Added the driver for zynqmp dma engine used in Zynq UltraScale+ MPSoC. This dma controller supports memory to memory and memory to I/O buffer transfers. Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xxxxxxxxxx> Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx> --- Changes for v7: - Fixed kbuild compilation warnings. - Fixed {src,dst}_addr_widths are supposed to be a bitmask of supported slave device widths as suggested by Rob. Changes in v6: - Removed unnecessary axcache properties from the driver - Fixed compilation issues Changes in v5: - Removed in_interrupt check from the tasklet cleanup as suggested by the vinod/lars. Changes in v4: - Modified the defines to start with ZYNQMP_DMA perfix - Changed the zynqmp_dma_alloc_chan_resources to return number of allocated descriptors - Changed the zynqmp_dma_device variable name - Released the locks before calling user callback - freeup irq in zynqmp_dma_chan_remove function. Changes in v3: - Modified the zynqmp_dma_chan_is_idle function return type to bool Changes in v2: - Corrected the function header documentation - Framework expects bus-width value in bytes. so, fixed it - Removed magic numbers for bus-width drivers/dma/Kconfig | 6 + drivers/dma/xilinx/zynqmp_dma.c | 1232 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 1238 insertions(+) create mode 100644 drivers/dma/xilinx/zynqmp_dma.c diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 2846753..33dc427 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -527,6 +527,12 @@ config ZX_DMA help Support the DMA engine for ZTE ZX296702 platform devices. +config XILINX_ZYNQMP_DMA + tristate "Xilinx ZynqMP DMA Engine" + depends on (ARCH_ZYNQ || MICROBLAZE || ARM64) + select DMA_ENGINE + help + Enable support for Xilinx ZynqMP DMA controller. # driver files source "drivers/dma/bestcomm/Kconfig" diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c new file mode 100644 index 0000000..9c44418 --- /dev/null +++ b/drivers/dma/xilinx/zynqmp_dma.c @@ -0,0 +1,1232 @@ +/* + * DMA driver for Xilinx ZynqMP DMA Engine + * + * Copyright (C) 2016 Xilinx, Inc. All rights reserved. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/bitops.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/dmapool.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_dma.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/slab.h> +#include <linux/clk.h> + +#include "../dmaengine.h" + +/* Register Offsets */ +#define ZYNQMP_DMA_ISR 0x100 +#define ZYNQMP_DMA_IMR 0x104 +#define ZYNQMP_DMA_IER 0x108 +#define ZYNQMP_DMA_IDS 0x10C +#define ZYNQMP_DMA_CTRL0 0x110 +#define ZYNQMP_DMA_CTRL1 0x114 +#define ZYNQMP_DMA_DATA_ATTR 0x120 +#define ZYNQMP_DMA_DSCR_ATTR 0x124 +#define ZYNQMP_DMA_SRC_DSCR_WRD0 0x128 +#define ZYNQMP_DMA_SRC_DSCR_WRD1 0x12C +#define ZYNQMP_DMA_SRC_DSCR_WRD2 0x130 +#define ZYNQMP_DMA_SRC_DSCR_WRD3 0x134 +#define ZYNQMP_DMA_DST_DSCR_WRD0 0x138 +#define ZYNQMP_DMA_DST_DSCR_WRD1 0x13C +#define ZYNQMP_DMA_DST_DSCR_WRD2 0x140 +#define ZYNQMP_DMA_DST_DSCR_WRD3 0x144 +#define ZYNQMP_DMA_SRC_START_LSB 0x158 +#define ZYNQMP_DMA_SRC_START_MSB 0x15C +#define ZYNQMP_DMA_DST_START_LSB 0x160 +#define ZYNQMP_DMA_DST_START_MSB 0x164 +#define ZYNQMP_DMA_RATE_CTRL 0x18C +#define ZYNQMP_DMA_IRQ_SRC_ACCT 0x190 +#define ZYNQMP_DMA_IRQ_DST_ACCT 0x194 +#define ZYNQMP_DMA_CTRL2 0x200 + +/* Interrupt registers bit field definitions */ +#define ZYNQMP_DMA_DONE BIT(10) +#define ZYNQMP_DMA_AXI_WR_DATA BIT(9) +#define ZYNQMP_DMA_AXI_RD_DATA BIT(8) +#define ZYNQMP_DMA_AXI_RD_DST_DSCR BIT(7) +#define ZYNQMP_DMA_AXI_RD_SRC_DSCR BIT(6) +#define ZYNQMP_DMA_IRQ_DST_ACCT_ERR BIT(5) +#define ZYNQMP_DMA_IRQ_SRC_ACCT_ERR BIT(4) +#define ZYNQMP_DMA_BYTE_CNT_OVRFL BIT(3) +#define ZYNQMP_DMA_DST_DSCR_DONE BIT(2) +#define ZYNQMP_DMA_INV_APB BIT(0) + +/* Control 0 register bit field definitions */ +#define ZYNQMP_DMA_OVR_FETCH BIT(7) +#define ZYNQMP_DMA_POINT_TYPE_SG BIT(6) +#define ZYNQMP_DMA_RATE_CTRL_EN BIT(3) + +/* Control 1 register bit field definitions */ +#define ZYNQMP_DMA_SRC_ISSUE GENMASK(4, 0) + +/* Data Attribute register bit field definitions */ +#define ZYNQMP_DMA_ARBURST GENMASK(27, 26) +#define ZYNQMP_DMA_ARCACHE GENMASK(25, 22) +#define ZYNQMP_DMA_ARCACHE_OFST 22 +#define ZYNQMP_DMA_ARQOS GENMASK(21, 18) +#define ZYNQMP_DMA_ARQOS_OFST 18 +#define ZYNQMP_DMA_ARLEN GENMASK(17, 14) +#define ZYNQMP_DMA_ARLEN_OFST 14 +#define ZYNQMP_DMA_AWBURST GENMASK(13, 12) +#define ZYNQMP_DMA_AWCACHE GENMASK(11, 8) +#define ZYNQMP_DMA_AWCACHE_OFST 8 +#define ZYNQMP_DMA_AWQOS GENMASK(7, 4) +#define ZYNQMP_DMA_AWQOS_OFST 4 +#define ZYNQMP_DMA_AWLEN