aic7xxx_linux.c

自己根据lkd和情境分析

static __inline void ahc_linux_run_complete_queue(struct ahc_softc *ahc,
						  struct ahc_cmd *acmd);
static __inline void ahc_linux_check_device_queue(struct ahc_softc *ahc,
						  struct ahc_linux_device *dev);
static __inline void ahc_linux_sniff_command(struct ahc_softc*, Scsi_Cmnd*,
					     struct scb*);
static __inline void ahc_linux_unmap_scb(struct ahc_softc*, struct scb*);

static __inline int ahc_linux_map_seg(struct ahc_softc *ahc, struct scb *scb,
		 		      struct ahc_dma_seg *sg,
				      bus_addr_t addr, bus_size_t len);

static __inline struct ahc_linux_device*
ahc_linux_get_device(struct ahc_softc *ahc, u_int channel, u_int target,
	       u_int lun, int alloc)
{
	struct ahc_linux_target *targ;
	struct ahc_linux_device *dev;
	u_int target_offset;

	target_offset = target;
	if (channel != 0)
		target_offset += 8;
	targ = ahc->platform_data->targets[target_offset];
	if (targ == NULL) {
		if (alloc != 0) {
			targ = ahc_linux_alloc_target(ahc, channel, target);
			if (targ == NULL)
				return (NULL);
		} else
			return (NULL);
	}
	dev = targ->devices[lun];
	if (dev == NULL && alloc != 0)
		dev = ahc_linux_alloc_device(ahc, targ, lun);
	return (dev);
}

static __inline void
ahc_linux_queue_cmd_complete(struct ahc_softc *ahc, Scsi_Cmnd *cmd)
{
	/*
	 * Typically, the complete queue has very few entries
	 * queued to it before the queue is emptied by
	 * ahc_linux_run_complete_queue, so sorting the entries
	 * by generation number should be inexpensive.
	 * We perform the sort so that commands that complete
	 * with an error are retuned in the order origionally
	 * queued to the controller so that any subsequent retries
	 * are performed in order.  The underlying ahc routines do
	 * not guarantee the order that aborted commands will be
	 * returned to us.
	 */
	struct ahc_completeq *completeq;
	struct ahc_cmd *list_cmd;
	struct ahc_cmd *acmd;

	/*
	 * If we want the request requeued, make sure there
	 * are sufficent retries.  In the old scsi error code,
	 * we used to be able to specify a result code that
	 * bypassed the retry count.  Now we must use this
	 * hack.
	 */
	if (cmd->result == (CAM_REQUEUE_REQ << 16))
		cmd->retries--;
	completeq = &ahc->platform_data->completeq;
	list_cmd = TAILQ_FIRST(completeq);
	acmd = (struct ahc_cmd *)cmd;
	while (list_cmd != NULL
	    && acmd_scsi_cmd(list_cmd).serial_number
	     < acmd_scsi_cmd(acmd).serial_number)
		list_cmd = TAILQ_NEXT(list_cmd, acmd_links.tqe);
	if (list_cmd != NULL)
		TAILQ_INSERT_BEFORE(list_cmd, acmd, acmd_links.tqe);
	else
		TAILQ_INSERT_TAIL(completeq, acmd, acmd_links.tqe);
}

static __inline void
ahc_linux_run_complete_queue(struct ahc_softc *ahc, struct ahc_cmd *acmd)
{	
	u_long done_flags;

	ahc_done_lock(ahc, &done_flags);
	while (acmd != NULL) {
		Scsi_Cmnd *cmd;

		cmd = &acmd_scsi_cmd(acmd);
		acmd = TAILQ_NEXT(acmd, acmd_links.tqe);
		cmd->host_scribble = NULL;
		cmd->scsi_done(cmd);
	}
	ahc_done_unlock(ahc, &done_flags);
}

static __inline void
ahc_linux_check_device_queue(struct ahc_softc *ahc,
			     struct ahc_linux_device *dev)
{
	if ((dev->flags & AHC_DEV_FREEZE_TIL_EMPTY) != 0
	 && dev->active == 0) {
		dev->flags &= ~AHC_DEV_FREEZE_TIL_EMPTY;
		dev->qfrozen--;
	}

