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Message-ID: <CAHp75Vf8WaDpL9ZyKL1VyY2e23mLzFZZx+Hfs_FHi5XFgWZ6XA@mail.gmail.com>
Date: Thu, 4 Feb 2016 19:50:53 +0200
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Jacek Lawrynowicz <jacek.lawrynowicz@...el.com>
Cc: Dan Williams <dan.j.williams@...el.com>,
Vinod Koul <vinod.koul@...el.com>,
dmaengine <dmaengine@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
ashutosh.dixit@...el.com, sudeep.dutt@...el.com,
andrzej.kacprowski@...el.com
Subject: Re: [PATCH RESEND 1/2] dmaengine: added MIC X200 Coprocessor DMA driver
On Thu, Feb 4, 2016 at 5:10 PM, Jacek Lawrynowicz
<jacek.lawrynowicz@...el.com> wrote:
> This patch implements the DMA Engine driver for the DMA controller on
> MIC X200 Coprocessors which are PCIe cards running Linux. Separate but
> identical DMA channels are available for the host and card. DMA
> transfers can be done from both the host and card in host<->card and
> host<->host directions.
>
Can it share code with 100 series?
> Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@...el.com>
> Signed-off-by: Sudeep Dutt <sudeep.dutt@...el.com>
> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@...el.com>
> Signed-off-by: Andrzej Kacprowski <andrzej.kacprowski@...el.com>
> ---
> drivers/dma/Kconfig | 18 +
> drivers/dma/Makefile | 1 +
> drivers/dma/mic_x200_dma.c | 1114 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 1133 insertions(+)
> create mode 100644 drivers/dma/mic_x200_dma.c
>
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index 79b1390..a3ea8b9 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -277,6 +277,24 @@ config INTEL_MIC_X100_DMA
> OS and tools for MIC to use with this driver are available from
> <http://software.intel.com/en-us/mic-developer>.
>
> +config INTEL_MIC_X200_DMA
> + tristate "Intel MIC X200 DMA Driver"
> + depends on 64BIT && X86 && PCI
Doesn't it the same like
depends on X86_64 && PCI
?
> + select DMAENGINE
> + help
> + This enables DMA support for the Intel Many Integrated Core
> + (MIC) family of PCIe form factor coprocessor X200 devices that
> + run a 64 bit Linux OS. This driver will be used by both MIC
> + host and card drivers.
> +
> + If you are building host kernel with a MIC device or a card
> + kernel for a MIC device, then say M (recommended) or Y, else
> + say N. If unsure say N.
> +
> + More information about the Intel MIC family as well as the Linux
> + OS and tools for MIC to use with this driver are available from
> + <http://software.intel.com/en-us/mic-developer>.
> +
> config K3_DMA
> tristate "Hisilicon K3 DMA support"
> depends on ARCH_HI3xxx
> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
> index 2dd0a067..a3756f5 100644
> --- a/drivers/dma/Makefile
> +++ b/drivers/dma/Makefile
> @@ -38,6 +38,7 @@ obj-$(CONFIG_INTEL_IDMA64) += idma64.o
> obj-$(CONFIG_INTEL_IOATDMA) += ioat/
> obj-$(CONFIG_INTEL_IOP_ADMA) += iop-adma.o
> obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
> +obj-$(CONFIG_INTEL_MIC_X200_DMA) += mic_x200_dma.o
> obj-$(CONFIG_K3_DMA) += k3dma.o
> obj-$(CONFIG_LPC18XX_DMAMUX) += lpc18xx-dmamux.o
> obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
> diff --git a/drivers/dma/mic_x200_dma.c b/drivers/dma/mic_x200_dma.c
> new file mode 100644
> index 0000000..80c4959
> --- /dev/null
> +++ b/drivers/dma/mic_x200_dma.c
> @@ -0,0 +1,1114 @@
> +/*
> + * Intel MIC Platform Software Stack (MPSS)
> + *
> + * Copyright(c) 2016 Intel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2, as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * The full GNU General Public License is included in this distribution in
> + * the file called "COPYING".
> + *
> + * Intel MIC X200 DMA driver
> + */
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/pci.h>
> +#include <linux/interrupt.h>
> +#include <linux/vmalloc.h>
> +
> +#include "dmaengine.h"
> +
> +#define MIC_DMA_DRV_NAME "mic_x200_dma"
> +
> +#define MIC_DMA_DESC_RX_SIZE (128 * 1024)
> +#define MIC_DMA_ABORT_TO_MS 3000
> +#define MIC_DMA_RING_TO_MS 20
> +#define MIC_DMA_PENDING_LEVEL 16
> +#define MIC_DMA_ABORT_LIMIT 5
> +
> +/* DMA Descriptor related flags */
> +#define MIC_DMA_DESC_VALID BIT(31)
> +#define MIC_DMA_DESC_INTR_ENABLE BIT(30)
> +#define MIC_DMA_DESC_SRC_LINK_ERR BIT(29)
> +#define MIC_DMA_DESC_DST_LINK_ERR BIT(28)
> +#define MIC_DMA_DESC_LOW_MASK (0xffffffffUL)
> +#define MIC_DMA_DESC_SRC_LOW_SHIFT 32
> +#define MIC_DMA_DESC_BITS_32_TO_47 (0xffffUL << 32)
> +#define MIC_DMA_DESC_SIZE_MASK ((1UL << 27) - 1)
> +
> +#define MIC_DMA_DESC_RING_ADDR_LOW 0x214
> +#define MIC_DMA_DESC_RING_ADDR_HIGH 0x218
> +#define MIC_DMA_NEXT_DESC_ADDR_LOW 0x21C
> +#define MIC_DMA_DESC_RING_SIZE 0x220
> +#define MIC_DMA_LAST_DESC_ADDR_LOW 0x224
