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linux/arch/frv/kernel/dma.c
Peter Zijlstra b0d8003ef4 frv: Rewrite atomic implementation 
Mostly complete rewrite of the FRV atomic implementation, instead of
using assembly files, use inline assembler.

The out-of-line CONFIG option makes a bit of a mess of things, but a
little CPP trickery gets that done too.

FRV already had the atomic logic ops but under a non standard name,
the reimplementation provides the generic names and provides the
intermediate form required for the bitops implementation.

The slightly inconsistent __atomic32_fetch_##op naming is because
__atomic_fetch_##op conlicts with GCC builtin functions.

The 64bit atomic ops use the inline assembly %Ln construct to access
the low word register (r+1), afaik this construct was not previously
used in the kernel and is completely undocumented, but I found it in
the FRV GCC code and it seems to work.

FRV had a non-standard definition of atomic_{clear,set}_mask() which
would work types other than atomic_t, the one user relying on that
(arch/frv/kernel/dma.c) got converted to use the new intermediate
form.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27 14:06:23 +02:00

464 lines
11 KiB
C
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/* dma.c: DMA controller management on FR401 and the like
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* 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/module.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <asm/dma.h>
#include <asm/gpio-regs.h>
#include <asm/irc-regs.h>
#include <asm/cpu-irqs.h>
struct frv_dma_channel {
uint8_t flags;
#define FRV_DMA_FLAGS_RESERVED 0x01
#define FRV_DMA_FLAGS_INUSE 0x02
#define FRV_DMA_FLAGS_PAUSED 0x04
uint8_t cap; /* capabilities available */
int irq; /* completion IRQ */
uint32_t dreqbit;
uint32_t dackbit;
uint32_t donebit;
const unsigned long ioaddr; /* DMA controller regs addr */
const char *devname;
dma_irq_handler_t handler;
void *data;
};
#define __get_DMAC(IO,X) ({ *(volatile unsigned long *)((IO) + DMAC_##X##x); })
#define __set_DMAC(IO,X,V) \
do { \
*(volatile unsigned long *)((IO) + DMAC_##X##x) = (V); \
mb(); \
} while(0)
#define ___set_DMAC(IO,X,V) \
do { \
*(volatile unsigned long *)((IO) + DMAC_##X##x) = (V); \
} while(0)
static struct frv_dma_channel frv_dma_channels[FRV_DMA_NCHANS] = {
[0] = {
.cap = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK | FRV_DMA_CAP_DONE,
.irq = IRQ_CPU_DMA0,
.dreqbit = SIR_DREQ0_INPUT,
.dackbit = SOR_DACK0_OUTPUT,
.donebit = SOR_DONE0_OUTPUT,
.ioaddr = 0xfe000900,
},
[1] = {
.cap = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK | FRV_DMA_CAP_DONE,
.irq = IRQ_CPU_DMA1,
.dreqbit = SIR_DREQ1_INPUT,
.dackbit = SOR_DACK1_OUTPUT,
.donebit = SOR_DONE1_OUTPUT,
.ioaddr = 0xfe000980,
},
[2] = {
.cap = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK,
.irq = IRQ_CPU_DMA2,
.dreqbit = SIR_DREQ2_INPUT,
.dackbit = SOR_DACK2_OUTPUT,
.ioaddr = 0xfe000a00,
},
[3] = {
.cap = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK,
.irq = IRQ_CPU_DMA3,
.dreqbit = SIR_DREQ3_INPUT,
.dackbit = SOR_DACK3_OUTPUT,
.ioaddr = 0xfe000a80,
},
[4] = {
.cap = FRV_DMA_CAP_DREQ,
.irq = IRQ_CPU_DMA4,
.dreqbit = SIR_DREQ4_INPUT,
.ioaddr = 0xfe001000,
},
[5] = {
.cap = FRV_DMA_CAP_DREQ,
.irq = IRQ_CPU_DMA5,
.dreqbit = SIR_DREQ5_INPUT,
.ioaddr = 0xfe001080,
},
[6] = {
.cap = FRV_DMA_CAP_DREQ,
.irq = IRQ_CPU_DMA6,
.dreqbit = SIR_DREQ6_INPUT,
.ioaddr = 0xfe001100,
},
[7] = {
.cap = FRV_DMA_CAP_DREQ,
.irq = IRQ_CPU_DMA7,
.dreqbit = SIR_DREQ7_INPUT,
.ioaddr = 0xfe001180,
},
};
static DEFINE_RWLOCK(frv_dma_channels_lock);
unsigned int frv_dma_inprogress;
#define frv_clear_dma_inprogress(channel) \
(void)__atomic32_fetch_and(~(1 << (channel)), &frv_dma_inprogress);
#define frv_set_dma_inprogress(channel) \
(void)__atomic32_fetch_or(1 << (channel), &frv_dma_inprogress);
/*****************************************************************************/
/*
* DMA irq handler - determine channel involved, grab status and call real handler
*/
