--- /dev/null
- static int blkif_control_rsp_valid;
+/******************************************************************************
+ * blkfront.c
+ *
+ * XenLinux virtual block-device driver.
+ *
+ * Copyright (c) 2003-2004, Keir Fraser & Steve Hand
+ * Modifications by Mark A. Williamson are (c) Intel Research Cambridge
+ * Copyright (c) 2004, Christian Limpach
+ */
+
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
+#include "block.h"
+#else
+#include "common.h"
+#include <linux/blk.h>
+#include <linux/tqueue.h>
+#endif
+
+#include <linux/cdrom.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <scsi/scsi.h>
+#include <asm-xen/ctrl_if.h>
+
+typedef unsigned char byte; /* from linux/ide.h */
+
+#define BLKIF_STATE_CLOSED 0
+#define BLKIF_STATE_DISCONNECTED 1
+#define BLKIF_STATE_CONNECTED 2
+static unsigned int blkif_state = BLKIF_STATE_CLOSED;
+static unsigned int blkif_evtchn, blkif_irq;
+
-
- blkif_state = BLKIF_STATE_CONNECTED;
++static volatile int blkif_control_rsp_valid;
+static blkif_response_t blkif_control_rsp;
+
+static blkif_ring_t *blk_ring;
+static BLKIF_RING_IDX resp_cons; /* Response consumer for comms ring. */
+static BLKIF_RING_IDX req_prod; /* Private request producer. */
+
+unsigned long rec_ring_free;
+blkif_request_t rec_ring[BLKIF_RING_SIZE];
+
+static int recovery = 0; /* "Recovery in progress" flag. Protected
+ * by the blkif_io_lock */
+
+/* We plug the I/O ring if the driver is suspended or if the ring is full. */
+#define BLKIF_RING_FULL (((req_prod - resp_cons) == BLKIF_RING_SIZE) || \
+ (blkif_state != BLKIF_STATE_CONNECTED))
+
+static inline void translate_req_to_mfn(blkif_request_t *xreq,
+ blkif_request_t *req);
+
+static inline void translate_req_to_pfn(blkif_request_t *xreq,
+ blkif_request_t *req);
+
+static inline void flush_requests(void);
+
+static void kick_pending_request_queues(void);
+
+int __init xlblk_init(void);
+
+void blkif_completion( blkif_request_t *req );
+
+static inline int GET_ID_FROM_FREELIST( void )
+{
+ unsigned long free = rec_ring_free;
+
+ if ( free > BLKIF_RING_SIZE )
+ BUG();
+
+ rec_ring_free = rec_ring[free].id;
+
+ rec_ring[free].id = 0x0fffffee; /* debug */
+
+ return free;
+}
+
+static inline void ADD_ID_TO_FREELIST( unsigned long id )
+{
+ rec_ring[id].id = rec_ring_free;
+ rec_ring_free = id;
+}
+
+
+/************************** KERNEL VERSION 2.6 **************************/
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
+
+#define DISABLE_SCATTERGATHER()
+
+__initcall(xlblk_init);
+
+
+static void kick_pending_request_queues(void)
+{
+
+ if ( (xlbd_blk_queue != NULL) &&
+ test_bit(QUEUE_FLAG_STOPPED, &xlbd_blk_queue->queue_flags) )
+ {
+ blk_start_queue(xlbd_blk_queue);
+ /* XXXcl call to request_fn should not be needed but
+ * we get stuck without... needs investigating
+ */
+ xlbd_blk_queue->request_fn(xlbd_blk_queue);
+ }
+
+}
+
+
+int blkif_open(struct inode *inode, struct file *filep)
+{
+ struct gendisk *gd = inode->i_bdev->bd_disk;
+ struct xlbd_disk_info *di = (struct xlbd_disk_info *)gd->private_data;
+
+ /* Update of usage count is protected by per-device semaphore. */
+ di->mi->usage++;
+
+ return 0;
+}
+
+
+int blkif_release(struct inode *inode, struct file *filep)
+{
+ struct gendisk *gd = inode->i_bdev->bd_disk;
+ struct xlbd_disk_info *di = (struct xlbd_disk_info *)gd->private_data;
+
+ /*
+ * When usage drops to zero it may allow more VBD updates to occur.
+ * Update of usage count is protected by a per-device semaphore.
+ */
+ if (--di->mi->usage == 0) {
+#if 0
+ update_tq.routine = update_vbds_task;
+ schedule_task(&update_tq);
+#endif
+ }
+
+ return 0;
+}
+
+
+int blkif_ioctl(struct inode *inode, struct file *filep,
+ unsigned command, unsigned long argument)
+{
+ /* struct gendisk *gd = inode->i_bdev->bd_disk; */
+
+ DPRINTK_IOCTL("command: 0x%x, argument: 0x%lx, dev: 0x%04x\n",
+ command, (long)argument, inode->i_rdev);
+
+ switch (command) {
+
+ case HDIO_GETGEO:
+ /* return ENOSYS to use defaults */
+ return -ENOSYS;
+
+ default:
+ printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n",
+ command);
+ return -ENOSYS;
+ }
+
+ return 0;
+}
+
+#if 0
+/* check media change: should probably do something here in some cases :-) */
+int blkif_check(kdev_t dev)
+{
+ DPRINTK("blkif_check\n");
+ return 0;
+}
+
+int blkif_revalidate(kdev_t dev)
+{
+ struct block_device *bd;
+ struct gendisk *gd;
+ xen_block_t *disk;
+ unsigned long capacity;
+ int i, rc = 0;
+
+ if ( (bd = bdget(dev)) == NULL )
+ return -EINVAL;
+
+ /*
+ * Update of partition info, and check of usage count, is protected
+ * by the per-block-device semaphore.