> +#define MIC_DMA_LAST_DESC_XFER_SIZE 0x228
> +
> +#define MIC_DMA_CTRL_STATUS 0x238
> +#define MIC_DMA_CTRL_PAUSE BIT(0)
> +#define MIC_DMA_CTRL_ABORT BIT(1)
> +#define MIC_DMA_CTRL_WB_ENABLE BIT(2)
> +#define MIC_DMA_CTRL_START BIT(3)
> +#define MIC_DMA_CTRL_RING_STOP BIT(4)
> +#define MIC_DMA_CTRL_ONCHIP_MODE BIT(5)
> +#define MIC_DMA_CTRL_OFFCHIP_MODE (2UL << 5)
> +#define MIC_DMA_CTRL_DESC_INVLD_STATUS BIT(8)
> +#define MIC_DMA_CTRL_PAUSE_DONE_STATUS BIT(9)
> +#define MIC_DMA_CTRL_ABORT_DONE_STATUS BIT(10)
> +#define MIC_DMA_CTRL_FACTORY_TEST BIT(11)
> +#define MIC_DMA_CTRL_IMM_PAUSE_DONE_STATUS BIT(12)
> +#define MIC_DMA_CTRL_SRC_MAX_TRANSFER_SIZE (3UL << 16)
> +#define MIC_DMA_CTRL_RELAXED_DATA_WRITE BIT(25)
> +#define MIC_DMA_CTRL_NO_SNOOP_DESC_READ BIT(26)
> +#define MIC_DMA_CTRL_NO_SNOOP_DATA_READ BIT(27)
> +#define MIC_DMA_CTRL_NO_SNOOP_DESC_WRITE BIT(28)
> +#define MIC_DMA_CTRL_IN_PROGRESS BIT(30)
> +#define MIC_DMA_CTRL_HEADER_LOG BIT(31)
> +#define MIC_DMA_CTRL_MODE_BITS (3UL << 5)
> +#define MIC_DMA_CTRL_STATUS_BITS (0x1FUL << 8)
> +#define MIC_DMA_CTRL_STATUS_INIT (MIC_DMA_CTRL_SRC_MAX_TRANSFER_SIZE | \
> + MIC_DMA_CTRL_RELAXED_DATA_WRITE | \
> + MIC_DMA_CTRL_NO_SNOOP_DESC_READ | \
> + MIC_DMA_CTRL_NO_SNOOP_DATA_READ | \
> + MIC_DMA_CTRL_NO_SNOOP_DESC_WRITE)
> +
> +#define MIC_DMA_INTR_CTRL_STATUS 0x23C
> +#define MIC_DMA_ERROR_INTR_EN BIT(0)
> +#define MIC_DMA_INVLD_DESC_INTR_EN BIT(1)
> +#define MIC_DMA_ABORT_DONE_INTR_EN BIT(3)
> +#define MIC_DMA_GRACE_PAUSE_INTR_EN BIT(4)
> +#define MIC_DMA_IMM_PAUSE_INTR_EN BIT(5)
> +#define MIC_DMA_IRQ_PIN_INTR_EN BIT(15)
> +#define MIC_DMA_ERROR_INTR_STATUS BIT(16)
> +#define MIC_DMA_INVLD_DESC_INTR_STATUS BIT(17)
> +#define MIC_DMA_DESC_DONE_INTR_STATUS BIT(18)
> +#define MIC_DMA_ABORT_DONE_INTR_STATUS BIT(19)
> +#define MIC_DMA_GRACE_PAUSE_INTR_STATUS BIT(20)
> +#define MIC_DMA_IMM_PAUSE_INTR_STATUS BIT(21)
> +#define MIC_DMA_ALL_INTR_EN (MIC_DMA_ERROR_INTR_EN | \
> + MIC_DMA_INVLD_DESC_INTR_EN | \
> + MIC_DMA_ABORT_DONE_INTR_EN | \
> + MIC_DMA_GRACE_PAUSE_INTR_EN | \
> + MIC_DMA_IMM_PAUSE_INTR_EN)
> +
> +#define MIC_DMA_ERROR_STATUS (MIC_DMA_ERROR_INTR_STATUS | \
> + MIC_DMA_ABORT_DONE_INTR_STATUS | \
> + MIC_DMA_GRACE_PAUSE_INTR_STATUS | \
> + MIC_DMA_IMM_PAUSE_INTR_STATUS)
> +
> +#define MIC_DMA_ALL_INTR_STATUS (MIC_DMA_ERROR_INTR_STATUS | \
> + MIC_DMA_INVLD_DESC_INTR_STATUS | \
> + MIC_DMA_DESC_DONE_INTR_STATUS | \
> + MIC_DMA_ABORT_DONE_INTR_STATUS | \
> + MIC_DMA_GRACE_PAUSE_INTR_STATUS | \
> + MIC_DMA_IMM_PAUSE_INTR_STATUS)
> +/*
> + * Performance tuning registers. For explanation of the values
> + * used please refer to mic x200 dma hardware specification.
> + */
> +#define MIC_DMA_CHAN_BANDWIDTH 0x22C
> +#define MIC_DMA_MAX_DST_MEM_WRITE (2 << 24)
> +
> +#define MIC_DMA_STA_RAM_THRESH 0x258
> +#define MIC_DMA_HDR_RAM_USAGE_THRESH 46UL
> +#define MIC_DMA_PLD_RAM_USAGE_THRESH (61UL << 16)
> +#define MIC_DMA_STA_RAM_THRESH_INIT (MIC_DMA_HDR_RAM_USAGE_THRESH | \
> + MIC_DMA_PLD_RAM_USAGE_THRESH)
> +
> +#define MIC_DMA_STA0_HDR_RAM 0x25C
> +#define MIC_DMA_STA1_HDR_RAM 0x2A4
> +#define MIC_DMA_HDR_RAM_UPPER_THRESH 160UL
> +#define MIC_DMA_HDR_RAM_LOWER_THRESH (152UL << 16)
> +#define MIC_DMA_STA_HDR_THRESH_INIT (MIC_DMA_HDR_RAM_UPPER_THRESH | \
> + MIC_DMA_HDR_RAM_LOWER_THRESH)
> +
> +#define MIC_DMA_STA0_PLD_RAM 0x260
> +#define MIC_DMA_STA1_PLD_RAM 0x2A8
> +#define MIC_DMA_PLD_RAM_UPPER_THRESH 256UL
> +#define MIC_DMA_PLD_RAM_LOWER_THRESH (248UL << 16)
> +#define MIC_DMA_STA_PLD_THRESH_INIT (MIC_DMA_PLD_RAM_UPPER_THRESH | \
> + MIC_DMA_PLD_RAM_LOWER_THRESH)
> +
> +/* HW DMA descriptor */
> +struct mic_dma_desc {
> + u64 qw0;
> + u64 qw1;
> +};
> +
> +/*
> + * mic_dma_chan - MIC X200 DMA channel specific data structures
> + *
> + * @ch_num: channel number
> + * @last_tail: cached value of descriptor ring tail
> + * @head: index of next descriptor in desc_ring
> + * @chan: dma engine api channel
> + * @desc_ring: dma descriptor ring
> + * @desc_ring_da: DMA address of desc_ring
> + * @tx_array: array of async_tx
> + * @cleanup_lock: used to synchronize descriptor cleanup
> + * @prep_lock: lock held in prep_memcpy & released in tx_submit
> + * @issue_lock: lock used to synchronize writes to head
> + * @notify_hw: flag used to notify HW that new descriptors are available
> + * @abort_tail: descriptor ring position at which last abort occurred
> + * @abort_counter: number of aborts at the last position in desc ring
> + */
> +struct mic_dma_chan {
> + int ch_num;
> + u32 last_tail;
> + u32 head;
> + struct dma_chan chan;
> + struct mic_dma_desc *desc_ring;
> + dma_addr_t desc_ring_da;
> + struct dma_async_tx_descriptor *tx_array;
Btw, can you use virt-chan API?
