Hi,
thx for reworking the memory ordering.
I just found few more nits:
On Mon, 2024-06-24 at 13:26 +0530, Basavaraj Natikar wrote:
> Add support for AMD AE4DMA controller. It performs high-bandwidth
> memory to memory and IO copy operation. Device commands are managed
> via a circular queue of 'descriptors', each of which specifies source
> and destination addresses for copying a single buffer of data.
>
> Reviewed-by: Raju Rangoju <Raju.Rangoju@xxxxxxx>
> Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx>
> ---
> MAINTAINERS | 6 +
> drivers/dma/amd/Kconfig | 1 +
> drivers/dma/amd/Makefile | 1 +
> drivers/dma/amd/ae4dma/Kconfig | 14 ++
> drivers/dma/amd/ae4dma/Makefile | 10 ++
> drivers/dma/amd/ae4dma/ae4dma-dev.c | 200
> ++++++++++++++++++++++++++++
> drivers/dma/amd/ae4dma/ae4dma-pci.c | 157 ++++++++++++++++++++++
> drivers/dma/amd/ae4dma/ae4dma.h | 77 +++++++++++
> drivers/dma/amd/common/amd_dma.h | 26 ++++
> 9 files changed, 492 insertions(+)
> create mode 100644 drivers/dma/amd/ae4dma/Kconfig
> create mode 100644 drivers/dma/amd/ae4dma/Makefile
> create mode 100644 drivers/dma/amd/ae4dma/ae4dma-dev.c
> create mode 100644 drivers/dma/amd/ae4dma/ae4dma-pci.c
> create mode 100644 drivers/dma/amd/ae4dma/ae4dma.h
> create mode 100644 drivers/dma/amd/common/amd_dma.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 537964afef55..42436e1cf1e2 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -947,6 +947,12 @@ L: linux-edac@xxxxxxxxxxxxxxx
> S: Supported
> F: drivers/ras/amd/atl/*
>
> +AMD AE4DMA DRIVER
> +M: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx>
> +L: dmaengine@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/dma/amd/ae4dma/
> +
> AMD AXI W1 DRIVER
> M: Kris Chaplin <kris.chaplin@xxxxxxx>
> R: Thomas Delev <thomas.delev@xxxxxxx>
> diff --git a/drivers/dma/amd/Kconfig b/drivers/dma/amd/Kconfig
> index 8246b463bcf7..8c25a3ed6b94 100644
> --- a/drivers/dma/amd/Kconfig
> +++ b/drivers/dma/amd/Kconfig
> @@ -3,3 +3,4 @@
> # AMD DMA Drivers
>
> source "drivers/dma/amd/ptdma/Kconfig"
> +source "drivers/dma/amd/ae4dma/Kconfig"
> diff --git a/drivers/dma/amd/Makefile b/drivers/dma/amd/Makefile
> index dd7257ba7e06..8049b06a9ff5 100644
> --- a/drivers/dma/amd/Makefile
> +++ b/drivers/dma/amd/Makefile
> @@ -4,3 +4,4 @@
> #
>
> obj-$(CONFIG_AMD_PTDMA) += ptdma/
> +obj-$(CONFIG_AMD_AE4DMA) += ae4dma/
> diff --git a/drivers/dma/amd/ae4dma/Kconfig
> b/drivers/dma/amd/ae4dma/Kconfig
> new file mode 100644
> index 000000000000..ea8a7fe68df5
> --- /dev/null
> +++ b/drivers/dma/amd/ae4dma/Kconfig
> @@ -0,0 +1,14 @@
> +# SPDX-License-Identifier: GPL-2.0
> +config AMD_AE4DMA
> + tristate "AMD AE4DMA Engine"
> + depends on (X86_64 || COMPILE_TEST) && PCI
> + depends on AMD_PTDMA
> + select DMA_ENGINE
> + select DMA_VIRTUAL_CHANNELS
> + help
> + Enable support for the AMD AE4DMA controller. This
> controller
> + provides DMA capabilities to perform high bandwidth memory
> to
> + memory and IO copy operations. It performs DMA transfer
> through
> + queue-based descriptor management. This DMA controller is
> intended
> + to be used with AMD Non-Transparent Bridge devices and not
> for
> + general purpose peripheral DMA.