GENMASK(3, 0) +#define ZYNQMP_DMA_AWLEN_OFST 0 + +/* Descriptor Attribute register bit field definitions */ +#define ZYNQMP_DMA_AXCOHRNT BIT(8) +#define ZYNQMP_DMA_AXCACHE GENMASK(7, 4) +#define ZYNQMP_DMA_AXCACHE_OFST 4 +#define ZYNQMP_DMA_AXQOS GENMASK(3, 0) +#define ZYNQMP_DMA_AXQOS_OFST 0 + +/* Control register 2 bit field definitions */ +#define ZYNQMP_DMA_ENABLE BIT(0) + +/* Buffer Descriptor definitions */ +#define ZYNQMP_DMA_DESC_CTRL_STOP 0x10 +#define ZYNQMP_DMA_DESC_CTRL_COMP_INT 0x4 +#define ZYNQMP_DMA_DESC_CTRL_SIZE_256 0x2 +#define ZYNQMP_DMA_DESC_CTRL_COHRNT 0x1 + +/* Interrupt Mask specific definitions */ +#define ZYNQMP_DMA_INT_ERR (ZYNQMP_DMA_AXI_RD_DATA | \ + ZYNQMP_DMA_AXI_WR_DATA | \ + ZYNQMP_DMA_AXI_RD_DST_DSCR | \ + ZYNQMP_DMA_AXI_RD_SRC_DSCR | \ + ZYNQMP_DMA_INV_APB) +#define ZYNQMP_DMA_INT_OVRFL (ZYNQMP_DMA_BYTE_CNT_OVRFL | \ + ZYNQMP_DMA_IRQ_SRC_ACCT_ERR | \ + ZYNQMP_DMA_IRQ_DST_ACCT_ERR) +#define ZYNQMP_DMA_INT_DONE (ZYNQMP_DMA_DONE | ZYNQMP_DMA_DST_DSCR_DONE) +#define ZYNQMP_DMA_INT_EN_DEFAULT_MASK (ZYNQMP_DMA_INT_DONE | \ + ZYNQMP_DMA_INT_ERR | \ + ZYNQMP_DMA_INT_OVRFL | \ + ZYNQMP_DMA_DST_DSCR_DONE) + +/* Max number of descriptors per channel */ +#define ZYNQMP_DMA_NUM_DESCS 32 + +/* Max transfer size per descriptor */ +#define ZYNQMP_DMA_MAX_TRANS_LEN 0x40000000 + +/* Reset values for data attributes */ +#define ZYNQMP_DMA_AXCACHE_VAL 0xF +#define ZYNQMP_DMA_ARLEN_RST_VAL 0xF +#define ZYNQMP_DMA_AWLEN_RST_VAL 0xF + +#define ZYNQMP_DMA_SRC_ISSUE_RST_VAL 0x1F + +#define ZYNQMP_DMA_IDS_DEFAULT_MASK 0xFFF + +/* Bus width in bits */ +#define ZYNQMP_DMA_BUS_WIDTH_64 64 +#define ZYNQMP_DMA_BUS_WIDTH_128 128 + +#define ZYNQMP_DMA_DESC_SIZE(chan) (chan->desc_size) + +#define to_chan(chan) container_of(chan, struct zynqmp_dma_chan, \ + common) +#define tx_to_desc(tx) container_of(tx, struct zynqmp_dma_desc_sw, \ + async_tx) + +/** + * struct zynqmp_dma_desc_ll - Hw linked list descriptor + * @addr: Buffer address + * @size: Size of the buffer + * @ctrl: Control word + * @nxtdscraddr: Next descriptor base address + * @rsvd: Reserved field and for Hw internal use. + */ +struct zynqmp_dma_desc_ll { + u64 addr; + u32 size; + u32 ctrl; + u64 nxtdscraddr; + u64 rsvd; +}; __aligned(64) + +/** + * struct zynqmp_dma_desc_sw - Per Transaction structure + * @src: Source address for simple mode dma + * @dst: Destination address for simple mode dma + * @len: Transfer length for simple mode dma + * @node: Node in the channel descriptor list + * @tx_list: List head for the current transfer + * @async_tx: Async transaction descriptor + * @src_v: Virtual address of the src descriptor + * @src_p: Physical address of the src descriptor + * @dst_v: Virtual address of the dst descriptor + * @dst_p: Physical address of the dst descriptor + */ +struct zynqmp_dma_desc_sw { + u64 src; + u64 dst; + u32 len; + struct list_head node; + struct list_head tx_list; + struct dma_async_tx_descriptor async_tx; + struct zynqmp_dma_desc_ll *src_v; + dma_addr_t src_p; + struct zynqmp_dma_desc_ll *dst_v; + dma_addr_t dst_p; +}; + +/** + * struct zynqmp_dma_chan - Driver specific DMA channel structure + * @zdev: Driver specific device structure + * @regs: Control registers offset + * @lock: Descriptor operation lock + * @pending_list: Descriptors waiting + * @free_list: Descriptors free + * @active_list: Descriptors active + * @sw_desc_pool: SW descriptor pool + * @done_list: Complete descriptors + * @common: DMA common channel + * @desc_pool_v: Statically allocated descriptor base + * @desc_pool_p: Physical allocated descriptor base + * @desc_free_cnt: Descriptor available count + * @dev: The dma device + * @irq: Channel IRQ + * @has_sg: Support scatter gather transfers + * @ovrfetch: Overfetch status + * @is_dmacoherent: Tells whether dma operations are coherent or not + * @ratectrl: Rate control value + * @tasklet: Cleanup work after irq + * @src_issue: Out standing transactions on source + * @idle : Channel status; + * @desc_size: Size of the low level descriptor + * @err: Channel has errors + * @bus_width: Bus width + * @src_burst_len: Source burst length + * @dst_burst_len: Dest burst length + * @clk_main: Pointer to main clock + * @clk_apb: Pointer to apb clock + */ +struct zynqmp_dma_chan { + struct zynqmp_dma_device *zdev; + void __iomem *regs; + spinlock_t lock; + struct list_head pending_list; + struct list_head free_list; + struct list_head active_list; + struct zynqmp_dma_desc_sw *sw_desc_pool; + struct list_head done_list; + struct dma_chan common; + void *desc_pool_v; + dma_addr_t desc_pool_p; + u32 desc_free_cnt; + struct