[PATCH 1/7] PL330: Add common core driver

Ben Dooks ben-linux at fluff.org
Mon Apr 26 00:54:20 EDT 2010


On Wed, Apr 21, 2010 at 04:27:28PM +0900, jassisinghbrar at gmail.com wrote:
> From: Jassi Brar <jassi.brar at samsung.com>
> 
> PL330 is a configurable DMA controller PrimeCell device.
> The register map of the device is well defined.
> The configuration of a particular implementation can be
> read from the six configuration registers CR0-4,Dn.
> 
> This patch implements a driver for the specification:-
> http://infocenter.arm.com/help/topic/com.arm.doc.ddi0424a/DDI0424A_dmac_pl330_r0p0_trm.pdf
> 
> The exported interface should be sufficient to implement
> a driver for any DMA API.
> 
> Signed-off-by: Jassi Brar <jassi.brar at samsung.com>
> ---
> 
> Design:-
> o  The DMA API driver submits 'request' to PL330 engine.
>     A request is a sequence of DMA 'xfers' to be done before the DMA
>     API driver wants to be notified.
>     A 'xfer' is the finest grain of DMA transaction that specifies
>     how many _bytes_ are to be move from 'source address' to 'destination
>     address'. A req can be a scatter-Gather-List.
> 
> o  PL330 engine accepts requests from DMA API drivers in ping-pong manner,
>    i.e, at any time maximum two reqs can be queued. Other reqs have
>    to be buffered by DMA API drivers and enqueued whenever a req-finish
>    callback is made.
> 
> o  Only necessary resources for a DMAC are allocated according to the
>    configuration read from DMAC during startup.
>    Since MicroCode(MC) buffers are a channel's resource, they are allocated
>    just once during startup and reused every time. A channel has its MC
>    buff divided into two equal parts - one for each ping-pong request.
>    The DMA API driver can specify the size of MC buffer that each channel
>    (hence req) has, which decides the maximum possible total xfer size that
>    the channel can do in one request.
> 
> o  It is possible to do DMA request at different channel configuration
>    every time; this feature can be used by DMA API drivers for implementing
>    'server' channels that are not dedicated to a particular client but accept
>    requests from any client. Of course, such channels won't be able to
>    guarantee any QOS.
> 
> o  Privilege options can be specified for each submitted request.
>    Whereas, this core driver automatically set appropriate security level
>    of the channel for each request, after taking into account the security
>    level of the DMAC and the peripheral the request is destined for.
> 
> o  TODO: Desirable is to implement true LLI using MicroCode modification
>    during each request enqueue, so that the xfer continues even while IRQ
>    is handled and callbacks made. That should avoid discontinuity of a few
>    usecs between active requests.
>    To me, there doesn't seem to be a way to flush ICACHE of a channel without
>    halting it, so we can't modify MicroCode in runtime. Using two channels
>    per client to achieve true LLI is the last resort.
>    So currently, cpu intervention is required to trigger each request.
> o  TODO: PAUSE/RESUME support. Currently the DMA API driver has to emulate it.
> 
> 
> Testing:-
> The implementation has been tested with the S3C DMA API driver
> submitted toady.
> 
> This exact driver, and slightly modified version of S3C DMA API Driver,
> has been tested rigorously for scenarios like 8 concurrent Mem->Mem
> transfers at various burst sizes while also playing AUDIO over another DMAC.
> 
> The implementation is efficient enough to play smooth CD quality audio
> with a period size as small as 12 bytes and buffer of 2 periods(best case
> scenario). Also, the driver recovers gracefully if some channel locks
> due to resource starvation and the next request submission has chance
> no lesser than the last successful one.
> 
>  arch/arm/common/Kconfig               |    3 +
>  arch/arm/common/Makefile              |    1 +
>  arch/arm/common/pl330.c               | 1966 +++++++++++++++++++++++++++++++++
>  arch/arm/include/asm/hardware/pl330.h |  217 ++++
>  4 files changed, 2187 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/common/pl330.c
>  create mode 100644 arch/arm/include/asm/hardware/pl330.h
> 
> diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
> index 4efbb9d..96ab169 100644
> --- a/arch/arm/common/Kconfig
> +++ b/arch/arm/common/Kconfig
> @@ -40,3 +40,6 @@ config SHARP_SCOOP
>  
>  config COMMON_CLKDEV
>  	bool
> +
> +config PL330
> +	bool
> diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
> index 76be7ff..2a0703d 100644
> --- a/arch/arm/common/Makefile
> +++ b/arch/arm/common/Makefile
> @@ -17,3 +17,4 @@ obj-$(CONFIG_ARCH_IXP2000)	+= uengine.o
>  obj-$(CONFIG_ARCH_IXP23XX)	+= uengine.o
>  obj-$(CONFIG_PCI_HOST_ITE8152)  += it8152.o
>  obj-$(CONFIG_COMMON_CLKDEV)	+= clkdev.o
> +obj-$(CONFIG_PL330)		+= pl330.o
> diff --git a/arch/arm/common/pl330.c b/arch/arm/common/pl330.c
> new file mode 100644
> index 0000000..5a12c9e
> --- /dev/null
> +++ b/arch/arm/common/pl330.c
> @@ -0,0 +1,1966 @@
> +/* linux/arch/arm/common/pl330.c
> + *
> + * Copyright (C) 2010 Samsung Electronics Co Ltd.
> + *	Jaswinder Singh <jassi.brar at samsung.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.
> + *
> + * 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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/string.h>
> +#include <linux/io.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/dma-mapping.h>
> +
> +#include <asm/hardware/pl330.h>
> +
> +/* Register and Bit field Definitions */
> +#define DS		0x0
> +#define DS_ST_STOP	0x0
> +#define DS_ST_EXEC	0x1
> +#define DS_ST_CMISS	0x2
> +#define DS_ST_UPDTPC	0x3
> +#define DS_ST_WFE	0x4
> +#define DS_ST_ATBRR	0x5
> +#define DS_ST_QBUSY	0x6
> +#define DS_ST_WFP	0x7
> +#define DS_ST_KILL	0x8
> +#define DS_ST_CMPLT	0x9
> +#define DS_ST_FLTCMP	0xe
> +#define DS_ST_FAULT	0xf
> +
> +#define DPC		0x4
> +#define INTEN		0x20
> +#define ES		0x24
> +#define INTSTATUS	0x28
> +#define INTCLR		0x2c
> +#define FSM		0x30
> +#define FSC		0x34
> +#define FTM		0x38
> +
> +#define _FTC		0x40
> +#define FTC(n)		(_FTC + (n)*0x4)
> +
> +#define _CS		0x100
> +#define CS(n)		(_CS + (n)*0x8)
> +#define CS_CNS		(1 << 21)
> +
> +#define _CPC		0x104
> +#define CPC(n)		(_CPC + (n)*0x8)
> +
> +#define _SA		0x400
> +#define SA(n)		(_SA + (n)*0x20)
> +
> +#define _DA		0x404
> +#define DA(n)		(_DA + (n)*0x20)
> +
> +#define _CC		0x408
> +#define CC(n)		(_CC + (n)*0x20)
> +
> +#define CC_SRCINC	(1 << 0)
> +#define CC_DSTINC	(1 << 14)
> +#define CC_SRCPRI	(1 << 8)
> +#define CC_DSTPRI	(1 << 22)
> +#define CC_SRCNS	(1 << 9)
> +#define CC_DSTNS	(1 << 23)
> +#define CC_SRCIA	(1 << 10)
> +#define CC_DSTIA	(1 << 24)
> +#define CC_SRCBRSTLEN_SHFT	4
> +#define CC_DSTBRSTLEN_SHFT	18
> +#define CC_SRCBRSTSIZE_SHFT	1
> +#define CC_DSTBRSTSIZE_SHFT	15
> +#define CC_SRCCCTRL_SHFT	11
> +#define CC_SRCCCTRL_MASK	0x7
> +#define CC_DSTCCTRL_SHFT	25
> +#define CC_DRCCCTRL_MASK	0x7
> +#define CC_SWAP_SHFT	28
> +
> +#define _LC0		0x40c
> +#define LC0(n)		(_LC0 + (n)*0x20)
> +
> +#define _LC1		0x410
> +#define LC1(n)		(_LC1 + (n)*0x20)

do we really need the _ versions of each of these, or can
they be merged into thier non _ counterparts?

> +#define DBGSTATUS	0xd00
> +#define DBG_BUSY	(1 << 0)
> +
> +#define DBGCMD		0xd04
> +#define DBGINST0	0xd08
> +#define DBGINST1	0xd0c
> +
> +#define CR0		0xe00
> +#define CR1		0xe04
> +#define CR2		0xe08
> +#define CR3		0xe0c
> +#define CR4		0xe10
> +#define CRD		0xe14
> +
> +#define PERIPH_ID	0xfe0
> +#define PCELL_ID	0xff0
> +
> +#define CR0_PERIPH_REQ_SET	(1 << 0)
> +#define CR0_BOOT_EN_SET		(1 << 1)
> +#define CR0_BOOT_MAN_NS		(1 << 2)
> +#define CR0_NUM_CHANS_SHIFT	4
> +#define CR0_NUM_CHANS_MASK	0x7
> +#define CR0_NUM_PERIPH_SHIFT	12
> +#define CR0_NUM_PERIPH_MASK	0x1f
> +#define CR0_NUM_EVENTS_SHIFT	17
> +#define CR0_NUM_EVENTS_MASK	0x1f
> +
> +#define CR1_ICACHE_LEN_SHIFT	0
> +#define CR1_ICACHE_LEN_MASK	0x7
> +#define CR1_NUM_ICACHELINES_SHIFT	4
> +#define CR1_NUM_ICACHELINES_MASK	0xf

are these aligned, or is it my mail client ignoring the formatting?