+ */
+ down(&bd->bd_sem);
+
+ if ( ((gd = get_gendisk(dev)) == NULL) ||
+ ((disk = xldev_to_xldisk(dev)) == NULL) ||
+ ((capacity = gd->part[MINOR(dev)].nr_sects) == 0) )
+ {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ if ( disk->usage > 1 )
+ {
+ rc = -EBUSY;
+ goto out;
+ }
+
+ /* Only reread partition table if VBDs aren't mapped to partitions. */
+ if ( !(gd->flags[MINOR(dev) >> gd->minor_shift] & GENHD_FL_VIRT_PARTNS) )
+ {
+ for ( i = gd->max_p - 1; i >= 0; i-- )
+ {
+ invalidate_device(dev+i, 1);
+ gd->part[MINOR(dev+i)].start_sect = 0;
+ gd->part[MINOR(dev+i)].nr_sects = 0;
+ gd->sizes[MINOR(dev+i)] = 0;
+ }
+
+ grok_partitions(gd, MINOR(dev)>>gd->minor_shift, gd->max_p, capacity);
+ }
+
+ out:
+ up(&bd->bd_sem);
+ bdput(bd);
+ return rc;
+}
+#endif
+
+/*
+ * blkif_queue_request
+ *
+ * request block io
+ *
+ * id: for guest use only.
+ * operation: BLKIF_OP_{READ,WRITE,PROBE}
+ * buffer: buffer to read/write into. this should be a
+ * virtual address in the guest os.
+ */
+static int blkif_queue_request(struct request *req)
+{
+ struct xlbd_disk_info *di =
+ (struct xlbd_disk_info *)req->rq_disk->private_data;
+ unsigned long buffer_ma;
+ blkif_request_t *ring_req;
+ struct bio *bio;
+ struct bio_vec *bvec;
+ int idx, s;
+ unsigned long id;
+ unsigned int fsect, lsect;
+
+ if (unlikely(blkif_state != BLKIF_STATE_CONNECTED))
+ return 1;
+
+ /* Fill out a communications ring structure. */
+ ring_req = &blk_ring->ring[MASK_BLKIF_IDX(req_prod)].req;
+ id = GET_ID_FROM_FREELIST();
+ rec_ring[id].id = (unsigned long) req;
+
+ ring_req->id = id;
+ ring_req->operation = rq_data_dir(req) ? BLKIF_OP_WRITE :
+ BLKIF_OP_READ;
+ ring_req->sector_number = (blkif_sector_t)req->sector;
+ ring_req->device = di->xd_device;
+
+ s = 0;
+ ring_req->nr_segments = 0;
+ rq_for_each_bio(bio, req) {
+ bio_for_each_segment(bvec, bio, idx) {
+ buffer_ma = page_to_phys(bvec->bv_page);
+ if (unlikely((buffer_ma & ((1<<9)-1)) != 0))
+ BUG();
+
+ fsect = bvec->bv_offset >> 9;
+ lsect = fsect + (bvec->bv_len >> 9) - 1;
+ if (unlikely(lsect > 7))
+ BUG();
+
+ ring_req->frame_and_sects[ring_req->nr_segments++] =
+ buffer_ma | (fsect << 3) | lsect;
+ s += bvec->bv_len >> 9;
+ }
+ }
+
+ req_prod++;
+
+ /* Keep a private copy so we can reissue requests when recovering. */
+ translate_req_to_pfn( &rec_ring[id], ring_req);
+
+ return 0;
+}
+
+
+/*
+ * do_blkif_request
+ * read a block; request is in a request queue
+ */
+void do_blkif_request(request_queue_t *rq)
+{
+ struct request *req;
+ int queued;
+
+ DPRINTK("Entered do_blkif_request\n");
+
+ queued = 0;
+
+ while ((req = elv_next_request(rq)) != NULL) {
+ if (!blk_fs_request(req)) {
+ end_request(req, 0);
+ continue;
+ }
+
+ if ( BLKIF_RING_FULL )
+ {
+ blk_stop_queue(rq);
+ break;
+ }
+ DPRINTK("do_blkif_request %p: cmd %p, sec %lx, (%u/%li) buffer:%p [%s]\n",
+ req, req->cmd, req->sector, req->current_nr_sectors,
+ req->nr_sectors, req->buffer,
+ rq_data_dir(req) ? "write" : "read");
+ blkdev_dequeue_request(req);
+ if (blkif_queue_request(req)) {
+ blk_stop_queue(rq);
+ break;
+ }
+ queued++;
+ }
+
+ if (queued != 0)
+ flush_requests();
+}
+
+
+static irqreturn_t blkif_int(int irq, void *dev_id, struct pt_regs *ptregs)
+{
+ struct request *req;
+ blkif_response_t *bret;
+ BLKIF_RING_IDX i, rp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&blkif_io_lock, flags);
+
+ if ( unlikely(blkif_state == BLKIF_STATE_CLOSED) ||
+ unlikely(recovery) )
+ {
+ spin_unlock_irqrestore(&blkif_io_lock, flags);
+ return IRQ_HANDLED;
+ }
+
+ rp = blk_ring->resp_prod;
+ rmb(); /* Ensure we see queued responses up to 'rp'. */