> + spinlock_t cleanup_lock;
> + spinlock_t prep_lock;
> + spinlock_t issue_lock;
> + bool notify_hw;
> + u32 abort_tail;
> + u32 abort_counter;
> +};
> +
> +/*
> + * mic_dma_device - Per MIC X200 DMA device driver specific data structures
> + *
> + * @pdev: PCIe device
> + * @dma_dev: underlying dma device
> + * @reg_base: virtual address of the mmio space
> + * @mic_chan: Array of MIC X200 DMA channels
> + * @max_xfer_size: maximum transfer size per dma descriptor
> + */
> +struct mic_dma_device {
> + struct pci_dev *pdev;
> + struct dma_device dma_dev;
> + void __iomem *reg_base;
> + struct mic_dma_chan mic_chan;
> + size_t max_xfer_size;
> +};
> +
> +static inline struct mic_dma_device *to_mic_dma_dev(struct mic_dma_chan *ch)
> +{
> + return
> + container_of((const typeof(((struct mic_dma_device *)0)->mic_chan) *)
> + (ch - ch->ch_num), struct mic_dma_device, mic_chan);
> +}
> +
> +static inline struct mic_dma_chan *to_mic_dma_chan(struct dma_chan *ch)
> +{
> + return container_of(ch, struct mic_dma_chan, chan);
> +}
> +
> +static inline struct device *mic_dma_ch_to_device(struct mic_dma_chan *ch)
> +{
> + return to_mic_dma_dev(ch)->dma_dev.dev;
> +}
> +
> +static inline u32 mic_dma_reg_read(struct mic_dma_device *pdma, u32 offset)
> +{
> + return ioread32(pdma->reg_base + offset);
> +}
> +
> +static inline void mic_dma_reg_write(struct mic_dma_device *pdma,
> + u32 offset, u32 value)
> +{
> + iowrite32(value, pdma->reg_base + offset);
> +}
> +
> +static inline u32 mic_dma_ch_reg_read(struct mic_dma_chan *ch, u32 offset)
> +{
> + return mic_dma_reg_read(to_mic_dma_dev(ch), offset);
> +}
> +
> +static inline void mic_dma_ch_reg_write(struct mic_dma_chan *ch,
> + u32 offset, u32 value)
> +{
> + mic_dma_reg_write(to_mic_dma_dev(ch), offset, value);
> +}
> +
> +static inline u32 mic_dma_ring_inc(u32 val)
> +{
> + return (val + 1) & (MIC_DMA_DESC_RX_SIZE - 1);
return (val + 1) % MIC_DMA_DESC_RX_SIZE;
More flexible, if the size is power of 2 it will be optimized by
compiler to the same you had previously.
> +}
> +
> +static inline u32 mic_dma_ring_dec(u32 val)
> +{
> + return val ? val - 1 : MIC_DMA_DESC_RX_SIZE - 1;
return (val - 1) % MIC_DMA_DESC_RX_SIZE;
Would it be issues with that?
> +}
> +
> +static inline void mic_dma_inc_head(struct mic_dma_chan *ch)
> +{
> + ch->head = mic_dma_ring_inc(ch->head);
> +}
> +
> +static int mic_dma_alloc_desc_ring(struct mic_dma_chan *ch)
> +{
> + /* Desc size must be >= depth of ring + prefetch size + 1 */
> + u64 desc_ring_size = MIC_DMA_DESC_RX_SIZE * sizeof(*ch->desc_ring);
> + struct device *dev = to_mic_dma_dev(ch)->dma_dev.dev;
> +
> + ch->desc_ring = dma_alloc_coherent(dev, desc_ring_size,
> + &ch->desc_ring_da,
> + GFP_KERNEL | __GFP_ZERO);
> + if (!ch->desc_ring)
> + return -ENOMEM;
> +
> + dev_dbg(dev, "DMA desc ring VA = %p DA 0x%llx size 0x%llx\n",
> + ch->desc_ring, ch->desc_ring_da, desc_ring_size);
%pad for DMA addresses.
> + ch->tx_array = vzalloc(MIC_DMA_DESC_RX_SIZE * sizeof(*ch->tx_array));
> + if (!ch->tx_array)
> + goto tx_error;
> + return 0;
> +tx_error:
> + dma_free_coherent(dev, desc_ring_size, ch->desc_ring, ch->desc_ring_da);
> + return -ENOMEM;
Only one user, may be you can move it there?
> +}
> +
> +static inline void mic_dma_disable_chan(struct mic_dma_chan *ch)
> +{
> + struct device *dev = mic_dma_ch_to_device(ch);
> + u32 ctrl_reg = mic_dma_ch_reg_read(ch, MIC_DMA_CTRL_STATUS);
> + int i;
unsigned int i;
> +
> + /* set abort bit and clear start bit */
> + ctrl_reg |= MIC_DMA_CTRL_ABORT;
> + ctrl_reg &= ~MIC_DMA_CTRL_START;
> + mic_dma_ch_reg_write(ch, MIC_DMA_CTRL_STATUS, ctrl_reg);
> +
> + for (i = 0; i < MIC_DMA_ABORT_TO_MS; i++) {
> + ctrl_reg = mic_dma_ch_reg_read(ch, MIC_DMA_CTRL_STATUS);
> +
> + if (ctrl_reg & MIC_DMA_CTRL_ABORT_DONE_STATUS)
> + return;
> +
> + mdelay(1);
> + }
> + dev_err(dev, "%s abort timed out 0x%x head %d tail %d\n",
> + __func__, ctrl_reg, ch->head, ch->last_tail);
> +}
> +
> +static inline void mic_dma_enable_chan(struct mic_dma_chan *ch)
> +{
> + u32 ctrl_reg = mic_dma_ch_reg_read(ch, MIC_DMA_CTRL_STATUS);
> +
> + ctrl_reg |= MIC_DMA_CTRL_WB_ENABLE;
> + /* Clear any active status bits ([31,12:8]) */
> + ctrl_reg |= MIC_DMA_CTRL_HEADER_LOG | MIC_DMA_CTRL_STATUS_BITS;
> + ctrl_reg &= ~MIC_DMA_CTRL_MODE_BITS;
> + /* Enable SGL off-chip mode */
> + ctrl_reg |= MIC_DMA_CTRL_OFFCHIP_MODE;
> + /* Set start and clear abort and abort done bits */
> + ctrl_reg |= MIC_DMA_CTRL_START;
> + ctrl_reg &= ~MIC_DMA_CTRL_ABORT;
> + mic_dma_ch_reg_write(ch, MIC_DMA_CTRL_STATUS, ctrl_reg);
> +}
> +
> +static inline void mic_dma_chan_mask_intr(struct mic_dma_chan *ch)
> +{
> + u32 intr_reg = mic_dma_ch_reg_read(ch, MIC_DMA_INTR_CTRL_STATUS);
> +
> + intr_reg &= ~(MIC_DMA_ALL_INTR_EN);
Redundant parens.
