alistair23-linux/drivers/dma/fsldma.h
Ira Snyder f04cd40701 fsldma: fix controller lockups
Enabling poisoning in the dmapool API quickly showed that the DMA
controller was fetching descriptors that should not have been in use.
This has caused intermittent controller lockups during testing.

I have been unable to figure out the exact set of conditions which cause
this to happen. However, I believe it is related to the driver using the
hardware registers to track whether the controller is busy or not. The
code can incorrectly decide that the hardware is idle due to lag between
register writes and the hardware actually becoming busy.

To fix this, the driver has been reworked to explicitly track the state
of the hardware, rather than try to guess what it is doing based on the
register values.

This has passed dmatest with 10 threads per channel, 100000 iterations
per thread several times without error. Previously, this would fail
within a few seconds.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-03-11 17:52:36 -08:00

208 lines
6.5 KiB
C

/*
* Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights reserved.
*
* Author:
* Zhang Wei <wei.zhang@freescale.com>, Jul 2007
* Ebony Zhu <ebony.zhu@freescale.com>, May 2007
*
* This 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.
*
*/
#ifndef __DMA_FSLDMA_H
#define __DMA_FSLDMA_H
#include <linux/device.h>
#include <linux/dmapool.h>
#include <linux/dmaengine.h>
/* Define data structures needed by Freescale
* MPC8540 and MPC8349 DMA controller.
*/
#define FSL_DMA_MR_CS 0x00000001
#define FSL_DMA_MR_CC 0x00000002
#define FSL_DMA_MR_CA 0x00000008
#define FSL_DMA_MR_EIE 0x00000040
#define FSL_DMA_MR_XFE 0x00000020
#define FSL_DMA_MR_EOLNIE 0x00000100
#define FSL_DMA_MR_EOLSIE 0x00000080
#define FSL_DMA_MR_EOSIE 0x00000200
#define FSL_DMA_MR_CDSM 0x00000010
#define FSL_DMA_MR_CTM 0x00000004
#define FSL_DMA_MR_EMP_EN 0x00200000
#define FSL_DMA_MR_EMS_EN 0x00040000
#define FSL_DMA_MR_DAHE 0x00002000
#define FSL_DMA_MR_SAHE 0x00001000
/*
* Bandwidth/pause control determines how many bytes a given
* channel is allowed to transfer before the DMA engine pauses
* the current channel and switches to the next channel
*/
#define FSL_DMA_MR_BWC 0x08000000
/* Special MR definition for MPC8349 */
#define FSL_DMA_MR_EOTIE 0x00000080
#define FSL_DMA_MR_PRC_RM 0x00000800
#define FSL_DMA_SR_CH 0x00000020
#define FSL_DMA_SR_PE 0x00000010
#define FSL_DMA_SR_CB 0x00000004
#define FSL_DMA_SR_TE 0x00000080
#define FSL_DMA_SR_EOSI 0x00000002
#define FSL_DMA_SR_EOLSI 0x00000001
#define FSL_DMA_SR_EOCDI 0x00000001
#define FSL_DMA_SR_EOLNI 0x00000008
#define FSL_DMA_SATR_SBPATMU 0x20000000
#define FSL_DMA_SATR_STRANSINT_RIO 0x00c00000
#define FSL_DMA_SATR_SREADTYPE_SNOOP_READ 0x00050000
#define FSL_DMA_SATR_SREADTYPE_BP_IORH 0x00020000
#define FSL_DMA_SATR_SREADTYPE_BP_NREAD 0x00040000
#define FSL_DMA_SATR_SREADTYPE_BP_MREAD 0x00070000
#define FSL_DMA_DATR_DBPATMU 0x20000000
#define FSL_DMA_DATR_DTRANSINT_RIO 0x00c00000
#define FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE 0x00050000
#define FSL_DMA_DATR_DWRITETYPE_BP_FLUSH 0x00010000
#define FSL_DMA_EOL ((u64)0x1)
#define FSL_DMA_SNEN ((u64)0x10)
#define FSL_DMA_EOSIE 0x8
#define FSL_DMA_NLDA_MASK (~(u64)0x1f)
#define FSL_DMA_BCR_MAX_CNT 0x03ffffffu
#define FSL_DMA_DGSR_TE 0x80
#define FSL_DMA_DGSR_CH 0x20
#define FSL_DMA_DGSR_PE 0x10
#define FSL_DMA_DGSR_EOLNI 0x08
#define FSL_DMA_DGSR_CB 0x04
#define FSL_DMA_DGSR_EOSI 0x02
#define FSL_DMA_DGSR_EOLSI 0x01
typedef u64 __bitwise v64;
typedef u32 __bitwise v32;
struct fsl_dma_ld_hw {
v64 src_addr;
v64 dst_addr;
v64 next_ln_addr;
v32 count;
v32 reserve;
