_REMOTEPROC
    > +	tristate "ZynqMP R5 remoteproc support"
    > +	depends on PM && ARCH_ZYNQMP
    > +	select RPMSG_VIRTIO
    > +	select ZYNQMP_IPI_MBOX
    > +	help
    > +	  Say y or m 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 3dfa28e6c701..ef1abff654c2 100644
    > --- a/drivers/remoteproc/Makefile
    > +++ b/drivers/remoteproc/Makefile
    > @@ -33,3 +33,4 @@ obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
    >  obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
    >  obj-$(CONFIG_STM32_RPROC)		+= stm32_rproc.o
    >  obj-$(CONFIG_TI_K3_DSP_REMOTEPROC)	+= ti_k3_dsp_remoteproc.o
    > +obj-$(CONFIG_ZYNQMP_R5_REMOTEPROC)	+= zynqmp_r5_remoteproc.o
    > diff --git a/drivers/remoteproc/zynqmp_r5_remoteproc.c b/drivers/remoteproc/zynqmp_r5_remoteproc.c
    > new file mode 100644
    > index 000000000000..4bcff2daceaf
    > --- /dev/null
    > +++ b/drivers/remoteproc/zynqmp_r5_remoteproc.c
    > @@ -0,0 +1,954 @@
    > +// SPDX-License-Identifier: GPL-2.0
    > +/*
    > + * Zynq R5 Remote Processor driver
    > + *
    > + * Based on origin OMAP and Zynq Remote Processor driver
    > + *
    > + */
    > +
    > +#include <linux/firmware/xlnx-zynqmp.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_platform.h>
    > +#include <linux/of_reserved_mem.h>
    > +#include <linux/platform_device.h>
    > +#include <linux/remoteproc.h>
    > +#include <linux/skbuff.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 BANK_LIST_PROP	"sram"
    > +#define DDR_LIST_PROP	"memory-region"
    > +
    > +/* 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))
    > +
    > +/*
    > + * Map each Xilinx on-chip SRAM  Bank address to their own respective
    > + * pm_node_id.
    > + *
    > + * size can differ based on R5 cluster configuration so record from
    > + * device tree in zynqmp_r5_probe.
    > + */
    > +struct sram_addr_data {
    > +	phys_addr_t addr;
    > +	enum pm_node_id id;
    > +	resource_size_t size;
    > +};
    > +
    > +#define NUM_SRAMS 4U
    > +static const struct sram_addr_data zynqmp_banks[NUM_SRAMS] = {
    > +	{0xffe00000UL, NODE_TCM_0_A, 0},
    > +	{0xffe20000UL, NODE_TCM_0_B, 0},
    > +	{0xffe90000UL, NODE_TCM_1_A, 0},
    > +	{0xffeb0000UL, NODE_TCM_1_B, 0},
    > +};
    > +
    > +/**
    > + * struct zynqmp_r5_rproc - ZynqMP R5 core structure
    > + *
    > + * @rx_mc_buf: rx mailbox client buffer to save the rx message
    > + * @srams : srams Xilinx mgmt IDs for srams that will be used by R5 core.
    > + * @tx_mc: tx mailbox client
    > + * @rx_mc: rx mailbox client
    > + * @mbox_work: mbox_work for the RPU remoteproc
    > + * @tx_mc_skbs: socket buffers for tx mailbox client
    > + * @rproc: rproc handle
    > + * @tx_chan: tx mailbox channel
    > + * @rx_chan: rx mailbox channel
    > + * @pnode_id: RPU CPU power domain id
    > + * @elem: linked list item
    > + */
    > +struct zynqmp_r5_rproc {
    > +	unsigned char rx_mc_buf[RX_MBOX_CLIENT_BUF_MAX];
    > +	struct sram_addr_data srams[NUM_SRAMS];
    > +	struct mbox_client tx_mc;
    > +	struct mbox_client rx_mc;
    > +	struct work_struct mbox_work;
    > +	struct sk_buff_head tx_mc_skbs;
    > +	struct rproc *rproc;
    > +	struct mbox_chan *tx_chan;
    > +	struct mbox_chan *rx_chan;
    > +	u32 pnode_id;
    > +	struct list_head elem;
    > +};
    > +
    > +/*
    > + * r5_set_mode
    > + * @z_rproc: Remote processor private data
    > + * @rpu_mode: mode specified by device tree to configure the RPU to
    > + *
    > + * set RPU operation mode
    > + *
    > + * Return: 0 for success, negative value for failure
    > + */
    > +static int r5_set_mode(struct zynqmp_r5_rproc *z_rproc,
    > +		       enum rpu_oper_mode rpu_mode)
    > +{
    > +	enum rpu_tcm_comb tcm_mode;
    > +	enum rpu_oper_mode cur_rpu_mode;
    > +	int ret;
    > +
    > +	ret = zynqmp_pm_get_rpu_mode(z_rproc->pnode_id, &cur_rpu_mode);
    > +	if (ret < 0)
    > +		return ret;
    > +
    > +	if (rpu_mode != cur_rpu_mode) {
    > +		ret = zynqmp_pm_set_rpu_mode(z_rproc->pnode_id, rpu_mode);
    > +		if (ret < 0)
    > +			return ret;
    > +	}
    > +
    > +	tcm_mode = (rpu_mode == PM_RPU_MODE_LOCKSTEP) ?
    > +		    PM_RPU_TCM_COMB : PM_RPU_TCM_SPLIT;
    > +	return zynqmp_pm_set_tcm_config(z_rproc->pnode_id, tcm_mode);
    > +}
    > +