static irqreturn_t dma_irq_handler(int irq, void *_channel)
{
struct frv_dma_channel *channel = _channel;
frv_clear_dma_inprogress(channel - frv_dma_channels);
return channel->handler(channel - frv_dma_channels,
__get_DMAC(channel->ioaddr, CSTR),
channel->data);
} /* end dma_irq_handler() */
/*****************************************************************************/
/*
* Determine which DMA controllers are present on this CPU
*/
void __init frv_dma_init(void)
{
unsigned long psr = __get_PSR();
int num_dma, i;
/* First, determine how many DMA channels are available */
switch (PSR_IMPLE(psr)) {
case PSR_IMPLE_FR405:
case PSR_IMPLE_FR451:
case PSR_IMPLE_FR501:
case PSR_IMPLE_FR551:
num_dma = FRV_DMA_8CHANS;
break;
case PSR_IMPLE_FR401:
default:
num_dma = FRV_DMA_4CHANS;
break;
}
/* Now mark all of the non-existent channels as reserved */
for(i = num_dma; i < FRV_DMA_NCHANS; i++)
frv_dma_channels[i].flags = FRV_DMA_FLAGS_RESERVED;
} /* end frv_dma_init() */
/*****************************************************************************/
/*
* allocate a DMA controller channel and the IRQ associated with it
*/
int frv_dma_open(const char *devname,
unsigned long dmamask,
int dmacap,
dma_irq_handler_t handler,
unsigned long irq_flags,
void *data)
{
struct frv_dma_channel *channel;
int dma, ret;
uint32_t val;
write_lock(&frv_dma_channels_lock);
ret = -ENOSPC;
for (dma = FRV_DMA_NCHANS - 1; dma >= 0; dma--) {
channel = &frv_dma_channels[dma];
if (!test_bit(dma, &dmamask))
continue;
if ((channel->cap & dmacap) != dmacap)
continue;
if (!frv_dma_channels[dma].flags)
goto found;
}
goto out;
found:
ret = request_irq(channel->irq, dma_irq_handler, irq_flags, devname, channel);
if (ret < 0)
goto out;
/* okay, we've allocated all the resources */
channel = &frv_dma_channels[dma];
channel->flags |= FRV_DMA_FLAGS_INUSE;
channel->devname = devname;
channel->handler = handler;
channel->data = data;
/* Now make sure we are set up for DMA and not GPIO */
/* SIR bit must be set for DMA to work */
__set_SIR(channel->dreqbit | __get_SIR());
/* SOR bits depend on what the caller requests */
val = __get_SOR();
if(dmacap & FRV_DMA_CAP_DACK)
val |= channel->dackbit;
else
val &= ~channel->dackbit;
if(dmacap & FRV_DMA_CAP_DONE)
val |= channel->donebit;
else
val &= ~channel->donebit;
__set_SOR(val);
ret = dma;
out:
write_unlock(&frv_dma_channels_lock);
return ret;
} /* end frv_dma_open() */
EXPORT_SYMBOL(frv_dma_open);
/*****************************************************************************/
/*
* close a DMA channel and its associated interrupt
*/
void frv_dma_close(int dma)
{
struct frv_dma_channel *channel = &frv_dma_channels[dma];
unsigned long flags;
write_lock_irqsave(&frv_dma_channels_lock, flags);
free_irq(channel->irq, channel);
frv_dma_stop(dma);
channel->flags &= ~FRV_DMA_FLAGS_INUSE;
write_unlock_irqrestore(&frv_dma_channels_lock, flags);
} /* end frv_dma_close() */
EXPORT_SYMBOL(frv_dma_close);
/*****************************************************************************/
/*
* set static configuration on a DMA channel
*/
void frv_dma_config(int dma, unsigned long ccfr, unsigned long cctr, unsigned long apr)
{
unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
___set_DMAC(ioaddr, CCFR, ccfr);
___set_DMAC(ioaddr, CCTR, cctr);
___set_DMAC(ioaddr, APR, apr);
mb();
} /* end frv_dma_config() */
EXPORT_SYMBOL(frv_dma_config);
/*****************************************************************************/
/*
* start a DMA channel
*/
void frv_dma_start(int dma,
unsigned long sba, unsigned long dba,
unsigned long pix, unsigned long six, unsigned long bcl)
{
unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
___set_DMAC(ioaddr, SBA, sba);
___set_DMAC(ioaddr, DBA, dba);
___set_DMAC(ioaddr, PIX, pix);
___set_DMAC(ioaddr, SIX, six);
___set_DMAC(ioaddr, BCL, bcl);
___set_DMAC(ioaddr, CSTR, 0);
mb();
__set_DMAC(ioaddr, CCTR, __get_DMAC(ioaddr, CCTR) | DMAC_CCTRx_ACT);
frv_set_dma_inprogress(dma);
} /* end frv_dma_start() */
EXPORT_SYMBOL(frv_dma_start);