device *dev; + int irq; + bool has_sg; + bool ovrfetch; + bool is_dmacoherent; + u32 ratectrl; + struct tasklet_struct tasklet; + u32 src_issue; + bool idle; + u32 desc_size; + bool err; + u32 bus_width; + u32 src_burst_len; + u32 dst_burst_len; + struct clk *clk_main; + struct clk *clk_apb; +}; + +/** + * struct zynqmp_dma_device - DMA device structure + * @dev: Device Structure + * @common: DMA device structure + * @chan: Driver specific DMA channel + */ +struct zynqmp_dma_device { + struct device *dev; + struct dma_device common; + struct zynqmp_dma_chan *chan; +}; + +/** + * zynqmp_dma_chan_is_idle - Provides the channel idle status + * @chan: ZynqMP DMA DMA channel pointer + * + * Return: 'true' if the channel is idle otherwise 'false' + */ +static inline bool zynqmp_dma_chan_is_idle(struct zynqmp_dma_chan *chan) +{ + return chan->idle; + +} + +/** + * zynqmp_dma_update_desc_to_ctrlr - Updates descriptor to the controller + * @chan: ZynqMP DMA DMA channel pointer + * @desc: Transaction descriptor pointer + */ +static void zynqmp_dma_update_desc_to_ctrlr(struct zynqmp_dma_chan *chan, + struct zynqmp_dma_desc_sw *desc) +{ + dma_addr_t addr; + + addr = desc->src_p; + writel(addr, chan->regs + ZYNQMP_DMA_SRC_START_LSB); + writel(upper_32_bits(addr), chan->regs + ZYNQMP_DMA_SRC_START_MSB); + addr = desc->dst_p; + writel(addr, chan->regs + ZYNQMP_DMA_DST_START_LSB); + writel(upper_32_bits(addr), chan->regs + ZYNQMP_DMA_DST_START_MSB); +} + +/** + * zynqmp_dma_desc_config_eod - Mark the descriptor as end descriptor + * @chan: ZynqMP DMA channel pointer + * @desc: Hw descriptor pointer + */ +static void zynqmp_dma_desc_config_eod(struct zynqmp_dma_chan *chan, void *desc) +{ + struct zynqmp_dma_desc_ll *hw = (struct zynqmp_dma_desc_ll *)desc; + + hw->ctrl |= ZYNQMP_DMA_DESC_CTRL_STOP; + hw++; + hw->ctrl |= ZYNQMP_DMA_DESC_CTRL_COMP_INT | ZYNQMP_DMA_DESC_CTRL_STOP; +} + +/** + * zynqmp_dma_config_simple_desc - Configure the transfer parameters + * @chan: ZynqMP DMA channel pointer + * @src: Source buffer address + * @dst: Destination buffer address + * @len: Transfer length + */ +static void zynqmp_dma_config_simple_desc(struct zynqmp_dma_chan *chan, + dma_addr_t src, dma_addr_t dst, + size_t len) +{ + u32 val; + + writel(src, chan->regs + ZYNQMP_DMA_SRC_DSCR_WRD0); + writel(upper_32_bits(src), chan->regs + ZYNQMP_DMA_SRC_DSCR_WRD1); + writel(len, chan->regs + ZYNQMP_DMA_SRC_DSCR_WRD2); + + if (chan->is_dmacoherent) + writel(ZYNQMP_DMA_DESC_CTRL_COHRNT, + chan->regs + ZYNQMP_DMA_SRC_DSCR_WRD3); + else + writel(0, chan->regs + ZYNQMP_DMA_SRC_DSCR_WRD3); + + writel(dst, chan->regs + ZYNQMP_DMA_DST_DSCR_WRD0); + writel(upper_32_bits(dst), chan->regs + ZYNQMP_DMA_DST_DSCR_WRD1); + writel(len, chan->regs + ZYNQMP_DMA_DST_DSCR_WRD2); + + if (chan->is_dmacoherent) + val = ZYNQMP_DMA_DESC_CTRL_COHRNT | + ZYNQMP_DMA_DESC_CTRL_COMP_INT; + else + val = ZYNQMP_DMA_DESC_CTRL_COMP_INT; + writel(val, chan->regs + ZYNQMP_DMA_DST_DSCR_WRD3); +} + +/** + * zynqmp_dma_config_sg_ll_desc - Configure the linked list descriptor + * @chan: ZynqMP DMA channel pointer + * @sdesc: Hw descriptor pointer + * @src: Source buffer address + * @dst: Destination buffer address + * @len: Transfer length + * @prev: Previous hw descriptor pointer + */ +static void zynqmp_dma_config_sg_ll_desc(struct zynqmp_dma_chan *chan, + struct zynqmp_dma_desc_ll *sdesc, + dma_addr_t src, dma_addr_t dst, size_t len, + struct zynqmp_dma_desc_ll *prev) +{ + struct zynqmp_dma_desc_ll *ddesc = sdesc + 1; + + sdesc->size = ddesc->size = len; + sdesc->addr = src; + ddesc->addr = dst; + + sdesc->ctrl = ddesc->ctrl = ZYNQMP_DMA_DESC_CTRL_SIZE_256; + if (chan->is_dmacoherent) { + sdesc->ctrl |= ZYNQMP_DMA_DESC_CTRL_COHRNT; + ddesc->ctrl |= ZYNQMP_DMA_DESC_CTRL_COHRNT; + } + + if (prev) { + dma_addr_t addr = chan->desc_pool_p + + ((dma_addr_t)sdesc - (dma_addr_t)chan->desc_pool_v); + ddesc = prev + 1; + prev->nxtdscraddr = addr; + ddesc->nxtdscraddr = addr + ZYNQMP_DMA_DESC_SIZE(chan); + } +} + +/** + * zynqmp_dma_init - Initialize the channel + * @chan: ZynqMP DMA channel pointer + */ +static void zynqmp_dma_init(struct zynqmp_dma_chan *chan) +{ + u32 val; + + writel(ZYNQMP_DMA_IDS_DEFAULT_MASK, chan->regs + ZYNQMP_DMA_IDS); + val = readl(chan->regs + ZYNQMP_DMA_ISR); + writel(val, chan->regs + ZYNQMP_DMA_ISR); + + val = readl(chan->regs + ZYNQMP_DMA_CTRL1); + if (chan->src_issue) + val = (val & ~ZYNQMP_DMA_SRC_ISSUE) | chan->src_issue; + writel(val, chan->regs + ZYNQMP_DMA_CTRL1); + + val = 0; + if (chan->ovrfetch) + val |= ZYNQMP_DMA_OVR_FETCH; + if (chan->has_sg) + val |= ZYNQMP_DMA_POINT_TYPE_SG; + if (chan->ratectrl) { + val |= ZYNQMP_DMA_RATE_CTRL_EN; + writel(chan->ratectrl, chan->regs + ZYNQMP_DMA_RATE_CTRL); + } + writel(val, chan->regs + ZYNQMP_DMA_CTRL0); + + val = 0; + if (chan->is_dmacoherent) { + val |= ZYNQMP_DMA_AXCOHRNT; + val = (val & ~ZYNQMP_DMA_AXCACHE) | + (ZYNQMP_DMA_AXCACHE_VAL << ZYNQMP_DMA_AXCACHE_OFST); + } + writel(val, chan->regs + ZYNQMP_DMA_DSCR_ATTR); + + val = readl(chan->regs + ZYNQMP_DMA_DATA_ATTR); + if (chan->is_dmacoherent) { + val = (val & ~ZYNQMP_DMA_ARCACHE) | + (ZYNQMP_DMA_AXCACHE_VAL << ZYNQMP_DMA_ARCACHE_OFST); + val = (val & ~ZYNQMP_DMA_AWCACHE) | + (ZYNQMP_DMA_AXCACHE_VAL << ZYNQMP_DMA_AWCACHE_OFST); + } + val = (val & ~ZYNQMP_DMA_ARLEN) | + (chan->src_burst_len << ZYNQMP_DMA_ARLEN_OFST); + val = (val & ~ZYNQMP_DMA_AWLEN) | + (chan->dst_burst_len << ZYNQMP_DMA_AWLEN_OFST); + writel(val, chan->regs + ZYNQMP_DMA_DATA_ATTR); + + /* Clearing the interrupt account rgisters */ + val = readl(chan->regs + ZYNQMP_DMA_IRQ_SRC_ACCT); + val = readl(chan->regs + ZYNQMP_DMA_IRQ_DST_ACCT); + + chan->idle = true; +} + +/** + * zynqmp_dma_tx_submit - Submit DMA transaction + * @tx: Async transaction descriptor pointer + * + * Return: cookie value + */ +static dma_cookie_t zynqmp_dma_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct zynqmp_dma_chan *chan = to_chan(tx->chan); + struct zynqmp_dma_desc_sw *desc, *new; + dma_cookie_t cookie; + + new = tx_to_desc(tx); + spin_lock_bh(&chan->lock); + cookie = dma_cookie_assign(tx); + + if (!list_empty(&chan->pending_list) && chan->has_sg) { + desc = list_last_entry(&chan->pending_list, + struct zynqmp_dma_desc_sw, node); + if (!list_empty(&desc->tx_list)) + desc = list_last_entry(&desc->tx_list, + struct zynqmp_dma_desc_sw, node); + desc->src_v->nxtdscraddr = new->src_p; + desc->src_v->ctrl &= ~ZYNQMP_DMA_DESC_CTRL_STOP; + desc->dst_v->nxtdscraddr = new->dst_p; + desc->dst_v->ctrl &= ~ZYNQMP_DMA_DESC_CTRL_STOP; + } + + list_add_tail(&new->node, &chan->pending_list); + spin_unlock_bh(&chan->lock); + + return cookie; +} + +/** + * zynqmp_dma_get_descriptor - Get the sw descriptor from the pool + * @chan: ZynqMP DMA channel pointer + * + * Return: The sw descriptor + */ +static struct zynqmp_dma_desc_sw * +zynqmp_dma_get_descriptor(struct zynqmp_dma_chan *chan) +{ + struct zynqmp_dma_desc_sw *desc; + + spin_lock_bh(&chan->lock); + desc = list_first_entry(&chan->free_list, struct zynqmp_dma_desc_sw, + node); + list_del(&desc->node); + spin_unlock_bh(&chan->lock); + + INIT_LIST_HEAD(&desc->tx_list); + /* Clear the src and dst descriptor memory */ + if (chan->has_sg) { + memset((void *)desc->src_v, 0, ZYNQMP_DMA_DESC_SIZE(chan)); + memset((void *)desc->dst_v, 0, ZYNQMP_DMA_DESC_SIZE(chan)); + } + + return desc; +} + +/** + * zynqmp_dma_free_descriptor - Issue pending transactions + * @chan: ZynqMP DMA channel pointer + * @sdesc: Transaction descriptor pointer + */ +static void zynqmp_dma_free_descriptor(struct zynqmp_dma_chan *chan, + struct zynqmp_dma_desc_sw *sdesc) +{ + struct zynqmp_dma_desc_sw *child, *next; + + chan->desc_free_cnt++; + list_add_tail(&sdesc->node, &chan->free_list); + list_for_each_entry_safe(child, next, &sdesc->tx_list, node) { + chan->desc_free_cnt++; + INIT_LIST_HEAD(&child->tx_list); + list_move_tail(&child->node, &chan->free_list); + } + INIT_LIST_HEAD(&sdesc->tx_list); +} + +/** + * zynqmp_dma_free_desc_list - Free descriptors list + * @chan: ZynqMP DMA channel pointer + * @list: List to parse and delete the descriptor + */ +static void zynqmp_dma_free_desc_list(struct zynqmp_dma_chan *chan, + struct list_head *list) +{ + struct zynqmp_dma_desc_sw *desc, *next; + + list_for_each_entry_safe(desc, next, list, node) + zynqmp_dma_free_descriptor(chan, desc); +} + +/** + * zynqmp_dma_alloc_chan_resources - Allocate channel resources + * @dchan: DMA channel + * + * Return: Number of descriptors on success and failure value on error + */ +static int zynqmp_dma_alloc_chan_resources(struct dma_chan *dchan) +{ + struct zynqmp_dma_chan *chan = to_chan(dchan); + struct zynqmp_dma_desc_sw *desc; + int i; + + chan->sw_desc_pool = kzalloc(sizeof(*desc) * ZYNQMP_DMA_NUM_DESCS, + GFP_KERNEL); + if (!chan->sw_desc_pool) + return -ENOMEM; + chan->idle = true; + chan->desc_free_cnt = ZYNQMP_DMA_NUM_DESCS; + + INIT_LIST_HEAD(&chan->free_list); + + for (i = 0; i < ZYNQMP_DMA_NUM_DESCS; i++) { + desc = chan->sw_desc_pool + i; + dma_async_tx_descriptor_init(&desc->async_tx, &chan->common); + desc->async_tx.tx_submit = zynqmp_dma_tx_submit; + list_add_tail(&desc->node, &chan->free_list); + } + + if (!chan->has_sg) + return 0; + + chan->desc_pool_v = dma_zalloc_coherent(chan->dev, + (2 * chan->desc_size * ZYNQMP_DMA_NUM_DESCS), + &chan->desc_pool_p, GFP_KERNEL); + if (!chan->desc_pool_v) + return -ENOMEM; + + for (i = 0; i < ZYNQMP_DMA_NUM_DESCS; i++) { + desc = chan->sw_desc_pool + i; + desc->src_v = (struct zynqmp_dma_desc_ll *) (chan->desc_pool_v + + (i * ZYNQMP_DMA_DESC_SIZE(chan) * 2)); + desc->dst_v = (struct zynqmp_dma_desc_ll *) (desc->src_v + 1); + desc->src_p = chan->desc_pool_p + + (i * ZYNQMP_DMA_DESC_SIZE(chan) * 2); + desc->dst_p = desc->src_p + ZYNQMP_DMA_DESC_SIZE(chan); + } + + return ZYNQMP_DMA_NUM_DESCS; +} + +/** + * zynqmp_dma_start - Start DMA channel + * @chan: ZynqMP DMA channel pointer + */ +static void zynqmp_dma_start(struct zynqmp_dma_chan *chan) +{ + writel(ZYNQMP_DMA_INT_EN_DEFAULT_MASK, chan->regs + ZYNQMP_DMA_IER); + chan->idle = false; + writel(ZYNQMP_DMA_ENABLE, chan->regs + ZYNQMP_DMA_CTRL2); +} + +/** + * zynqmp_dma_handle_ovfl_int - Process the overflow interrupt + * @chan: ZynqMP DMA channel pointer + * @status: Interrupt status value + */ +static void zynqmp_dma_handle_ovfl_int(struct zynqmp_dma_chan *chan, u32 status) +{ + u32 val; + + if (status & ZYNQMP_DMA_IRQ_DST_ACCT_ERR) + val = readl(chan->regs + ZYNQMP_DMA_IRQ_DST_ACCT); + if (status & ZYNQMP_DMA_IRQ_SRC_ACCT_ERR) + val = readl(chan->regs + ZYNQMP_DMA_IRQ_SRC_ACCT); +} + +/** + * zynqmp_dma_start_transfer - Initiate the new transfer + * @chan: ZynqMP DMA channel pointer + */ +static void zynqmp_dma_start_transfer(struct zynqmp_dma_chan *chan) +{ + struct zynqmp_dma_desc_sw *desc; + + if (!zynqmp_dma_chan_is_idle(chan)) + return; + + desc = list_first_entry_or_null(&chan->pending_list, + struct zynqmp_dma_desc_sw, node); + if (!desc) + return; + + if (chan->has_sg) + list_splice_tail_init(&chan->pending_list, &chan->active_list); + else + list_move_tail(&desc->node, &chan->active_list); + + if (chan->has_sg) + zynqmp_dma_update_desc_to_ctrlr(chan, desc); + else + zynqmp_dma_config_simple_desc(chan, desc->src, desc->dst, + desc->len); + + zynqmp_dma_start(chan); +} + + +/** + * zynqmp_dma_chan_desc_cleanup - Cleanup the completed descriptors + * @chan: ZynqMP DMA channel + */ +static void zynqmp_dma_chan_desc_cleanup(struct zynqmp_dma_chan *chan) +{ + struct zynqmp_dma_desc_sw *desc, *next; + + list_for_each_entry_safe(desc, next, &chan->done_list, node) { + dma_async_tx_callback callback; + void *callback_param; + + list_del(&desc->node); + + callback = desc->async_tx.callback; + callback_param = desc->async_tx.callback_param; + if (callback) { + spin_unlock(&chan->lock); + callback(callback_param); + spin_lock(&chan->lock); + } + + /* Run any dependencies, then free the descriptor */ + zynqmp_dma_free_descriptor(chan, desc); + } +} + +/** + * zynqmp_dma_complete_descriptor - Mark the active descriptor as complete + * @chan: ZynqMP DMA channel pointer + */ +static void zynqmp_dma_complete_descriptor(struct zynqmp_dma_chan *chan) +{ + struct zynqmp_dma_desc_sw *desc; + + desc = list_first_entry_or_null(&chan->active_list, + struct zynqmp_dma_desc_sw, node); + if (!desc) + return; + list_del(&desc->node); + dma_cookie_complete(&desc->async_tx); + list_add_tail(&desc->node, &chan->done_list); +} + +/** + * zynqmp_dma_issue_pending - Issue pending transactions + * @dchan: DMA channel pointer + */ +static void zynqmp_dma_issue_pending(struct dma_chan *dchan) +{ + struct zynqmp_dma_chan *chan = to_chan(dchan); + + spin_lock_bh(&chan->lock); + zynqmp_dma_start_transfer(chan); + spin_unlock_bh(&chan->lock); +} + +/** + * zynqmp_dma_free_descriptors - Free channel descriptors + * @dchan: DMA channel pointer + */ +static void zynqmp_dma_free_descriptors(struct zynqmp_dma_chan *chan) +{ + zynqmp_dma_free_desc_list(chan, &chan->active_list); + zynqmp_dma_free_desc_list(chan, &chan->pending_list); + zynqmp_dma_free_desc_list(chan, &chan->done_list); +} + +/** + * zynqmp_dma_free_chan_resources - Free channel resources + * @dchan: DMA channel pointer + */ +static void zynqmp_dma_free_chan_resources(struct dma_chan *dchan) +{ + struct zynqmp_dma_chan *chan = to_chan(dchan); + + spin_lock_bh(&chan->lock); + zynqmp_dma_free_descriptors(chan); + spin_unlock_bh(&chan->lock); + dma_free_coherent(chan->dev, + (2 * ZYNQMP_DMA_DESC_SIZE(chan) * ZYNQMP_DMA_NUM_DESCS), + chan->desc_pool_v, chan->desc_pool_p); + kfree(chan->sw_desc_pool); +} + +/** + * zynqmp_dma_tx_status - Get dma transaction status + * @dchan: DMA channel pointer + * @cookie: Transaction identifier + * @txstate: Transaction state + * + * Return: DMA