Re: [PATCH V3 XRT Alveo 12/18] fpga: xrt: ICAP platform driver

Lizhi Hou
2021-03-17T20:57:40Z

Hi Tom,

On 03/03/2021 07:12 AM, Tom Rix wrote:
> On 2/17/21 10:40 PM, Lizhi Hou wrote:
>> Add ICAP driver. ICAP is a hardware function discovered by walking
> What does ICAP stand for ?
ICAP stands for Hardware Internal Configuration Access Port. I will add
this.
>> firmware metadata. A platform device node will be created for it.
>> FPGA bitstream is written to hardware through ICAP.
>>
>> Signed-off-by: Sonal Santan <sonal.santan@xilinx.com>
>> Signed-off-by: Max Zhen <max.zhen@xilinx.com>
>> Signed-off-by: Lizhi Hou <lizhih@xilinx.com>
>> ---
>> drivers/fpga/xrt/include/xleaf/icap.h | 29 +++
>> drivers/fpga/xrt/lib/xleaf/icap.c | 317 ++++++++++++++++++++++++++
>> 2 files changed, 346 insertions(+)
>> create mode 100644 drivers/fpga/xrt/include/xleaf/icap.h
>> create mode 100644 drivers/fpga/xrt/lib/xleaf/icap.c
>>
>> diff --git a/drivers/fpga/xrt/include/xleaf/icap.h b/drivers/fpga/xrt/include/xleaf/icap.h
>> new file mode 100644
>> index 000000000000..a14fc0ffa78f
>> --- /dev/null
>> +++ b/drivers/fpga/xrt/include/xleaf/icap.h
>> @@ -0,0 +1,29 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * Header file for XRT ICAP Leaf Driver
>> + *
>> + * Copyright (C) 2020-2021 Xilinx, Inc.
>> + *
>> + * Authors:
>> + * Lizhi Hou <Lizhi.Hou@xilinx.com>
>> + */
>> +
>> +#ifndef _XRT_ICAP_H_
>> +#define _XRT_ICAP_H_
>> +
>> +#include "xleaf.h"
>> +
>> +/*
>> + * ICAP driver IOCTL calls.
>> + */
>> +enum xrt_icap_ioctl_cmd {
>> + XRT_ICAP_WRITE = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
> maybe XRT_ICAP_GET_IDCODE
Sure.
>> + XRT_ICAP_IDCODE,
>> +};
>> +
>> +struct xrt_icap_ioctl_wr {
>> + void *xiiw_bit_data;
>> + u32 xiiw_data_len;
>> +};
>> +
>> +#endif /* _XRT_ICAP_H_ */
>> diff --git a/drivers/fpga/xrt/lib/xleaf/icap.c b/drivers/fpga/xrt/lib/xleaf/icap.c
>> new file mode 100644
>> index 000000000000..0500a97bdef9
>> --- /dev/null
>> +++ b/drivers/fpga/xrt/lib/xleaf/icap.c
>> @@ -0,0 +1,317 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Xilinx Alveo FPGA ICAP Driver
>> + *
>> + * Copyright (C) 2020-2021 Xilinx, Inc.