    > +/*
    > + * r5_rproc_prepare
    > + * @rproc: single R5 core's corresponding rproc instance
    > + *
    > + * The Xilinx Versal and ZU+ SoC's require devices (in this case srams) to be
    > + * requested for a given device to be used. As the R5's TCM banks may be used
    > + * by the cores, each of these banks has to be requested before they can be
    > + * used.
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int r5_rproc_prepare(struct rproc *rproc)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc = rproc->priv;
    > +	int ret, i;
    > +
    > +	for (i = 0; i < NUM_SRAMS; i++) {
    > +		if (!z_rproc->srams[i].id)
    > +			continue;
    > +
    > +		ret = zynqmp_pm_request_node(z_rproc->srams[i].id,
    > +					     ZYNQMP_PM_CAPABILITY_ACCESS, 0,
    > +					     ZYNQMP_PM_REQUEST_ACK_BLOCKING);
    > +		if (ret < 0)
    > +			return ret;
    > +	}
    > +
    > +	return ret;
    > +}
    > +
    > +/*
    > + * r5_rproc_unprepare
    > + * @rproc: single R5 core's corresponding rproc instance
    > + *
    > + * This function implements the .unprepare() ops and performs the complementary
    > + * operations to that of the .prepare() ops. This instructs the power
    > + * management controller that the node is no longer needed by that cluster,
    > + * allowing the node to be placed into an inactive state. The cores
    > + * themselves are only halted in the .stop() callback. The .unprepare() ops are
    > + * invoked by the remoteproc core after the remoteproc is stopped.
    > + *
    > + * Return on first error seen as whatever causes the first error
    > + * may cause subsequent iterations to fail with a different error.
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int r5_rproc_unprepare(struct rproc *rproc)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc = rproc->priv;
    > +	int ret, i;
    > +
    > +	for (i = 0; i < NUM_SRAMS; i++) {
    > +		if (!z_rproc->srams[i].id)
    > +			continue;
    > +
    > +		ret = zynqmp_pm_release_node(z_rproc->srams[i].id);
    > +		if (ret < 0)
    > +			return ret;
    > +	}
    > +
    > +	return ret;
    > +}
    > +
    > +/*
    > + * zynqmp_r5_rproc_start
    > + * @rproc: single R5 core's corresponding rproc instance
    > + *
    > + * Start R5 Core from designated boot address.
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int zynqmp_r5_rproc_start(struct rproc *rproc)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc = rproc->priv;
    > +	enum rpu_boot_mem bootmem;
    > +
    > +	bootmem = (rproc->bootaddr & 0xF0000000) == 0xF0000000 ?
    > +		   PM_RPU_BOOTMEM_HIVEC : PM_RPU_BOOTMEM_LOVEC;
    > +
    > +	dev_dbg(rproc->dev.parent, "RPU boot from %s.",
    > +		bootmem == PM_RPU_BOOTMEM_HIVEC ? "OCM" : "TCM");
    > +
    > +	return zynqmp_pm_request_wake(z_rproc->pnode_id, 1,
    > +				      bootmem, ZYNQMP_PM_REQUEST_ACK_NO);
    > +}
    > +
    > +/*
    > + * zynqmp_r5_rproc_stop
    > + * @rproc: single R5 core's corresponding rproc instance
    > + *
    > + * Power down  R5 Core.
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int zynqmp_r5_rproc_stop(struct rproc *rproc)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc = rproc->priv;
    > +
    > +	return zynqmp_pm_force_pwrdwn(z_rproc->pnode_id,
    > +				      ZYNQMP_PM_REQUEST_ACK_BLOCKING);
    > +}
    > +
    > +/*
    > + * zynqmp_r5_rproc_mem_alloc
    > + * @rproc: single R5 core's corresponding rproc instance
    > + * @mem: mem entry to map
    > + *
    > + * Callback to map va for memory-region's carveout.
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int zynqmp_r5_rproc_mem_alloc(struct rproc *rproc,
    > +				     struct rproc_mem_entry *mem)
    > +{
    > +	void *va;
    > +
    > +	va = ioremap_wc(mem->dma, mem->len);
    > +	if (IS_ERR_OR_NULL(va))
    > +		return -ENOMEM;
    > +
    > +	mem->va = va;
    > +
    > +	return 0;
    > +}
    > +
    > +/*
    > + * zynqmp_r5_rproc_mem_release
    > + * @rproc: single R5 core's corresponding rproc instance
    > + * @mem: mem entry to unmap
    > + *
    > + * Unmap memory-region carveout
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int zynqmp_r5_rproc_mem_release(struct rproc *rproc,
    > +				       struct rproc_mem_entry *mem)
    > +{
    > +	iounmap(mem->va);
    > +	return 0;