+
+ for ( i = resp_cons; i != rp; i++ )
+ {
+ unsigned long id;
+ bret = &blk_ring->ring[MASK_BLKIF_IDX(i)].resp;
+
+ id = bret->id;
+ req = (struct request *)rec_ring[id].id;
+
+ blkif_completion( &rec_ring[id] );
+
+ ADD_ID_TO_FREELIST(id); /* overwrites req */
+
+ switch ( bret->operation )
+ {
+ case BLKIF_OP_READ:
+ case BLKIF_OP_WRITE:
+ if ( unlikely(bret->status != BLKIF_RSP_OKAY) )
+ DPRINTK("Bad return from blkdev data request: %x\n",
+ bret->status);
+
+ if ( unlikely(end_that_request_first
+ (req,
+ (bret->status == BLKIF_RSP_OKAY),
+ req->hard_nr_sectors)) )
+ BUG();
+ end_that_request_last(req);
+
+ break;
+ case BLKIF_OP_PROBE:
+ memcpy(&blkif_control_rsp, bret, sizeof(*bret));
+ blkif_control_rsp_valid = 1;
+ break;
+ default:
+ BUG();
+ }
+ }
+
+ resp_cons = i;
+
+ kick_pending_request_queues();
+
+ spin_unlock_irqrestore(&blkif_io_lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+#else
+/************************** KERNEL VERSION 2.4 **************************/
+
+static kdev_t sg_dev;
+static int sg_operation = -1;
+static unsigned long sg_next_sect;
+
+/*
+ * Request queues with outstanding work, but ring is currently full.
+ * We need no special lock here, as we always access this with the
+ * blkif_io_lock held. We only need a small maximum list.
+ */
+#define MAX_PENDING 8
+static request_queue_t *pending_queues[MAX_PENDING];
+static int nr_pending;
+
+
+#define DISABLE_SCATTERGATHER() (sg_operation = -1)
+
+#define blkif_io_lock io_request_lock
+
+/*
+ * blkif_update_int/update-vbds_task - handle VBD update events.
+ * Schedule a task for keventd to run, which will update the VBDs and perform
+ * the corresponding updates to our view of VBD state.
+ */
+
+#if 0
+static struct tq_struct update_tq;
+static void update_vbds_task(void *unused)
+{
+ xlvbd_update_vbds();
+}
+#endif
+
+static void kick_pending_request_queues(void)
+{
+ /* We kick pending request queues if the ring is reasonably empty. */
+ if ( (nr_pending != 0) &&
+ ((req_prod - resp_cons) < (BLKIF_RING_SIZE >> 1)) )
+ {
+ /* Attempt to drain the queue, but bail if the ring becomes full. */
+ while ( (nr_pending != 0) && !BLKIF_RING_FULL )
+ do_blkif_request(pending_queues[--nr_pending]);
+ }
+}
+
+int blkif_open(struct inode *inode, struct file *filep)
+{
+ short xldev = inode->i_rdev;
+ struct gendisk *gd = get_gendisk(xldev);
+ xl_disk_t *disk = xldev_to_xldisk(inode->i_rdev);
+ short minor = MINOR(xldev);
+
+ if ( gd->part[minor].nr_sects == 0 )
+ {
+ /*
+ * Device either doesn't exist, or has zero capacity; we use a few
+ * cheesy heuristics to return the relevant error code
+ */
+ if ( (gd->sizes[minor >> gd->minor_shift] != 0) ||
+ ((minor & (gd->max_p - 1)) != 0) )
+ {
+ /*
+ * We have a real device, but no such partition, or we just have a
+ * partition number so guess this is the problem.
+ */
+ return -ENXIO; /* no such device or address */
+ }
+ else if ( gd->flags[minor >> gd->minor_shift] & GENHD_FL_REMOVABLE )
+ {
+ /* This is a removable device => assume that media is missing. */
+ return -ENOMEDIUM; /* media not present (this is a guess) */
+ }
+ else
+ {
+ /* Just go for the general 'no such device' error. */
+ return -ENODEV; /* no such device */
+ }
+ }
+
+ /* Update of usage count is protected by per-device semaphore. */
+ disk->usage++;
+
+ return 0;
+}
+
+
+int blkif_release(struct inode *inode, struct file *filep)
+{
+ xl_disk_t *disk = xldev_to_xldisk(inode->i_rdev);
+
+ /*
+ * When usage drops to zero it may allow more VBD updates to occur.
+ * Update of usage count is protected by a per-device semaphore.
