On Thu, Feb 4, 2016 at 5:10 PM, Jacek Lawrynowicz <jacek.lawrynowicz@xxxxxxxxx> 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@xxxxxxxxx> > Signed-off-by: Sudeep Dutt <sudeep.dutt@xxxxxxxxx> > Signed-off-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx> > Signed-off-by: Andrzej Kacprowski <andrzej.kacprowski@xxxxxxxxx> > --- > 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 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