    > +}
    > +
    > +/*
    > + * parse_mem_regions
    > + * @rproc: single R5 core's corresponding rproc instance
    > + *
    > + * Construct rproc mem carveouts from carveout provided in
    > + * memory-region property
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int parse_mem_regions(struct rproc *rproc)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc = rproc->priv;
    > +	struct device_node *np = z_rproc->rproc->dev.parent->of_node;
    > +	struct device *dev = &rproc->dev;
    > +	struct of_phandle_iterator it;
    > +	struct rproc_mem_entry *mem;
    > +	struct reserved_mem *rmem;
    > +	int index = 0;
    > +
    > +	/* Register associated reserved memory regions */
    > +	of_phandle_iterator_init(&it, np, DDR_LIST_PROP, NULL, 0);
    > +	while (of_phandle_iterator_next(&it) == 0) {
    > +		rmem = of_reserved_mem_lookup(it.node);
    > +		if (!rmem) {
    > +			dev_err(dev, "unable to acquire %s\n", DDR_LIST_PROP);
    > +			return -EINVAL;
    > +		}
    > +
    > +		if (strstr(it.node->name, "vdev0buffer")) {
    > +			mem = rproc_of_resm_mem_entry_init(dev, index,
    > +							   rmem->size,
    > +							   rmem->base,
    > +							   "vdev0buffer");
    > +		} else {
    > +			/*
    > +			 * The ensuing carveout is either for vring, which has
    > +			 * device tree node name of length 15 characters, or
    > +			 * firmware mem, where name is not used by remoteproc
    > +			 * core later on. So default to vring length of 15.
    > +			 *
    > +			 * Extra char for null-terminated string.
    > +			 *
    > +			 * only allocate in negative case as strstr returns
    > +			 * pointer + offset to string in positive case.
    > +			 */
    > +			char *name;
    > +
    > +			name = strstr(it.node->name, "vdev0vring");
    > +			if (name) {
    > +				/*
    > +				 * Expect "rpuXvdev0vringX" as documented
    > +				 * in xilinx remoteproc device tree binding
    > +				 */
    > +				if (strlen(it.node->name) < 15) {
    > +					dev_err(dev, "%pOF is less than 15 chars",
    > +						it.node);
    > +					return -EINVAL;
    > +				}
    > +			} else {
    > +				name = devm_kzalloc(dev, 16 * sizeof(char),
    > +						    GFP_KERNEL);
    > +				if (!name)
    > +					return -ENOMEM;
    > +				strncpy(name, it.node->name, 16);
    > +			}
    > +
    > +			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);
    > +		}
    > +
    > +		if (!mem)
    > +			return -ENOMEM;
    > +
    > +		rproc_add_carveout(rproc, mem);
    > +		index++;
    > +	}
    > +
    > +	return 0;
    > +}
    > +
    > +/*
    > + * tcm_mem_alloc
    > + * @rproc: single R5 core's corresponding rproc instance
    > + * @mem: mem entry to initialize the va and da fields of
    > + *
    > + * Given TCM bank entry, this callback will set device address for R5
    > + * running on TCM and also setup virtual address for TCM bank
    > + * remoteproc carveout.
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int tcm_mem_alloc(struct rproc *rproc,
    > +			 struct rproc_mem_entry *mem)
    > +{
    > +	void *va;
    > +	struct device *dev = rproc->dev.parent;
    > +
    > +	va = ioremap_wc(mem->dma, mem->len);
    > +	if (IS_ERR_OR_NULL(va))
    > +		return -ENOMEM;
    > +
    > +	/* Update memory entry va */
    > +	mem->va = va;
    > +
    > +	/*
    > +	 * The R5s expect their TCM banks to be at address 0x0 and 0x2000,
    > +	 * while on the Linux side they are at 0xffexxxxx.
    > +	 *
    > +	 * Zero out the high 12 bits of the address. This will give
    > +	 * expected values for TCM Banks 0A and 0B (0x0 and 0x20000).
    > +	 */
    > +	mem->da &= 0x000fffff;
    > +
    > +	/*
    > +	 * TCM Banks 1A and 1B still have to be translated.
    > +	 *
    > +	 * Below handle these two banks' absolute addresses (0xffe90000 and
    > +	 * 0xffeb0000) and convert to the expected relative addresses
    > +	 * (0x0 and 0x20000).
    > +	 */
    > +	if (mem->da == 0x90000 || mem->da == 0xB0000)
    > +		mem->da -= 0x90000;
    > +
    > +	/* if translated TCM bank address is not valid report error */
    > +	if (mem->da != 0x0 && mem->da != 0x20000) {
    > +		dev_err(dev, "invalid TCM bank address: %x\n", mem->da);
    > +		return -EINVAL;
    > +	}
    > +
    > +	return 0;
    > +}
    > +
    > +/*
    > + * tcm_mem_release