+ */
+ if ( --disk->usage == 0 )
+ {
+#if 0
+ update_tq.routine = update_vbds_task;
+ schedule_task(&update_tq);
+#endif
+ }
+
+ return 0;
+}
+
+
+int blkif_ioctl(struct inode *inode, struct file *filep,
+ unsigned command, unsigned long argument)
+{
+ kdev_t dev = inode->i_rdev;
+ struct hd_geometry *geo = (struct hd_geometry *)argument;
+ struct gendisk *gd;
+ struct hd_struct *part;
+ int i;
+
+ /* NB. No need to check permissions. That is done for us. */
+
+ DPRINTK_IOCTL("command: 0x%x, argument: 0x%lx, dev: 0x%04x\n",
+ command, (long) argument, dev);
+
+ gd = get_gendisk(dev);
+ part = &gd->part[MINOR(dev)];
+
+ switch ( command )
+ {
+ case BLKGETSIZE:
+ DPRINTK_IOCTL(" BLKGETSIZE: %x %lx\n", BLKGETSIZE, part->nr_sects);
+ return put_user(part->nr_sects, (unsigned long *) argument);
+
+ case BLKGETSIZE64:
+ DPRINTK_IOCTL(" BLKGETSIZE64: %x %llx\n", BLKGETSIZE64,
+ (u64)part->nr_sects * 512);
+ return put_user((u64)part->nr_sects * 512, (u64 *) argument);
+
+ case BLKRRPART: /* re-read partition table */
+ DPRINTK_IOCTL(" BLKRRPART: %x\n", BLKRRPART);
+ return blkif_revalidate(dev);
+
+ case BLKSSZGET:
+ return hardsect_size[MAJOR(dev)][MINOR(dev)];
+
+ case BLKBSZGET: /* get block size */
+ DPRINTK_IOCTL(" BLKBSZGET: %x\n", BLKBSZGET);
+ break;
+
+ case BLKBSZSET: /* set block size */
+ DPRINTK_IOCTL(" BLKBSZSET: %x\n", BLKBSZSET);
+ break;
+
+ case BLKRASET: /* set read-ahead */
+ DPRINTK_IOCTL(" BLKRASET: %x\n", BLKRASET);
+ break;
+
+ case BLKRAGET: /* get read-ahead */
+ DPRINTK_IOCTL(" BLKRAFET: %x\n", BLKRAGET);
+ break;
+
+ case HDIO_GETGEO:
+ /* note: these values are complete garbage */
+ DPRINTK_IOCTL(" HDIO_GETGEO: %x\n", HDIO_GETGEO);
+ if (!argument) return -EINVAL;
+ if (put_user(0x00, (unsigned long *) &geo->start)) return -EFAULT;
+ if (put_user(0xff, (byte *)&geo->heads)) return -EFAULT;
+ if (put_user(0x3f, (byte *)&geo->sectors)) return -EFAULT;
+ if (put_user(0x106, (unsigned short *)&geo->cylinders)) return -EFAULT;
+ return 0;
+
+ case HDIO_GETGEO_BIG:
+ /* note: these values are complete garbage */
+ DPRINTK_IOCTL(" HDIO_GETGEO_BIG: %x\n", HDIO_GETGEO_BIG);
+ if (!argument) return -EINVAL;
+ if (put_user(0x00, (unsigned long *) &geo->start)) return -EFAULT;
+ if (put_user(0xff, (byte *)&geo->heads)) return -EFAULT;
+ if (put_user(0x3f, (byte *)&geo->sectors)) return -EFAULT;
+ if (put_user(0x106, (unsigned int *) &geo->cylinders)) return -EFAULT;
+ return 0;
+
+ case CDROMMULTISESSION:
+ DPRINTK("FIXME: support multisession CDs later\n");
+ for ( i = 0; i < sizeof(struct cdrom_multisession); i++ )
+ if ( put_user(0, (byte *)(argument + i)) ) return -EFAULT;
+ return 0;
+
+ case SCSI_IOCTL_GET_BUS_NUMBER:
+ DPRINTK("FIXME: SCSI_IOCTL_GET_BUS_NUMBER ioctl in XL blkif");
+ return -ENOSYS;
+
+ default:
+ printk(KERN_ALERT "ioctl %08x not supported by XL blkif\n", command);
+ return -ENOSYS;
+ }
+
+ return 0;
+}
+
+
+
+/* check media change: should probably do something here in some cases :-) */
+int blkif_check(kdev_t dev)
+{
+ DPRINTK("blkif_check\n");
+ return 0;
+}
+
+int blkif_revalidate(kdev_t dev)
+{
+ struct block_device *bd;
+ struct gendisk *gd;
+ xl_disk_t *disk;
+ unsigned long capacity;
+ int i, rc = 0;
+
+ if ( (bd = bdget(dev)) == NULL )
+ return -EINVAL;
+
+ /*
+ * Update of partition info, and check of usage count, is protected
+ * by the per-block-device semaphore.
+ */
+ down(&bd->bd_sem);
+
+ if ( ((gd = get_gendisk(dev)) == NULL) ||
+ ((disk = xldev_to_xldisk(dev)) == NULL) ||
+ ((capacity = gd->part[MINOR(dev)].nr_sects) == 0) )
+ {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ if ( disk->usage > 1 )
+ {
+ rc = -EBUSY;
+ goto out;
+ }
+
+ /* Only reread partition table if VBDs aren't mapped to partitions. */
+ if ( !(gd->flags[MINOR(dev) >> gd->minor_shift] & GENHD_FL_VIRT_PARTNS) )
+ {
+ for ( i = gd->max_p - 1; i >= 0; i-- )
+ {
+ invalidate_device(dev+i, 1);
+ gd->part[MINOR(dev+i)].start_sect = 0;
+ gd->part[MINOR(dev+i)].nr_sects = 0;
+ gd->sizes[MINOR(dev+i)] = 0;
+ }
+
+ grok_partitions(gd, MINOR(dev)>>gd->minor_shift, gd->max_p, capacity);
+ }
+
+ out:
+ up(&bd->bd_sem);
+ bdput(bd);
+ return rc;
+}
+
+
+
+
+/*
+ * blkif_queue_request
+ *
+ * request block io
+ *
+ * id: for guest use only.
