[PATCH v2 5/6] remoteproc/pru: Add support for various PRU cores on K3 AM65x SoCs
Mathieu Poirier
mathieu.poirier at linaro.org
Thu Dec 3 13:51:18 EST 2020
On Thu, Nov 19, 2020 at 03:08:49PM +0100, Grzegorz Jaszczyk wrote:
> From: Suman Anna <s-anna at ti.com>
>
> The K3 AM65x family of SoCs have the next generation of the PRU-ICSS
> processor subsystem, commonly referred to as ICSSG. Each ICSSG processor
> subsystem on AM65x SR1.0 contains two primary PRU cores and two new
> auxiliary PRU cores called RTUs. The AM65x SR2.0 SoCs have a revised
> ICSSG IP that is based off the subsequent IP revision used on J721E
> SoCs. This IP instance has two new custom auxiliary PRU cores called
> Transmit PRUs (Tx_PRUs) in addition to the existing PRUs and RTUs.
>
> Each RTU and Tx_PRU cores have their own dedicated IRAM (smaller than
> a PRU), Control and debug feature sets, but is different in terms of
> sub-modules integrated around it and does not have the full capabilities
> associated with a PRU core. The RTU core is typically used to aid a
> PRU core in accelerating data transfers, while the Tx_PRU cores is
> normally used to control the TX L2 FIFO if enabled in Ethernet
> applications. Both can also be used to run independent applications.
> The RTU and Tx_PRU cores though share the same Data RAMs as the PRU
> cores, so the memories have to be partitioned carefully between different
> applications. The new cores also support a new sub-module called Task
> Manager to support two different context thread executions.
>
> Enhance the existing PRU remoteproc driver to support these new PRU, RTU
> and Tx PRU cores by using specific compatibles. The initial names for the
> firmware images for each PRU core are retrieved from DT nodes, and can
> be adjusted through sysfs if required.
>
> The PRU remoteproc driver has to be specifically modified to use a
> custom memcpy function within its ELF loader implementation for these
> new cores in order to overcome a limitation with copying data into each
> of the core's IRAM memories. These memory ports support only 4-byte
> writes, and any sub-word order byte writes clear out the remaining
> bytes other than the bytes being written within the containing word.
> The default ARM64 memcpy also cannot be used as it throws an exception
> when the preferred 8-byte copy operation is attempted. This choice is
> made by using a state flag that is set only on K3 SoCs.
>
> Signed-off-by: Suman Anna <s-anna at ti.com>
> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>
> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>
> ---
> v1->v2:
> - Update documentation of pru_rproc_memcpy() according to Suman
> comments.
> - Update documentation of is_k3 flag.
> ---
> drivers/remoteproc/pru_rproc.c | 140 ++++++++++++++++++++++++++++++---
> 1 file changed, 131 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
> index d5f04d77ad54..48c1c51e0d42 100644
> --- a/drivers/remoteproc/pru_rproc.c
> +++ b/drivers/remoteproc/pru_rproc.c
> @@ -46,10 +46,14 @@
> #define PRU_DEBUG_GPREG(x) (0x0000 + (x) * 4)
> #define PRU_DEBUG_CT_REG(x) (0x0080 + (x) * 4)
>
> -/* PRU Core IRAM address masks */
> +/* PRU/RTU/Tx_PRU Core IRAM address masks */
> #define PRU_IRAM_ADDR_MASK 0x3ffff
> #define PRU0_IRAM_ADDR_MASK 0x34000
> #define PRU1_IRAM_ADDR_MASK 0x38000
> +#define RTU0_IRAM_ADDR_MASK 0x4000
> +#define RTU1_IRAM_ADDR_MASK 0x6000
> +#define TX_PRU0_IRAM_ADDR_MASK 0xa000
> +#define TX_PRU1_IRAM_ADDR_MASK 0xc000
>
> /* PRU device addresses for various type of PRU RAMs */
> #define PRU_IRAM_DA 0 /* Instruction RAM */
> @@ -74,12 +78,38 @@ enum pru_iomem {
> PRU_IOMEM_MAX,
> };
>
> +/**
> + * enum pru_type - PRU core type identifier
> + *
> + * @PRU_TYPE_PRU: Programmable Real-time Unit