>> + *
>> + * Authors:
>> + * Lizhi Hou<Lizhi.Hou@xilinx.com>
>> + * Sonal Santan <sonals@xilinx.com>
>> + * Max Zhen <maxz@xilinx.com>
>> + */
>> +
>> +#include <linux/mod_devicetable.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/delay.h>
>> +#include <linux/device.h>
>> +#include <linux/io.h>
>> +#include "metadata.h"
>> +#include "xleaf.h"
>> +#include "xleaf/icap.h"
>> +#include "xclbin-helper.h"
>> +
>> +#define XRT_ICAP "xrt_icap"
>> +
>> +#define ICAP_ERR(icap, fmt, arg...) \
>> + xrt_err((icap)->pdev, fmt "\n", ##arg)
>> +#define ICAP_WARN(icap, fmt, arg...) \
>> + xrt_warn((icap)->pdev, fmt "\n", ##arg)
>> +#define ICAP_INFO(icap, fmt, arg...) \
>> + xrt_info((icap)->pdev, fmt "\n", ##arg)
>> +#define ICAP_DBG(icap, fmt, arg...) \
>> + xrt_dbg((icap)->pdev, fmt "\n", ##arg)
>> +
>> +/*
>> + * AXI-HWICAP IP register layout
>> + */
>> +struct icap_reg {
>> + u32 ir_rsvd1[7];
>> + u32 ir_gier;
>> + u32 ir_isr;
>> + u32 ir_rsvd2;
>> + u32 ir_ier;
>> + u32 ir_rsvd3[53];
>> + u32 ir_wf;
>> + u32 ir_rf;
>> + u32 ir_sz;
>> + u32 ir_cr;
>> + u32 ir_sr;
>> + u32 ir_wfv;
>> + u32 ir_rfo;
>> + u32 ir_asr;
>> +} __packed;
>> +
>> +struct icap {
>> + struct platform_device *pdev;
>> + struct icap_reg *icap_regs;
>> + struct mutex icap_lock; /* icap dev lock */
>> +
>> + unsigned int idcode;
> returned as a 64 bit value, but could be stored as 32 bit
Will change return to u32.
>> +};
>> +
>> +static inline u32 reg_rd(void __iomem *reg)
>> +{
>> + if (!reg)
>> + return -1;
>> +
>> + return ioread32(reg);
> Look at converting the io access to using regmap* api
Will change it.
>> +}
>> +
>> +static inline void reg_wr(void __iomem *reg, u32 val)
>> +{
>> + if (!reg)
>> + return;
>> +
>> + iowrite32(val, reg);
>> +}
>> +
>> +static int wait_for_done(struct icap *icap)
>> +{
>> + u32 w;
>> + int i = 0;
>> +
>> + WARN_ON(!mutex_is_locked(&icap->icap_lock));
> is this needed ? wait_for_done is only called in one place.
Will remove it.
>> + for (i = 0; i < 10; i++) {
>> + udelay(5);
> comment on delay.
>> + w = reg_rd(&icap->icap_regs->ir_sr);
>> + ICAP_INFO(icap, "XHWICAP_SR: %x", w);
>> + if (w & 0x5)
> 0x5 is a magic number, should be #defined
Sure.
>> + return 0;
>> + }
>> +
>> + ICAP_ERR(icap, "bitstream download timeout");
>> + return -ETIMEDOUT;
>> +}
>> +
>> +static int icap_write(struct icap *icap, const u32 *word_buf, int size)
>> +{
>> + int i;
>> + u32 value = 0;
>> +
>> + for (i = 0; i < size; i++) {
>> + value = be32_to_cpu(word_buf[i]);
>> + reg_wr(&icap->icap_regs->ir_wf, value);
>> + }
>> +
>> + reg_wr(&icap->icap_regs->ir_cr, 0x1);
>> +
>> + for (i = 0; i < 20; i++) {
>> + value = reg_rd(&icap->icap_regs->ir_cr);
>> + if ((value & 0x1) == 0)
>> + return 0;
>> + ndelay(50);
>> + }
>> +
>> + ICAP_ERR(icap, "writing %d dwords timeout", size);
>> + return -EIO;
>> +}
>> +
>> +static int bitstream_helper(struct icap *icap, const u32 *word_buffer,
>> + u32 word_count)
>> +{
>> + u32 remain_word;
>> + u32 word_written = 0;
>> + int wr_fifo_vacancy = 0;
>> + int err = 0;
>> +
>> + WARN_ON(!mutex_is_locked(&icap->icap_lock));
>> + for (remain_word = word_count; remain_word > 0;
>> + remain_word -= word_written, word_buffer += word_written) {
>> + wr_fifo_vacancy = reg_rd(&icap->icap_regs->ir_wfv);
>> + if (wr_fifo_vacancy <= 0) {
>> + ICAP_ERR(icap, "no vacancy: %d", wr_fifo_vacancy);
>> + err = -EIO;
>> + break;
>> + }
>> + word_written = (wr_fifo_vacancy < remain_word) ?