    > + * @rproc: single R5 core's corresponding rproc instance
    > + * @mem: mem entry to unmap
    > + *
    > + * Unmap TCM banks when powering down R5 core.
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int tcm_mem_release(struct rproc *rproc, struct rproc_mem_entry *mem)
    > +{
    > +	iounmap(mem->va);
    > +	return 0;
    > +}
    > +
    > +/*
    > + * parse_tcm_banks
    > + * @rproc: single R5 core's corresponding rproc instance
    > + *
    > + * Given R5 node in remoteproc instance
    > + * allocate remoteproc carveout for TCM memory
    > + * needed for firmware to be loaded
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int parse_tcm_banks(struct rproc *rproc)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc = rproc->priv;
    > +	struct rproc_mem_entry *mem;
    > +	int i;
    > +
    > +	for (i = 0; i < NUM_SRAMS; i++) {
    > +		if (!z_rproc->srams[i].id)
    > +			continue;
    > +
    > +		mem = rproc_mem_entry_init(&rproc->dev, NULL,
    > +					   z_rproc->srams[i].addr,
    > +					   (size_t)z_rproc->srams[i].size,
    > +					   z_rproc->srams[i].addr,
    > +					   tcm_mem_alloc,
    > +					   tcm_mem_release, "sram");
    > +		if (!mem)
    > +			return -ENOMEM;
    > +
    > +		rproc_add_carveout(rproc, mem);
    > +	}
    > +
    > +	return 0;
    > +}
    > +
    > +/*
    > + * zynqmp_r5_parse_fw
    > + * @rproc: single R5 core's corresponding rproc instance
    > + * @fw: ptr to firmware to be loaded onto r5 core
    > + *
    > + * When loading firmware, ensure the necessary carveouts are in remoteproc
    > + *
    > + * return 0 on success, otherwise non-zero value on failure
    > + */
    > +static int zynqmp_r5_parse_fw(struct rproc *rproc, const struct firmware *fw)
    > +{
    > +	int ret;
    > +
    > +	ret = parse_tcm_banks(rproc);
    > +	if (ret)
    > +		return ret;
    > +
    > +	ret = parse_mem_regions(rproc);
    > +	if (ret)
    > +		return ret;
    > +
    > +	ret = rproc_elf_load_rsc_table(rproc, fw);
    > +	if (ret == -EINVAL) {
    > +		/*
    > +		 * resource table only required for IPC.
    > +		 * if not present, this is not necessarily an error;
    > +		 * for example, loading r5 hello world application
    > +		 * so simply inform user and keep going.
    > +		 */
    > +		dev_info(&rproc->dev, "no resource table found.\n");
    > +		ret = 0;
    > +	}
    > +	return ret;
    > +}
    > +
    > +/*
    > + * zynqmp_r5_rproc_kick - kick a firmware if mbox is provided
    > + * @rproc: r5 core's corresponding rproc structure
    > + * @vqid: virtqueue ID
    > + */
    > +static void zynqmp_r5_rproc_kick(struct rproc *rproc, int vqid)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc = rproc->priv;
    > +	struct device *dev = rproc->dev.parent;
    > +	struct zynqmp_ipi_message *mb_msg = NULL;
    > +	unsigned int skb_len;
    > +	struct sk_buff *skb;
    > +	int ret;
    > +
    > +	/* If vqid is negative, do not pass the vqid to
    > +	 * mailbox as vqid is supposed to be 0 or positive.
    > +	 * It also gives a way to just kick instead but
    > +	 * not use the IPI buffer.
    > +	 *
    > +	 * 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 ZynqMP/Versal IPI message buffer.
    > +	 */
    > +	if (vqid >= 0) {
    > +		skb_len = (unsigned int)(sizeof(vqid) + sizeof(mb_msg));
    > +		skb = alloc_skb(skb_len, GFP_KERNEL);
    > +		if (!skb)
    > +			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(&z_rproc->tx_mc_skbs, skb);
    > +	}
    > +
    > +	ret = mbox_send_message(z_rproc->tx_chan, mb_msg);
    > +	if (ret < 0) {
    > +		dev_warn(dev, "Failed to kick remote.\n");
    > +		if (mb_msg) {
    > +			skb_dequeue_tail(&z_rproc->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,
    > +	.prepare	= r5_rproc_prepare,
    > +	.unprepare	= r5_rproc_unprepare,
    > +};
    > +
    > +/**
    > + * 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;
    > +
    > +	if (rproc_vq_interrupt(rproc, id) == IRQ_NONE)
    > +		dev_dbg(&rproc->dev, "no message was found in idr with id: %d\n", id);
    > +	return 0;
    > +}
    > +
    > +/**
    > + * handle_event_notified - remoteproc notification work function
    > + * @work: pointer to the work structure
    > + *
    > + * It checks each registered remoteproc notify IDs.
    > + */