	if (TAILQ_FIRST(&dev->busyq) == NULL
	 || dev->openings == 0 || dev->qfrozen != 0)
		return;

	ahc_linux_run_device_queue(ahc, dev);
}

static __inline void
ahc_linux_run_device_queues(struct ahc_softc *ahc)
{
	struct ahc_linux_device *dev;

	while ((ahc->flags & AHC_RESOURCE_SHORTAGE) == 0
	    && ahc->platform_data->qfrozen == 0
	    && (dev = TAILQ_FIRST(&ahc->platform_data->device_runq)) != NULL) {
		TAILQ_REMOVE(&ahc->platform_data->device_runq, dev, links);
		dev->flags &= ~AHC_DEV_ON_RUN_LIST;
		ahc_linux_check_device_queue(ahc, dev);
	}
}

static __inline void
ahc_linux_sniff_command(struct ahc_softc *ahc, Scsi_Cmnd *cmd, struct scb *scb)
{
	/*
	 * Determine whether we care to filter
	 * information out of this command.  If so,
	 * pass it on to ahc_linux_filter_command() for more
	 * heavy weight processing.
	 */
	if (cmd->cmnd[0] == INQUIRY)
		ahc_linux_filter_command(ahc, cmd, scb);
}

static __inline void
ahc_linux_unmap_scb(struct ahc_softc *ahc, struct scb *scb)
{
	Scsi_Cmnd *cmd;

	cmd = scb->io_ctx;
	ahc_sync_sglist(ahc, scb, BUS_DMASYNC_POSTWRITE);
	if (cmd->use_sg != 0) {
		struct scatterlist *sg;

		sg = (struct scatterlist *)cmd->request_buffer;
		pci_unmap_sg(ahc->dev_softc, sg, cmd->use_sg,
			     scsi_to_pci_dma_dir(cmd->sc_data_direction));
	} else if (cmd->request_bufflen != 0) {
		u_int32_t high_addr;

		high_addr = ahc_le32toh(scb->sg_list[0].len)
			  & AHC_SG_HIGH_ADDR_MASK;
		pci_unmap_single(ahc->dev_softc,
				 ahc_le32toh(scb->sg_list[0].addr)
			        | (((dma_addr_t)high_addr) << 8),
				 cmd->request_bufflen,
				 scsi_to_pci_dma_dir(cmd->sc_data_direction));
	}
}

static __inline int
ahc_linux_map_seg(struct ahc_softc *ahc, struct scb *scb,
		  struct ahc_dma_seg *sg, bus_addr_t addr, bus_size_t len)
{
	int	 consumed;

	if ((scb->sg_count + 1) > AHC_NSEG)
		panic("Too few segs for dma mapping.  "
		      "Increase AHC_NSEG\n");

	consumed = 1;
	sg->addr = ahc_htole32(addr & 0xFFFFFFFF);
	scb->platform_data->xfer_len += len;
	if (sizeof(bus_addr_t) > 4
	 && (ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
		/*
		 * Due to DAC restrictions, we can't
		 * cross a 4GB boundary.
		 */
		if ((addr ^ (addr + len - 1)) & ~0xFFFFFFFF) {
			struct	 ahc_dma_seg *next_sg;
			uint32_t next_len;

			printf("Crossed Seg\n");
			if ((scb->sg_count + 2) > AHC_NSEG)
				panic("Too few segs for dma mapping.  "
				      "Increase AHC_NSEG\n");

			consumed++;
			next_sg = sg + 1;
			next_sg->addr = 0;
			next_len = 0x100000000 - (addr & 0xFFFFFFFF);
			len -= next_len;
			next_len |= ((addr >> 8) + 0x1000000) & 0x7F000000;
			next_sg->len = ahc_htole32(next_len);
		}
		len |= (addr >> 8) & 0x7F000000;
	}
	sg->len = ahc_htole32(len);
	return (consumed);
}

/************************ Shutdown/halt/reboot hook ***************************/
#include <linux/notifier.h>
#include <linux/reboot.h>

static struct notifier_block ahc_linux_notifier = {
	ahc_linux_halt, NULL, 0
};

static int ahc_linux_halt(struct notifier_block *nb, u_long event, void *buf)
{
	struct ahc_softc *ahc;

	if (event == SYS_DOWN || event == SYS_HALT) {
		TAILQ_FOREACH(ahc, &ahc_tailq, links) {
			ahc_shutdown(ahc);
		}
	}
	return (NOTIFY_OK);
}