> diff --git a/drivers/dma/amd/ae4dma/Makefile
> b/drivers/dma/amd/ae4dma/Makefile
> new file mode 100644
> index 000000000000..e918f85a80ec
> --- /dev/null
> +++ b/drivers/dma/amd/ae4dma/Makefile
> @@ -0,0 +1,10 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# AMD AE4DMA driver
> +#
> +
> +obj-$(CONFIG_AMD_AE4DMA) += ae4dma.o
> +
> +ae4dma-objs := ae4dma-dev.o
> +
> +ae4dma-$(CONFIG_PCI) += ae4dma-pci.o
> diff --git a/drivers/dma/amd/ae4dma/ae4dma-dev.c
> b/drivers/dma/amd/ae4dma/ae4dma-dev.c
> new file mode 100644
> index 000000000000..cb05fcb47987
> --- /dev/null
> +++ b/drivers/dma/amd/ae4dma/ae4dma-dev.c
> @@ -0,0 +1,200 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * AMD AE4DMA driver
> + *
> + * Copyright (c) 2024, Advanced Micro Devices, Inc.
> + * All Rights Reserved.
> + *
> + * Author: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx>
> + */
> +
> +#include "ae4dma.h"
> +
> +static unsigned int max_hw_q = 1;
> +module_param(max_hw_q, uint, 0444);
> +MODULE_PARM_DESC(max_hw_q, "max hw queues supported by engine (any
> non-zero value, default: 1)");
> +
> +static char *ae4_error_codes[] = {
> + "",
> + "ERR 01: INVALID HEADER DW0",
> + "ERR 02: INVALID STATUS",
> + "ERR 03: INVALID LENGTH - 4 BYTE ALIGNMENT",
> + "ERR 04: INVALID SRC ADDR - 4 BYTE ALIGNMENT",
> + "ERR 05: INVALID DST ADDR - 4 BYTE ALIGNMENT",
> + "ERR 06: INVALID ALIGNMENT",
> + "ERR 07: INVALID DESCRIPTOR",
> +};
> +
> +static void ae4_log_error(struct pt_device *d, int e)
> +{
> + if (e <= 7)
> + dev_info(d->dev, "AE4DMA error: %s (0x%x)\n",
> ae4_error_codes[e], e);
> + else if (e > 7 && e <= 15)
> + dev_info(d->dev, "AE4DMA error: %s (0x%x)\n",
> "INVALID DESCRIPTOR", e);
> + else if (e > 15 && e <= 31)
> + dev_info(d->dev, "AE4DMA error: %s (0x%x)\n",
> "INVALID DESCRIPTOR", e);
> + else if (e > 31 && e <= 63)
> + dev_info(d->dev, "AE4DMA error: %s (0x%x)\n",
> "INVALID DESCRIPTOR", e);
> + else if (e > 63 && e <= 127)
> + dev_info(d->dev, "AE4DMA error: %s (0x%x)\n", "PTE
> ERROR", e);
> + else if (e > 127 && e <= 255)
> + dev_info(d->dev, "AE4DMA error: %s (0x%x)\n", "PTE
> ERROR", e);
Those numbers are hardware-specific I guess? Would it make sense to
define constants for them? Or have a short comment where they come
from?