    > +static void handle_event_notified(struct work_struct *work)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc;
    > +	struct rproc *rproc;
    > +
    > +	z_rproc = container_of(work, struct zynqmp_r5_rproc, mbox_work);
    > +	rproc = z_rproc->rproc;
    > +
    > +	/*
    > +	 * This is to simply raise interrupt as ACK for remote.
    > +	 *
    > +	 * Xilinx mailbox, ATF and SoC specific IPI mapping will handle
    > +	 * mapping to remote processor.
    > +	 */
    > +	if (mbox_send_message(z_rproc->rx_chan, NULL) < 0)
    > +		dev_warn(rproc->dev.parent, "Failed to kick remote.\n");
    > +
    > +	/*
    > +	 * 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
    > + * @msg: message pointer
    > + *
    > + * It will schedule the R5 notification work.
    > + */
    > +static void zynqmp_r5_mb_rx_cb(struct mbox_client *cl, void *msg)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc;
    > +
    > +	z_rproc = container_of(cl, struct zynqmp_r5_rproc, rx_mc);
    > +	/*
    > +	 * Notification can be received with message payload.
    > +	 * To handle this, check for message contents.
    > +	 * If there are contents, copy to ipi message buffer payload location.
    > +	 *
    > +	 * If message is empty, then that means that was simple raising
    > +	 * of interrupt. no payload to process.
    > +	 *
    > +	 * Note: enqueue work regardless of msg as kick may imply that remote
    > +	 * is waiting for ack.
    > +	 */
    > +	if (msg) {
    > +		struct zynqmp_ipi_message *ipi_msg, *buf_msg;
    > +		size_t len;
    > +
    > +		ipi_msg = (struct zynqmp_ipi_message *)msg;
    > +		buf_msg = (struct zynqmp_ipi_message *)z_rproc->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(&z_rproc->mbox_work);
    > +}
    > +
    > +/**
    > + * zynqmp_r5_mb_tx_done - Request has been sent to the remote
    > + * @cl: mailbox client
    > + * @msg: 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 *msg, int r)
    > +{
    > +	struct zynqmp_r5_rproc *z_rproc;
    > +	struct sk_buff *skb;
    > +
    > +	if (!msg)
    > +		return;
    > +	z_rproc = container_of(cl, struct zynqmp_r5_rproc, tx_mc);
    > +	skb = skb_dequeue(&z_rproc->tx_mc_skbs);
    > +	kfree_skb(skb);
    > +}
    > +
    > +/**
    > + * zynqmp_r5_setup_mbox - Setup mailboxes
    > + *			    this is used for each individual R5 core
    > + *
    > + * @z_rproc: 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_rproc *z_rproc,
    > +				struct device_node *node)
    > +{
    > +	struct mbox_client *mclient;
    > +
    > +	/* Setup TX mailbox channel client */
    > +	mclient			= &z_rproc->tx_mc;
    > +	mclient->dev		= z_rproc->rproc->dev.parent;
    > +	mclient->tx_done	= zynqmp_r5_mb_tx_done;
    > +	mclient->tx_block	= false;
    > +	mclient->knows_txdone	= false;
    > +	mclient->rx_callback	= NULL;
    > +
    > +	/* Setup RX mailbox channel client */
    > +	mclient			= &z_rproc->rx_mc;
    > +	mclient->dev		= z_rproc->rproc->dev.parent;
    > +	mclient->tx_done	= NULL;
    > +	mclient->tx_block	= false;
    > +	mclient->knows_txdone	= false;
    > +	mclient->rx_callback	= zynqmp_r5_mb_rx_cb;
    > +
    > +	INIT_WORK(&z_rproc->mbox_work, handle_event_notified);
    > +
    > +	/* Request TX and RX channels */
    > +	z_rproc->tx_chan = mbox_request_channel_byname(&z_rproc->tx_mc, "tx");
    > +	if (IS_ERR(z_rproc->tx_chan)) {
    > +		dev_err(z_rproc->rproc->dev.parent,
    > +			"failed to request mbox tx channel.\n");
    > +		return PTR_ERR(z_rproc->tx_chan);
    > +	}
    > +
    > +	z_rproc->rx_chan = mbox_request_channel_byname(&z_rproc->rx_mc, "rx");
    > +	if (IS_ERR(z_rproc->rx_chan)) {
    > +		dev_err(z_rproc->rproc->dev.parent,
    > +			"failed to request mbox rx channel.\n");
    > +		return PTR_ERR(z_rproc->rx_chan);
    > +	}
    > +	skb_queue_head_init(&z_rproc->tx_mc_skbs);
    > +
    > +	return 0;
    > +}
    > +
    > +static void zynqmp_r5_cleanup_mbox(struct zynqmp_r5_rproc *z_rproc)
    > +{
    > +	mbox_free_channel(z_rproc->tx_chan);
    > +	mbox_free_channel(z_rproc->rx_chan);
    > +}
    > +
    > +/**
    > + * zynqmp_r5_probe - Probes ZynqMP R5 processor device node
    > + *		       this is called for each individual R5 core to
    > + *		       set up mailbox, Xilinx platform manager unique ID,
    > + *		       add to rproc core