> + mic_dma_ch_reg_write(ch, MIC_DMA_INTR_CTRL_STATUS, intr_reg);
> +}
> +
> +static inline void mic_dma_chan_unmask_intr(struct mic_dma_chan *ch)
> +{
> + u32 intr_reg = mic_dma_ch_reg_read(ch, MIC_DMA_INTR_CTRL_STATUS);
> +
> + intr_reg |= (MIC_DMA_ALL_INTR_EN);
Ditto
> + mic_dma_ch_reg_write(ch, MIC_DMA_INTR_CTRL_STATUS, intr_reg);
> +}
> +
> +static void mic_dma_chan_set_desc_ring(struct mic_dma_chan *ch)
> +{
> + /* Set up the descriptor ring base address and size */
> + mic_dma_ch_reg_write(ch, MIC_DMA_DESC_RING_ADDR_LOW,
> + ch->desc_ring_da & 0xffffffff);
> + mic_dma_ch_reg_write(ch, MIC_DMA_DESC_RING_ADDR_HIGH,
> + (ch->desc_ring_da >> 32) & 0xffffffff);
Better to provide mic_dma_ch_reg_writeq() based on lo_hi_writel().
> + mic_dma_ch_reg_write(ch, MIC_DMA_DESC_RING_SIZE, MIC_DMA_DESC_RX_SIZE);
> + /* Set up the next descriptor to the base of the descriptor ring */
> + mic_dma_ch_reg_write(ch, MIC_DMA_NEXT_DESC_ADDR_LOW,
> + ch->desc_ring_da & 0xffffffff);
Only low?
> +}
> +
> +static void mic_dma_cleanup(struct mic_dma_chan *ch)
> +{
> + struct dma_async_tx_descriptor *tx;
> + u32 last_tail;
> + u32 cached_head;
> +
> + spin_lock(&ch->cleanup_lock);
> + /*
> + * Use a cached head rather than using ch->head directly, since a
> + * different thread can be updating ch->head potentially leading to an
> + * infinite loop below.
> + */
> + cached_head = ACCESS_ONCE(ch->head);
> + /*
> + * This is the barrier pair for smp_wmb() in fn.
> + * mic_dma_tx_submit_unlock. It's required so that we read the
> + * updated cookie value from tx->cookie.
> + */
> + smp_rmb();
> +
> + for (last_tail = ch->last_tail; last_tail != cached_head;) {
> + /* Break out of the loop if this desc is not yet complete */
> + if (ch->desc_ring[last_tail].qw0 & MIC_DMA_DESC_VALID)
> + break;
> +
> + tx = &ch->tx_array[last_tail];
> + if (tx->cookie) {
> + dma_cookie_complete(tx);
> + if (tx->callback) {
> + tx->callback(tx->callback_param);
> + tx->callback = NULL;
> + }
> + }
> + last_tail = mic_dma_ring_inc(last_tail);
> + }
> + /* finish all completion callbacks before incrementing tail */
> + smp_mb();
> + ch->last_tail = last_tail;
> + spin_unlock(&ch->cleanup_lock);
> +}
> +
> +static int mic_dma_chan_setup(struct mic_dma_chan *ch)
> +{
> + mic_dma_chan_set_desc_ring(ch);
> + ch->last_tail = 0;
> + ch->head = 0;
> + ch->notify_hw = 1;
> + mic_dma_chan_unmask_intr(ch);
> + mic_dma_enable_chan(ch);
Seems alogical. Perhaps first is to enable channel and then enable interrupts?
> + return 0;
> +}
> +
> +static void mic_dma_free_desc_ring(struct mic_dma_chan *ch)
> +{
> + u64 desc_ring_size = MIC_DMA_DESC_RX_SIZE * sizeof(*ch->desc_ring);
> + struct device *dev = to_mic_dma_dev(ch)->dma_dev.dev;
> +
> + vfree(ch->tx_array);
> + dma_free_coherent(dev, desc_ring_size, ch->desc_ring, ch->desc_ring_da);
> + ch->desc_ring = NULL;
> + ch->desc_ring_da = 0;
> +
> + /* Reset description ring registers */
> + mic_dma_chan_set_desc_ring(ch);
> +}
> +
> +static int mic_dma_chan_init(struct mic_dma_chan *ch)
> +{
> + struct device *dev = mic_dma_ch_to_device(ch);
> + int rc;
> +
> + rc = mic_dma_alloc_desc_ring(ch);
> + if (rc)
> + goto ring_error;
> + rc = mic_dma_chan_setup(ch);
> + if (rc)
> + goto chan_error;
> + return rc;
> +chan_error:
> + mic_dma_free_desc_ring(ch);
> +ring_error:
> + dev_err(dev, "%s ret %d\n", __func__, rc);
Is it useful?
> + return rc;
> +}
> +
> +static int mic_dma_alloc_chan_resources(struct dma_chan *ch)
> +{
> + struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
> + struct device *dev = mic_dma_ch_to_device(mic_ch);
> + int rc = mic_dma_chan_init(mic_ch);
> +
> + if (rc) {
> + dev_err(dev, "%s ret %d\n", __func__, rc);
Ditto.
> + return rc;
> + }
> + return MIC_DMA_DESC_RX_SIZE;
> +}
> +
> +static inline u32 desc_ring_da_to_index(struct mic_dma_chan *ch, u32 descr)
> +{
> + dma_addr_t last_dma_off = descr - (ch->desc_ring_da & ULONG_MAX);
Hmm… Why do you need that strange masking?