> + else
> + dev_info(d->dev, "Unknown AE4DMA error");
> +}
> +
> +static void ae4_check_status_error(struct ae4_cmd_queue *ae4cmd_q,
> int idx)
> +{
> + struct pt_cmd_queue *cmd_q = &ae4cmd_q->cmd_q;
> + struct ae4dma_desc desc;
> + u8 status;
> +
> + memcpy(&desc, &cmd_q->qbase[idx], sizeof(struct
> ae4dma_desc));
> + status = desc.dw1.status;
> + if (status && status != AE4_DESC_COMPLETED) {
> + cmd_q->cmd_error = desc.dw1.err_code;
> + if (cmd_q->cmd_error)
> + ae4_log_error(cmd_q->pt, cmd_q->cmd_error);
> + }
> +}
> +
> +static void ae4_pending_work(struct work_struct *work)
> +{
> + struct ae4_cmd_queue *ae4cmd_q = container_of(work, struct
> ae4_cmd_queue, p_work.work);
> + struct pt_cmd_queue *cmd_q = &ae4cmd_q->cmd_q;
> + struct pt_cmd *cmd;
> + u32 cridx;
> +
> + while (true) {
Nit: I think
for (;;) {
is more idiomatic in the kernel
> + wait_event_interruptible(ae4cmd_q->q_w,
> + ((atomic64_read(&ae4cmd_q-
> >done_cnt)) <
> + atomic64_read(&ae4cmd_q-
> >intr_cnt)));
> +
> + atomic64_inc(&ae4cmd_q->done_cnt);
> +
> + mutex_lock(&ae4cmd_q->cmd_lock);
> +
> + cridx = readl(cmd_q->reg_control + 0x0C);
Magic number 0x0C – what does it mean? I'd define a constant.
> +
> + while ((ae4cmd_q->dridx != cridx) &&
> !list_empty(&ae4cmd_q->cmd)) {
> + cmd = list_first_entry(&ae4cmd_q->cmd, struct
> pt_cmd, entry);
> + list_del(&cmd->entry);
> +
> + ae4_check_status_error(ae4cmd_q, ae4cmd_q-
> >dridx);
> + cmd->pt_cmd_callback(cmd->data, cmd->ret);
> +
> + ae4cmd_q->q_cmd_count--;
> + ae4cmd_q->dridx = (ae4cmd_q->dridx + 1) %
> CMD_Q_LEN;
> +
> + complete_all(&ae4cmd_q->cmp);
> + }
> +
> + mutex_unlock(&ae4cmd_q->cmd_lock);
> + }
> +}
> +
> +static irqreturn_t ae4_core_irq_handler(int irq, void *data)
> +{
> + struct ae4_cmd_queue *ae4cmd_q = data;
> + struct pt_cmd_queue *cmd_q;
> + struct pt_device *pt;
> + u32 status;
> +
> + cmd_q = &ae4cmd_q->cmd_q;
> + pt = cmd_q->pt;
> +
> + pt->total_interrupts++;
> + atomic64_inc(&ae4cmd_q->intr_cnt);
> +
> + wake_up(&ae4cmd_q->q_w);
> +
> + status = readl(cmd_q->reg_control + 0x14);
> + if (status & BIT(0)) {
> + status &= GENMASK(31, 1);
> + writel(status, cmd_q->reg_control + 0x14);
same with 0x14
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +void ae4_destroy_work(struct ae4_device *ae4)
> +{
> + struct ae4_cmd_queue *ae4cmd_q;
> + int i;
> +
> + for (i = 0; i < ae4->cmd_q_count; i++) {
> + ae4cmd_q = &ae4->ae4cmd_q[i];
> +
> + if (!ae4cmd_q->pws)
> + break;
> +
> + cancel_delayed_work_sync(&ae4cmd_q->p_work);