    The above has changed since last time, which makes it harder for me to
    review your work.  From hereon please change only the things I point out so that
    we keep the same goal posts from one revision to the other.

    The tabulation needs to be fixed:  

            * zynqmp_r5_probe - Probes ZynqMP R5 processor device node
            *
            * This is called for each individual R5 core to set up mailbox, Xilinx
            * platform manager unique ID, add to rproc core.

    The description is also broken.

[Ben] Ok. How is the following:
/**                                                                                
 * zynqmp_r5_probe - Probes ZynqMP R5 processor device node                        
 *                                                                                 
 * This is called for each individual R5 core to set up mailbox, Xilinx            
 * platform manager unique ID, collect SRAM information and wire in                
 * driver-specific data to to rproc core.                                          
 *                                                                                 
 * @pdev: domain platform device for current R5 core                               
 * @node: pointer of the device node for current R5 core                           
 * @rpu_mode: mode to configure RPU, split or lockstep                             
 *                                                                                 
 * Return: 0 for success, negative value for failure.                              
 */                                                                                
static struct zynqmp_r5_rproc *zynqmp_r5_probe(struct platform_device *pdev,       
                                               struct device_node *node,           
                                               enum rpu_oper_mode rpu_mode) 


    > + *
    > + * @pdev: domain platform device for current R5 core
    > + * @node: pointer of the device node for current R5 core
    > + * @rpu_mode: mode to configure RPU, split or lockstep
    > + *
    > + * Return: 0 for success, negative value for failure.
    > + */
    > +static struct zynqmp_r5_rproc *zynqmp_r5_probe(struct platform_device *pdev,
    > +					       struct device_node *node,
    > +					       enum rpu_oper_mode rpu_mode)
    > +{
    > +	int ret, num_banks;
    > +	struct device *dev = &pdev->dev;
    > +	struct rproc *rproc_ptr;
    > +	struct zynqmp_r5_rproc *z_rproc;
    > +	struct device_node *r5_node;
    > +
    > +	/* Allocate remoteproc instance */
    > +	rproc_ptr = devm_rproc_alloc(dev, dev_name(dev), &zynqmp_r5_rproc_ops,
    > +				     NULL, sizeof(struct zynqmp_r5_rproc));
    > +	if (!rproc_ptr) {
    > +		ret = -ENOMEM;
    > +		goto error;
    > +	}
    > +
    > +	rproc_ptr->auto_boot = false;
    > +	z_rproc = rproc_ptr->priv;
    > +	z_rproc->rproc = rproc_ptr;
    > +	r5_node = z_rproc->rproc->dev.parent->of_node;
    > +
    > +	/* Set up DMA mask */
    > +	ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
    > +	if (ret)
    > +		goto error;
    > +
    > +	/* Get R5 power domain node */
    > +	ret = of_property_read_u32(node, "power-domain", &z_rproc->pnode_id);
    > +	if (ret)
    > +		goto error;
    > +
    > +	ret = r5_set_mode(z_rproc, rpu_mode);
    > +	if (ret)
    > +		goto error;
    > +
    > +	if (of_property_read_bool(node, "mboxes")) {
    > +		ret = zynqmp_r5_setup_mbox(z_rproc, node);
    > +		if (ret)
    > +			goto error;
    > +	}
    > +
    > +	/* go through TCM banks for r5 node */
    > +	num_banks = of_count_phandle_with_args(r5_node, BANK_LIST_PROP, NULL);