+ * operation: BLKIF_OP_{READ,WRITE,PROBE}
+ * buffer: buffer to read/write into. this should be a
+ * virtual address in the guest os.
+ */
+static int blkif_queue_request(unsigned long id,
+ int operation,
+ char * buffer,
+ unsigned long sector_number,
+ unsigned short nr_sectors,
+ kdev_t device)
+{
+ unsigned long buffer_ma = phys_to_machine(virt_to_phys(buffer));
+ unsigned long xid;
+ struct gendisk *gd;
+ blkif_request_t *req;
+ struct buffer_head *bh;
+ unsigned int fsect, lsect;
+
+ fsect = (buffer_ma & ~PAGE_MASK) >> 9;
+ lsect = fsect + nr_sectors - 1;
+
+ /* Buffer must be sector-aligned. Extent mustn't cross a page boundary. */
+ if ( unlikely((buffer_ma & ((1<<9)-1)) != 0) )
+ BUG();
+ if ( lsect > 7 )
+ BUG();
+
+ buffer_ma &= PAGE_MASK;
+
+ if ( unlikely(blkif_state != BLKIF_STATE_CONNECTED) )
+ return 1;
+
+ switch ( operation )
+ {
+
+ case BLKIF_OP_READ:
+ case BLKIF_OP_WRITE:
+ gd = get_gendisk(device);
+
+ /*
+ * Update the sector_number we'll pass down as appropriate; note that
+ * we could sanity check that resulting sector will be in this
+ * partition, but this will happen in driver backend anyhow.
+ */
+ sector_number += gd->part[MINOR(device)].start_sect;
+
+ /*
+ * If this unit doesn't consist of virtual partitions then we clear
+ * the partn bits from the device number.
+ */
+ if ( !(gd->flags[MINOR(device)>>gd->minor_shift] &
+ GENHD_FL_VIRT_PARTNS) )
+ device &= ~(gd->max_p - 1);
+
+ if ( (sg_operation == operation) &&
+ (sg_dev == device) &&
+ (sg_next_sect == sector_number) )
+ {
+
+ req = &blk_ring->ring[MASK_BLKIF_IDX(req_prod-1)].req;
+ bh = (struct buffer_head *)id;
+
+ bh->b_reqnext = (struct buffer_head *)rec_ring[req->id].id;
+
+
+ rec_ring[req->id].id = id;
+
+ req->frame_and_sects[req->nr_segments] =
+ buffer_ma | (fsect<<3) | lsect;
+ if ( ++req->nr_segments < BLKIF_MAX_SEGMENTS_PER_REQUEST )
+ sg_next_sect += nr_sectors;
+ else
+ DISABLE_SCATTERGATHER();
+
+ /* Update the copy of the request in the recovery ring. */
+ translate_req_to_pfn(&rec_ring[req->id], req );
+
+ return 0;
+ }
+ else if ( BLKIF_RING_FULL )
+ {
+ return 1;
+ }
+ else
+ {
+ sg_operation = operation;
+ sg_dev = device;
+ sg_next_sect = sector_number + nr_sectors;
+ }
+ break;
+
+ default:
+ panic("unknown op %d\n", operation);
+ }
+
+ /* Fill out a communications ring structure. */
+ req = &blk_ring->ring[MASK_BLKIF_IDX(req_prod)].req;
+
+ xid = GET_ID_FROM_FREELIST();
+ rec_ring[xid].id = id;
+
+ req->id = xid;
+ req->operation = operation;
+ req->sector_number = (blkif_sector_t)sector_number;
+ req->device = device;
+ req->nr_segments = 1;
+ req->frame_and_sects[0] = buffer_ma | (fsect<<3) | lsect;
+
+ req_prod++;
+
+ /* Keep a private copy so we can reissue requests when recovering. */
+ translate_req_to_pfn(&rec_ring[xid], req );
+
+
+
+ return 0;
+}
+
+
+/*
+ * do_blkif_request
+ * read a block; request is in a request queue
+ */
+void do_blkif_request(request_queue_t *rq)
+{
+ struct request *req;
+ struct buffer_head *bh, *next_bh;
+ int rw, nsect, full, queued = 0;
+
+ DPRINTK("Entered do_blkif_request\n");
+
+ while ( !rq->plugged && !list_empty(&rq->queue_head))
+ {
+ if ( (req = blkdev_entry_next_request(&rq->queue_head)) == NULL )
+ goto out;
+
+ DPRINTK("do_blkif_request %p: cmd %i, sec %lx, (%li/%li) bh:%p\n",
+ req, req->cmd, req->sector,
+ req->current_nr_sectors, req->nr_sectors, req->bh);
+
+ rw = req->cmd;
+ if ( rw == READA )
+ rw = READ;