> + destroy_workqueue(ae4cmd_q->pws);
> + }
> +}
> +
> +int ae4_core_init(struct ae4_device *ae4)
> +{
> + struct pt_device *pt = &ae4->pt;
> + struct ae4_cmd_queue *ae4cmd_q;
> + struct device *dev = pt->dev;
> + struct pt_cmd_queue *cmd_q;
> + int i, ret = 0;
> +
> + writel(max_hw_q, pt->io_regs);
> +
> + for (i = 0; i < max_hw_q; i++) {
> + ae4cmd_q = &ae4->ae4cmd_q[i];
> + ae4cmd_q->id = ae4->cmd_q_count;
> + ae4->cmd_q_count++;
> +
> + cmd_q = &ae4cmd_q->cmd_q;
> + cmd_q->pt = pt;
> +
> + /* Preset some register values (Q size is 32byte
> (0x20)) */
> + cmd_q->reg_control = pt->io_regs + ((i + 1) * 0x20);
OK, here's a comment. Could think about doing:
#define Q_SIZE 0x20
> +
> + ret = devm_request_irq(dev, ae4->ae4_irq[i],
> ae4_core_irq_handler, 0,
> + dev_name(pt->dev), ae4cmd_q);
> + if (ret)
> + return ret;
> +
> + cmd_q->qsize = Q_SIZE(sizeof(struct ae4dma_desc));
> +
> + cmd_q->qbase = dmam_alloc_coherent(dev, cmd_q->qsize,
> &cmd_q->qbase_dma,
> + GFP_KERNEL);
> + if (!cmd_q->qbase)
> + return -ENOMEM;
> + }
> +
> + for (i = 0; i < ae4->cmd_q_count; i++) {
> + ae4cmd_q = &ae4->ae4cmd_q[i];
> +
> + cmd_q = &ae4cmd_q->cmd_q;
> +
> + /* Preset some register values (Q size is 32byte
> (0x20)) */
> + cmd_q->reg_control = pt->io_regs + ((i + 1) * 0x20);
same
> +
> + /* Update the device registers with queue
> information. */
> + writel(CMD_Q_LEN, cmd_q->reg_control + 0x08);
same
> +
> + cmd_q->qdma_tail = cmd_q->qbase_dma;
> + writel(lower_32_bits(cmd_q->qdma_tail), cmd_q-
> >reg_control + 0x18);
> + writel(upper_32_bits(cmd_q->qdma_tail), cmd_q-
> >reg_control + 0x1C);
same with those two
> +
> + INIT_LIST_HEAD(&ae4cmd_q->cmd);
> + init_waitqueue_head(&ae4cmd_q->q_w);
> +
> + ae4cmd_q->pws = alloc_ordered_workqueue("ae4dma_%d",
> WQ_MEM_RECLAIM, ae4cmd_q->id);
> + if (!ae4cmd_q->pws) {
> + ae4_destroy_work(ae4);
> + return -ENOMEM;
> + }
> + INIT_DELAYED_WORK(&ae4cmd_q->p_work,
> ae4_pending_work);
> + queue_delayed_work(ae4cmd_q->pws, &ae4cmd_q->p_work,
> usecs_to_jiffies(100));
> +
> + init_completion(&ae4cmd_q->cmp);
> + }
> +
> + return ret;
> +}
> diff --git a/drivers/dma/amd/ae4dma/ae4dma-pci.c
> b/drivers/dma/amd/ae4dma/ae4dma-pci.c
> new file mode 100644
> index 000000000000..43d36e9d1efb
> --- /dev/null
> +++ b/drivers/dma/amd/ae4dma/ae4dma-pci.c
> @@ -0,0 +1,157 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * AMD AE4DMA driver
> + *
> + * Copyright (c) 2024, Advanced Micro Devices, Inc.
> + * All Rights Reserved.