> +#define CRD_DATA_WIDTH_SHIFT	0
> +#define CRD_DATA_WIDTH_MASK	0x7
> +#define CRD_WR_CAP_SHIFT	4
> +#define CRD_WR_CAP_MASK		0x7
> +#define CRD_WR_Q_DEP_SHIFT	8
> +#define CRD_WR_Q_DEP_MASK	0xf
> +#define CRD_RD_CAP_SHIFT	12
> +#define CRD_RD_CAP_MASK		0x7
> +#define CRD_RD_Q_DEP_SHIFT	16
> +#define CRD_RD_Q_DEP_MASK	0xf
> +#define CRD_DATA_BUFF_SHIFT	20
> +#define CRD_DATA_BUFF_MASK	0x3ff
> +
> +#define	PART		0x330
> +#define DESIGNER	0x41
> +#define REVISION	0x0
> +#define INTEG_CFG	0x0
> +#define PERIPH_ID_VAL	((PART << 0) | (DESIGNER << 12) \
> +			  | (REVISION << 20) | (INTEG_CFG << 24))
> +
> +#define PCELL_ID_VAL	0xb105f00d
> +
> +#define PL330_STATE_STOPPED		(1 << 0)
> +#define PL330_STATE_EXECUTING		(1 << 1)
> +#define PL330_STATE_WFE			(1 << 2)
> +#define PL330_STATE_FAULTING		(1 << 3)
> +#define PL330_STATE_COMPLETING		(1 << 4)
> +#define PL330_STATE_WFP			(1 << 5)
> +#define PL330_STATE_KILLING		(1 << 6)
> +#define PL330_STATE_FAULT_COMPLETING	(1 << 7)
> +#define PL330_STATE_CACHEMISS		(1 << 8)
> +#define PL330_STATE_UPDTPC		(1 << 9)
> +#define PL330_STATE_ATBARRIER		(1 << 10)
> +#define PL330_STATE_QUEUEBUSY		(1 << 11)
> +#define PL330_STATE_INVALID		(1 << 15)
> +
> +#define PL330_STABLE_STATES (PL330_STATE_STOPPED | PL330_STATE_EXECUTING \
> +				| PL330_STATE_WFE | PL330_STATE_FAULTING)
> +
> +#define CMD_DMAADDH	0x54
> +#define CMD_DMAEND	0x00
> +#define CMD_DMAFLUSHP	0x35
> +#define CMD_DMAGO	0xa0
> +#define CMD_DMALD	0x04
> +#define CMD_DMALDP	0x25
> +#define CMD_DMALP	0x20
> +#define CMD_DMALPEND	0x28
> +#define CMD_DMAKILL	0x01
> +#define CMD_DMAMOV	0xbc
> +#define CMD_DMANOP	0x18
> +#define CMD_DMARMB	0x12
> +#define CMD_DMASEV	0x34
> +#define CMD_DMAST	0x08
> +#define CMD_DMASTP	0x29
> +#define CMD_DMASTZ	0x0c
> +#define CMD_DMAWFE	0x36
> +#define CMD_DMAWFP	0x30
> +#define CMD_DMAWMB	0x13
> +
> +#define SZ_DMAADDH	3
> +#define SZ_DMAEND	1
> +#define SZ_DMAFLUSHP	2
> +#define SZ_DMALD	1
> +#define SZ_DMALDP	2
> +#define SZ_DMALP	2
> +#define SZ_DMALPEND	2
> +#define SZ_DMAKILL	1
> +#define SZ_DMAMOV	6
> +#define SZ_DMANOP	1
> +#define SZ_DMARMB	1
> +#define SZ_DMASEV	2
> +#define SZ_DMAST	1
> +#define SZ_DMASTP	2
> +#define SZ_DMASTZ	1
> +#define SZ_DMAWFE	2
> +#define SZ_DMAWFP	2
> +#define SZ_DMAWMB	1
> +#define SZ_DMAGO	6
> +
> +#define BRST_LEN(ccr)	((((ccr) >> CC_SRCBRSTLEN_SHFT) & 0xf) + 1)
> +#define BRST_SIZE(ccr)	(1 << (((ccr) >> CC_SRCBRSTSIZE_SHFT) & 0x7))
> +
> +#define BYTE_TO_BURST(b, ccr)  ((b) / BRST_SIZE(ccr) / BRST_LEN(ccr))
> +#define BURST_TO_BYTE(c, ccr)  ((c) * BRST_SIZE(ccr) * BRST_LEN(ccr))
> +
> +/*
> + * With 256 bytes, we can do more than 2.5MB and 5MB xfers per req
> + * at 1byte/burst for P<->M and M<->M respectively.
> + * For typical scenario, at 1word/burst, 10MB and 20MB xfers per req
> + * should be enough for P<->M and M<->M respectively.
> + */
> +#define MCODE_BUFF_PER_REQ	256
> +
> +/*
> + * Mark a _pl330_req as free.
> + * We do it by writing DMAEND as the first instruction
> + * because no valid request is going to have DMAEND as
> + * its first instruction to execute.
> + */
> +#define MARK_FREE(req)	do { \
> +				_emit_END(0, (req)->mc_cpu); \
> +				(req)->mc_len = 0; \
> +			} while (0)

I think inline functions for these would be easier to read.

> +/* If the _pl330_req is available to the client */
> +#define IS_FREE(req)	(*((u8 *)((req)->mc_cpu)) == CMD_DMAEND)
> +
> +/* Use this _only_ to wait on transient states */
> +#define UNTIL(t, s)	while (!(_state(t) & (s))) cpu_relax();
> +
> +#ifdef PL330_DEBUG_MCGEN
> +static unsigned cmd_line;
> +#define PL330_DBGCMD_DUMP(off, x...)	do { \
> +						printk("%x:", cmd_line); \
> +						printk(x); \
> +						cmd_line += off; \
> +					} while (0)
> +#define PL330_DBGMC_START(addr)		(cmd_line = addr)
> +#else
> +#define PL330_DBGCMD_DUMP(off, x...)	do {} while (0)
> +#define PL330_DBGMC_START(addr)		do {} while (0)
> +#endif
> +
> +struct _xfer_spec {
> +	u32 ccr;
> +	struct pl330_req *r;
> +	struct pl330_xfer *x;
> +};

would have been nice to kerneldoc this or at-least document it.

> +enum dmamov_dst {
> +	SAR = 0,
> +	CCR,
> +	DAR,
> +};
> +
> +enum pl330_dst {
> +	SRC = 0,
> +	DST,
> +};
> +
> +enum pl330_cond {
> +	SINGLE,
> +	BURST,
> +	ALWAYS,
> +};
> +
> +struct _pl330_req {
> +	u32 mc_bus;
> +	void *mc_cpu;
> +	/* Number of bytes taken to setup MC for the req */
> +	u32 mc_len;
> +	struct pl330_req *r;
> +	/* Hook to attach to DMAC's list of reqs with due callback */
> +	struct list_head rqd;
> +};
> +
> +/* ToBeDone for tasklet */
> +struct _pl330_tbd {
> +	bool reset_dmac;
> +	bool reset_mngr;
> +	u8 reset_chan;
> +};
> +
> +/* A DMAC Thread */
> +struct pl330_thread {
> +	u8 id;
> +	int ev;
> +	/* If the channel is not yet acquired by any client */
> +	bool free;
> +	/* Parent DMAC */
> +	struct pl330_dmac *dmac;
> +	/* Only two at a time */
> +	struct _pl330_req req[2];
> +	/* Index of the last submitted request */
> +	unsigned lstenq;
> +};
> +
> +enum pl330_dmac_state {
> +	UNINIT,
> +	INIT,
> +	DYING,
> +};
> +
> +/* A DMAC */
> +struct pl330_dmac {
> +	spinlock_t		lock;
> +	/* Holds list of reqs with due callbacks */
> +	struct list_head	req_done;
> +	/* Pointer to platform specific stuff */
> +	struct pl330_info	*pinfo;
> +	/* Maximum possible events/irqs */
> +	int			events[32];
> +	/* BUS address of MicroCode buffer */
> +	u32			mcode_bus;
> +	/* CPU address of MicroCode buffer */
> +	void			*mcode_cpu;
> +	/* List of all Channel threads */
> +	struct pl330_thread	*channels;
> +	/* Pointer to the MANAGER thread */
> +	struct pl330_thread	*manager;
> +	/* To handle bad news in interrupt */
> +	struct tasklet_struct	tasks;
> +	struct _pl330_tbd	dmac_tbd;
> +	/* State of DMAC operation */
> +	enum pl330_dmac_state	state;
> +};
> +
> +static inline void _callback(struct pl330_req *r, enum pl330_op_err err)
> +{
> +	if (r && r->xfer_cb)
> +		r->xfer_cb(r->token, err);
> +}
> +
> +static inline bool _queue_empty(struct pl330_thread *thrd)
> +{
> +	return (IS_FREE(&thrd->req[0]) && IS_FREE(&thrd->req[1]))
> +		? true : false;
> +}
> +
> +static inline bool _queue_full(struct pl330_thread *thrd)
> +{
> +	return (IS_FREE(&thrd->req[0]) || IS_FREE(&thrd->req[1]))
> +		? false : true;
> +}

return !(IS_FREE(&thrd->req[0]) || IS_FREE(&thrd->req[1]) should
also work here.

> +static inline bool is_manager(struct pl330_thread *thrd)
> +{
> +	struct pl330_dmac *pl330 = thrd->dmac;
> +
> +	/* MANAGER is indexed at the end */
> +	if (thrd->id == pl330->pinfo->pcfg.num_chan)
> +		return true;
> +	else
> +		return false;
> +}
> +
> +/* If manager of the thread is in Non-Secure mode */
> +static inline bool _manager_ns(struct pl330_thread *thrd)
> +{
> +	struct pl330_dmac *pl330 = thrd->dmac;
> +
> +	return (pl330->pinfo->pcfg.mode & DMAC_MODE_NS) ? true : false;
> +}
> +
> +static inline u32 get_id(struct pl330_info *pi, u32 off)
> +{
> +	void __iomem *regs = pi->base;
> +	u32 id = 0;
> +
> +	id |= (readb(regs + off + 0x0) << 0);
> +	id |= (readb(regs + off + 0x4) << 8);
> +	id |= (readb(regs + off + 0x8) << 16);
> +	id |= (readb(regs + off + 0xc) << 24);
> +
> +	return id;
> +}
> +
> +static inline u32 _emit_ADDH(unsigned dry_run, u8 buf[],
> +		enum pl330_dst da, u16 val)
> +{

think that should be u8 *buf.