/******************************** Macros **************************************/
#define BUILD_SCSIID(ahc, cmd)						\
	((((cmd)->target << TID_SHIFT) & TID)				\
	| (((cmd)->channel == 0) ? (ahc)->our_id : (ahc)->our_id_b)	\
	| (((cmd)->channel == 0) ? 0 : TWIN_CHNLB))

/******************************** Bus DMA *************************************/
int
ahc_dma_tag_create(struct ahc_softc *ahc, bus_dma_tag_t parent,
		   bus_size_t alignment, bus_size_t boundary,
		   bus_addr_t lowaddr, bus_addr_t highaddr,
		   bus_dma_filter_t *filter, void *filterarg,
		   bus_size_t maxsize, int nsegments,
		   bus_size_t maxsegsz, int flags, bus_dma_tag_t *ret_tag)
{
	bus_dma_tag_t dmat;

	dmat = malloc(sizeof(*dmat), M_DEVBUF, M_NOWAIT);
	if (dmat == NULL)
		return (ENOMEM);

	/*
	 * Linux is very simplistic about DMA memory.  For now don't
	 * maintain all specification information.  Once Linux supplies
	 * better facilities for doing these operations, or the
	 * needs of this particular driver change, we might need to do
	 * more here.
	 */
	dmat->alignment = alignment;
	dmat->boundary = boundary;
	dmat->maxsize = maxsize;
	*ret_tag = dmat;
	return (0);
}

void
ahc_dma_tag_destroy(struct ahc_softc *ahc, bus_dma_tag_t dmat)
{
	free(dmat, M_DEVBUF);
}

int
ahc_dmamem_alloc(struct ahc_softc *ahc, bus_dma_tag_t dmat, void** vaddr,
		 int flags, bus_dmamap_t *mapp)
{
	bus_dmamap_t map;

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
	map = malloc(sizeof(*map), M_DEVBUF, M_NOWAIT);
	if (map == NULL)
		return (ENOMEM);
	/*
	 * Although we can dma data above 4GB, our
	 * "consistent" memory is below 4GB for
	 * space efficiency reasons (only need a 4byte
	 * address).  For this reason, we have to reset
	 * our dma mask when doing allocations.
	 */
	if(ahc->dev_softc)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,3)
		pci_set_dma_mask(ahc->dev_softc, 0xFFFFFFFF);
#else
		ahc->dev_softc->dma_mask = 0xFFFFFFFF;
#endif
	*vaddr = pci_alloc_consistent(ahc->dev_softc,
				      dmat->maxsize, &map->bus_addr);
	if (ahc->dev_softc)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,3)
		pci_set_dma_mask(ahc->dev_softc, ahc->platform_data->hw_dma_mask);
#else
		ahc->dev_softc->dma_mask = ahc->platform_data->hw_dma_mask;
#endif
#else /* LINUX_VERSION_CODE < KERNEL_VERSION(2,3,0) */
	/*
	 * At least in 2.2.14, malloc is a slab allocator so all
	 * allocations are aligned.  We assume for these kernel versions
	 * that all allocations will be bellow 4Gig, physically contiguous,
	 * and accessable via DMA by the controller.
	 */
	map = NULL; /* No additional information to store */
	*vaddr = malloc(dmat->maxsize, M_DEVBUF, M_NOWAIT);
#endif
	if (*vaddr == NULL)
		return (ENOMEM);
	*mapp = map;
	return(0);
}

void
ahc_dmamem_free(struct ahc_softc *ahc, bus_dma_tag_t dmat,
		void* vaddr, bus_dmamap_t map)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
	pci_free_consistent(ahc->dev_softc, dmat->maxsize,
			    vaddr, map->bus_addr);
#else
	free(vaddr, M_DEVBUF);
#endif
}

int
ahc_dmamap_load(struct ahc_softc *ahc, bus_dma_tag_t dmat, bus_dmamap_t map,
		void *buf, bus_size_t buflen, bus_dmamap_callback_t *cb,
		void *cb_arg, int flags)
{
	/*
	 * Assume for now that this will only be used during
	 * initialization and not for per-transaction buffer mapping.
	 */
	bus_dma_segment_t stack_sg;

