From: Arnd Bergmann <arnd@arndb•de>
To: linuxppc-dev@ozlabs•org
Cc: Geert.Uytterhoeven@sonycom•com, linux-kernel@vger•kernel.org
Subject: Re: [patch 5/7] ps3: Disk Storage Driver
Date: Fri, 25 May 2007 18:26:25 +0200 [thread overview]
Message-ID: <200705251826.25572.arnd@arndb.de> (raw)
In-Reply-To: <20070525083632.575306000@sonycom.com>
On Friday 25 May 2007, Geert.Uytterhoeven@sonycom•com wrote:
> +static void ps3disk_scatter_gather(struct ps3_storage_device *dev,
> + struct request *req, int gather)
> +{
> + unsigned int sectors = 0, offset = 0;
> + struct bio *bio;
> + sector_t sector;
> + struct bio_vec *bvec;
> + unsigned int i = 0, j;
> + size_t size;
> + void *buf;
> +
> + rq_for_each_bio(bio, req) {
> + sector = bio->bi_sector;
> + dev_dbg(&dev->sbd.core,
> + "%s:%u: bio %u: %u segs %u sectors from %lu\n",
> + __func__, __LINE__, i, bio_segments(bio),
> + bio_sectors(bio), sector);
> + bio_for_each_segment(bvec, bio, j) {
> + size = bio_cur_sectors(bio)*KERNEL_SECTOR_SIZE;
> + buf = __bio_kmap_atomic(bio, j, KM_USER0);
> + if (gather)
> + memcpy(dev->bounce_buf+offset, buf, size);
> + else
> + memcpy(buf, dev->bounce_buf+offset, size);
> + offset += size;
> + __bio_kunmap_atomic(bio, KM_USER0);
> + }
> + sectors += bio_sectors(bio);
> + i++;
> + }
> +}
So the hypervison uses guest-real addresses here? I would have expected
it to use the kernel page tables, which lets you use vmap() to do
scatter-gather.
> +static int ps3disk_thread(void *data)
> +{
> + struct ps3_storage_device *dev = data;
> + struct ps3disk_private *priv = ps3disk_priv(dev);
> + request_queue_t *q = priv->queue;
> + struct request *req;
> +
> + dev_dbg(&dev->sbd.core, "%s thread init\n", __func__);
> +
> + current->flags |= PF_NOFREEZE;
> +
> + while (!kthread_should_stop()) {
> + spin_lock_irq(&priv->lock);
> + set_current_state(TASK_INTERRUPTIBLE);
> + req = elv_next_request(q);
> + if (!req) {
> + spin_unlock_irq(&priv->lock);
> + schedule();
> + continue;
> + }
> + if (!blk_fs_request(req)) {
> + blk_dump_rq_flags(req, DEVICE_NAME " bad request");
> + end_request(req, 0);
> + spin_unlock_irq(&priv->lock);
> + continue;
> + }
> + spin_unlock_irq(&priv->lock);
> + ps3disk_handle_request_sg(dev, req);
> + }
> +
> + dev_dbg(&dev->sbd.core, "%s thread exit\n", __func__);
> + return 0;
> +}
I don't really understand what the kthread is needed for. You probably
thought about multiple options and ended up with this, but having
a comment in front of it might be helpful.
Arnd <><
next prev parent reply other threads:[~2007-05-25 16:27 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-25 8:36 [patch 0/7] RFC: PS3 Storage Drivers Geert.Uytterhoeven
2007-05-25 8:36 ` [patch 1/7] ps3: Preallocate bootmem memory for the PS3 FLASH ROM storage driver Geert.Uytterhoeven
2007-05-25 22:35 ` Benjamin Herrenschmidt
2007-05-26 8:51 ` Geert Uytterhoeven
2007-05-26 22:17 ` Benjamin Herrenschmidt
2007-05-27 18:24 ` Arnd Bergmann
2007-05-25 8:36 ` [patch 2/7] ps3: Extract ps3_repository_find_bus() Geert.Uytterhoeven
2007-05-25 8:36 ` [patch 3/7] ps3: Storage Driver Core Geert.Uytterhoeven
2007-05-25 8:36 ` [patch 4/7] ps3: Storage Driver Probing Geert.Uytterhoeven
2007-05-25 16:18 ` Arnd Bergmann
2007-05-25 17:09 ` Geoff Levand
2007-05-25 19:48 ` Geert Uytterhoeven
2007-05-25 22:54 ` Benjamin Herrenschmidt
2007-05-25 22:47 ` Benjamin Herrenschmidt
2007-05-26 8:56 ` Geert Uytterhoeven
2007-05-25 8:36 ` [patch 5/7] ps3: Disk Storage Driver Geert.Uytterhoeven
2007-05-25 11:45 ` Olaf Hering
2007-05-25 19:43 ` Geert Uytterhoeven
2007-05-25 20:47 ` Olaf Hering
2007-05-25 16:26 ` Arnd Bergmann [this message]
2007-05-25 19:40 ` Geert Uytterhoeven
2007-05-25 20:43 ` Arnd Bergmann
2007-05-25 21:22 ` Geert Uytterhoeven
2007-05-25 22:45 ` Arnd Bergmann
2007-05-25 22:53 ` Benjamin Herrenschmidt
2007-05-25 22:48 ` Benjamin Herrenschmidt
2007-05-25 8:36 ` [patch 6/7] ps3: ROM " Geert.Uytterhoeven
2007-05-25 11:24 ` Olaf Hering
2007-05-25 22:45 ` Benjamin Herrenschmidt
2007-05-26 8:52 ` Geert Uytterhoeven
2007-05-26 22:18 ` Benjamin Herrenschmidt
2007-05-29 9:55 ` Christoph Hellwig
2007-05-25 16:50 ` Arnd Bergmann
2007-05-25 19:36 ` Geert Uytterhoeven
2007-05-25 21:04 ` Arnd Bergmann
2007-05-29 10:51 ` Christoph Hellwig
2007-05-29 10:49 ` Christoph Hellwig
2007-05-29 11:11 ` Geert Uytterhoeven
2007-05-29 11:31 ` Benjamin Herrenschmidt
2007-05-30 10:13 ` Christoph Hellwig
2007-05-30 11:45 ` Benjamin Herrenschmidt
2007-05-30 17:18 ` Geoff Levand
2007-05-29 16:21 ` Geert Uytterhoeven
2007-05-30 10:01 ` Christoph Hellwig
2007-05-25 8:36 ` [patch 7/7] ps3: FLASH " Geert.Uytterhoeven
2007-05-29 9:53 ` Christoph Hellwig
2007-05-29 9:57 ` Geert Uytterhoeven
2007-05-29 10:51 ` Christoph Hellwig
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