> +		return SZ_DMAADDH;
> +
> +	buf[0] = CMD_DMAADDH;
> +	buf[0] |= (da << 1);
> +	*((u16 *)&buf[1]) = val;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMAADDH, "\tDMAADDH %s %u\n",
> +		da == 1 ? "DA" : "SA", val);
> +
> +	return SZ_DMAADDH;
> +}
> +
> +static inline u32 _emit_END(unsigned dry_run, u8 buf[])
> +{
> +	if (dry_run)
> +		return SZ_DMAEND;
> +
> +	buf[0] = CMD_DMAEND;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMAEND, "\tDMAEND\n");
> +
> +	return SZ_DMAEND;
> +}
> +
> +static inline u32 _emit_FLUSHP(unsigned dry_run, u8 buf[], u8 peri)
> +{
> +	if (dry_run)
> +		return SZ_DMAFLUSHP;
> +
> +	buf[0] = CMD_DMAFLUSHP;
> +
> +	peri &= 0x1f;
> +	peri <<= 3;
> +	buf[1] = peri;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMAFLUSHP, "\tDMAFLUSHP %u\n", peri >> 3);
> +
> +	return SZ_DMAFLUSHP;
> +}
> +
> +static inline u32 _emit_LD(unsigned dry_run, u8 buf[],	enum pl330_cond cond)
> +{
> +	if (dry_run)
> +		return SZ_DMALD;
> +
> +	buf[0] = CMD_DMALD;
> +
> +	if (cond == SINGLE)
> +		buf[0] |= (0 << 1) | (1 << 0);
> +	else if (cond == BURST)
> +		buf[0] |= (1 << 1) | (1 << 0);

easir to merge CMD_DMALD into these to and just set buf[0] to the value
in the first place.

> +	PL330_DBGCMD_DUMP(SZ_DMALD, "\tDMALD%c\n",
> +		cond == SINGLE ? 'S' : (cond == BURST ? 'B' : 'A'));
> +
> +	return SZ_DMALD;
> +}
> +
> +static inline u32 _emit_LDP(unsigned dry_run, u8 buf[],
> +		enum pl330_cond cond, u8 peri)
> +{
> +	if (dry_run)
> +		return SZ_DMALDP;
> +
> +	buf[0] = CMD_DMALDP;
> +
> +	if (cond == BURST)
> +		buf[0] |= (1 << 1);
> +
> +	peri &= 0x1f;
> +	peri <<= 3;
> +	buf[1] = peri;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMALDP, "\tDMALDP%c %u\n",
> +		cond == SINGLE ? 'S' : 'B', peri >> 3);
> +
> +	return SZ_DMALDP;
> +}
> +
> +static inline u32 _emit_LP(unsigned dry_run, u8 buf[],
> +		unsigned loop, u8 cnt)
> +{
could loop be a bool? dry_run certainly should be.

> +	if (dry_run)
> +		return SZ_DMALP;

I'm just wondering if these shouldn't be if (!dry_run) { } return SZ_;\

> +	buf[0] = CMD_DMALP;
> +
> +	if (loop)
> +		buf[0] |= (1 << 1);

again, you could probably do

       buf[0] = loop ? CMD_DMALP | (1 << 1) : CMD_DMALP;

> +	cnt--; /* DMAC increments by 1 internally */
> +	buf[1] = cnt;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMALP, "\tDMALP_%c %u\n", loop ? '1' : '0', cnt);
> +
> +	return SZ_DMALP;
> +}
> +
> +struct _arg_LPEND {
> +	enum pl330_cond cond;
> +	bool forever;
> +	unsigned loop;
> +	u8 bjump;
> +};
> +
> +static inline u32 _emit_LPEND(unsigned dry_run, u8 buf[],
> +		const struct _arg_LPEND *arg)
> +{
> +	enum pl330_cond cond = arg->cond;
> +	bool forever = arg->forever;
> +	unsigned loop = arg->loop;
> +	u8 bjump = arg->bjump;
> +
> +	if (dry_run)
> +		return SZ_DMALPEND;
> +
> +	buf[0] = CMD_DMALPEND;
> +
> +	if (loop)
> +		buf[0] |= (1 << 2);
> +
> +	if (!forever)
> +		buf[0] |= (1 << 4);
> +
> +	if (cond == SINGLE)
> +		buf[0] |= (0 << 1) | (1 << 0);
> +	else if (cond == BURST)
> +		buf[0] |= (1 << 1) | (1 << 0);
> +
> +	buf[1] = bjump;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMALPEND, "\tDMALP%s%c_%c bjmpto_%x\n",
> +			forever ? "FE" : "END",
> +			cond == SINGLE ? 'S' : (cond == BURST ? 'B' : 'A'),
> +			loop ? '1' : '0',
> +			bjump);
> +
> +	return SZ_DMALPEND;
> +}
> +
> +static inline u32 _emit_KILL(unsigned dry_run, u8 buf[])
> +{
> +	if (dry_run)
> +		return SZ_DMAKILL;
> +
> +	buf[0] = CMD_DMAKILL;
> +
> +	return SZ_DMAKILL;
> +}
> +
> +static inline u32 _emit_MOV(unsigned dry_run, u8 buf[],
> +		enum dmamov_dst dst, u32 val)
> +{
> +	if (dry_run)
> +		return SZ_DMAMOV;
> +
> +	buf[0] = CMD_DMAMOV;
> +	buf[1] = dst;
> +	*((u32 *)&buf[2]) = val;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMAMOV, "\tDMAMOV %s 0x%x\n",
> +		dst == SAR ? "SAR" : (dst == DAR ? "DAR" : "CCR"), val);
> +
> +	return SZ_DMAMOV;
> +}
> +
> +static inline u32 _emit_NOP(unsigned dry_run, u8 buf[])
> +{
> +	if (dry_run)
> +		return SZ_DMANOP;
> +
> +	buf[0] = CMD_DMANOP;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMANOP, "\tDMANOP\n");
> +
> +	return SZ_DMANOP;
> +}
> +
> +static inline u32 _emit_RMB(unsigned dry_run, u8 buf[])
> +{
> +	if (dry_run)
> +		return SZ_DMARMB;
> +
> +	buf[0] = CMD_DMARMB;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMARMB, "\tDMARMB\n");
> +
> +	return SZ_DMARMB;
> +}
> +
> +static inline u32 _emit_SEV(unsigned dry_run, u8 buf[], u8 ev)
> +{
> +	if (dry_run)
> +		return SZ_DMASEV;
> +
> +	buf[0] = CMD_DMASEV;
> +
> +	ev &= 0x1f;
> +	ev <<= 3;

is this some common op that should have some form of macro/inline defn?

> +	buf[1] = ev;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMASEV, "\tDMASEV %u\n", ev >> 3);
> +
> +	return SZ_DMASEV;
> +}
> +
> +static inline u32 _emit_ST(unsigned dry_run, u8 buf[], enum pl330_cond cond)
> +{
> +	if (dry_run)
> +		return SZ_DMAST;
> +
> +	buf[0] = CMD_DMAST;
> +
> +	if (cond == SINGLE)
> +		buf[0] |= (0 << 1) | (1 << 0);
> +	else if (cond == BURST)
> +		buf[0] |= (1 << 1) | (1 << 0);
> +
> +	PL330_DBGCMD_DUMP(SZ_DMAST, "\tDMAST%c\n",
> +		cond == SINGLE ? 'S' : (cond == BURST ? 'B' : 'A'));
> +
> +	return SZ_DMAST;
> +}
> +
> +static inline u32 _emit_STP(unsigned dry_run, u8 buf[],
> +		enum pl330_cond cond, u8 peri)
> +{
> +	if (dry_run)
> +		return SZ_DMASTP;
> +
> +	buf[0] = CMD_DMASTP;
> +
> +	if (cond == BURST)
> +		buf[0] |= (1 << 1);
> +
> +	peri &= 0x1f;
> +	peri <<= 3;
> +	buf[1] = peri;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMASTP, "\tDMASTP%c %u\n",
> +		cond == SINGLE ? 'S' : 'B', peri >> 3);
> +
> +	return SZ_DMASTP;
> +}
> +
> +static inline u32 _emit_STZ(unsigned dry_run, u8 buf[])
> +{
> +	if (dry_run)
> +		return SZ_DMASTZ;
> +
> +	buf[0] = CMD_DMASTZ;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMASTZ, "\tDMASTZ\n");
> +
> +	return SZ_DMASTZ;
> +}
> +
> +static inline u32 _emit_WFE(unsigned dry_run, u8 buf[], u8 ev,
> +		unsigned invalidate)
> +{
> +	if (dry_run)
> +		return SZ_DMAWFE;
> +
> +	buf[0] = CMD_DMAWFE;
> +
> +	ev &= 0x1f;
> +	ev <<= 3;
> +	buf[1] = ev;
> +
> +	if (invalidate)
> +		buf[1] |= (1 << 1);
> +
> +	PL330_DBGCMD_DUMP(SZ_DMAWFE, "\tDMAWFE %u%s\n",
> +		ev >> 3, invalidate ? ", I" : "");
> +
> +	return SZ_DMAWFE;
> +}
> +
> +static inline u32 _emit_WFP(unsigned dry_run, u8 buf[],
> +		enum pl330_cond cond, u8 peri)
> +{
> +	if (dry_run)
> +		return SZ_DMAWFP;
> +
> +	buf[0] = CMD_DMAWFP;
> +
> +	if (cond == SINGLE)
> +		buf[0] |= (0 << 1) | (0 << 0);
> +	else if (cond == BURST)
> +		buf[0] |= (1 << 1) | (0 << 0);
> +	else
> +		buf[0] |= (0 << 1) | (1 << 0);
> +
> +	peri &= 0x1f;
> +	peri <<= 3;
> +	buf[1] = peri;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMAWFP, "\tDMAWFP%c %u\n",
> +		cond == SINGLE ? 'S' : (cond == BURST ? 'B' : 'P'), peri >> 3);
> +
> +	return SZ_DMAWFP;
> +}
> +
> +static inline u32 _emit_WMB(unsigned dry_run, u8 buf[])
> +{
> +	if (dry_run)
> +		return SZ_DMAWMB;
> +
> +	buf[0] = CMD_DMAWMB;
> +
> +	PL330_DBGCMD_DUMP(SZ_DMAWMB, "\tDMAWMB\n");
> +
> +	return SZ_DMAWMB;
> +}
> +
> +struct _arg_GO {
> +	u8 chan;
> +	u32 addr;
> +	unsigned ns;
> +};
> +
> +static inline u32 _emit_GO(unsigned dry_run, u8 buf[],
> +		const struct _arg_GO *arg)
> +{
> +	u8 chan = arg->chan;
> +	u32 addr = arg->addr;
> +	unsigned ns = arg->ns;
> +
> +	if (dry_run)
> +		return SZ_DMAGO;
> +
> +	buf[0] = CMD_DMAGO;
> +	buf[0] |= (ns << 1);

again, you could have probably merged these two into one.