>> + wr_fifo_vacancy : remain_word;
>> + if (icap_write(icap, word_buffer, word_written) != 0) {
>> + ICAP_ERR(icap, "write failed remain %d, written %d",
>> + remain_word, word_written);
>> + err = -EIO;
>> + break;
>> + }
>> + }
>> +
>> + return err;
>> +}
>> +
>> +static int icap_download(struct icap *icap, const char *buffer,
>> + unsigned long length)
>> +{
>> + u32 num_chars_read = DMA_HWICAP_BITFILE_BUFFER_SIZE;
>> + u32 byte_read;
>> + int err = 0;
>> +
>> + mutex_lock(&icap->icap_lock);
>> + for (byte_read = 0; byte_read < length; byte_read += num_chars_read) {
>> + num_chars_read = length - byte_read;
>> + if (num_chars_read > DMA_HWICAP_BITFILE_BUFFER_SIZE)
>> + num_chars_read = DMA_HWICAP_BITFILE_BUFFER_SIZE;
>> +
>> + err = bitstream_helper(icap, (u32 *)buffer, num_chars_read / sizeof(u32));
> assumption that num_chars_read % 4 == 0
>
> Add a check, or handle.
Sure.
>
>> + if (err)
>> + goto failed;
>> + buffer += num_chars_read;
>> + }
>> +
>> + err = wait_for_done(icap);
> timeout is not handled
>> +
>> +failed:
>> + mutex_unlock(&icap->icap_lock);
>> +
>> + return err;
>> +}
>> +
>> +/*
>> + * Run the following sequence of canned commands to obtain IDCODE of the FPGA
>> + */
>> +static void icap_probe_chip(struct icap *icap)
>> +{
>> + u32 w;
> De magic this.
>
> If this is a documented startup sequence, please add a link to the document.
>
> Else add a comment about what you are doing here.
>
> Where possible, convert the hex values to #defines.
Will add comment for this.

Thanks,
Lizhi
>
> Tom
>
>> +
>> + w = reg_rd(&icap->icap_regs->ir_sr);
>> + w = reg_rd(&icap->icap_regs->ir_sr);
>> + reg_wr(&icap->icap_regs->ir_gier, 0x0);
>> + w = reg_rd(&icap->icap_regs->ir_wfv);
>> + reg_wr(&icap->icap_regs->ir_wf, 0xffffffff);
>> + reg_wr(&icap->icap_regs->ir_wf, 0xaa995566);
>> + reg_wr(&icap->icap_regs->ir_wf, 0x20000000);
>> + reg_wr(&icap->icap_regs->ir_wf, 0x20000000);
>> + reg_wr(&icap->icap_regs->ir_wf, 0x28018001);
>> + reg_wr(&icap->icap_regs->ir_wf, 0x20000000);
>> + reg_wr(&icap->icap_regs->ir_wf, 0x20000000);
>> + w = reg_rd(&icap->icap_regs->ir_cr);
>> + reg_wr(&icap->icap_regs->ir_cr, 0x1);
>> + w = reg_rd(&icap->icap_regs->ir_cr);
>> + w = reg_rd(&icap->icap_regs->ir_cr);
>> + w = reg_rd(&icap->icap_regs->ir_sr);
>> + w = reg_rd(&icap->icap_regs->ir_cr);
>> + w = reg_rd(&icap->icap_regs->ir_sr);
>> + reg_wr(&icap->icap_regs->ir_sz, 0x1);
>> + w = reg_rd(&icap->icap_regs->ir_cr);
>> + reg_wr(&icap->icap_regs->ir_cr, 0x2);
>> + w = reg_rd(&icap->icap_regs->ir_rfo);
>> + icap->idcode = reg_rd(&icap->icap_regs->ir_rf);