> + *
> + * Author: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx>
> + */
> +
> +#include "ae4dma.h"
> +
> +static int ae4_get_irqs(struct ae4_device *ae4)
> +{
> + struct ae4_msix *ae4_msix = ae4->ae4_msix;
> + struct pt_device *pt = &ae4->pt;
> + struct device *dev = pt->dev;
> + struct pci_dev *pdev;
> + int i, v, ret;
> +
> + pdev = to_pci_dev(dev);
> +
> + for (v = 0; v < ARRAY_SIZE(ae4_msix->msix_entry); v++)
> + ae4_msix->msix_entry[v].entry = v;
> +
> + ret = pci_alloc_irq_vectors(pdev, v, v, PCI_IRQ_MSIX);
> + if (ret != v) {
> + if (ret > 0)
> + pci_free_irq_vectors(pdev);
> +
> + dev_err(dev, "could not enable MSI-X (%d), trying
> MSI\n", ret);
> + ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
> + if (ret < 0) {
> + dev_err(dev, "could not enable MSI (%d)\n",
> ret);
> + return ret;
> + }
> +
> + ret = pci_irq_vector(pdev, 0);
> + if (ret < 0) {
> + pci_free_irq_vectors(pdev);
> + return ret;
> + }
> +
> + for (i = 0; i < MAX_AE4_HW_QUEUES; i++)
> + ae4->ae4_irq[i] = ret;
> +
> + } else {
> + ae4_msix->msix_count = ret;
> + for (i = 0; i < MAX_AE4_HW_QUEUES; i++)
> + ae4->ae4_irq[i] = ae4_msix-
> >msix_entry[i].vector;
> + }
> +
> + return ret;
> +}
> +
> +static void ae4_free_irqs(struct ae4_device *ae4)
> +{
> + struct ae4_msix *ae4_msix = ae4->ae4_msix;
> + struct pt_device *pt = &ae4->pt;
> + struct device *dev = pt->dev;
> + struct pci_dev *pdev;
> +
> + pdev = to_pci_dev(dev);
> +
> + if (ae4_msix && (ae4_msix->msix_count || ae4-
> >ae4_irq[MAX_AE4_HW_QUEUES - 1]))
> + pci_free_irq_vectors(pdev);
> +}
> +
> +static void ae4_deinit(struct ae4_device *ae4)
> +{
> + ae4_free_irqs(ae4);
> +}
> +
> +static int ae4_pci_probe(struct pci_dev *pdev, const struct
> pci_device_id *id)
> +{
> + struct device *dev = &pdev->dev;
> + struct ae4_device *ae4;
> + struct pt_device *pt;
> + int bar_mask;
> + int ret = 0;
> +
> + ae4 = devm_kzalloc(dev, sizeof(*ae4), GFP_KERNEL);
> + if (!ae4)
> + return -ENOMEM;
> +
> + ae4->ae4_msix = devm_kzalloc(dev, sizeof(struct ae4_msix),
> GFP_KERNEL);
> + if (!ae4->ae4_msix)
> + return -ENOMEM;
> +
> + ret = pcim_enable_device(pdev);
> + if (ret)
> + goto ae4_error;
> +
> + bar_mask = pci_select_bars(pdev, IORESOURCE_MEM);
> + ret = pcim_iomap_regions(pdev, bar_mask, "ae4dma");
> + if (ret)
> + goto ae4_error;
> +
> + pt = &ae4->pt;
> + pt->dev = dev;
> +
> + pt->io_regs = pcim_iomap_table(pdev)[0];
> + if (!pt->io_regs) {
> + ret = -ENOMEM;
> + goto ae4_error;
> + }
> +
> + ret = ae4_get_irqs(ae4);
> + if (ret < 0)
> + goto ae4_error;
> +
> + pci_set_master(pdev);
> +
> + dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48));
> +
> + dev_set_drvdata(dev, ae4);
> +
> + ret = ae4_core_init(ae4);
> + if (ret)
> + goto ae4_error;
> +
> + return 0;
> +
> +ae4_error:
> + ae4_deinit(ae4);
> +
> + return ret;
> +}
> +
> +static void ae4_pci_remove(struct pci_dev *pdev)
> +{
> + struct ae4_device *ae4 = dev_get_drvdata(&pdev->dev);
> +
> + ae4_destroy_work(ae4);
> + ae4_deinit(ae4);
> +}
> +
> +static const struct pci_device_id ae4_pci_table[] = {
> + { PCI_VDEVICE(AMD, 0x14C8), },
> + { PCI_VDEVICE(AMD, 0x14DC), },
> + { PCI_VDEVICE(AMD, 0x149B), },
> + /* Last entry must be zero */
> + { 0, }
> +};
> +MODULE_DEVICE_TABLE(pci, ae4_pci_table);
> +
> +static struct pci_driver ae4_pci_driver = {
> + .name = "ae4dma",
> + .id_table = ae4_pci_table,
> + .probe = ae4_pci_probe,
> + .remove = ae4_pci_remove,
> +};
> +
> +module_pci_driver(ae4_pci_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("AMD AE4DMA driver");
> diff --git a/drivers/dma/amd/ae4dma/ae4dma.h
> b/drivers/dma/amd/ae4dma/ae4dma.h
> new file mode 100644
> index 000000000000..59a0ea3293cb
> --- /dev/null
> +++ b/drivers/dma/amd/ae4dma/ae4dma.h
> @@ -0,0 +1,77 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * AMD AE4DMA driver
> + *
> + * Copyright (c) 2024, Advanced Micro Devices, Inc.