    Shouldn't this be @node instead of @r5_node?

[Ben]  Yes this should and will be node.

    > +	if (num_banks <= 0) {
    > +		dev_err(dev, "need to specify TCM banks\n");
    > +		ret = -EINVAL;
    > +		goto error;
    > +	}
    > +
    > +	if (num_banks > NUM_SRAMS) {
    > +		dev_err(dev, "max number of srams is %d. given: %d \r\n",
    > +			NUM_SRAMS, num_banks);
    > +		ret = -EINVAL;
    > +		goto error;
    > +	}
    > +
    > +	/* construct collection of srams used by the current R5 core */
    > +	for (; num_banks; num_banks--) {
    > +		struct resource rsc;
    > +		struct device_node *dt_node;
    > +		resource_size_t size;
    > +		int i;
    > +
    > +		dt_node = of_parse_phandle(r5_node, BANK_LIST_PROP, i);
    > +		if (!dt_node) {
    > +			ret = -EINVAL;
    > +			goto error;
    > +		}
    > +
    > +		ret = of_address_to_resource(dt_node, 0, &rsc);
    > +		if (ret < 0) {
    > +			of_node_put(dt_node);
    > +			goto error;
    > +		}
    > +
    > +		of_node_put(dt_node);
    > +		size = resource_size(&rsc);
    > +
    > +		/*
    > +		 * Find corresponding Xilinx platform management ID.
    > +		 * The bank information is used in prepare/unprepare and
    > +		 * parse_fw.
    > +		 */
    > +		for (i = 0; i < NUM_SRAMS; i++) {
    > +			if (rsc.start == zynqmp_banks[i].addr) {
    > +				z_rproc->srams[i].addr = rsc.start;
    > +				z_rproc->srams[i].size = size;
    > +				z_rproc->srams[i].id = zynqmp_banks[i].id;
    > +				break;
    > +			}
    > +		}
    > +
    > +		if (i == NUM_SRAMS) {
    > +			dev_err(dev, "sram %llx is not valid.\n", rsc.start);
    > +			ret = -EINVAL;
    > +			goto error;
    > +		}
    > +	}

    Everything that is related to the initialisation of srams above should be in a
    function on its own.  This too is new code that wasn't requested - the next
    revision needs to include *only* the changes I request.  Any improvement on the
    current implementation can be made in future patchsets. 


[Ben] Makes sense. I will do that going forward. For probe() I will put all the sram information collection functionality in 1 function.