> +
> + return (last_dma_off / sizeof(struct mic_dma_desc)) &
> + (MIC_DMA_DESC_RX_SIZE - 1);
% _RX_SIZE
> +}
> +
> +static inline u32 desc_ring_index_to_da(struct mic_dma_chan *ch, u32 index)
> +{
> + dma_addr_t addr = ch->desc_ring_da +
> + sizeof(struct mic_dma_desc) * index;
> +
> + return (addr & ULONG_MAX);
> +}
> +
> +static void mic_dma_free_chan_resources(struct dma_chan *ch)
> +{
> + struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
> +
> + mic_dma_disable_chan(mic_ch);
> + mic_dma_chan_mask_intr(mic_ch);
> + mic_dma_cleanup(mic_ch);
> + mic_dma_free_desc_ring(mic_ch);
> +}
> +
> +static enum dma_status
> +mic_dma_tx_status(struct dma_chan *ch, dma_cookie_t cookie,
> + struct dma_tx_state *txstate)
> +{
> + struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
> +
> + if (dma_cookie_status(ch, cookie, txstate) != DMA_COMPLETE)
> + mic_dma_cleanup(mic_ch);
> +
> + return dma_cookie_status(ch, cookie, txstate);
> +}
> +
> +static int mic_dma_ring_count(u32 head, u32 tail)
> +{
> + int count;
> +
> + if (head >= tail)
> + count = (tail - 0) + (MIC_DMA_DESC_RX_SIZE - head);
> + else
> + count = tail - head;
> + return count - 1;
> +}
> +
> +static int mic_dma_avail_desc_ring_space(struct mic_dma_chan *ch, int required)
> +{
> + struct device *dev = mic_dma_ch_to_device(ch);
> + int count;
> + unsigned long timeout = jiffies +
> + msecs_to_jiffies(MIC_DMA_RING_TO_MS);
> +
> + count = mic_dma_ring_count(ch->head, ch->last_tail);
> + while (count < required) {
> + mic_dma_cleanup(ch);
> + count = mic_dma_ring_count(ch->head, ch->last_tail);
> + if ((count >= required) || time_after_eq(jiffies, timeout))
> + break;
> + usleep_range(50, 100);
> + }
> +
> + if (count < required) {
> + dev_err(dev, "%s count %d reqd %d head %d tail %d\n",
> + __func__, count, required, ch->head, ch->last_tail);
> + return -ENOMEM;
> + }
> + return count;
> +}
> +
> +static void
> +mic_dma_memcpy_desc(struct mic_dma_desc *desc, dma_addr_t src_phys,
> + dma_addr_t dst_phys, u64 size, int flags)
> +{
> + u64 qw0, qw1;
> +
> + qw0 = (src_phys & MIC_DMA_DESC_BITS_32_TO_47) << 16;
> + qw0 |= (dst_phys & MIC_DMA_DESC_BITS_32_TO_47);
> + qw0 |= size & MIC_DMA_DESC_SIZE_MASK;
> + qw0 |= MIC_DMA_DESC_VALID;
> + if (flags & DMA_PREP_INTERRUPT)
> + qw0 |= MIC_DMA_DESC_INTR_ENABLE;
> +
> + qw1 = (src_phys & MIC_DMA_DESC_LOW_MASK) << MIC_DMA_DESC_SRC_LOW_SHIFT;
> + qw1 |= dst_phys & MIC_DMA_DESC_LOW_MASK;
> +
> + desc->qw1 = qw1;
> + /*
> + * Update QW1 before QW0 since QW0 has the valid bit and the
> + * descriptor might be picked up by the hardware DMA engine
> + * immediately if it finds a valid descriptor.
> + */
> + wmb();
> + desc->qw0 = qw0;
> + /*
> + * This is not smp_wmb() on purpose since we are also publishing the
> + * descriptor updates to a dma device
> + */
> + wmb();
> +}
> +
> +static void mic_dma_fence_intr_desc(struct mic_dma_chan *ch, int flags)
> +{
> + /*
> + * Zero-length DMA memcpy needs valid source and destination addresses
> + */
> + mic_dma_memcpy_desc(&ch->desc_ring[ch->head],
> + ch->desc_ring_da, ch->desc_ring_da, 0, flags);
> + mic_dma_inc_head(ch);
> +}
> +
> +static int mic_dma_prog_memcpy_desc(struct mic_dma_chan *ch, dma_addr_t src,
> + dma_addr_t dst, size_t len, int flags)
> +{
> + struct device *dev = mic_dma_ch_to_device(ch);
> + size_t current_transfer_len;
> + size_t max_xfer_size = to_mic_dma_dev(ch)->max_xfer_size;
> + int num_desc = len / max_xfer_size;
> + int ret;
> +
> + if (len % max_xfer_size)
> + num_desc++;
> + /*
> + * A single additional descriptor is programmed for fence/interrupt
> + * during submit(..)
> + */
> + if (flags)
> + num_desc++;
> +
> + if (!num_desc) {
> + dev_err(dev, "%s nothing to do: rc %d\n", __func__, -EINVAL);
> + return -EINVAL;
> + }
> +
> + ret = mic_dma_avail_desc_ring_space(ch, num_desc);
> + if (ret <= 0) {
> + dev_err(dev, "%s desc ring full ret %d\n", __func__, ret);
> + return ret;
> + }
> +
> + while (len > 0) {
> + current_transfer_len = min(len, max_xfer_size);
> + /*
> + * Set flags to 0 here, we don't want memcpy descriptors to
> + * generate interrupts, a separate descriptor will be programmed
> + * for fence/interrupt during submit, after a callback is
> + * guaranteed to have been assigned
> + */
> + mic_dma_memcpy_desc(&ch->desc_ring[ch->head],
> + src, dst, current_transfer_len, 0);
> + mic_dma_inc_head(ch);
> + len -= current_transfer_len;
> + dst = dst + current_transfer_len;
> + src = src + current_transfer_len;
> + }
> + return 0;
> +}
> +
> +static int mic_dma_do_dma(struct mic_dma_chan *ch, int flags, dma_addr_t src,
> + dma_addr_t dst, size_t len)
> +{
> + return mic_dma_prog_memcpy_desc(ch, src, dst, len, flags);
> +}
> +
> +static inline void mic_dma_issue_pending(struct dma_chan *ch)
> +{
> + struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
> + unsigned long flags;
> + u32 ctrl_reg;
> +
> + spin_lock_irqsave(&mic_ch->issue_lock, flags);
> + /*
> + * The notify_hw is introduced because occasionally we were seeing an
> + * issue where the HW tail seemed stuck, i.e. the DMA engine would not
> + * pick up new descriptors available in the ring. We found that
> + * serializing operations between SW and HW made this issue
> + * disappear. We believe this issue arises because of a race between SW
> + * and HW. SW adds new descriptors to the ring and clears
> + * DESC_INVLD_STATUS to ask HW to pick them up. However HW has
> + * prefetched descriptors and writes DESC_INVLD_STATUS to let SW know it
> + * has fetched an invalid descriptor. It appears that in this way HW can
> + * overwrite the clearing of DESC_INVLD_STATUS by SW (though we never
> + * saw DESC_INVLD_STATUS set to 1 when the DMA engine had stopped) and
> + * therefore HW never picks up these descriptors.
> + *
> + * Therefore it is necessary for SW to clear DESC_INVLD_STATUS only
> + * after HW has set it, and the notify_hw flag accomplishes this
> + * between issue_pending(..) and the invld_desc interrupt handler.