> + * All Rights Reserved.
> + *
> + * Author: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx>
> + */
> +#ifndef __AE4DMA_H__
> +#define __AE4DMA_H__
> +
> +#include "../common/amd_dma.h"
> +
> +#define MAX_AE4_HW_QUEUES 16
> +
> +#define AE4_DESC_COMPLETED 0x3
Here you define some :)
Thanks,
P.
> +
> +struct ae4_msix {
> + int msix_count;
> + struct msix_entry msix_entry[MAX_AE4_HW_QUEUES];
> +};
> +
> +struct ae4_cmd_queue {
> + struct ae4_device *ae4;
> + struct pt_cmd_queue cmd_q;
> + struct list_head cmd;
> + /* protect command operations */
> + struct mutex cmd_lock;
> + struct delayed_work p_work;
> + struct workqueue_struct *pws;
> + struct completion cmp;
> + wait_queue_head_t q_w;
> + atomic64_t intr_cnt;
> + atomic64_t done_cnt;
> + u64 q_cmd_count;
> + u32 dridx;
> + u32 id;
> +};
> +
> +union dwou {
> + u32 dw0;
> + struct dword0 {
> + u8 byte0;
> + u8 byte1;
> + u16 timestamp;
> + } dws;
> +};
> +
> +struct dword1 {
> + u8 status;
> + u8 err_code;
> + u16 desc_id;
> +};
> +
> +struct ae4dma_desc {
> + union dwou dwouv;
> + struct dword1 dw1;
> + u32 length;
> + u32 rsvd;
> + u32 src_hi;
> + u32 src_lo;
> + u32 dst_hi;
> + u32 dst_lo;
> +};
> +
> +struct ae4_device {
> + struct pt_device pt;
> + struct ae4_msix *ae4_msix;
> + struct ae4_cmd_queue ae4cmd_q[MAX_AE4_HW_QUEUES];
> + unsigned int ae4_irq[MAX_AE4_HW_QUEUES];
> + unsigned int cmd_q_count;
> +};
> +
> +int ae4_core_init(struct ae4_device *ae4);
> +void ae4_destroy_work(struct ae4_device *ae4);
> +#endif
> diff --git a/drivers/dma/amd/common/amd_dma.h
> b/drivers/dma/amd/common/amd_dma.h
> new file mode 100644
> index 000000000000..f9f396cd4371
> --- /dev/null
> +++ b/drivers/dma/amd/common/amd_dma.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * AMD DMA Driver common
> + *
> + * Copyright (c) 2024, Advanced Micro Devices, Inc.
> + * All Rights Reserved.
> + *
> + * Author: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx>
> + */
> +
> +#ifndef AMD_DMA_H
> +#define AMD_DMA_H
> +
> +#include <linux/device.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dmapool.h>
> +#include <linux/list.h>
> +#include <linux/mutex.h>
> +#include <linux/pci.h>
> +#include <linux/spinlock.h>
> +#include <linux/wait.h>
> +
> +#include "../ptdma/ptdma.h"
> +#include "../../virt-dma.h"
> +
> +#endif