    > +
    > +	/* Add R5 remoteproc */
    > +	ret = devm_rproc_add(dev, rproc_ptr);
    > +	if (ret) {
    > +		zynqmp_r5_cleanup_mbox(z_rproc);
    > +		goto error;
    > +	}
    > +
    > +	return z_rproc;
    > +error:
    > +	return ERR_PTR(ret);
    > +}
    > +
    > +/*
    > + * zynqmp_r5_remoteproc_probe
    > + *
    > + * @pdev: domain platform device for R5 cluster
    > + *
    > + * called when driver is probed, for each R5 core specified in DT,
    > + * setup as needed to do remoteproc-related operations
    > + *
    > + * Return: 0 for success, negative value for failure.
    > + */
    > +static int zynqmp_r5_remoteproc_probe(struct platform_device *pdev)
    > +{
    > +	int ret, core_count;
    > +	struct device *dev = &pdev->dev;
    > +	struct device_node *nc;
    > +	enum rpu_oper_mode rpu_mode = PM_RPU_MODE_LOCKSTEP;
    > +	struct list_head *cluster; /* list to track each core's rproc */
    > +	struct zynqmp_r5_rproc *z_rproc;
    > +	struct platform_device *child_pdev;
    > +	struct list_head *pos;
    > +
    > +	ret = of_property_read_u32(dev->of_node, "xlnx,cluster-mode", &rpu_mode);
    > +	if (ret < 0 || (rpu_mode != PM_RPU_MODE_LOCKSTEP &&
    > +			rpu_mode != PM_RPU_MODE_SPLIT)) {
    > +		dev_err(dev, "invalid cluster mode: ret %d mode %x\n",
    > +			ret, rpu_mode);
    > +		return ret;
    > +	}
    > +
    > +	dev_dbg(dev, "RPU configuration: %s\n",
    > +		rpu_mode == PM_RPU_MODE_LOCKSTEP ? "lockstep" : "split");
    > +
    > +	/*
    > +	 * if 2 RPUs provided but one is lockstep, then we have an
    > +	 * invalid configuration.
    > +	 */
    > +
    > +	core_count = of_get_available_child_count(dev->of_node);
    > +	if ((rpu_mode == PM_RPU_MODE_LOCKSTEP && core_count != 1) ||
    > +	    core_count > MAX_RPROCS)
    > +		return -EINVAL;
    > +
    > +	cluster = devm_kzalloc(dev, sizeof(*cluster), GFP_KERNEL);
    > +	if (!cluster)
    > +		return -ENOMEM;
    > +	INIT_LIST_HEAD(cluster);
    > +
    > +	ret = devm_of_platform_populate(dev);
    > +	if (ret) {
    > +		dev_err(dev, "devm_of_platform_populate failed, ret = %d\n", ret);
    > +		return ret;
    > +	}
    > +
    > +	/* probe each individual r5 core's remoteproc-related info */
    > +	for_each_available_child_of_node(dev->of_node, nc) {
    > +		child_pdev = of_find_device_by_node(nc);

    The device reference needs to be dropped after use, as described in the function
    documentation.

    I'm out of time - I will continue tomorrow.

    Mathieu


[Ben] By this do you mean that for each platform_device should have a call like
	platform_set_drvdata(child_pdev, NULL); if it fails? or something else?

I will reply to your remaining feedback for this revision in the other email you sent.

Thanks
Ben

    > +		if (!child_pdev) {
    > +			dev_err(dev, "could not get R5 core platform device\n");
    > +			ret = -ENODEV;
    > +			goto out;
    > +		}
    > +
    > +		z_rproc = zynqmp_r5_probe(child_pdev, nc, rpu_mode);
    > +		dev_dbg(dev, "%s to probe rpu %pOF\n",
    > +			ret ? "Failed" : "Able", nc);
    > +		if (IS_ERR(z_rproc)) {
    > +			ret = PTR_ERR(z_rproc);
    > +			goto out;
    > +		}
    > +		list_add_tail(&z_rproc->elem, cluster);
    > +	}
    > +	/* wire in so each core can be cleaned up at driver remove */
    > +	platform_set_drvdata(pdev, cluster);
    > +	return 0;
    > +out:
    > +	list_for_each(pos, cluster) {
    > +		z_rproc = list_entry(pos, struct zynqmp_r5_rproc, elem);
    > +		zynqmp_r5_cleanup_mbox(z_rproc);
    > +	}
    > +	return ret;
    > +}
    > +
    > +/*
    > + * zynqmp_r5_remoteproc_remove
    > + *
    > + * @pdev: domain platform device for R5 cluster
    > + *
    > + * When the driver is unloaded, clean up the mailboxes for each
    > + * remoteproc that was initially probed.
    > + */
    > +static int zynqmp_r5_remoteproc_remove(struct platform_device *pdev)
    > +{
    > +	struct list_head *pos, *temp, *cluster = (struct list_head *)
    > +						 platform_get_drvdata(pdev);
    > +	struct zynqmp_r5_rproc *z_rproc = NULL;
    > +
    > +	list_for_each_safe(pos, temp, cluster) {
    > +		z_rproc = list_entry(pos, struct zynqmp_r5_rproc, elem);
    > +		zynqmp_r5_cleanup_mbox(z_rproc);
    > +	}
    > +	return 0;
    > +}
    > +
    > +/* Match table for OF platform binding */
    > +static const struct of_device_id zynqmp_r5_remoteproc_match[] = {
    > +	{ .compatible = "xlnx,zynqmp-r5-remoteproc", },
    > +	{ /* 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_AUTHOR("Ben Levinsky <ben.levinsky at xilinx.com>");
    > +MODULE_LICENSE("GPL v2");
    > -- 
    > 2.17.1
    > 



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