> + */
> + if (mic_ch->notify_hw) {
> + ctrl_reg = mic_dma_ch_reg_read(mic_ch, MIC_DMA_CTRL_STATUS);
> + if (ctrl_reg & MIC_DMA_CTRL_DESC_INVLD_STATUS) {
> + mic_ch->notify_hw = 0;
> + /* Clear DESC_INVLD_STATUS flag */
> + mic_dma_ch_reg_write(mic_ch, MIC_DMA_CTRL_STATUS,
> + ctrl_reg);
> + } else {
> + dev_err(mic_dma_ch_to_device(mic_ch),
> + "%s: DESC_INVLD_STATUS not set\n", __func__);
> + }
> + }
> + spin_unlock_irqrestore(&mic_ch->issue_lock, flags);
> +}
> +
> +static inline void mic_dma_update_pending(struct mic_dma_chan *ch)
> +{
> + if (mic_dma_ring_count(ch->head, ch->last_tail)
> + > MIC_DMA_PENDING_LEVEL)
One line?
> + mic_dma_issue_pending(&ch->chan);
> +}
> +
> +static dma_cookie_t mic_dma_tx_submit_unlock(struct dma_async_tx_descriptor *tx)
> +{
> + struct mic_dma_chan *mic_ch = to_mic_dma_chan(tx->chan);
> + dma_cookie_t cookie;
> +
> + dma_cookie_assign(tx);
> + cookie = tx->cookie;
> + /*
> + * smp_wmb pairs with smb_rmb in mic_dma_cleanup to ensure
> + * that tx->cookie is visible before updating ch->head
> + */
> + smp_wmb();
> +
> + /*
> + * The final fence/interrupt desc is now programmed in submit after the
> + * cookie has been assigned
> + */
> + if (tx->flags) {
> + mic_dma_fence_intr_desc(mic_ch, tx->flags);
> + tx->flags = 0;
> + }
> +
> + spin_unlock(&mic_ch->prep_lock);
> + mic_dma_update_pending(mic_ch);
> + return cookie;
> +}
> +
> +static inline struct dma_async_tx_descriptor *
> +allocate_tx(struct mic_dma_chan *ch, unsigned long flags)
> +{
> + /* index of the final desc which is or will be programmed */
> + u32 idx = flags ? ch->head : mic_dma_ring_dec(ch->head);
> + struct dma_async_tx_descriptor *tx = &ch->tx_array[idx];
> +
> + dma_async_tx_descriptor_init(tx, &ch->chan);
> + tx->tx_submit = mic_dma_tx_submit_unlock;
> + tx->flags = flags;
> + return tx;
> +}
> +
> +static struct dma_async_tx_descriptor *
> +mic_dma_prep_memcpy_lock(struct dma_chan *ch, dma_addr_t dma_dest,
> + dma_addr_t dma_src, size_t len, unsigned long flags)
> +{
> + struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
> + struct device *dev = mic_dma_ch_to_device(mic_ch);
> + int result;
> +
> + /*
> + * return holding prep_lock which will be released in submit
> + */
> + spin_lock(&mic_ch->prep_lock);
> + result = mic_dma_do_dma(mic_ch, flags, dma_src, dma_dest, len);
> + if (result >= 0)
> + return allocate_tx(mic_ch, flags);
Hmm… Usual pattern is
if (err)
do error path();
> + dev_err(dev, "Error enqueueing dma, error=%d\n", result);
> + spin_unlock(&mic_ch->prep_lock);
> + return NULL;
> +}
> +
> +static struct dma_async_tx_descriptor *
> +mic_dma_prep_interrupt_lock(struct dma_chan *ch, unsigned long flags)
> +{
> + struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
> + /*
> + * Program 0 length DMA. Interrupt desc to be programmed in submit.
> + * All DMA transfers need a valid source and destination.
> + */
> + return mic_dma_prep_memcpy_lock(ch, mic_ch->desc_ring_da,
> + mic_ch->desc_ring_da, 0, flags);
> +}
> +
> +static irqreturn_t mic_dma_thread_fn(int irq, void *data)
> +{
> + struct mic_dma_device *mic_dma_dev = ((struct mic_dma_device *)data);
> +
> + mic_dma_cleanup(&mic_dma_dev->mic_chan);
> + return IRQ_HANDLED;
> +}
> +
> +static void mic_dma_invld_desc_interrupt(struct mic_dma_chan *ch)
> +{
> + u32 ctrl_reg;
> +
> + spin_lock(&ch->issue_lock);
> + if (!ch->notify_hw) {
> + ctrl_reg = mic_dma_ch_reg_read(ch, MIC_DMA_CTRL_STATUS);
> + if (ctrl_reg & MIC_DMA_CTRL_DESC_INVLD_STATUS) {
Isn't too long?
MIC_DMA_CTRL_DESC_INVLD_STATUS -> MIC_DMA_CTRL_DESC_INVAL ?
> + /*
> + * Check the descriptor ring for valid descriptors. If
> + * valid descriptors are available clear the
> + * DESC_INVLD_STATUS bit to signal to the hardware to
> + * pick them up. If no valid descriptors are available,
> + * when issue_pending is called, it will clear the
> + * INVLD_STATUS bit to signal to the hardware to pick up
> + * the posted descriptors.
> + */
> + if (ch->desc_ring[mic_dma_ring_dec(ch->head)].qw0 &
> + MIC_DMA_DESC_VALID) {
> + mic_dma_ch_reg_write(ch, MIC_DMA_CTRL_STATUS,
> + ctrl_reg);
> + } else {
> + ch->notify_hw = 1;
> + }
> + } else {
> + dev_err(mic_dma_ch_to_device(ch),
> + "%s: DESC_INVLD_STATUS not set\n", __func__);
> + }
> + }
> + spin_unlock(&ch->issue_lock);
> +}
> +
> +static void mic_dma_abort_interrupt(struct mic_dma_chan *ch, u32 intr_reg)
> +{
> + u32 reg;
> + u32 ring_pos;
> +
> + spin_lock(&ch->issue_lock);
> + reg = mic_dma_ch_reg_read(ch, MIC_DMA_LAST_DESC_ADDR_LOW);
> + ring_pos = desc_ring_da_to_index(ch, reg);
> +
> + if (ch->desc_ring[ring_pos].qw0 & MIC_DMA_DESC_VALID) {
> + /*
> + * Move back the HW next pointer so it points to the tail of
> + * the ring descriptor.
> + */
> + mic_dma_ch_reg_write(ch, MIC_DMA_NEXT_DESC_ADDR_LOW, reg);
> + } else {
> + /* Last descriptor is not valid, find a valid one or head */
> + u32 tail = ch->last_tail;
> + u32 new_next;
> +
> + while (tail != ch->head) {
> + tail = mic_dma_ring_inc(tail);
> + if (ch->desc_ring[ring_pos].qw0 & MIC_DMA_DESC_VALID)
> + break;
> + }
> + new_next = desc_ring_index_to_da(ch, tail);
> + mic_dma_ch_reg_write(ch, MIC_DMA_NEXT_DESC_ADDR_LOW, new_next);
> +
> + dev_err(mic_dma_ch_to_device(ch),
> + "Abort at %d with invalid descriptor, new descr %d, head = %d, tail %d\n",
> + ring_pos, tail, ch->head, ch->last_tail);
> + }
> +
> + /*
> + * If abort was caused by hw error then restart DMA engine.