} __attribute__((aligned(32)));
struct fsl_desc_sw {
struct fsl_dma_ld_hw hw;
struct list_head node;
struct list_head tx_list;
struct dma_async_tx_descriptor async_tx;
} __attribute__((aligned(32)));
struct fsldma_chan_regs {
u32 mr; /* 0x00 - Mode Register */
u32 sr; /* 0x04 - Status Register */
u64 cdar; /* 0x08 - Current descriptor address register */
u64 sar; /* 0x10 - Source Address Register */
u64 dar; /* 0x18 - Destination Address Register */
u32 bcr; /* 0x20 - Byte Count Register */
u64 ndar; /* 0x24 - Next Descriptor Address Register */
};
struct fsldma_chan;
#define FSL_DMA_MAX_CHANS_PER_DEVICE 4
struct fsldma_device {
void __iomem *regs; /* DGSR register base */
struct device *dev;
struct dma_device common;
struct fsldma_chan *chan[FSL_DMA_MAX_CHANS_PER_DEVICE];
u32 feature; /* The same as DMA channels */
int irq; /* Channel IRQ */
};
/* Define macros for fsldma_chan->feature property */
#define FSL_DMA_LITTLE_ENDIAN 0x00000000
#define FSL_DMA_BIG_ENDIAN 0x00000001
#define FSL_DMA_IP_MASK 0x00000ff0
#define FSL_DMA_IP_85XX 0x00000010
#define FSL_DMA_IP_83XX 0x00000020
#define FSL_DMA_CHAN_PAUSE_EXT 0x00001000
#define FSL_DMA_CHAN_START_EXT 0x00002000
struct fsldma_chan {
char name[8]; /* Channel name */
struct fsldma_chan_regs __iomem *regs;
dma_cookie_t completed_cookie; /* The maximum cookie completed */
spinlock_t desc_lock; /* Descriptor operation lock */
struct list_head ld_pending; /* Link descriptors queue */
struct list_head ld_running; /* Link descriptors queue */
struct dma_chan common; /* DMA common channel */
struct dma_pool *desc_pool; /* Descriptors pool */
struct device *dev; /* Channel device */
int irq; /* Channel IRQ */
int id; /* Raw id of this channel */
struct tasklet_struct tasklet;
u32 feature;
bool idle; /* DMA controller is idle */
void (*toggle_ext_pause)(struct fsldma_chan *fsl_chan, int enable);
void (*toggle_ext_start)(struct fsldma_chan *fsl_chan, int enable);
void (*set_src_loop_size)(struct fsldma_chan *fsl_chan, int size);
void (*set_dst_loop_size)(struct fsldma_chan *fsl_chan, int size);
void (*set_request_count)(struct fsldma_chan *fsl_chan, int size);
};
#define to_fsl_chan(chan) container_of(chan, struct fsldma_chan, common)
#define to_fsl_desc(lh) container_of(lh, struct fsl_desc_sw, node)
#define tx_to_fsl_desc(tx) container_of(tx, struct fsl_desc_sw, async_tx)
#ifndef __powerpc64__
static u64 in_be64(const u64 __iomem *addr)
{
return ((u64)in_be32((u32 __iomem *)addr) << 32) |
(in_be32((u32 __iomem *)addr + 1));
}
static void out_be64(u64 __iomem *addr, u64 val)
{
out_be32((u32 __iomem *)addr, val >> 32);
out_be32((u32 __iomem *)addr + 1, (u32)val);
}
/* There is no asm instructions for 64 bits reverse loads and stores */
static u64 in_le64(const u64 __iomem *addr)
{
return ((u64)in_le32((u32 __iomem *)addr + 1) << 32) |
(in_le32((u32 __iomem *)addr));
}
static void out_le64(u64 __iomem *addr, u64 val)
{
out_le32((u32 __iomem *)addr + 1, val >> 32);
out_le32((u32 __iomem *)addr, (u32)val);
}
#endif
#define DMA_IN(fsl_chan, addr, width) \
(((fsl_chan)->feature & FSL_DMA_BIG_ENDIAN) ? \
in_be##width(addr) : in_le##width(addr))
#define DMA_OUT(fsl_chan, addr, val, width) \
(((fsl_chan)->feature & FSL_DMA_BIG_ENDIAN) ? \
out_be##width(addr, val) : out_le##width(addr, val))
#define DMA_TO_CPU(fsl_chan, d, width) \
(((fsl_chan)->feature & FSL_DMA_BIG_ENDIAN) ? \
be##width##_to_cpu((__force __be##width)(v##width)d) : \
le##width##_to_cpu((__force __le##width)(v##width)d))
#define CPU_TO_DMA(fsl_chan, c, width) \
(((fsl_chan)->feature & FSL_DMA_BIG_ENDIAN) ? \
(__force v##width)cpu_to_be##width(c) : \
(__force v##width)cpu_to_le##width(c))
#endif /* __DMA_FSLDMA_H */