+ if ( unlikely((rw != READ) && (rw != WRITE)) )
+ panic("XenoLinux Virtual Block Device: bad cmd: %d\n", rw);
+
+ req->errors = 0;
+
+ bh = req->bh;
+ while ( bh != NULL )
+ {
+ next_bh = bh->b_reqnext;
+ bh->b_reqnext = NULL;
+
+ full = blkif_queue_request(
+ (unsigned long)bh,
+ (rw == READ) ? BLKIF_OP_READ : BLKIF_OP_WRITE,
+ bh->b_data, bh->b_rsector, bh->b_size>>9, bh->b_rdev);
+
+ if ( full )
+ {
+ bh->b_reqnext = next_bh;
+ pending_queues[nr_pending++] = rq;
+ if ( unlikely(nr_pending >= MAX_PENDING) )
+ BUG();
+ goto out;
+ }
+
+ queued++;
+
+ /* Dequeue the buffer head from the request. */
+ nsect = bh->b_size >> 9;
+ bh = req->bh = next_bh;
+
+ if ( bh != NULL )
+ {
+ /* There's another buffer head to do. Update the request. */
+ req->hard_sector += nsect;
+ req->hard_nr_sectors -= nsect;
+ req->sector = req->hard_sector;
+ req->nr_sectors = req->hard_nr_sectors;
+ req->current_nr_sectors = bh->b_size >> 9;
+ req->buffer = bh->b_data;
+ }
+ else
+ {
+ /* That was the last buffer head. Finalise the request. */
+ if ( unlikely(end_that_request_first(req, 1, "XenBlk")) )
+ BUG();
+ blkdev_dequeue_request(req);
+ end_that_request_last(req);
+ }
+ }
+ }
+
+ out:
+ if ( queued != 0 )
+ flush_requests();
+}
+
+
+static void blkif_int(int irq, void *dev_id, struct pt_regs *ptregs)
+{
+ BLKIF_RING_IDX i, rp;
+ unsigned long flags;
+ struct buffer_head *bh, *next_bh;
+
+ spin_lock_irqsave(&io_request_lock, flags);
+
+ if ( unlikely(blkif_state == BLKIF_STATE_CLOSED || recovery) )
+ {
+ spin_unlock_irqrestore(&io_request_lock, flags);
+ return;
+ }
+
+ rp = blk_ring->resp_prod;
+ rmb(); /* Ensure we see queued responses up to 'rp'. */
+
+ for ( i = resp_cons; i != rp; i++ )
+ {
+ unsigned long id;
+ blkif_response_t *bret = &blk_ring->ring[MASK_BLKIF_IDX(i)].resp;
+
+ id = bret->id;
+ bh = (struct buffer_head *)rec_ring[id].id;
+
+ blkif_completion( &rec_ring[id] );
+
+ ADD_ID_TO_FREELIST(id);
+
+ switch ( bret->operation )
+ {
+ case BLKIF_OP_READ:
+ case BLKIF_OP_WRITE:
+ if ( unlikely(bret->status != BLKIF_RSP_OKAY) )
+ DPRINTK("Bad return from blkdev data request: %lx\n",
+ bret->status);
+ for ( ; bh != NULL; bh = next_bh )
+ {
+ next_bh = bh->b_reqnext;
+ bh->b_reqnext = NULL;
+ bh->b_end_io(bh, bret->status == BLKIF_RSP_OKAY);
+ }
+
+ break;
+ case BLKIF_OP_PROBE:
+ memcpy(&blkif_control_rsp, bret, sizeof(*bret));
+ blkif_control_rsp_valid = 1;
+ break;
+ default:
+ BUG();
+ }
+ }
+
+ resp_cons = i;
+
+ kick_pending_request_queues();
+
+ spin_unlock_irqrestore(&io_request_lock, flags);
+}
+
+#endif
+
+/***************************** COMMON CODE *******************************/
+
+
+static inline void translate_req_to_pfn(blkif_request_t *xreq,
+ blkif_request_t *req)
+{
+ int i;
+
+ xreq->operation = req->operation;
+ xreq->nr_segments = req->nr_segments;
+ xreq->device = req->device;
+ /* preserve id */
+ xreq->sector_number = req->sector_number;
+
+ for ( i = 0; i < req->nr_segments; i++ )
+ xreq->frame_and_sects[i] = machine_to_phys(req->frame_and_sects[i]);
+}
+
+static inline void translate_req_to_mfn(blkif_request_t *xreq,
+ blkif_request_t *req)
+{
+ int i;
+
+ xreq->operation = req->operation;
+ xreq->nr_segments = req->nr_segments;
+ xreq->device = req->device;
+ xreq->id = req->id; /* copy id (unlike above) */
+ xreq->sector_number = req->sector_number;
+
+ for ( i = 0; i < req->nr_segments; i++ )
+ xreq->frame_and_sects[i] = phys_to_machine(req->frame_and_sects[i]);