> +	buf[1] = chan & 0x7;
> +
> +	*((u32 *)&buf[2]) = addr;
> +
> +	return SZ_DMAGO;
> +}
> +
> +#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
> +
> +/* Returns Time-Out */
> +static bool _until_dmac_idle(struct pl330_thread *thrd)
> +{
> +	void __iomem *regs = thrd->dmac->pinfo->base;
> +	unsigned long loops = msecs_to_loops(5);
> +
> +	do {
> +		/* Until Manager is Idle */
> +		if (!(readl(regs + DBGSTATUS) & DBG_BUSY))
> +			break;
> +
> +		cpu_relax();
> +	} while (--loops);
> +
> +	if (!loops)
> +		return true;
> +
> +	return false;
> +}
> +
> +static inline void _execute_DBGINSN(struct pl330_thread *thrd,
> +		u8 insn[], bool as_manager)
> +{
> +	void __iomem *regs = thrd->dmac->pinfo->base;
> +	u32 val;
> +
> +	val = (insn[0] << 16) | (insn[1] << 24);
> +	if (!as_manager) {
> +		val |= (1 << 0);
> +		val |= (thrd->id << 8); /* Channel Number */
> +	}
> +	writel(val, regs + DBGINST0);
> +
> +	val = *((u32 *)&insn[2]);
> +	writel(val, regs + DBGINST1);
> +
> +	/* If timed out due to halted state-machine */
> +	if (_until_dmac_idle(thrd)) {
> +		dev_err(thrd->dmac->pinfo->dev, "DMAC halted!\n");
> +		return;
> +	}
> +
> +	/* Get going */
> +	writel(0, regs + DBGCMD);
> +}
> +
> +static inline u32 _state(struct pl330_thread *thrd)
> +{
> +	void __iomem *regs = thrd->dmac->pinfo->base;
> +	u32 val;
> +
> +	if (is_manager(thrd))
> +		val = readl(regs + DS) & 0xf;
> +	else
> +		val = readl(regs + CS(thrd->id)) & 0xf;
> +
> +	switch (val) {
> +	case DS_ST_STOP:
> +		return PL330_STATE_STOPPED;
> +	case DS_ST_EXEC:
> +		return PL330_STATE_EXECUTING;
> +	case DS_ST_CMISS:
> +		return PL330_STATE_CACHEMISS;
> +	case DS_ST_UPDTPC:
> +		return PL330_STATE_UPDTPC;
> +	case DS_ST_WFE:
> +		return PL330_STATE_WFE;
> +	case DS_ST_FAULT:
> +		return PL330_STATE_FAULTING;
> +	case DS_ST_ATBRR:
> +		if (is_manager(thrd))
> +			return PL330_STATE_INVALID;

might be more code efficient to break the case into two
and have a is_manager() check between the two switches.

> +		else
> +			return PL330_STATE_ATBARRIER;
> +	case DS_ST_QBUSY:
> +		if (is_manager(thrd))
> +			return PL330_STATE_INVALID;
> +		else
> +			return PL330_STATE_QUEUEBUSY;
> +	case DS_ST_WFP:
> +		if (is_manager(thrd))
> +			return PL330_STATE_INVALID;
> +		else
> +			return PL330_STATE_WFP;
> +	case DS_ST_KILL:
> +		if (is_manager(thrd))
> +			return PL330_STATE_INVALID;
> +		else
> +			return PL330_STATE_KILLING;
> +	case DS_ST_CMPLT:
> +		if (is_manager(thrd))
> +			return PL330_STATE_INVALID;
> +		else
> +			return PL330_STATE_COMPLETING;
> +	case DS_ST_FLTCMP:
> +		if (is_manager(thrd))
> +			return PL330_STATE_INVALID;
> +		else
> +			return PL330_STATE_FAULT_COMPLETING;
> +	default:
> +		return PL330_STATE_INVALID;
> +	}
> +}
> +
> +/* If the request 'req' of thread 'thrd' is currently active */
> +static inline bool _req_active(struct pl330_thread *thrd,
> +		struct _pl330_req *req)
> +{
> +	void __iomem *regs = thrd->dmac->pinfo->base;
> +	u32 buf = req->mc_bus, pc = readl(regs + CPC(thrd->id));
> +
> +	if (IS_FREE(req))
> +		return false;
> +
> +	return (pc >= buf && pc <= buf + req->mc_len) ? true : false;
> +}

hmm, doesn't linux bool allow just a
      return (pc >= buf && pc <= buf + req->mc_len); ?