> + * @PRU_TYPE_RTU: Auxiliary Programmable Real-Time Unit
> + * @PRU_TYPE_TX_PRU: Transmit Programmable Real-Time Unit
> + * @PRU_TYPE_MAX: just keep this one at the end
> + */
> +enum pru_type {
> + PRU_TYPE_PRU = 0,
> + PRU_TYPE_RTU,
> + PRU_TYPE_TX_PRU,
> + PRU_TYPE_MAX,
> +};
> +
> +/**
> + * struct pru_private_data - device data for a PRU core
> + * @type: type of the PRU core (PRU, RTU, Tx_PRU)
> + * @is_k3: flag used to identify the need for special load handling
> + */
> +struct pru_private_data {
> + enum pru_type type;
> + unsigned int is_k3 : 1;
> +};
> +
> /**
> * struct pru_rproc - PRU remoteproc structure
> * @id: id of the PRU core within the PRUSS
> * @dev: PRU core device pointer
> * @pruss: back-reference to parent PRUSS structure
> * @rproc: remoteproc pointer for this PRU core
> + * @data: PRU core specific data
> * @mem_regions: data for each of the PRU memory regions
> * @fw_name: name of firmware image used during loading
> * @mapped_irq: virtual interrupt numbers of created fw specific mapping
> @@ -94,6 +124,7 @@ struct pru_rproc {
> struct device *dev;
> struct pruss *pruss;
> struct rproc *rproc;
> + const struct pru_private_data *data;
> struct pruss_mem_region mem_regions[PRU_IOMEM_MAX];
> const char *fw_name;
> int *mapped_irq;
> @@ -319,11 +350,12 @@ static int pru_rproc_start(struct rproc *rproc)
> {
> struct device *dev = &rproc->dev;
> struct pru_rproc *pru = rproc->priv;
> + const char *names[PRU_TYPE_MAX] = { "PRU", "RTU", "Tx_PRU" };
> u32 val;
> int ret;
>
> - dev_dbg(dev, "starting PRU%d: entry-point = 0x%llx\n",
> - pru->id, (rproc->bootaddr >> 2));
> + dev_dbg(dev, "starting %s%d: entry-point = 0x%llx\n",
> + names[pru->data->type], pru->id, (rproc->bootaddr >> 2));
>
> ret = pru_handle_intrmap(rproc);
> /*
> @@ -345,9 +377,10 @@ static int pru_rproc_stop(struct rproc *rproc)
> {
> struct device *dev = &rproc->dev;
> struct pru_rproc *pru = rproc->priv;
> + const char *names[PRU_TYPE_MAX] = { "PRU", "RTU", "Tx_PRU" };
> u32 val;
>
> - dev_dbg(dev, "stopping PRU%d\n", pru->id);
> + dev_dbg(dev, "stopping %s%d\n", names[pru->data->type], pru->id);
>
> val = pru_control_read_reg(pru, PRU_CTRL_CTRL);
> val &= ~CTRL_CTRL_EN;
> @@ -459,9 +492,52 @@ static struct rproc_ops pru_rproc_ops = {
> .da_to_va = pru_rproc_da_to_va,
> };
>
> +/*
> + * Custom memory copy implementation for ICSSG PRU/RTU/Tx_PRU Cores
> + *
> + * The ICSSG PRU/RTU/Tx_PRU cores have a memory copying issue with IRAM
> + * memories, that is not seen on previous generation SoCs. The data is reflected
> + * properly in the IRAM memories only for integer (4-byte) copies. Any unaligned
> + * copies result in all the other pre-existing bytes zeroed out within that
> + * 4-byte boundary, thereby resulting in wrong text/code in the IRAMs. Also, the
> + * IRAM memory port interface does not allow any 8-byte copies (as commonly used
> + * by ARM64 memcpy implementation) and throws an exception. The DRAM memory
> + * ports do not show this behavior.
> + */
> +static int pru_rproc_memcpy(void *dest, const void *src, size_t count)
> +{
> + const int *s = src;
> + int *d = dest;
> + int size = count / 4;
> + int *tmp_src = NULL;
> +
> + /*
> + * TODO: relax limitation of 4-byte aligned dest addresses and copy
> + * sizes
> + */
> + if ((long)dest % 4 || count % 4)
> + return -EINVAL;
> +
> + /* src offsets in ELF firmware image can be non-aligned */
> + if ((long)src % 4) {
> + tmp_src = kmemdup(src, count, GFP_KERNEL);
> + if (!tmp_src)
> + return -ENOMEM;
> + s = tmp_src;
> + }
> +
> + while (size--)
> + *d++ = *s++;
I would have expected *d and *s to be u32 * ...
It doesn't matter much because the end result will be the same but it seems odd
to me, especially when doing memory manipulations.