transaction status + */ +static enum dma_status zynqmp_dma_tx_status(struct dma_chan *dchan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + return dma_cookie_status(dchan, cookie, txstate); +} + +/** + * zynqmp_dma_reset - Reset the channel + * @chan: ZynqMP DMA channel pointer + */ +static void zynqmp_dma_reset(struct zynqmp_dma_chan *chan) +{ + writel(ZYNQMP_DMA_IDS_DEFAULT_MASK, chan->regs + ZYNQMP_DMA_IDS); + + zynqmp_dma_complete_descriptor(chan); + zynqmp_dma_chan_desc_cleanup(chan); + zynqmp_dma_free_descriptors(chan); + zynqmp_dma_init(chan); +} + +/** + * zynqmp_dma_irq_handler - ZynqMP DMA Interrupt handler + * @irq: IRQ number + * @data: Pointer to the ZynqMP DMA channel structure + * + * Return: IRQ_HANDLED/IRQ_NONE + */ +static irqreturn_t zynqmp_dma_irq_handler(int irq, void *data) +{ + struct zynqmp_dma_chan *chan = (struct zynqmp_dma_chan *)data; + u32 isr, imr, status; + irqreturn_t ret = IRQ_NONE; + + isr = readl(chan->regs + ZYNQMP_DMA_ISR); + imr = readl(chan->regs + ZYNQMP_DMA_IMR); + status = isr & ~imr; + + writel(isr, chan->regs + ZYNQMP_DMA_ISR); + if (status & ZYNQMP_DMA_INT_DONE) { + tasklet_schedule(&chan->tasklet); + ret = IRQ_HANDLED; + } + + if (status & ZYNQMP_DMA_DONE) + chan->idle = true; + + if (status & ZYNQMP_DMA_INT_ERR) { + chan->err = true; + tasklet_schedule(&chan->tasklet); + dev_err(chan->dev, "Channel %p has errors\n", chan); + ret = IRQ_HANDLED; + } + + if (status & ZYNQMP_DMA_INT_OVRFL) { + zynqmp_dma_handle_ovfl_int(chan, status); + dev_info(chan->dev, "Channel %p overflow interrupt\n", chan); + ret = IRQ_HANDLED; + } + + return ret; +} + +/** + * zynqmp_dma_do_tasklet - Schedule completion tasklet + * @data: Pointer to the ZynqMP DMA channel structure + */ +static void zynqmp_dma_do_tasklet(unsigned long data) +{ + struct zynqmp_dma_chan *chan = (struct zynqmp_dma_chan *)data; + u32 count; + + spin_lock(&chan->lock); + + if (chan->err) { + zynqmp_dma_reset(chan); + chan->err = false; + goto unlock; + } + + count = readl(chan->regs + ZYNQMP_DMA_IRQ_DST_ACCT); + + while (count) { + zynqmp_dma_complete_descriptor(chan); + zynqmp_dma_chan_desc_cleanup(chan); + count--; + } + + if (chan->idle) + zynqmp_dma_start_transfer(chan); + +unlock: + spin_unlock(&chan->lock); +} + +/** + * zynqmp_dma_device_terminate_all - Aborts all transfers on a channel + * @dchan: DMA channel pointer + * + * Return: Always '0' + */ +static int zynqmp_dma_device_terminate_all(struct dma_chan *dchan) +{ + struct zynqmp_dma_chan *chan = to_chan(dchan); + + spin_lock_bh(&chan->lock); + writel(ZYNQMP_DMA_IDS_DEFAULT_MASK, chan->regs + ZYNQMP_DMA_IDS); + zynqmp_dma_free_descriptors(chan); + spin_unlock_bh(&chan->lock); + + return 0; +} + +/** + * zynqmp_dma_prep_memcpy - prepare descriptors for memcpy transaction + * @dchan: DMA channel + * @dma_dst: Destination buffer address + * @dma_src: Source buffer address + * @len: Transfer length + * @flags: transfer ack flags + * + * Return: Async transaction descriptor on success and NULL on failure + */ +static struct dma_async_tx_descriptor *zynqmp_dma_prep_memcpy( + struct dma_chan *dchan, dma_addr_t dma_dst, + dma_addr_t dma_src, size_t len, ulong flags) +{ + struct zynqmp_dma_chan *chan; + struct zynqmp_dma_desc_sw *new, *first = NULL; + void *desc = NULL, *prev = NULL; + size_t copy; + u32 desc_cnt; + + chan = to_chan(dchan); + + if ((len > ZYNQMP_DMA_MAX_TRANS_LEN) && !chan->has_sg) + return NULL; + + desc_cnt = DIV_ROUND_UP(len, ZYNQMP_DMA_MAX_TRANS_LEN); + + spin_lock_bh(&chan->lock); + if ((desc_cnt > chan->desc_free_cnt) && chan->has_sg) { + spin_unlock_bh(&chan->lock); + dev_dbg(chan->dev, "chan %p descs are not available\n", chan); + return NULL; + } + chan->desc_free_cnt = chan->desc_free_cnt - desc_cnt; + spin_unlock_bh(&chan->lock); + + do { + /* Allocate and populate the descriptor */ + new = zynqmp_dma_get_descriptor(chan); + + copy = min_t(size_t, len, ZYNQMP_DMA_MAX_TRANS_LEN); + if (chan->has_sg) { + desc = (struct zynqmp_dma_desc_ll *)new->src_v; + zynqmp_dma_config_sg_ll_desc(chan, desc, dma_src, + dma_dst, copy, prev); + } else { + new->src = dma_src; + new->dst = dma_dst; + new->len = len; + } + + prev = desc; + len -= copy; + dma_src += copy; + dma_dst += copy; + if (!first) + first = new; + else + list_add_tail(&new->node, &first->tx_list); + } while (len); + + if (chan->has_sg) + zynqmp_dma_desc_config_eod(chan, desc); + + async_tx_ack(&first->async_tx); + first->async_tx.flags = flags; + return &first->async_tx; +} + +/** + * zynqmp_dma_prep_slave_sg - prepare descriptors for a memory sg transaction + * @dchan: DMA channel + * @dst_sg: Destination scatter list + * @dst_sg_len: Number of entries in destination scatter list + * @src_sg: Source scatter list + * @src_sg_len: Number of entries in source scatter list + * @flags: transfer ack flags + * + * Return: Async transaction descriptor on success and NULL on failure + */ +static struct dma_async_tx_descriptor *zynqmp_dma_prep_sg( + struct dma_chan *dchan, struct scatterlist *dst_sg, + unsigned int dst_sg_len, struct scatterlist *src_sg, + unsigned int src_sg_len, unsigned long flags) +{ + struct zynqmp_dma_desc_sw *new, *first = NULL; + struct zynqmp_dma_chan *chan = to_chan(dchan); + void *desc = NULL, *prev = NULL; + size_t len, dst_avail, src_avail; + dma_addr_t dma_dst, dma_src; + u32 desc_cnt = 0, i; + struct scatterlist *sg; + + if (!chan->has_sg) + return NULL; + + for_each_sg(src_sg, sg, src_sg_len, i) + desc_cnt += DIV_ROUND_UP(sg_dma_len(sg), + ZYNQMP_DMA_MAX_TRANS_LEN); + + spin_lock_bh(&chan->lock); + if (desc_cnt > chan->desc_free_cnt) { + spin_unlock_bh(&chan->lock); + dev_dbg(chan->dev, "chan %p descs are not available\n", chan); + return NULL; + } + chan->desc_free_cnt = chan->desc_free_cnt - desc_cnt; + spin_unlock_bh(&chan->lock); + + dst_avail = sg_dma_len(dst_sg); + src_avail = sg_dma_len(src_sg); + + /* Run until we are out of scatterlist entries */ + while (true) { + /* Allocate and populate the descriptor */ + new = zynqmp_dma_get_descriptor(chan); + desc = (struct zynqmp_dma_desc_ll *)new->src_v; + len = min_t(size_t, src_avail, dst_avail); + len = min_t(size_t, len, ZYNQMP_DMA_MAX_TRANS_LEN); + if (len == 0) + goto fetch; + dma_dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - + dst_avail; + dma_src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - + src_avail; + + zynqmp_dma_config_sg_ll_desc(chan, desc, dma_src, dma_dst, + len, prev); + prev = desc; + dst_avail -= len; + src_avail -= len; + + if (!first) + first = new; + else + list_add_tail(&new->node, &first->tx_list); +fetch: + /* Fetch the next dst scatterlist entry */ + if (dst_avail == 0) { + if (dst_sg_len == 0) + break; + dst_sg = sg_next(dst_sg); + if (dst_sg == NULL) + break; + dst_sg_len--; + dst_avail = sg_dma_len(dst_sg); + } + /* Fetch the next src scatterlist entry */ + if (src_avail == 0) { + if (src_sg_len == 0) + break; + src_sg = sg_next(src_sg); + if (src_sg == NULL) + break; + src_sg_len--; + src_avail = sg_dma_len(src_sg); + } + } + + zynqmp_dma_desc_config_eod(chan, desc); + first->async_tx.flags = flags; + return &first->async_tx; +} + +/** + * zynqmp_dma_chan_remove - Channel remove function + * @chan: ZynqMP DMA channel pointer + */ +static void zynqmp_dma_chan_remove(struct zynqmp_dma_chan *chan) +{ + if (!chan) + return; + + devm_free_irq(chan->zdev->dev, chan->irq, chan); + tasklet_kill(&chan->tasklet); + list_del(&chan->common.device_node); + clk_disable_unprepare(chan->clk_apb); + clk_disable_unprepare(chan->clk_main); +} + +/** + * zynqmp_dma_chan_probe - Per Channel Probing + * @zdev: Driver specific device structure + * @pdev: Pointer to the platform_device structure + * + * Return: '0' on success and failure value on error + */ +static int zynqmp_dma_chan_probe(struct zynqmp_dma_device *zdev, + struct platform_device *pdev) +{ + struct zynqmp_dma_chan *chan; + struct resource *res; + struct device_node *node = pdev->dev.of_node; + int err; + + chan = devm_kzalloc(zdev->dev, sizeof(*chan), GFP_KERNEL); + if (!chan) + return -ENOMEM; + chan->dev = zdev->dev; + chan->zdev = zdev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + chan->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(chan->regs)) + return PTR_ERR(chan->regs); + + chan->bus_width = ZYNQMP_DMA_BUS_WIDTH_64; + chan->src_issue = ZYNQMP_DMA_SRC_ISSUE_RST_VAL; + chan->dst_burst_len = ZYNQMP_DMA_AWLEN_RST_VAL; + chan->src_burst_len = ZYNQMP_DMA_ARLEN_RST_VAL; + err = of_property_read_u32(node, "xlnx,bus-width", &chan->bus_width); + if ((err < 0) && ((chan->bus_width != ZYNQMP_DMA_BUS_WIDTH_64) || + (chan->bus_width != ZYNQMP_DMA_BUS_WIDTH_128))) { + dev_err(zdev->dev, "invalid bus-width value"); + return err; + } + + chan->bus_width = chan->bus_width / 8; + chan->has_sg = of_property_read_bool(node, "xlnx,include-sg"); + chan->ovrfetch = of_property_read_bool(node, "xlnx,overfetch"); + chan->is_dmacoherent = of_property_read_bool(node, "dma-coherent"); + of_property_read_u32(node, "xlnx,src-burst-len", &chan->src_burst_len); + of_property_read_u32(node, "xlnx,dst-burst-len", &chan->dst_burst_len); + of_property_read_u32(node, "xlnx,ratectrl", &chan->ratectrl); + of_property_read_u32(node, "xlnx,src-issue", &chan->src_issue); + + zdev->chan = chan; + tasklet_init(&chan->tasklet, zynqmp_dma_do_tasklet, (ulong)chan); + spin_lock_init(&chan->lock); + INIT_LIST_HEAD(&chan->active_list); + INIT_LIST_HEAD(&chan->pending_list); + INIT_LIST_HEAD(&chan->done_list); + INIT_LIST_HEAD(&chan->free_list); + + dma_cookie_init(&chan->common); + chan->common.device = &zdev->common; + list_add_tail(&chan->common.device_node, &zdev->common.channels); + + zynqmp_dma_init(chan); + chan->irq = platform_get_irq(pdev, 0); + if (chan->irq < 0) + return -ENXIO; + err = devm_request_irq(&pdev->dev, chan->irq, zynqmp_dma_irq_handler, 0, + "zynqmp-dma", chan); + if (err) + return err; + chan->clk_main = devm_clk_get(&pdev->dev, "clk_main"); + if (IS_ERR(chan->clk_main)) { + dev_err(&pdev->dev, "main clock not found.\n"); + return PTR_ERR(chan->clk_main); + } + + chan->clk_apb = devm_clk_get(&pdev->dev, "clk_apb"); + if (IS_ERR(chan->clk_apb)) { + dev_err(&pdev->dev, "apb clock not found.\n"); + return PTR_ERR(chan->clk_apb); + } + + err = clk_prepare_enable(chan->clk_main); + if (err) { + dev_err(&pdev->dev, "Unable to enable main clock.\n"); + return err; + } + + err = clk_prepare_enable(chan->clk_apb); + if (err) { + dev_err(&pdev->dev, "Unable to enable apb clock.\n"); + return err; + } + + chan->desc_size = sizeof(struct zynqmp_dma_desc_ll); + chan->idle = true; + return 0; +} + +/** + * of_zynqmp_dma_xlate - Translation function + * @dma_spec: Pointer to DMA specifier as found in the device tree + * @ofdma: Pointer to DMA controller data + * + * Return: DMA channel pointer on success and NULL on error + */ +static struct dma_chan *of_zynqmp_dma_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct zynqmp_dma_device *zdev = ofdma->of_dma_data; + + return dma_get_slave_channel(&zdev->chan->common); +} + +/** + * zynqmp_dma_probe - Driver probe function + * @pdev: Pointer to the platform_device structure + * + * Return: '0' on success and failure value on error + */ +static int zynqmp_dma_probe(struct platform_device *pdev) +{ + struct zynqmp_dma_device *zdev; + struct dma_device *p; + int ret; + + zdev = devm_kzalloc(&pdev->dev, sizeof(*zdev), GFP_KERNEL); + if (!zdev) + return -ENOMEM; + + zdev->dev = &pdev->dev; + INIT_LIST_HEAD(&zdev->common.channels); + + dma_set_mask(&pdev->dev, DMA_BIT_MASK(44)); + dma_cap_set(DMA_SG, zdev->common.cap_mask); + dma_cap_set(DMA_MEMCPY, zdev->common.cap_mask); + + p = &zdev->common; + p->device_prep_dma_sg = zynqmp_dma_prep_sg; + p->device_prep_dma_memcpy = zynqmp_dma_prep_memcpy; + p->device_terminate_all = zynqmp_dma_device_terminate_all; + p->device_issue_pending = zynqmp_dma_issue_pending; + p->device_alloc_chan_resources = zynqmp_dma_alloc_chan_resources; + p->device_free_chan_resources = zynqmp_dma_free_chan_resources; + p->device_tx_status = zynqmp_dma_tx_status; + p->dev = &pdev->dev; + + platform_set_drvdata(pdev, zdev); + + ret = zynqmp_dma_chan_probe(zdev, pdev); + if (ret) { + dev_err(&pdev->dev, "Probing channel failed\n"); + goto free_chan_resources; + } + + p->dst_addr_widths = BIT(zdev->chan->bus_width); + p->src_addr_widths = BIT(zdev->chan->bus_width); + + dma_async_device_register(&zdev->common); + + ret = of_dma_controller_register(pdev->dev.of_node, + of_zynqmp_dma_xlate, zdev); + if (ret) { + dev_err(&pdev->dev, "Unable to register DMA to DT\n"); + dma_async_device_unregister(&zdev->common); + goto free_chan_resources; + } + + dev_info(&pdev->dev, "ZynqMP DMA driver Probe success\n"); + + return 0; + +free_chan_resources: + zynqmp_dma_chan_remove(zdev->chan); + return ret; +} + +/** + * zynqmp_dma_remove - Driver remove function + * @pdev: Pointer to the platform_device structure + * + * Return: Always '0' + */ +static int zynqmp_dma_remove(struct platform_device *pdev) +{ + struct zynqmp_dma_device *zdev = platform_get_drvdata(pdev); + + of_dma_controller_free(pdev->dev.of_node); + dma_async_device_unregister(&zdev->common); + + zynqmp_dma_chan_remove(zdev->chan); + + return 0; +} + +static const struct of_device_id zynqmp_dma_of_match[] = { + { .compatible = "xlnx,zynqmp-dma-1.0", }, + {} +}; +MODULE_DEVICE_TABLE(of, zynqmp_dma_of_match); + +static struct platform_driver zynqmp_dma_driver = { + .driver = { + .name = "xilinx-zynqmp-dma", + .of_match_table = zynqmp_dma_of_match, + }, + .probe = zynqmp_dma_probe, + .remove = zynqmp_dma_remove, +}; + +module_platform_driver(zynqmp_dma_driver); + +MODULE_AUTHOR("Xilinx, Inc."); +MODULE_DESCRIPTION("Xilinx ZynqMP DMA driver"); +MODULE_LICENSE("GPL"); -- 2.1.2 -- 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