> +/* Returns 0 if the thread is inactive, ID of active req + 1 otherwise */
> +static inline unsigned _thrd_active(struct pl330_thread *thrd)
> +{
> +	if (_req_active(thrd, &thrd->req[0]))
> +		return 1; /* First req active */
> +
> +	if (_req_active(thrd, &thrd->req[1]))
> +		return 2; /* Second req active */
> +
> +	return 0;
> +}
> +
> +static void _stop(struct pl330_thread *thrd)
> +{
> +	void __iomem *regs = thrd->dmac->pinfo->base;
> +	u8 insn[6] = {0, 0, 0, 0, 0, 0};
> +
> +	if (_state(thrd) == PL330_STATE_FAULT_COMPLETING)
> +		UNTIL(thrd, PL330_STATE_FAULTING | PL330_STATE_KILLING);
> +
> +	/* Return if nothing needs to be done */
> +	if (_state(thrd) == PL330_STATE_COMPLETING
> +		  || _state(thrd) == PL330_STATE_KILLING
> +		  || _state(thrd) == PL330_STATE_STOPPED)
> +		return;
> +
> +	_emit_KILL(0, insn);
> +
> +	/* Stop generating interrupts for SEV */
> +	writel(readl(regs + INTEN) & ~(1 << thrd->ev), regs + INTEN);
> +
> +	_execute_DBGINSN(thrd, insn, is_manager(thrd));
> +}
> +
> +/* Start doing req 'idx' of thread 'thrd' */
> +static bool _trigger(struct pl330_thread *thrd)
> +{
> +	void __iomem *regs = thrd->dmac->pinfo->base;
> +	struct _pl330_req *req;
> +	struct pl330_req *r;
> +	struct _arg_GO go;
> +	unsigned ns;
> +	u8 insn[6] = {0, 0, 0, 0, 0, 0};
> +
> +	/* Return if already ACTIVE */
> +	if (_state(thrd) != PL330_STATE_STOPPED)
> +		return true;
> +
> +	if (!IS_FREE(&thrd->req[1 - thrd->lstenq]))
> +		req = &thrd->req[1 - thrd->lstenq];
> +	else if (!IS_FREE(&thrd->req[thrd->lstenq]))
> +		req = &thrd->req[thrd->lstenq];
> +	else
> +		req = NULL;
> +
> +	/* Return if no request */
> +	if (!req || !req->r)
> +		return true;
> +
> +	r = req->r;
> +
> +	if (r->cfg)
> +		ns = r->cfg->nonsecure ? 1 : 0;
> +	else if (readl(regs + CS(thrd->id)) & CS_CNS)
> +		ns = 1;
> +	else
> +		ns = 0;
> +
> +	/* See 'Abort Sources' point-4 at Page 2-25 */
> +	if (_manager_ns(thrd) && !ns)
> +		dev_info(thrd->dmac->pinfo->dev, "%s:%d Recipe for ABORT!\n",
> +			__func__, __LINE__);
> +
> +	go.chan = thrd->id;
> +	go.addr = req->mc_bus;
> +	go.ns = ns;
> +	_emit_GO(0, insn, &go);
> +
> +	/* Set to generate interrupts for SEV */
> +	writel(readl(regs + INTEN) | (1 << thrd->ev), regs + INTEN);
> +
> +	/* Only manager can execute GO */
> +	_execute_DBGINSN(thrd, insn, true);
> +
> +	return true;
> +}
> +
> +static bool _start(struct pl330_thread *thrd)
> +{
> +	switch (_state(thrd)) {
> +	case PL330_STATE_FAULT_COMPLETING:
> +		UNTIL(thrd, PL330_STATE_FAULTING | PL330_STATE_KILLING);
> +
> +		if (_state(thrd) == PL330_STATE_KILLING)
> +			UNTIL(thrd, PL330_STATE_STOPPED)
> +
> +	case PL330_STATE_FAULTING:
> +		_stop(thrd);
> +
> +	case PL330_STATE_KILLING:
> +	case PL330_STATE_COMPLETING:
> +		UNTIL(thrd, PL330_STATE_STOPPED)
> +
> +	case PL330_STATE_STOPPED:
> +		return _trigger(thrd);
> +
> +	case PL330_STATE_WFP:
> +	case PL330_STATE_QUEUEBUSY:
> +	case PL330_STATE_ATBARRIER:
> +	case PL330_STATE_UPDTPC:
> +	case PL330_STATE_CACHEMISS:
> +	case PL330_STATE_EXECUTING:
> +		return true;
> +
> +	case PL330_STATE_WFE: /* For RESUME, nothing yet */
> +	default:
> +		return false;
> +	}
> +}
> +
> +static inline int _ldst_memtomem(unsigned dry_run, u8 buf[],
> +		const struct _xfer_spec *pxs, int cyc)
> +{
> +	int off = 0;
> +
> +	while (cyc--) {
> +		off += _emit_LD(dry_run, &buf[off], ALWAYS);
> +		off += _emit_RMB(dry_run, &buf[off]);
> +		off += _emit_ST(dry_run, &buf[off], ALWAYS);
> +		off += _emit_WMB(dry_run, &buf[off]);
> +	}
> +
> +	return off;
> +}
> +
> +static inline int _ldst_devtomem(unsigned dry_run, u8 buf[],
> +		const struct _xfer_spec *pxs, int cyc)
> +{
> +	int off = 0;
> +
> +	while (cyc--) {
> +		off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->r->peri);
> +		off += _emit_LDP(dry_run, &buf[off], SINGLE, pxs->r->peri);
> +		off += _emit_ST(dry_run, &buf[off], ALWAYS);
> +		off += _emit_FLUSHP(dry_run, &buf[off], pxs->r->peri);
> +	}
> +
> +	return off;
> +}
> +
> +static inline int _ldst_memtodev(unsigned dry_run, u8 buf[],
> +		const struct _xfer_spec *pxs, int cyc)
> +{
> +	int off = 0;
> +
> +	while (cyc--) {
> +		off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->r->peri);
> +		off += _emit_LD(dry_run, &buf[off], ALWAYS);
> +		off += _emit_STP(dry_run, &buf[off], SINGLE, pxs->r->peri);
> +		off += _emit_FLUSHP(dry_run, &buf[off], pxs->r->peri);
> +	}
> +
> +	return off;
> +}
> +
> +static int _bursts(unsigned dry_run, u8 buf[],
> +		const struct _xfer_spec *pxs, int cyc)
> +{
> +	int off = 0;
> +
> +	switch (pxs->r->rqtype) {
> +	case MEMTODEV:
> +		off += _ldst_memtodev(dry_run, &buf[off], pxs, cyc);
> +		break;
> +	case DEVTOMEM:
> +		off += _ldst_devtomem(dry_run, &buf[off], pxs, cyc);
> +		break;
> +	case MEMTOMEM:
> +		off += _ldst_memtomem(dry_run, &buf[off], pxs, cyc);
> +		break;
> +	default:
> +		off += 0x40000000; /* Scare off the Client */
> +		break;
> +	}
> +
> +	return off;
> +}
> +
> +/* Returns bytes consumed and updates bursts */
> +static inline int _loop(unsigned dry_run, u8 buf[],
> +		unsigned long *bursts, const struct _xfer_spec *pxs)
> +{
> +	int cyc, cycmax, szlp, szlpend, szbrst, off;
> +	unsigned lcnt0, lcnt1, ljmp0, ljmp1;
> +	struct _arg_LPEND lpend;
> +
> +	/* Max iterations possibile in DMALP is 256 */
> +	if (*bursts >= 256*256) {
> +		lcnt1 = 256;
> +		lcnt0 = 256;
> +		cyc = *bursts / lcnt1 / lcnt0;
> +	} else if (*bursts > 256) {
> +		lcnt1 = 256;
> +		lcnt0 = *bursts / lcnt1;
> +		cyc = 1;
> +	} else {
> +		lcnt1 = *bursts;
> +		lcnt0 = 0;
> +		cyc = 1;
> +	}
> +
> +	szlp = _emit_LP(1, buf, 0, 0);
> +	szbrst = _bursts(1, buf, pxs, 1);
> +
> +	lpend.cond = ALWAYS;
> +	lpend.forever = false;
> +	lpend.loop = 0;
> +	lpend.bjump = 0;
> +	szlpend = _emit_LPEND(1, buf, &lpend);
> +
> +	if (lcnt0) {
> +		szlp *= 2;
> +		szlpend *= 2;
> +	}
> +
> +	/*
> +	 * Max bursts that we can unroll due to limit on the
> +	 * size of backward jump that can be encoded in DMALPEND
> +	 * which is 8-bits and hence 255
> +	 */
> +	cycmax = (255 - (szlp + szlpend)) / szbrst;
> +
> +	cyc = (cycmax < cyc) ? cycmax : cyc;
> +
> +	off = 0;
> +
> +	if (lcnt0) {
> +		off += _emit_LP(dry_run, &buf[off], 0, lcnt0);
> +		ljmp0 = off;
> +	}
> +
> +	off += _emit_LP(dry_run, &buf[off], 1, lcnt1);
> +	ljmp1 = off;
> +
> +	off += _bursts(dry_run, &buf[off], pxs, cyc);
> +
> +	lpend.cond = ALWAYS;
> +	lpend.forever = false;
> +	lpend.loop = 1;
> +	lpend.bjump = off - ljmp1;
> +	off += _emit_LPEND(dry_run, &buf[off], &lpend);
> +
> +	if (lcnt0) {
> +		lpend.cond = ALWAYS;
> +		lpend.forever = false;
> +		lpend.loop = 0;
> +		lpend.bjump = off - ljmp0;
> +		off += _emit_LPEND(dry_run, &buf[off], &lpend);
> +	}
> +
> +	*bursts = lcnt1 * cyc;
> +	if (lcnt0)
> +		*bursts *= lcnt0;
> +
> +	return off;
> +}
> +
> +static inline int _setup_loops(unsigned dry_run, u8 buf[],
> +		const struct _xfer_spec *pxs)
> +{
> +	struct pl330_xfer *x = pxs->x;
> +	u32 ccr = pxs->ccr;
> +	unsigned long c, bursts = BYTE_TO_BURST(x->bytes, ccr);
> +	int off = 0;
> +
> +	while (bursts) {
> +		c = bursts;
> +		off += _loop(dry_run, &buf[off], &c, pxs);
> +		bursts -= c;
> +	}
> +
> +	return off;
> +}
> +
> +static inline int _setup_xfer(unsigned dry_run, u8 buf[],
> +		const struct _xfer_spec *pxs)
> +{
> +	struct pl330_xfer *x = pxs->x;
> +	int off = 0;
> +
> +	/* DMAMOV SAR, x->src_addr */
> +	off += _emit_MOV(dry_run, &buf[off], SAR, x->src_addr);
> +	/* DMAMOV DAR, x->dst_addr */
> +	off += _emit_MOV(dry_run, &buf[off], DAR, x->dst_addr);
> +
> +	/* Setup Loop(s) */
> +	off += _setup_loops(dry_run, &buf[off], pxs);
> +
> +	return off;
> +}
> +
> +/*
> + * A req is a sequence of one or more xfer units.
> + * Returns the number of bytes taken to setup the MC for the req.
> + */
> +static int _setup_req(unsigned dry_run, struct pl330_thread *thrd,
> +		unsigned index, struct _xfer_spec *pxs)
> +{
> +	struct _pl330_req *req = &thrd->req[index];
> +	struct pl330_xfer *x;
> +	u8 *buf = req->mc_cpu;
> +	int off = 0;
> +
> +	PL330_DBGMC_START(req->mc_bus);
> +
> +	/* DMAMOV CCR, ccr */
> +	off += _emit_MOV(dry_run, &buf[off], CCR, pxs->ccr);
> +
> +	x = pxs->r->x;
> +	do {
> +		/* Error if xfer length is not aligned at burst size */
> +		if (x->bytes % (BRST_SIZE(pxs->ccr) * BRST_LEN(pxs->ccr)))