+}
+
+
+
+static inline void flush_requests(void)
+{
+ DISABLE_SCATTERGATHER();
+ wmb(); /* Ensure that the frontend can see the requests. */
+ blk_ring->req_prod = req_prod;
+ notify_via_evtchn(blkif_evtchn);
+}
+
+
+void blkif_control_send(blkif_request_t *req, blkif_response_t *rsp)
+{
+ unsigned long flags, id;
+
+ retry:
+ while ( (req_prod - resp_cons) == BLKIF_RING_SIZE )
+ {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(1);
+ }
+
+ spin_lock_irqsave(&blkif_io_lock, flags);
+ if ( (req_prod - resp_cons) == BLKIF_RING_SIZE )
+ {
+ spin_unlock_irqrestore(&blkif_io_lock, flags);
+ goto retry;
+ }
+
+ DISABLE_SCATTERGATHER();
+ blk_ring->ring[MASK_BLKIF_IDX(req_prod)].req = *req;
+
+ id = GET_ID_FROM_FREELIST();
+ blk_ring->ring[MASK_BLKIF_IDX(req_prod)].req.id = id;
+ rec_ring[id].id = (unsigned long) req;
+
+ translate_req_to_pfn( &rec_ring[id], req );
+
+ req_prod++;
+ flush_requests();
+
+ spin_unlock_irqrestore(&blkif_io_lock, flags);
+
+ while ( !blkif_control_rsp_valid )
+ {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(1);
+ }
+
+ memcpy(rsp, &blkif_control_rsp, sizeof(*rsp));
+ blkif_control_rsp_valid = 0;
+}
+
+
+static void blkif_status_change(blkif_fe_interface_status_changed_t *status)
+{
+ ctrl_msg_t cmsg;
+ blkif_fe_interface_connect_t up;
+ long rc;
+
+ if ( status->handle != 0 )
+ {
+ printk(KERN_WARNING "Status change on unsupported blkif %d\n",
+ status->handle);
+ return;
+ }
+
+ switch ( status->status )
+ {
+ case BLKIF_INTERFACE_STATUS_DESTROYED:
+ printk(KERN_WARNING "Unexpected blkif-DESTROYED message in state %d\n",
+ blkif_state);
+ break;
+
+ case BLKIF_INTERFACE_STATUS_DISCONNECTED:
+ if ( blkif_state != BLKIF_STATE_CLOSED )
+ {
+ printk(KERN_WARNING "Unexpected blkif-DISCONNECTED message"
+ " in state %d\n", blkif_state);
+
+ printk(KERN_INFO "VBD driver recovery in progress\n");
+
+ /* Prevent new requests being issued until we fix things up. */
+ spin_lock_irq(&blkif_io_lock);
+ recovery = 1;
+ blkif_state = BLKIF_STATE_DISCONNECTED;
+ spin_unlock_irq(&blkif_io_lock);
+
+ /* Free resources associated with old device channel. */
+ free_page((unsigned long)blk_ring);
+ free_irq(blkif_irq, NULL);
+ unbind_evtchn_from_irq(blkif_evtchn);
+ }
+
+ /* Move from CLOSED to DISCONNECTED state. */
+ blk_ring = (blkif_ring_t *)__get_free_page(GFP_KERNEL);
+ blk_ring->req_prod = blk_ring->resp_prod = resp_cons = req_prod = 0;
+ blkif_state = BLKIF_STATE_DISCONNECTED;
+
+ /* Construct an interface-CONNECT message for the domain controller. */
+ cmsg.type = CMSG_BLKIF_FE;
+ cmsg.subtype = CMSG_BLKIF_FE_INTERFACE_CONNECT;
+ cmsg.length = sizeof(blkif_fe_interface_connect_t);
+ up.handle = 0;
+ up.shmem_frame = virt_to_machine(blk_ring) >> PAGE_SHIFT;
+ memcpy(cmsg.msg, &up, sizeof(up));
+
+ /* Tell the controller to bring up the interface. */
+ ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
+ break;
+
+ case BLKIF_INTERFACE_STATUS_CONNECTED:
+ if ( blkif_state == BLKIF_STATE_CLOSED )
+ {
+ printk(KERN_WARNING "Unexpected blkif-CONNECTED message"
+ " in state %d\n", blkif_state);
+ break;
+ }
+
+ blkif_evtchn = status->evtchn;
+ blkif_irq = bind_evtchn_to_irq(blkif_evtchn);
+
+ if ( (rc = request_irq(blkif_irq, blkif_int,
+ SA_SAMPLE_RANDOM, "blkif", NULL)) )
+ printk(KERN_ALERT"blkfront request_irq failed (%ld)\n",rc);
+
+ if ( recovery )
+ {
+ int i;
+
+ /* Hmm, requests might be re-ordered when we re-issue them.