/*****************************************************************************/
/*
* restart a DMA channel that's been stopped in circular addressing mode by comparison-end
*/
void frv_dma_restart_circular(int dma, unsigned long six)
{
unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
___set_DMAC(ioaddr, SIX, six);
___set_DMAC(ioaddr, CSTR, __get_DMAC(ioaddr, CSTR) & ~DMAC_CSTRx_CE);
mb();
__set_DMAC(ioaddr, CCTR, __get_DMAC(ioaddr, CCTR) | DMAC_CCTRx_ACT);
frv_set_dma_inprogress(dma);
} /* end frv_dma_restart_circular() */
EXPORT_SYMBOL(frv_dma_restart_circular);
/*****************************************************************************/
/*
* stop a DMA channel
*/
void frv_dma_stop(int dma)
{
unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
uint32_t cctr;
___set_DMAC(ioaddr, CSTR, 0);
cctr = __get_DMAC(ioaddr, CCTR);
cctr &= ~(DMAC_CCTRx_IE | DMAC_CCTRx_ACT);
cctr |= DMAC_CCTRx_FC; /* fifo clear */
__set_DMAC(ioaddr, CCTR, cctr);
__set_DMAC(ioaddr, BCL, 0);
frv_clear_dma_inprogress(dma);
} /* end frv_dma_stop() */
EXPORT_SYMBOL(frv_dma_stop);
/*****************************************************************************/
/*
* test interrupt status of DMA channel
*/
int is_frv_dma_interrupting(int dma)
{
unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
return __get_DMAC(ioaddr, CSTR) & (1 << 23);
} /* end is_frv_dma_interrupting() */
EXPORT_SYMBOL(is_frv_dma_interrupting);
/*****************************************************************************/
/*
* dump data about a DMA channel
*/
void frv_dma_dump(int dma)
{
unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
unsigned long cstr, pix, six, bcl;
cstr = __get_DMAC(ioaddr, CSTR);
pix = __get_DMAC(ioaddr, PIX);
six = __get_DMAC(ioaddr, SIX);
bcl = __get_DMAC(ioaddr, BCL);
printk("DMA[%d] cstr=%lx pix=%lx six=%lx bcl=%lx\n", dma, cstr, pix, six, bcl);
} /* end frv_dma_dump() */
EXPORT_SYMBOL(frv_dma_dump);
/*****************************************************************************/
/*
* pause all DMA controllers
* - called by clock mangling routines
* - caller must be holding interrupts disabled
*/
void frv_dma_pause_all(void)
{
struct frv_dma_channel *channel;
unsigned long ioaddr;
unsigned long cstr, cctr;
int dma;
write_lock(&frv_dma_channels_lock);
for (dma = FRV_DMA_NCHANS - 1; dma >= 0; dma--) {
channel = &frv_dma_channels[dma];
if (!(channel->flags & FRV_DMA_FLAGS_INUSE))
continue;
ioaddr = channel->ioaddr;
cctr = __get_DMAC(ioaddr, CCTR);
if (cctr & DMAC_CCTRx_ACT) {
cctr &= ~DMAC_CCTRx_ACT;
__set_DMAC(ioaddr, CCTR, cctr);
do {
cstr = __get_DMAC(ioaddr, CSTR);
} while (cstr & DMAC_CSTRx_BUSY);
if (cstr & DMAC_CSTRx_FED)
channel->flags |= FRV_DMA_FLAGS_PAUSED;
frv_clear_dma_inprogress(dma);
}
}
} /* end frv_dma_pause_all() */
EXPORT_SYMBOL(frv_dma_pause_all);
/*****************************************************************************/
/*
* resume paused DMA controllers
* - called by clock mangling routines
* - caller must be holding interrupts disabled
*/
void frv_dma_resume_all(void)
{
struct frv_dma_channel *channel;
unsigned long ioaddr;
unsigned long cstr, cctr;
int dma;
for (dma = FRV_DMA_NCHANS - 1; dma >= 0; dma--) {
channel = &frv_dma_channels[dma];
if (!(channel->flags & FRV_DMA_FLAGS_PAUSED))
continue;
ioaddr = channel->ioaddr;
cstr = __get_DMAC(ioaddr, CSTR);
cstr &= ~(DMAC_CSTRx_FED | DMAC_CSTRx_INT);
__set_DMAC(ioaddr, CSTR, cstr);
cctr = __get_DMAC(ioaddr, CCTR);
cctr |= DMAC_CCTRx_ACT;
__set_DMAC(ioaddr, CCTR, cctr);
channel->flags &= ~FRV_DMA_FLAGS_PAUSED;
frv_set_dma_inprogress(dma);
}
write_unlock(&frv_dma_channels_lock);
} /* end frv_dma_resume_all() */
EXPORT_SYMBOL(frv_dma_resume_all);
/*****************************************************************************/
/*
* dma status clear
*/
void frv_dma_status_clear(int dma)
{
unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
uint32_t cctr;
___set_DMAC(ioaddr, CSTR, 0);
cctr = __get_DMAC(ioaddr, CCTR);
} /* end frv_dma_status_clear() */
EXPORT_SYMBOL(frv_dma_status_clear);
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