> +			return -EINVAL;
> +
> +		pxs->x = x;
> +		off += _setup_xfer(dry_run, &buf[off], pxs);
> +
> +		x = x->next;
> +	} while (x);
> +
> +	/* DMASEV peripheral/event */
> +	off += _emit_SEV(dry_run, &buf[off], thrd->ev);
> +	/* DMAEND */
> +	off += _emit_END(dry_run, &buf[off]);
> +
> +	return off;
> +}
> +
> +static inline u32 _prepare_ccr(const struct pl330_reqcfg *rqc)
> +{
> +	u32 ccr = 0;
> +
> +	if (rqc->src_inc)
> +		ccr |= CC_SRCINC;
> +
> +	if (rqc->dst_inc)
> +		ccr |= CC_DSTINC;
> +
> +	/* We set same protection levels for Src and DST for now */
> +	if (rqc->privileged)
> +		ccr |= CC_SRCPRI | CC_DSTPRI;
> +	if (rqc->nonsecure)
> +		ccr |= CC_SRCNS | CC_DSTNS;
> +	if (rqc->insnaccess)
> +		ccr |= CC_SRCIA | CC_DSTIA;
> +
> +	ccr |= (((rqc->brst_len - 1) & 0xf) << CC_SRCBRSTLEN_SHFT);
> +	ccr |= (((rqc->brst_len - 1) & 0xf) << CC_DSTBRSTLEN_SHFT);
> +
> +	ccr |= (rqc->brst_size << CC_SRCBRSTSIZE_SHFT);
> +	ccr |= (rqc->brst_size << CC_DSTBRSTSIZE_SHFT);
> +
> +	ccr |= (rqc->dcctl << CC_SRCCCTRL_SHFT);
> +	ccr |= (rqc->scctl << CC_DSTCCTRL_SHFT);
> +
> +	ccr |= (rqc->swap << CC_SWAP_SHFT);
> +
> +	return ccr;
> +}
> +
> +static inline bool _is_valid(u32 ccr)
> +{
> +	enum pl330_dstcachectrl dcctl;
> +	enum pl330_srccachectrl scctl;
> +
> +	dcctl = (ccr >> CC_DSTCCTRL_SHFT) & CC_DRCCCTRL_MASK;
> +	scctl = (ccr >> CC_SRCCCTRL_SHFT) & CC_SRCCCTRL_MASK;
> +
> +	if (dcctl == DINVALID1 || dcctl == DINVALID2
> +			|| scctl == SINVALID1 || scctl == SINVALID2)
> +		return false;
> +	else
> +		return true;
> +}
> +
> +/*
> + * Submit a list of xfers after which the client wants notification.
> + * Client is not notified after each xfer unit, just once after all
> + * xfer units are done or some error occurs.
> + */
> +int pl330_submit_req(void *ch_id, struct pl330_req *r)
> +{
> +	struct pl330_thread *thrd = ch_id;
> +	struct pl330_dmac *pl330;
> +	struct pl330_info *pi;
> +	struct _xfer_spec xs;
> +	unsigned long flags;
> +	void __iomem *regs;
> +	unsigned idx;
> +	u32 ccr;
> +	int ret = 0;
> +
> +	/* No Req or Unacquired Channel or DMAC */
> +	if (!r || !thrd || thrd->free)
> +		return -EINVAL;
> +
> +	pl330 = thrd->dmac;
> +	pi = pl330->pinfo;
> +	regs = pi->base;
> +
> +	if (pl330->state == DYING
> +		|| pl330->dmac_tbd.reset_chan & (1 << thrd->id)) {
> +		dev_info(thrd->dmac->pinfo->dev, "%s:%d\n",
> +			__func__, __LINE__);
> +		return -EAGAIN;
> +	}
> +
> +	/* If request for non-existing peripheral */
> +	if (r->rqtype != MEMTOMEM && r->peri >= pi->pcfg.num_peri) {
> +		dev_info(thrd->dmac->pinfo->dev,
> +				"%s:%d Invalid peripheral(%u)!\n",
> +				__func__, __LINE__, r->peri);
> +		return -EINVAL;
> +	}
> +
> +	spin_lock_irqsave(&pl330->lock, flags);
> +
> +	if (_queue_full(thrd)) {
> +		ret = -EAGAIN;
> +		goto xfer_exit;
> +	}
> +
> +	/* Prefer Secure Channel */
> +	if (!_manager_ns(thrd))
> +		r->cfg->nonsecure = 0;
> +	else
> +		r->cfg->nonsecure = 1;
> +
> +	/* Use last settings, if not provided */
> +	if (r->cfg)
> +		ccr = _prepare_ccr(r->cfg);
> +	else
> +		ccr = readl(regs + CC(thrd->id));
> +
> +	/* If this req doesn't have valid xfer settings */
> +	if (!_is_valid(ccr)) {
> +		ret = -EINVAL;
> +		dev_info(thrd->dmac->pinfo->dev, "%s:%d Invalid CCR(%x)!\n",
> +			__func__, __LINE__, ccr);
> +		goto xfer_exit;
> +	}
> +
> +	idx = IS_FREE(&thrd->req[0]) ? 0 : 1;
> +
> +	xs.ccr = ccr;
> +	xs.r = r;
> +
> +	/* First dry run to check if req is acceptable */
> +	ret = _setup_req(1, thrd, idx, &xs);
> +	if (ret < 0)
> +		goto xfer_exit;
> +
> +	if (ret > pi->mcbufsz / 2) {
> +		dev_info(thrd->dmac->pinfo->dev,
> +			"%s:%d Trying increasing mcbufsz\n",
> +				__func__, __LINE__);
> +		ret = -ENOMEM;
> +		goto xfer_exit;
> +	}
> +
> +	/* Hook the request */
> +	thrd->lstenq = idx;
> +	thrd->req[idx].mc_len = _setup_req(0, thrd, idx, &xs);
> +	thrd->req[idx].r = r;
> +
> +	ret = 0;
> +
> +xfer_exit:
> +	spin_unlock_irqrestore(&pl330->lock, flags);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(pl330_submit_req);
> +
> +static void pl330_dotask(unsigned long data)
> +{
> +	struct pl330_dmac *pl330 = (struct pl330_dmac *) data;
> +	struct pl330_info *pi = pl330->pinfo;
> +	unsigned long flags;
> +	int i;
> +
> +	spin_lock_irqsave(&pl330->lock, flags);
> +
> +	/* The DMAC itself gone nuts */
> +	if (pl330->dmac_tbd.reset_dmac) {
> +		pl330->state = DYING;
> +		/* Reset the manager too */
> +		pl330->dmac_tbd.reset_mngr = true;
> +		/* Clear the reset flag */
> +		pl330->dmac_tbd.reset_dmac = false;
> +	}
> +
> +	if (pl330->dmac_tbd.reset_mngr) {
> +		_stop(pl330->manager);
> +		/* Reset all channels */
> +		pl330->dmac_tbd.reset_chan = (1 << pi->pcfg.num_chan) - 1;
> +		/* Clear the reset flag */
> +		pl330->dmac_tbd.reset_mngr = false;
> +	}
> +
> +	for (i = 0; i < pi->pcfg.num_chan; i++) {
> +
> +		if (pl330->dmac_tbd.reset_chan & (1 << i)) {
> +			struct pl330_thread *thrd = &pl330->channels[i];
> +			void __iomem *regs = pi->base;
> +			enum pl330_op_err err;
> +
> +			_stop(thrd);
> +
> +			if (readl(regs + FSC) & (1 << thrd->id))
> +				err = PL330_ERR_FAIL;
> +			else
> +				err = PL330_ERR_ABORT;
> +
> +			spin_unlock_irqrestore(&pl330->lock, flags);
> +
> +			_callback(thrd->req[1 - thrd->lstenq].r, err);
> +			_callback(thrd->req[thrd->lstenq].r, err);
> +
> +			spin_lock_irqsave(&pl330->lock, flags);
> +
> +			thrd->req[0].r = NULL;
> +			thrd->req[1].r = NULL;
> +			MARK_FREE(&thrd->req[0]);
> +			MARK_FREE(&thrd->req[1]);
> +
> +			/* Clear the reset flag */
> +			pl330->dmac_tbd.reset_chan &= ~(1 << i);
> +		}
> +	}
> +
> +	spin_unlock_irqrestore(&pl330->lock, flags);
> +
> +	return;
> +}
> +
> +/* Returns 1 if state was updated, 0 otherwise */
> +int pl330_update(const struct pl330_info *pi)
> +{
> +	struct _pl330_req *rqdone;
> +	struct pl330_dmac *pl330;
> +	unsigned long flags;
> +	void __iomem *regs;
> +	u32 val;
> +	int id, ev, ret = 0;
> +
> +	if (!pi || !pi->pl330_data)
> +		return 0;
> +
> +	regs = pi->base;
> +	pl330 = pi->pl330_data;
> +
> +	spin_lock_irqsave(&pl330->lock, flags);
> +
> +	val = readl(regs + FSM) & 0x1;
> +	if (val)
> +		pl330->dmac_tbd.reset_mngr = true;
> +	else
> +		pl330->dmac_tbd.reset_mngr = false;
> +
> +	val = readl(regs + FSC) & ((1 << pi->pcfg.num_chan) - 1);
> +	pl330->dmac_tbd.reset_chan |= val;
> +	if (val) {
> +		int i = 0;
> +		while (i < pi->pcfg.num_chan) {
> +			if (val & (1 << i)) {
> +				dev_info(pi->dev,
> +					"Reset Channel-%d\t CS-%x FTC-%x\n",
> +						i, readl(regs + CS(i)),
> +						readl(regs + FTC(i)));
> +				_stop(&pl330->channels[i]);
> +			}
> +			i++;
> +		}
> +	}
> +
> +	/* Check which event happened i.e, thread notified */
> +	val = readl(regs + ES);
> +	if (pi->pcfg.num_events < 32
> +			&& val & ~((1 << pi->pcfg.num_events) - 1)) {
> +		pl330->dmac_tbd.reset_dmac = true;
> +		dev_err(pi->dev, "%s:%d Unexpected!\n", __func__, __LINE__);
> +		ret = 1;
> +		goto updt_exit;
> +	}
> +
> +	for (ev = 0; ev < pi->pcfg.num_events; ev++) {
> +		if (val & (1 << ev)) { /* Event occured */
> +			struct pl330_thread *thrd;
> +			u32 inten = readl(regs + INTEN);
> +			int active;
> +
> +			/* Clear the event */
> +			if (inten & (1 << ev))
> +				writel(1 << ev, regs + INTCLR);
> +
> +			ret = 1;
> +
> +			id = pl330->events[ev];
> +
> +			thrd = &pl330->channels[id];
> +
> +			active = _thrd_active(thrd);
> +			if (!active) /* Aborted */
> +				continue;
> +
> +			active -= 1;
> +
> +			rqdone = &thrd->req[active];
> +			MARK_FREE(rqdone);
> +
> +			/* Get going again ASAP */
> +			_start(thrd);
> +
> +			/* For now, just make a list of callbacks to be done */
> +			list_add_tail(&rqdone->rqd, &pl330->req_done);
> +		}
> +	}
> +
> +	/* Now that we are in no hurry, do the callbacks */
> +	while (!list_empty(&pl330->req_done)) {
> +		rqdone = container_of(pl330->req_done.next,
> +					struct _pl330_req, rqd);
> +
> +		list_del_init(&rqdone->rqd);
> +
> +		spin_unlock_irqrestore(&pl330->lock, flags);
> +		_callback(rqdone->r, PL330_ERR_NONE);
> +		spin_lock_irqsave(&pl330->lock, flags);
> +	}
> +
> +updt_exit:
> +	spin_unlock_irqrestore(&pl330->lock, flags);
> +
> +	if (pl330->dmac_tbd.reset_dmac
> +			|| pl330->dmac_tbd.reset_mngr
> +			|| pl330->dmac_tbd.reset_chan) {