> + * If abort was requested by driver then leave it stopped.
> + */
> + if (intr_reg & MIC_DMA_ERROR_INTR_STATUS) {
> + if (ch->abort_tail != desc_ring_da_to_index(ch, reg)) {
> + ch->abort_tail = desc_ring_da_to_index(ch, reg);
> + ch->abort_counter = 0;
> + } else {
> + ch->abort_counter++;
> + }
> +
> + if (ch->abort_counter < MIC_DMA_ABORT_LIMIT) {
> + dev_err(mic_dma_ch_to_device(ch),
> + "Abort/Error at %d (retry %d), reenabling DMA engine.\n",
> + ch->abort_tail, ch->abort_counter);
> + mic_dma_enable_chan(ch);
> + } else {
> + /*
> + * We have tried same descriptor several times and it is
> + * still generating abort.
> + */
> + dev_err(mic_dma_ch_to_device(ch),
> + "Abort Error at %d (retry %d), give up.\n",
> + ch->abort_tail, ch->abort_counter);
> + }
> + }
> + spin_unlock(&ch->issue_lock);
> +}
> +
> +static u32 mic_dma_ack_interrupt(struct mic_dma_chan *ch)
> +{
> + u32 intr_reg = mic_dma_ch_reg_read(ch, MIC_DMA_INTR_CTRL_STATUS);
> +
> + mic_dma_ch_reg_write(ch, MIC_DMA_INTR_CTRL_STATUS, intr_reg);
> + return intr_reg;
> +}
> +
> +static irqreturn_t mic_dma_intr_handler(int irq, void *data)
> +{
> + struct mic_dma_device *mic_dma_dev = ((struct mic_dma_device *)data);
> + bool wake_thread = false, error = false;
> + struct mic_dma_chan *ch = &mic_dma_dev->mic_chan;
> + struct device *dev = mic_dma_ch_to_device(ch);
> + u32 reg;
> +
> + reg = mic_dma_ack_interrupt(&mic_dma_dev->mic_chan);
> + wake_thread = !!(reg & MIC_DMA_DESC_DONE_INTR_STATUS);
> + error = !!(reg & MIC_DMA_ERROR_STATUS);
> + if (error)
> + dev_err(dev, "%s error status 0x%x\n", __func__, reg);
> +
> + if (reg & MIC_DMA_INVLD_DESC_INTR_STATUS)
> + mic_dma_invld_desc_interrupt(&mic_dma_dev->mic_chan);
> +
> + if (reg & MIC_DMA_ABORT_DONE_INTR_STATUS)
> + mic_dma_abort_interrupt(&mic_dma_dev->mic_chan, reg);
> +
> + if (wake_thread)
> + return IRQ_WAKE_THREAD;
> +
> + if (error || reg & MIC_DMA_INVLD_DESC_INTR_STATUS ||
> + reg & MIC_DMA_ABORT_DONE_INTR_STATUS)
> + return IRQ_HANDLED;
> +
> + return IRQ_NONE;
> +}
> +
> +static int mic_dma_setup_irq(struct mic_dma_device *mic_dma_dev)
> +{
> + struct pci_dev *pdev = mic_dma_dev->pdev;
> + struct device *dev = &pdev->dev;
> + int rc = pci_enable_msi(pdev);
> +
> + if (rc)
> + pci_intx(pdev, 1);
> +
> + return devm_request_threaded_irq(dev, pdev->irq, mic_dma_intr_handler,
> + mic_dma_thread_fn, IRQF_SHARED,
> + "mic-x200-dma-intr", mic_dma_dev);
> +}
> +
> +static inline void mic_dma_free_irq(struct mic_dma_device *mic_dma_dev)
> +{
> + struct pci_dev *pdev = mic_dma_dev->pdev;
> + struct device *dev = &pdev->dev;
> +
> + devm_free_irq(dev, pdev->irq, mic_dma_dev);
> + if (pci_dev_msi_enabled(pdev))
> + pci_disable_msi(pdev);
pcim_enable_device() will take care of this one.
> +}
> +
> +static void mic_dma_hw_init(struct mic_dma_device *mic_dma_dev)
> +{
> + struct mic_dma_chan *ch = &mic_dma_dev->mic_chan;
> + u32 intr_reg;
> +
> + dev_dbg(mic_dma_dev->dma_dev.dev, "Ctrl reg 0x%0x, Intr reg 0x%0x\n",
> + mic_dma_reg_read(mic_dma_dev, MIC_DMA_CTRL_STATUS),
> + mic_dma_reg_read(mic_dma_dev, MIC_DMA_INTR_CTRL_STATUS));
> +
> + intr_reg = mic_dma_ch_reg_read(ch, MIC_DMA_INTR_CTRL_STATUS);
> + if (intr_reg & MIC_DMA_ALL_INTR_EN) {
> + /*
> + * Interrupts are enabled - that means card has been reset
> + * without resetting DMA HW.
> + * Disable interrupts and issue abort to stop DMA HW.
> + */
> + intr_reg &= ~(MIC_DMA_ALL_INTR_EN);
Redundant parens.
> + mic_dma_ch_reg_write(ch, MIC_DMA_INTR_CTRL_STATUS, intr_reg);
> + mic_dma_disable_chan(ch);
> + }
> +
> + mic_dma_reg_write(mic_dma_dev, MIC_DMA_CTRL_STATUS,
> + MIC_DMA_CTRL_STATUS_INIT);
> +
> + mic_dma_reg_write(mic_dma_dev, MIC_DMA_CHAN_BANDWIDTH,
> + MIC_DMA_MAX_DST_MEM_WRITE);
> +
> + mic_dma_reg_write(mic_dma_dev, MIC_DMA_STA_RAM_THRESH,
> + MIC_DMA_STA_RAM_THRESH_INIT);
> +
> + mic_dma_reg_write(mic_dma_dev, MIC_DMA_STA0_HDR_RAM,
> + MIC_DMA_STA_HDR_THRESH_INIT);
> + mic_dma_reg_write(mic_dma_dev, MIC_DMA_STA1_HDR_RAM,
> + MIC_DMA_STA_HDR_THRESH_INIT);
> +
> + mic_dma_reg_write(mic_dma_dev, MIC_DMA_STA0_PLD_RAM,
> + MIC_DMA_STA_PLD_THRESH_INIT);
> + mic_dma_reg_write(mic_dma_dev, MIC_DMA_STA1_PLD_RAM,
> + MIC_DMA_STA_PLD_THRESH_INIT);
> +}
> +
> +static int mic_dma_init(struct mic_dma_device *mic_dma_dev)
> +{
> + struct mic_dma_chan *ch;
> + int rc = 0;
Useless assignment.