+ This will need to be fixed once we have barriers */
+
+ /* Stage 1 : Find active and move to safety. */
+ for ( i = 0; i < BLKIF_RING_SIZE; i++ )
+ {
+ if ( rec_ring[i].id >= PAGE_OFFSET )
+ {
+ translate_req_to_mfn(
+ &blk_ring->ring[req_prod].req, &rec_ring[i]);
+ req_prod++;
+ }
+ }
+
+ printk(KERN_ALERT"blkfront: recovered %d descriptors\n",req_prod);
+
+ /* Stage 2 : Set up shadow list. */
+ for ( i = 0; i < req_prod; i++ )
+ {
+ rec_ring[i].id = blk_ring->ring[i].req.id;
+ blk_ring->ring[i].req.id = i;
+ translate_req_to_pfn(&rec_ring[i], &blk_ring->ring[i].req);
+ }
+
+ /* Stage 3 : Set up free list. */
+ for ( ; i < BLKIF_RING_SIZE; i++ )
+ rec_ring[i].id = i+1;
+ rec_ring_free = req_prod;
+ rec_ring[BLKIF_RING_SIZE-1].id = 0x0fffffff;
+
+ /* blk_ring->req_prod will be set when we flush_requests().*/
+ wmb();
+
+ /* Switch off recovery mode, using a memory barrier to ensure that
+ * it's seen before we flush requests - we don't want to miss any
+ * interrupts. */
+ recovery = 0;
+ wmb();
+
++ blkif_state = BLKIF_STATE_CONNECTED;
++
+ /* Kicks things back into life. */
+ flush_requests();
+ }
+ else
+ {
++ /* transtion to connected in case we need to do a
++ a partion probe on a whole disk */
++ blkif_state = BLKIF_STATE_CONNECTED;
++
+ /* Probe for discs that are attached to the interface. */
+ xlvbd_init();
+ }
+
+ /* Kick pending requests. */
+ spin_lock_irq(&blkif_io_lock);
+ kick_pending_request_queues();
+ spin_unlock_irq(&blkif_io_lock);
+
+ break;
+
+ default:
+ printk(KERN_WARNING "Status change to unknown value %d\n",
+ status->status);
+ break;
+ }
+}
+
+
+static void blkif_ctrlif_rx(ctrl_msg_t *msg, unsigned long id)
+{
+ switch ( msg->subtype )
+ {
+ case CMSG_BLKIF_FE_INTERFACE_STATUS_CHANGED:
+ if ( msg->length != sizeof(blkif_fe_interface_status_changed_t) )
+ goto parse_error;
+ blkif_status_change((blkif_fe_interface_status_changed_t *)
+ &msg->msg[0]);
+ break;
+#if 0
+ case CMSG_BLKIF_FE_VBD_STATUS_CHANGED:
+ update_tq.routine = update_vbds_task;
+ schedule_task(&update_tq);
+ break;
+#endif
+ default:
+ goto parse_error;
+ }
+
+ ctrl_if_send_response(msg);
+ return;
+
+ parse_error:
+ msg->length = 0;
+ ctrl_if_send_response(msg);
+}
+
+
+int __init xlblk_init(void)
+{
+ ctrl_msg_t cmsg;
+ blkif_fe_driver_status_changed_t st;
+ int i;
+
+ if ( (start_info.flags & SIF_INITDOMAIN)
+ || (start_info.flags & SIF_BLK_BE_DOMAIN) )
+ return 0;
+
+ printk(KERN_INFO "Initialising Xen virtual block device\n");
+
+ rec_ring_free = 0;
+ for (i=0; i<BLKIF_RING_SIZE; i++)
+ {
+ rec_ring[i].id = i+1;
+ }
+ rec_ring[BLKIF_RING_SIZE-1].id = 0x0fffffff;
+
+ (void)ctrl_if_register_receiver(CMSG_BLKIF_FE, blkif_ctrlif_rx,
+ CALLBACK_IN_BLOCKING_CONTEXT);
+
+ /* Send a driver-UP notification to the domain controller. */
+ cmsg.type = CMSG_BLKIF_FE;
+ cmsg.subtype = CMSG_BLKIF_FE_DRIVER_STATUS_CHANGED;
+ cmsg.length = sizeof(blkif_fe_driver_status_changed_t);
+ st.status = BLKIF_DRIVER_STATUS_UP;
+ memcpy(cmsg.msg, &st, sizeof(st));
+ ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
+
+ /*
+ * We should read 'nr_interfaces' from response message and wait
+ * for notifications before proceeding. For now we assume that we
+ * will be notified of exactly one interface.
+ */
+ for ( i=0; (blkif_state != BLKIF_STATE_CONNECTED) && (i < 10*HZ); i++ )
+ {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(1);
+ }
+
+ if (blkif_state != BLKIF_STATE_CONNECTED)
+ printk(KERN_INFO "Timeout connecting block device driver!\n");
+
+ return 0;
+}
+
+void blkdev_suspend(void)
+{
+}
+
+void blkdev_resume(void)
+{
+ ctrl_msg_t cmsg;
+ blkif_fe_driver_status_changed_t st;
+
+ /* Send a driver-UP notification to the domain controller. */
+ cmsg.type = CMSG_BLKIF_FE;
+ cmsg.subtype = CMSG_BLKIF_FE_DRIVER_STATUS_CHANGED;
+ cmsg.length = sizeof(blkif_fe_driver_status_changed_t);
+ st.status = BLKIF_DRIVER_STATUS_UP;
+ memcpy(cmsg.msg, &st, sizeof(st));
+ ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
+}
+
+/* XXXXX THIS IS A TEMPORARY FUNCTION UNTIL WE GET GRANT TABLES */
+
+void blkif_completion(blkif_request_t *req)
+{
+ int i;
+
+ switch ( req->operation )
+ {
+ case BLKIF_OP_READ:
+ for ( i = 0; i < req->nr_segments; i++ )
+ {
+ unsigned long pfn = req->frame_and_sects[i] >> PAGE_SHIFT;
+ unsigned long mfn = phys_to_machine_mapping[pfn];
+ queue_machphys_update(mfn, pfn);
+ }
+ break;
+ }
+
+}
+
+
projects / xen.git / commitdiff