iirc, style is:
      if (a ||
      	  b ||
	  c)

could be wrong, definetly prefer the above.

> +		ret = 1;
> +		tasklet_schedule(&pl330->tasks);
> +	}
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(pl330_update);
> +
> +int pl330_chan_ctrl(void *ch_id, enum pl330_chan_op op)
> +{
> +	struct pl330_thread *thrd = ch_id;
> +	struct pl330_dmac *pl330;
> +	unsigned long flags;
> +	int ret = 0, active;
> +
> +	if (!thrd || thrd->free || thrd->dmac->state == DYING)
> +		return -EINVAL;
> +
> +	pl330 = thrd->dmac;
> +
> +	spin_lock_irqsave(&pl330->lock, flags);
> +
> +	switch (op) {
> +	case PL330_OP_FLUSH:
> +		/* Make sure the channel is stopped */
> +		_stop(thrd);
> +
> +		thrd->req[0].r = NULL;
> +		thrd->req[1].r = NULL;
> +		MARK_FREE(&thrd->req[0]);
> +		MARK_FREE(&thrd->req[1]);
> +		break;
> +
> +	case PL330_OP_ABORT:
> +		active = _thrd_active(thrd);
> +
> +		/* Make sure the channel is stopped */
> +		_stop(thrd);
> +
> +		/* ABORT is only for the active req */
> +		if (!active)
> +			break;
> +
> +		active--;
> +
> +		thrd->req[active].r = NULL;
> +		MARK_FREE(&thrd->req[active]);
> +
> +		/* Start the next */
> +	case PL330_OP_START:
> +		if (!_start(thrd))
> +			ret = -EIO;
> +		break;
> +
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	spin_unlock_irqrestore(&pl330->lock, flags);
> +	return ret;
> +}
> +EXPORT_SYMBOL(pl330_chan_ctrl);
> +
> +int pl330_chan_status(void *ch_id, struct pl330_chanstatus *pstatus)
> +{
> +	struct pl330_thread *thrd = ch_id;
> +	struct pl330_dmac *pl330;
> +	struct pl330_info *pi;
> +	void __iomem *regs;
> +	int active;
> +	u32 val;
> +
> +	if (!pstatus || !thrd || thrd->free)
> +		return -EINVAL;
> +
> +	pl330 = thrd->dmac;
> +	pi = pl330->pinfo;
> +	regs = pi->base;
> +
> +	/* The client should remove the DMAC and add again */
> +	if (pl330->state == DYING)
> +		pstatus->dmac_halted = true;
> +	else
> +		pstatus->dmac_halted = false;
> +
> +	val = readl(regs + FSC);
> +	if (val & (1 << thrd->id))
> +		pstatus->faulting = true;
> +	else
> +		pstatus->faulting = false;
> +
> +	active = _thrd_active(thrd);
> +
> +	if (!active) {
> +		/* Indicate that the thread is not running */
> +		pstatus->top_req = NULL;
> +		pstatus->wait_req = NULL;
> +	} else {
> +		active--;
> +		pstatus->top_req = thrd->req[active].r;
> +		pstatus->wait_req = !IS_FREE(&thrd->req[1 - active])
> +					? thrd->req[1 - active].r : NULL;
> +	}
> +
> +	pstatus->src_addr = readl(regs + SA(thrd->id));
> +	pstatus->dst_addr = readl(regs + DA(thrd->id));
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pl330_chan_status);
> +
> +/* Reserve an event */
> +static inline int _alloc_event(struct pl330_thread *thrd)
> +{
> +	struct pl330_dmac *pl330 = thrd->dmac;
> +	struct pl330_info *pi = pl330->pinfo;
> +	int ev;
> +
> +	for (ev = 0; ev < pi->pcfg.num_events; ev++)
> +		if (pl330->events[ev] == -1) {
> +			pl330->events[ev] = thrd->id;
> +			return ev;
> +		}
> +
> +	return -1;
> +}
> +
> +/* Upon success, returns IdentityToken for the
> + * allocated channel, NULL otherwise.
> + */
> +void *pl330_request_channel(const struct pl330_info *pi)
> +{
> +	struct pl330_thread *thrd = NULL;
> +	struct pl330_dmac *pl330;
> +	unsigned long flags;
> +	int chans, i;
> +
> +	if (!pi || !pi->pl330_data)
> +		return NULL;
> +
> +	pl330 = pi->pl330_data;
> +
> +	if (pl330->state == DYING)
> +		return NULL;
> +
> +	chans = pi->pcfg.num_chan;
> +
> +	spin_lock_irqsave(&pl330->lock, flags);
> +
> +	for (i = 0; i < chans; i++) {
> +		thrd = &pl330->channels[i];
> +		if (thrd->free) {
> +			thrd->ev = _alloc_event(thrd);
> +			if (thrd->ev >= 0) {
> +				thrd->free = false;
> +				thrd->lstenq = 1;
> +				thrd->req[0].r = NULL;
> +				MARK_FREE(&thrd->req[0]);
> +				thrd->req[1].r = NULL;
> +				MARK_FREE(&thrd->req[1]);
> +				break;
> +			}
> +		}
> +		thrd = NULL;
> +	}
> +
> +	spin_unlock_irqrestore(&pl330->lock, flags);
> +
> +	return thrd;
> +}
> +EXPORT_SYMBOL(pl330_request_channel);
> +
> +/* Release an event */
> +static inline void _free_event(struct pl330_thread *thrd, int ev)
> +{
> +	struct pl330_dmac *pl330 = thrd->dmac;
> +	struct pl330_info *pi = pl330->pinfo;
> +
> +	/* If the event is valid and was held by the thread */
> +	if (ev >= 0 && ev < pi->pcfg.num_events
> +			&& pl330->events[ev] == thrd->id)
> +		pl330->events[ev] = -1;
> +}
> +
> +void pl330_release_channel(void *ch_id)
> +{
> +	struct pl330_thread *thrd = ch_id;
> +	struct pl330_dmac *pl330;
> +	unsigned long flags;
> +
> +	if (!thrd || thrd->free)
> +		return;
> +
> +	_stop(thrd);
> +
> +	_callback(thrd->req[1 - thrd->lstenq].r, PL330_ERR_ABORT);
> +	_callback(thrd->req[thrd->lstenq].r, PL330_ERR_ABORT);
> +
> +	pl330 = thrd->dmac;
> +
> +	spin_lock_irqsave(&pl330->lock, flags);
> +	_free_event(thrd, thrd->ev);
> +	thrd->free = true;
> +	spin_unlock_irqrestore(&pl330->lock, flags);
> +}
> +EXPORT_SYMBOL(pl330_release_channel);
> +
> +/* Initialize the structure for PL330 configuration, that can be used
> + * by the client driver the make best use of the DMAC
> + */
> +static void read_dmac_config(struct pl330_info *pi)
> +{
> +	void __iomem *regs = pi->base;
> +	u32 val;
> +
> +	val = readl(regs + CRD) >> CRD_DATA_WIDTH_SHIFT;
> +	val &= CRD_DATA_WIDTH_MASK;
> +	pi->pcfg.data_bus_width = 8 * (1 << val);
> +
> +	val = readl(regs + CRD) >> CRD_DATA_BUFF_SHIFT;
> +	val &= CRD_DATA_BUFF_MASK;
> +	pi->pcfg.data_buf_dep = val + 1;
> +
> +	val = readl(regs + CR0) >> CR0_NUM_CHANS_SHIFT;
> +	val &= CR0_NUM_CHANS_MASK;
> +	val += 1;
> +	pi->pcfg.num_chan = val;
> +
> +	val = readl(regs + CR0);
> +	if (val & CR0_PERIPH_REQ_SET) {
> +		val = (val >> CR0_NUM_PERIPH_SHIFT) & CR0_NUM_PERIPH_MASK;
> +		val += 1;
> +		pi->pcfg.num_peri = val;
> +		pi->pcfg.peri_ns = readl(regs + CR4);
> +	} else {
> +		pi->pcfg.num_peri = 0;
> +	}
> +
> +	val = readl(regs + CR0);
> +	if (val & CR0_BOOT_MAN_NS)
> +		pi->pcfg.mode |= DMAC_MODE_NS;
> +	else
> +		pi->pcfg.mode &= ~DMAC_MODE_NS;
> +
> +	val = readl(regs + CR0) >> CR0_NUM_EVENTS_SHIFT;
> +	val &= CR0_NUM_EVENTS_MASK;
> +	val += 1;
> +	pi->pcfg.num_events = val;
> +
> +	pi->pcfg.irq_ns = readl(regs + CR3);
> +
> +	pi->pcfg.periph_id = get_id(pi, PERIPH_ID);
> +	pi->pcfg.pcell_id = get_id(pi, PCELL_ID);
> +}
> +
> +static inline void _reset_thread(struct pl330_thread *thrd)
> +{
> +	struct pl330_dmac *pl330 = thrd->dmac;
> +	struct pl330_info *pi = pl330->pinfo;
> +
> +	thrd->req[0].mc_cpu = pl330->mcode_cpu
> +				+ (thrd->id * pi->mcbufsz);
> +	thrd->req[0].mc_bus = pl330->mcode_bus
> +				+ (thrd->id * pi->mcbufsz);
> +	thrd->req[0].r = NULL;
> +	MARK_FREE(&thrd->req[0]);
> +
> +	thrd->req[1].mc_cpu = thrd->req[0].mc_cpu
> +				+ pi->mcbufsz / 2;
> +	thrd->req[1].mc_bus = thrd->req[0].mc_bus
> +				+ pi->mcbufsz / 2;
> +	thrd->req[1].r = NULL;
> +	MARK_FREE(&thrd->req[1]);
> +}
> +
> +static int dmac_alloc_threads(struct pl330_dmac *pl330)
> +{
> +	struct pl330_info *pi = pl330->pinfo;
> +	int chans = pi->pcfg.num_chan;
> +	struct pl330_thread *thrd;
> +	int i;
> +
> +	/* Allocate 1 Manager and 'chans' Channel threads */
> +	pl330->channels = kzalloc((1 + chans) * sizeof(*thrd),
> +					GFP_KERNEL);
> +	if (!pl330->channels)
> +		return -ENOMEM;
> +
> +	/* Init Channel threads */
> +	for (i = 0; i < chans; i++) {
> +		thrd = &pl330->channels[i];
> +		thrd->id = i;
> +		thrd->dmac = pl330;
> +		_reset_thread(thrd);
> +		thrd->free = true;
> +	}
> +
> +	/* MANAGER is indexed at the end */
> +	thrd = &pl330->channels[chans];
> +	thrd->id = chans;
> +	thrd->dmac = pl330;
> +	thrd->free = false;
> +	pl330->manager = thrd;
> +
> +	return 0;
> +}
> +
> +static int dmac_alloc_resources(struct pl330_dmac *pl330)
> +{
> +	struct pl330_info *pi = pl330->pinfo;
> +	int chans = pi->pcfg.num_chan;
> +	int ret;
> +
> +	/*
> +	 * Alloc MicroCode buffer for 'chans' Channel threads.
> +	 * A channel's buffer offset is (Channel_Id * MCODE_BUFF_PERCHAN)
> +	 */
> +	pl330->mcode_cpu = dma_alloc_coherent(pi->dev,
> +				chans * pi->mcbufsz,
> +				&pl330->mcode_bus, GFP_KERNEL);
> +	if (!pl330->mcode_cpu) {
> +		dev_err(pi->dev, "%s:%d Can't allocate memory!\n",

no need to add an ! at the end of the line.

> +			__func__, __LINE__);
> +		return -ENOMEM;
> +	}
> +
> +	ret = dmac_alloc_threads(pl330);
> +	if (ret) {
> +		dev_err(pi->dev, "%s:%d Can't to create channels for DMAC!\n",
> +			__func__, __LINE__);
> +		dma_free_coherent(pi->dev,
> +				chans * pi->mcbufsz,
> +				pl330->mcode_cpu, pl330->mcode_bus);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +int pl330_add(struct pl330_info *pi)
> +{
> +	struct pl330_dmac *pl330;
> +	void __iomem *regs;
> +	int i, ret;
> +
> +	if (!pi || !pi->dev)
> +		return -EINVAL;
> +
> +	/* If already added */
> +	if (pi->pl330_data)
> +		return -EINVAL;
> +
> +	/*
> +	 * If the SoC can perform reset on the DMAC, then do it
> +	 * before reading its configuration.
> +	 */
> +	if (pi->dmac_reset)
> +		pi->dmac_reset(pi);
> +
> +	regs = pi->base;
> +
> +	/* Check if we can handle this DMAC */
> +	if (get_id(pi, PERIPH_ID) != PERIPH_ID_VAL
> +	   || get_id(pi, PCELL_ID) != PCELL_ID_VAL) {
> +		dev_err(pi->dev, "PERIPH_ID 0x%x, PCELL_ID 0x%x !\n",
> +			readl(regs + PERIPH_ID), readl(regs + PCELL_ID));

get_id and readl() ?

Also, please don;'t keep getting suprised by errors, erro messages don't
need a ! in them.