>> + w = reg_rd(&icap->icap_regs->ir_cr);
>> + (void)w;
>> +}
>> +
>> +static int
>> +xrt_icap_leaf_ioctl(struct platform_device *pdev, u32 cmd, void *arg)
>> +{
>> + struct xrt_icap_ioctl_wr *wr_arg = arg;
>> + struct icap *icap;
>> + int ret = 0;
>> +
>> + icap = platform_get_drvdata(pdev);
>> +
>> + switch (cmd) {
>> + case XRT_XLEAF_EVENT:
>> + /* Does not handle any event. */
>> + break;
>> + case XRT_ICAP_WRITE:
>> + ret = icap_download(icap, wr_arg->xiiw_bit_data,
>> + wr_arg->xiiw_data_len);
>> + break;
>> + case XRT_ICAP_IDCODE:
>> + *(u64 *)arg = icap->idcode;
>> + break;
>> + default:
>> + ICAP_ERR(icap, "unknown command %d", cmd);
>> + return -EINVAL;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int xrt_icap_remove(struct platform_device *pdev)
>> +{
>> + struct icap *icap;
>> +
>> + icap = platform_get_drvdata(pdev);
>> +
>> + platform_set_drvdata(pdev, NULL);
>> + devm_kfree(&pdev->dev, icap);
>> +
>> + return 0;
>> +}
>> +
>> +static int xrt_icap_probe(struct platform_device *pdev)
>> +{
>> + struct icap *icap;
>> + int ret = 0;
>> + struct resource *res;
>> +
>> + icap = devm_kzalloc(&pdev->dev, sizeof(*icap), GFP_KERNEL);
>> + if (!icap)
>> + return -ENOMEM;
>> +
>> + icap->pdev = pdev;
>> + platform_set_drvdata(pdev, icap);
>> + mutex_init(&icap->icap_lock);
>> +
>> + xrt_info(pdev, "probing");
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (res) {
>> + icap->icap_regs = ioremap(res->start, res->end - res->start + 1);
>> + if (!icap->icap_regs) {
>> + xrt_err(pdev, "map base failed %pR", res);
>> + ret = -EIO;
>> + goto failed;
>> + }
>> + }
>> +
>> + icap_probe_chip(icap);
>> +failed:
>> + return ret;
>> +}
>> +
>> +static struct xrt_subdev_endpoints xrt_icap_endpoints[] = {
>> + {
>> + .xse_names = (struct xrt_subdev_ep_names[]) {
>> + { .ep_name = XRT_MD_NODE_FPGA_CONFIG },
>> + { NULL },
>> + },
>> + .xse_min_ep = 1,
>> + },
>> + { 0 },
>> +};
>> +
>> +static struct xrt_subdev_drvdata xrt_icap_data = {
>> + .xsd_dev_ops = {
>> + .xsd_ioctl = xrt_icap_leaf_ioctl,
>> + },
>> +};
>> +
>> +static const struct platform_device_id xrt_icap_table[] = {
>> + { XRT_ICAP, (kernel_ulong_t)&xrt_icap_data },
>> + { },
>> +};
>> +
>> +static struct platform_driver xrt_icap_driver = {
>> + .driver = {
>> + .name = XRT_ICAP,
>> + },
>> + .probe = xrt_icap_probe,
>> + .remove = xrt_icap_remove,
>> + .id_table = xrt_icap_table,
>> +};
>> +
>> +void icap_leaf_init_fini(bool init)
>> +{
>> + if (init)
>> + xleaf_register_driver(XRT_SUBDEV_ICAP, &xrt_icap_driver, xrt_icap_endpoints);
>> + else
>> + xleaf_unregister_driver(XRT_SUBDEV_ICAP);
>> +}