> +
> + mic_dma_hw_init(mic_dma_dev);
> +
> + rc = mic_dma_setup_irq(mic_dma_dev);
> + if (rc) {
> + dev_err(mic_dma_dev->dma_dev.dev,
> + "%s %d func error line %d\n", __func__, __LINE__, rc);
> + goto error;
> + }
> + ch = &mic_dma_dev->mic_chan;
> + spin_lock_init(&ch->cleanup_lock);
> + spin_lock_init(&ch->prep_lock);
> + spin_lock_init(&ch->issue_lock);
> +error:
Useless label.
> + return rc;
> +}
> +
> +static void mic_dma_uninit(struct mic_dma_device *mic_dma_dev)
> +{
> + mic_dma_free_irq(mic_dma_dev);
> +}
> +
> +static int mic_register_dma_device(struct mic_dma_device *mic_dma_dev)
> +{
> + struct dma_device *dma_dev = &mic_dma_dev->dma_dev;
> + struct mic_dma_chan *ch;
> +
> + dma_cap_zero(dma_dev->cap_mask);
> +
> + dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
> + dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
> +
> + dma_dev->device_alloc_chan_resources = mic_dma_alloc_chan_resources;
> + dma_dev->device_free_chan_resources = mic_dma_free_chan_resources;
> + dma_dev->device_tx_status = mic_dma_tx_status;
> + dma_dev->device_prep_dma_memcpy = mic_dma_prep_memcpy_lock;
> + dma_dev->device_prep_dma_interrupt = mic_dma_prep_interrupt_lock;
> + dma_dev->device_issue_pending = mic_dma_issue_pending;
> + INIT_LIST_HEAD(&dma_dev->channels);
> +
> + /* Associate dma_dev with dma_chan */
> + ch = &mic_dma_dev->mic_chan;
> + ch->chan.device = dma_dev;
> + dma_cookie_init(&ch->chan);
> + list_add_tail(&ch->chan.device_node, &dma_dev->channels);
> + return dma_async_device_register(dma_dev);
> +}
> +
> +static int mic_dma_probe(struct mic_dma_device *mic_dma_dev)
> +{
> + struct dma_device *dma_dev;
> + int rc = -EINVAL;
> +
> + dma_dev = &mic_dma_dev->dma_dev;
> + dma_dev->dev = &mic_dma_dev->pdev->dev;
> +
> + /* MIC X200 has one DMA channel per function */
> + dma_dev->chancnt = 1;
> +
> + mic_dma_dev->max_xfer_size = MIC_DMA_DESC_SIZE_MASK;
> +
> + rc = mic_dma_init(mic_dma_dev);
> + if (rc) {
> + dev_err(&mic_dma_dev->pdev->dev,
> + "%s %d rc %d\n", __func__, __LINE__, rc);
> + goto init_error;
> + }
> +
> + rc = mic_register_dma_device(mic_dma_dev);
> + if (rc) {
> + dev_err(&mic_dma_dev->pdev->dev,
> + "%s %d rc %d\n", __func__, __LINE__, rc);
> + goto reg_error;
> + }
> + return rc;
> +reg_error:
> + mic_dma_uninit(mic_dma_dev);
> +init_error:
Ditto.
> + return rc;
> +}
> +
> +static void mic_dma_remove(struct mic_dma_device *mic_dma_dev)
> +{
> + dma_async_device_unregister(&mic_dma_dev->dma_dev);
> + mic_dma_uninit(mic_dma_dev);
> +}
> +
> +static struct mic_dma_device *
> +mic_x200_alloc_dma(struct pci_dev *pdev, void __iomem *iobase)
> +{
> + struct mic_dma_device *d = kzalloc(sizeof(*d), GFP_KERNEL);
devm_
> +
> + if (!d)
> + return NULL;
> + d->pdev = pdev;
> + d->reg_base = iobase;
> + return d;
> +}
> +
> +static int
> +mic_x200_dma_probe(struct pci_dev *pdev, const struct pci_device_id *pdev_id)
> +{
> + int rc;
> + struct mic_dma_device *dma_dev;
> + void __iomem * const *iomap;
> +
> + rc = pcim_enable_device(pdev);
> + if (rc)
> + goto done;
> + rc = pcim_iomap_regions(pdev, 0x1, MIC_DMA_DRV_NAME);
> + if (rc)
> + goto done;
> + iomap = pcim_iomap_table(pdev);
> + if (!iomap) {
> + rc = -ENOMEM;
> + goto done;
> + }
Redundant check. Previous one fail otherwise this is valid.
> + rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(48));
> + if (rc)
> + goto done;
> + rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(48));
> + if (rc)
> + goto done;
> + dma_dev = mic_x200_alloc_dma(pdev, iomap[0]);
> + if (!dma_dev) {
> + rc = -ENOMEM;
> + goto done;
> + }
> + pci_set_master(pdev);
> + pci_set_drvdata(pdev, dma_dev);
> + rc = mic_dma_probe(dma_dev);
> + if (rc)
> + goto probe_err;
> + return 0;
> +probe_err:
> + kfree(dma_dev);
devm_ takes care of.
> +done:
> + dev_err(&pdev->dev, "probe error rc %d\n", rc);
Useless. You may learn "initcall_debug" parameter.
And thus label is useless.
> + return rc;
> +}
> +
> +static void mic_x200_dma_remove(struct pci_dev *pdev)
> +{
> + struct mic_dma_device *dma_dev = pci_get_drvdata(pdev);
> +
> + mic_dma_remove(dma_dev);
> + kfree(dma_dev);
devm_
> +}
> +
> +static struct pci_device_id mic_x200_dma_pci_id_table[] = {
> + {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2264)},
> + {}
> +};
> +MODULE_DEVICE_TABLE(pci, mic_x200_dma_pci_id_table);
> +
> +static struct pci_driver mic_x200_dma_driver = {
> + .name = MIC_DMA_DRV_NAME,
> + .id_table = mic_x200_dma_pci_id_table,
> + .probe = mic_x200_dma_probe,
> + .remove = mic_x200_dma_remove
> +};
> +
> +static int __init mic_x200_dma_init(void)
> +{
> + int rc = pci_register_driver(&mic_x200_dma_driver);
> +
> + if (rc)
> + pr_err("%s %d rc %x\n", __func__, __LINE__, rc);
> + return rc;
> +}
> +
> +static void __exit mic_x200_dma_exit(void)
> +{
> + pci_unregister_driver(&mic_x200_dma_driver);
> +}
> +
> +module_init(mic_x200_dma_init);
> +module_exit(mic_x200_dma_exit);
module_pci_driver();
> +
> +MODULE_AUTHOR("Intel Corporation");
> +MODULE_DESCRIPTION("Intel(R) MIC X200 DMA Driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.1.4
>
--
With Best Regards,
Andy Shevchenko
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