> +		return -EINVAL;
> +	}
> +
> +	/* Read the configuration of the DMAC */
> +	read_dmac_config(pi);
> +
> +	if (pi->pcfg.num_events == 0) {
> +		dev_err(pi->dev, "%s:%d Can't work without events!\n",
> +			__func__, __LINE__);
> +		return -EINVAL;
> +	}
> +
> +	pl330 = kzalloc(sizeof(*pl330), GFP_KERNEL);
> +	if (!pl330) {
> +		dev_err(pi->dev, "%s:%d Can't allocate memory!\n",
> +			__func__, __LINE__);
> +		return -ENOMEM;
> +	}
> +
> +	/* Assign the info structure and private data */
> +	pl330->pinfo = pi;
> +	pi->pl330_data = pl330;
> +
> +	spin_lock_init(&pl330->lock);
> +
> +	INIT_LIST_HEAD(&pl330->req_done);
> +
> +	/* Use default MC buffer size if not provided */
> +	if (!pi->mcbufsz)
> +		pi->mcbufsz = MCODE_BUFF_PER_REQ * 2;
> +
> +	/* Mark all events as free */
> +	for (i = 0; i < pi->pcfg.num_events; i++)
> +		pl330->events[i] = -1;
> +
> +	/* Allocate resources needed by the DMAC */
> +	ret = dmac_alloc_resources(pl330);
> +	if (ret) {
> +		dev_err(pi->dev, "Unable to create channels for DMAC\n");
> +		kfree(pl330);
> +		return ret;
> +	}
> +
> +	tasklet_init(&pl330->tasks, pl330_dotask, (unsigned long) pl330);
> +
> +	pl330->state = INIT;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(pl330_add);
> +
> +static int dmac_free_threads(struct pl330_dmac *pl330)
> +{
> +	struct pl330_info *pi = pl330->pinfo;
> +	int chans = pi->pcfg.num_chan;
> +	struct pl330_thread *thrd;
> +	int i;
> +
> +	/* Release Channel threads */
> +	for (i = 0; i < chans; i++) {
> +		thrd = &pl330->channels[i];
> +		pl330_release_channel((void *)thrd);
> +	}
> +
> +	/* Free memory */
> +	kfree(pl330->channels);
> +
> +	return 0;
> +}
> +
> +static void dmac_free_resources(struct pl330_dmac *pl330)
> +{
> +	struct pl330_info *pi = pl330->pinfo;
> +	int chans = pi->pcfg.num_chan;
> +
> +	dmac_free_threads(pl330);
> +
> +	dma_free_coherent(pi->dev, chans * pi->mcbufsz,
> +				pl330->mcode_cpu, pl330->mcode_bus);
> +}
> +
> +void pl330_del(struct pl330_info *pi)
> +{
> +	struct pl330_dmac *pl330;
> +
> +	if (!pi || !pi->pl330_data)
> +		return;
> +
> +	pl330 = pi->pl330_data;
> +
> +	pl330->state = UNINIT;
> +
> +	tasklet_kill(&pl330->tasks);
> +
> +	/* Free DMAC resources */
> +	dmac_free_resources(pl330);
> +
> +	kfree(pl330);
> +	pi->pl330_data = NULL;
> +}
> +EXPORT_SYMBOL(pl330_del);
> diff --git a/arch/arm/include/asm/hardware/pl330.h b/arch/arm/include/asm/hardware/pl330.h
> new file mode 100644
> index 0000000..575fa81
> --- /dev/null
> +++ b/arch/arm/include/asm/hardware/pl330.h
> @@ -0,0 +1,217 @@
> +/* linux/include/asm/hardware/pl330.h
> + *
> + * Copyright (C) 2010 Samsung Electronics Co. Ltd.
> + *	Jaswinder Singh <jassi.brar at samsung.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.
> + *
> + * 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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> + */
> +
> +#ifndef __PL330_CORE_H
> +#define __PL330_CORE_H
> +
> +#define PL330_MAX_CHAN		8
> +#define PL330_MAX_IRQS		32
> +#define PL330_MAX_PERI		32
> +
> +enum pl330_srccachectrl {
> +	SCCTRL0 = 0, /* Noncacheable and nonbufferable */
> +	SCCTRL1, /* Bufferable only */
> +	SCCTRL2, /* Cacheable, but do not allocate */
> +	SCCTRL3, /* Cacheable and bufferable, but do not allocate */
> +	SINVALID1,
> +	SINVALID2,
> +	SCCTRL6, /* Cacheable write-through, allocate on reads only */
> +	SCCTRL7, /* Cacheable write-back, allocate on reads only */
> +};
> +
> +enum pl330_dstcachectrl {
> +	DCCTRL0 = 0, /* Noncacheable and nonbufferable */
> +	DCCTRL1, /* Bufferable only */
> +	DCCTRL2, /* Cacheable, but do not allocate */
> +	DCCTRL3, /* Cacheable and bufferable, but do not allocate */
> +	DINVALID1 = 8,
> +	DINVALID2,
> +	DCCTRL6, /* Cacheable write-through, allocate on writes only */
> +	DCCTRL7, /* Cacheable write-back, allocate on writes only */
> +};
> +
> +/* Populated by the PL330 core driver for DMA API driver's info */
> +struct pl330_config {
> +	u32	periph_id;
> +	u32	pcell_id;
> +#define DMAC_MODE_NS	(1 << 0)
> +	unsigned int	mode;
> +	unsigned int	data_bus_width:10; /* In number of bits */
> +	unsigned int	data_buf_dep:10;
> +	unsigned int	num_chan:4;
> +	unsigned int	num_peri:6;
> +	u32		peri_ns;
> +	unsigned int	num_events:6;
> +	u32		irq_ns;
> +};

If this is matching an in-memory structure, then please don't use :x to
define these. Also you'll need to ensure it is packed.

If not matching an in memory structure, then unsigned char or u8s would
probably generate more efficient code without sacrificing a lot of memory
space.

> +/* Handle to the DMAC provided to the PL330 core */
> +struct pl330_info {
> +	/* Owning device */
> +	struct device *dev;
> +	/* Size of MicroCode buffers for each channel. */
> +	unsigned mcbufsz;
> +	/* ioremap'ed address of PL330 registers. */
> +	void __iomem	*base;
> +	/* Client can freely use it. */
> +	void	*client_data;
> +	/* PL330 core data, Client must not touch it. */
> +	void	*pl330_data;
> +	/* Populated by the PL330 core driver during pl330_add */
> +	struct pl330_config	pcfg;
> +	/*
> +	 * If the DMAC has some reset mechanism, then the
> +	 * client may want to provide pointer to the method.
> +	 */
> +	void (*dmac_reset)(struct pl330_info *pi);
> +};
> +
> +enum pl330_byteswap {
> +	SWAP_NO = 0,
> +	SWAP_2,
> +	SWAP_4,
> +	SWAP_8,
> +	SWAP_16,
> +};
> +
> +/**
> + * Request Configuration.
> + * The PL330 core does not modify this and uses the last
> + * working configuration if the request doesn't provide any.
> + *
> + * The Client may want to provide this info only for the
> + * first request and a request with new settings.
> + */
> +struct pl330_reqcfg {
> +	/* Address Incrementing */
> +	unsigned dst_inc:1;
> +	unsigned src_inc:1;
> +
> +	/*
> +	 * For now, the SRC & DST protection levels
> +	 * and burst size/length are assumed same.
> +	 */
> +	bool nonsecure;
> +	bool privileged;
> +	bool insnaccess;
> +	unsigned brst_len:5;
> +	unsigned brst_size:3; /* in power of 2 */

see previous comments.

> +	enum pl330_dstcachectrl dcctl;
> +	enum pl330_srccachectrl scctl;
> +	enum pl330_byteswap swap;
> +};
> +
> +/*
> + * One cycle of DMAC operation.
> + * There may be more than one xfer in a request.
> + */
> +struct pl330_xfer {
> +	u32 src_addr;
> +	u32 dst_addr;
> +	/* Size to xfer */
> +	u32 bytes;
> +	/*
> +	 * Pointer to next xfer in the list.
> +	 * The last xfer in the req must point to NULL.
> +	 */
> +	struct pl330_xfer *next;
> +};
> +
> +/* The xfer callbacks are made with one of these arguments. */
> +enum pl330_op_err {
> +	/* The all xfers in the request were success. */
> +	PL330_ERR_NONE,
> +	/* If req aborted due to global error. */
> +	PL330_ERR_ABORT,
> +	/* If req failed due to problem with Channel. */
> +	PL330_ERR_FAIL,
> +};
> +
> +enum pl330_reqtype {
> +	MEMTOMEM,
> +	MEMTODEV,
> +	DEVTOMEM,
> +	DEVTODEV,
> +};
> +
> +/* A request defining Scatter-Gather List ending with NULL xfer. */
> +struct pl330_req {
> +	enum pl330_reqtype rqtype;
> +	/* Index of peripheral for the xfer. */
> +	unsigned peri:5;
> +	/* Unique token for this xfer, set by the client. */
> +	void *token;
> +	/* Callback to be called after xfer. */
> +	void (*xfer_cb)(void *token, enum pl330_op_err err);
> +	/* If NULL, req will be done at last set parameters. */
> +	struct pl330_reqcfg *cfg;
> +	/* Pointer to first xfer in the request. */
> +	struct pl330_xfer *x;
> +};
> +
> +/*
> + * To know the status of the channel and DMAC, the client
> + * provides a pointer to this structure. The PL330 core
> + * fills it with current information.
> + */
> +struct pl330_chanstatus {
> +	/*
> +	 * If the DMAC engine halted due to some error,
> +	 * the client should remove-add DMAC.
> +	 */
> +	bool dmac_halted;
> +	/*
> +	 * If channel is halted due to some error,
> +	 * the client should ABORT/FLUSH and START the channel.
> +	 */
> +	bool faulting;
> +	/* Location of last load */
> +	u32 src_addr;
> +	/* Location of last store */
> +	u32 dst_addr;
> +	/*
> +	 * Pointer to the currently active req, NULL if channel is
> +	 * inactive, even though the requests may be present.
> +	 */
> +	struct pl330_req *top_req;
> +	/* Pointer to req waiting second in the queue if any. */
> +	struct pl330_req *wait_req;
> +};
> +
> +enum pl330_chan_op {
> +	/* Start the channel */
> +	PL330_OP_START,
> +	/* Abort the active xfer */
> +	PL330_OP_ABORT,
> +	/* Stop xfer and flush queue */
> +	PL330_OP_FLUSH,
> +};
> +
> +extern int pl330_add(struct pl330_info *);
> +extern void pl330_del(struct pl330_info *pi);
> +extern int pl330_update(const struct pl330_info *pi);
> +extern void pl330_release_channel(void *ch_id);
> +extern void *pl330_request_channel(const struct pl330_info *pi);
> +extern int pl330_chan_status(void *ch_id, struct pl330_chanstatus *pstatus);
> +extern int pl330_chan_ctrl(void *ch_id, enum pl330_chan_op op);
> +extern int pl330_submit_req(void *ch_id, struct pl330_req *r);
> +
> +#endif	/* __PL330_CORE_H */
> -- 
> 1.6.2.5
> 

-- 
Ben

Q:      What's a light-year?
A:      One-third less calories than a regular year.




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