Regardless:
Reviewed-by: Mathieu Poirier <mathieu.poirier at linaro.org>
> +
> + kfree(tmp_src);
> +
> + return 0;
> +}
> +
> static int
> pru_rproc_load_elf_segments(struct rproc *rproc, const struct firmware *fw)
> {
> + struct pru_rproc *pru = rproc->priv;
> struct device *dev = &rproc->dev;
> struct elf32_hdr *ehdr;
> struct elf32_phdr *phdr;
> @@ -513,7 +589,17 @@ pru_rproc_load_elf_segments(struct rproc *rproc, const struct firmware *fw)
> if (!phdr->p_filesz)
> continue;
>
> - memcpy(ptr, elf_data + phdr->p_offset, filesz);
> + if (pru->data->is_k3 && is_iram) {
> + ret = pru_rproc_memcpy(ptr, elf_data + phdr->p_offset,
> + filesz);
> + if (ret) {
> + dev_err(dev, "PRU memory copy failed for da 0x%x memsz 0x%x\n",
> + da, memsz);
> + break;
> + }
> + } else {
> + memcpy(ptr, elf_data + phdr->p_offset, filesz);
> + }
> }
>
> return ret;
> @@ -617,9 +703,17 @@ static int pru_rproc_set_id(struct pru_rproc *pru)
> int ret = 0;
>
> switch (pru->mem_regions[PRU_IOMEM_IRAM].pa & PRU_IRAM_ADDR_MASK) {
> + case TX_PRU0_IRAM_ADDR_MASK:
> + fallthrough;
> + case RTU0_IRAM_ADDR_MASK:
> + fallthrough;
> case PRU0_IRAM_ADDR_MASK:
> pru->id = 0;
> break;
> + case TX_PRU1_IRAM_ADDR_MASK:
> + fallthrough;
> + case RTU1_IRAM_ADDR_MASK:
> + fallthrough;
> case PRU1_IRAM_ADDR_MASK:
> pru->id = 1;
> break;
> @@ -640,8 +734,13 @@ static int pru_rproc_probe(struct platform_device *pdev)
> struct rproc *rproc = NULL;
> struct resource *res;
> int i, ret;
> + const struct pru_private_data *data;
> const char *mem_names[PRU_IOMEM_MAX] = { "iram", "control", "debug" };
>
> + data = of_device_get_match_data(&pdev->dev);
> + if (!data)
> + return -ENODEV;
> +
> ret = of_property_read_string(np, "firmware-name", &fw_name);
> if (ret) {
> dev_err(dev, "unable to retrieve firmware-name %d\n", ret);
> @@ -674,6 +773,7 @@ static int pru_rproc_probe(struct platform_device *pdev)
>
> pru = rproc->priv;
> pru->dev = dev;
> + pru->data = data;
> pru->pruss = platform_get_drvdata(ppdev);
> pru->rproc = rproc;
> pru->fw_name = fw_name;
> @@ -725,11 +825,33 @@ static int pru_rproc_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static const struct pru_private_data pru_data = {
> + .type = PRU_TYPE_PRU,
> +};
> +
> +static const struct pru_private_data k3_pru_data = {
> + .type = PRU_TYPE_PRU,
> + .is_k3 = 1,
> +};
> +
> +static const struct pru_private_data k3_rtu_data = {
> + .type = PRU_TYPE_RTU,
> + .is_k3 = 1,
> +};
> +
> +static const struct pru_private_data k3_tx_pru_data = {
> + .type = PRU_TYPE_TX_PRU,
> + .is_k3 = 1,
> +};
> +
> static const struct of_device_id pru_rproc_match[] = {
> - { .compatible = "ti,am3356-pru", },
> - { .compatible = "ti,am4376-pru", },
> - { .compatible = "ti,am5728-pru", },
> - { .compatible = "ti,k2g-pru", },
> + { .compatible = "ti,am3356-pru", .data = &pru_data },
> + { .compatible = "ti,am4376-pru", .data = &pru_data },
> + { .compatible = "ti,am5728-pru", .data = &pru_data },
> + { .compatible = "ti,k2g-pru", .data = &pru_data },
> + { .compatible = "ti,am654-pru", .data = &k3_pru_data },
> + { .compatible = "ti,am654-rtu", .data = &k3_rtu_data },
> + { .compatible = "ti,am654-tx-pru", .data = &k3_tx_pru_data },
> {},
> };
> MODULE_DEVICE_TABLE(of, pru_rproc_match);
> --
> 2.29.0
>
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