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,0)
	stack_sg.ds_addr = map->bus_addr;
#else
	stack_sg.ds_addr = VIRT_TO_BUS(buf);
#endif
	stack_sg.ds_len = dmat->maxsize;
	cb(cb_arg, &stack_sg, /*nseg*/1, /*error*/0);
	return (0);
}

void
ahc_dmamap_destroy(struct ahc_softc *ahc, bus_dma_tag_t dmat, bus_dmamap_t map)
{
	/*
	 * The map may is NULL in our < 2.3.X implementation.
	 */
	if (map != NULL)
		free(map, M_DEVBUF);
}

int
ahc_dmamap_unload(struct ahc_softc *ahc, bus_dma_tag_t dmat, bus_dmamap_t map)
{
	/* Nothing to do */
	return (0);
}

/********************* Platform Dependent Functions ***************************/
int
ahc_softc_comp(struct ahc_softc *lahc, struct ahc_softc *rahc)
{
	int	value;
	int	rvalue;
	int	lvalue;

	/*
	 * Under Linux, cards are ordered as follows:
	 *	1) VLB/EISA BIOS enabled devices sorted by BIOS address.
	 *	2) PCI devices with BIOS enabled sorted by bus/slot/func.
	 *	3) All remaining VLB/EISA devices sorted by ioport.
	 *	4) All remaining PCI devices sorted by bus/slot/func.
	 */
	value = (lahc->flags & AHC_BIOS_ENABLED)
	      - (rahc->flags & AHC_BIOS_ENABLED);
	if (value != 0)
		/* Controllers with BIOS enabled have a *higher* priority */
		return (-value);

	/*
	 * Same BIOS setting, now sort based on bus type.
	 * EISA and VL controllers sort together.  EISA/VL
	 * have higher priority than PCI.
	 */
	rvalue = (rahc->chip & AHC_BUS_MASK);
 	if (rvalue == AHC_VL)
		rvalue = AHC_EISA;
	lvalue = (lahc->chip & AHC_BUS_MASK);
 	if (lvalue == AHC_VL)
		lvalue = AHC_EISA;
	value = lvalue - rvalue;
	if (value != 0)
		return (value);

	/* Still equal.  Sort by BIOS address, ioport, or bus/slot/func. */
	switch (rvalue) {
	case AHC_PCI:
	{
		char primary_channel;

		if (aic7xxx_reverse_scan != 0)
			value = ahc_get_pci_bus(rahc->dev_softc)
			      - ahc_get_pci_bus(lahc->dev_softc);
		else
			value = ahc_get_pci_bus(lahc->dev_softc)
			      - ahc_get_pci_bus(rahc->dev_softc);
		if (value != 0)
			break;
		if (aic7xxx_reverse_scan != 0)
			value = ahc_get_pci_slot(rahc->dev_softc)
			      - ahc_get_pci_slot(lahc->dev_softc);
		else
			value = ahc_get_pci_slot(lahc->dev_softc)
			      - ahc_get_pci_slot(rahc->dev_softc);
		if (value != 0)
			break;
		/*
		 * On multi-function devices, the user can choose
		 * to have function 1 probed before function 0.
		 * Give whichever channel is the primary channel
		 * the lowest priority.
		 */
		primary_channel = (lahc->flags & AHC_PRIMARY_CHANNEL) + 'A';
		value = 1;
		if (lahc->channel == primary_channel)
			value = -1;
		break;
	}
	case AHC_EISA:
		if ((rahc->flags & AHC_BIOS_ENABLED) != 0) {
			value = lahc->platform_data->bios_address
			      - rahc->platform_data->bios_address; 
		} else {
			value = lahc->bsh.ioport
			      - rahc->bsh.ioport; 
		}
		break;
	default:
		panic("ahc_softc_sort: invalid bus type");
	}
	return (value);
}

static void
ahc_linux_setup_tag_info(char *p, char *end)
{
	char	*base;