aoe: jumbo frame support 1 of 2

Add support for jumbo ethernet frames.
(This patch depends on patch 7 to follow.)

Signed-off-by: "Ed L. Cashin" <ecashin@coraid.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 72 insertions, 17 deletions

diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h
index fa2d804b2665..1cec19986c40 100644
--- a/drivers/block/aoe/aoe.h
+++ b/drivers/block/aoe/aoe.h
@@ -65,7 +65,7 @@ struct aoe_atahdr {
 struct aoe_cfghdr {
         __be16 bufcnt;
         __be16 fwver;
-        unsigned char res;
+        unsigned char scnt;
         unsigned char aoeccmd;
         unsigned char cslen[2];
 };
@@ -78,12 +78,13 @@ enum {
         DEVFL_GDALLOC = (1<<4), /* need to alloc gendisk */
         DEVFL_PAUSE = (1<<5),
         DEVFL_NEWSIZE = (1<<6), /* need to update dev size in block layer */
+        DEVFL_MAXBCNT = (1<<7), /* d->maxbcnt is not changeable */
 
         BUFFL_FAIL = 1,
 };
 
 enum {
-        MAXATADATA = 1024,
+        DEFAULTBCNT = 2 * 512,  /* 2 sectors */
         NPERSHELF = 16,         /* number of slots per shelf address */
         FREETAG = -1,
         MIN_BUFS = 8,
@@ -107,6 +108,8 @@ struct frame {
         ulong waited;
         struct buf *buf;
         char *bufaddr;
+        ulong bcnt;
+        sector_t lba;
         struct sk_buff *skb;
 };
 
@@ -120,6 +123,7 @@ struct aoedev {
         ulong nopen;            /* (bd_openers isn't available without sleeping) */
         ulong rttavg;           /* round trip average of requests/responses */
         u16 fw_ver;             /* version of blade's firmware */
+        u16 maxbcnt;
         struct work_struct work;/* disk create work struct */
         struct gendisk *gd;
         request_queue_t blkq;
@@ -134,7 +138,8 @@ struct aoedev {
         struct list_head bufq;  /* queue of bios to work on */
         struct buf *inprocess;  /* the one we're currently working on */
         ulong lasttag;          /* last tag sent */
-        ulong nframes;          /* number of frames below */
+        ushort lostjumbo;
+        ushort nframes;         /* number of frames below */
         struct frame *frames;
 };
 
diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c
index 0c543d3bfe58..2b5256cc733d 100644
--- a/drivers/block/aoe/aoechr.c
+++ b/drivers/block/aoe/aoechr.c
@@ -89,6 +89,7 @@ revalidate(const char __user *str, size_t size)
                 return -EINVAL;
 
         spin_lock_irqsave(&d->lock, flags);
+        d->flags &= ~DEVFL_MAXBCNT;
         d->flags |= DEVFL_PAUSE;
         spin_unlock_irqrestore(&d->lock, flags);
         aoecmd_cfg(major, minor);
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 1aeb2969987f..666797d646d6 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -83,6 +83,17 @@ aoehdr_atainit(struct aoedev *d, struct aoe_hdr *h)
         return host_tag;
 }
 
+static inline void
+put_lba(struct aoe_atahdr *ah, sector_t lba)
+{
+        ah->lba0 = lba;
+        ah->lba1 = lba >>= 8;
+        ah->lba2 = lba >>= 8;
+        ah->lba3 = lba >>= 8;
+        ah->lba4 = lba >>= 8;
+        ah->lba5 = lba >>= 8;
+}
+
 static void
 aoecmd_ata_rw(struct aoedev *d, struct frame *f)
 {
@@ -101,8 +112,8 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f)
 
         sector = buf->sector;
         bcnt = buf->bv_resid;
-        if (bcnt > MAXATADATA)
-                bcnt = MAXATADATA;
+        if (bcnt > d->maxbcnt)
+                bcnt = d->maxbcnt;
 
         /* initialize the headers & frame */
         skb = f->skb;
@@ -114,17 +125,14 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f)
         f->waited = 0;
         f->buf = buf;
         f->bufaddr = buf->bufaddr;
+        f->bcnt = bcnt;
+        f->lba = sector;
 
         /* set up ata header */
         ah->scnt = bcnt >> 9;
-        ah->lba0 = sector;
-        ah->lba1 = sector >>= 8;
-        ah->lba2 = sector >>= 8;
-        ah->lba3 = sector >>= 8;
+        put_lba(ah, sector);
         if (d->flags & DEVFL_EXT) {
                 ah->aflags |= AOEAFL_EXT;
-                ah->lba4 = sector >>= 8;
-                ah->lba5 = sector >>= 8;
         } else {
                 extbit = 0;
                 ah->lba3 &= 0x0f;
@@ -251,6 +259,7 @@ rexmit(struct aoedev *d, struct frame *f)
 {
         struct sk_buff *skb;
         struct aoe_hdr *h;
+        struct aoe_atahdr *ah;
         char buf[128];
         u32 n;
 
@@ -264,11 +273,27 @@ rexmit(struct aoedev *d, struct frame *f)
 
         skb = f->skb;
         h = (struct aoe_hdr *) skb->mac.raw;
+        ah = (struct aoe_atahdr *) (h+1);
         f->tag = n;
         h->tag = cpu_to_be32(n);
         memcpy(h->dst, d->addr, sizeof h->dst);
         memcpy(h->src, d->ifp->dev_addr, sizeof h->src);
 
+        n = DEFAULTBCNT / 512;
+        if (ah->scnt > n) {
+                ah->scnt = n;
+                if (ah->aflags & AOEAFL_WRITE)
+                        skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr),
+                                offset_in_page(f->bufaddr), DEFAULTBCNT);
+                if (++d->lostjumbo > (d->nframes << 1))
+                if (d->maxbcnt != DEFAULTBCNT) {
+                        printk(KERN_INFO "aoe: rexmit: too many lost jumbo.  "
+                                "dropping back to 1KB frames.\n");
+                        d->maxbcnt = DEFAULTBCNT;
+                        d->flags |= DEVFL_MAXBCNT;
+                }
+        }
+
         skb->dev = d->ifp;
         skb_get(skb);
         skb->next = NULL;
@@ -506,10 +531,10 @@ aoecmd_ata_rsp(struct sk_buff *skb)
                 if (buf)
                         buf->flags |= BUFFL_FAIL;
         } else {
+                n = ahout->scnt << 9;
                 switch (ahout->cmdstat) {
                 case WIN_READ:
                 case WIN_READ_EXT:
-                        n = ahout->scnt << 9;
                         if (skb->len - sizeof *hin - sizeof *ahin < n) {
                                 printk(KERN_CRIT "aoe: aoecmd_ata_rsp: runt "
                                         "ata data size in read.  skb->len=%d\n",
@@ -521,6 +546,22 @@ aoecmd_ata_rsp(struct sk_buff *skb)
                         memcpy(f->bufaddr, ahin+1, n);
                 case WIN_WRITE:
                 case WIN_WRITE_EXT:
+                        if (f->bcnt -= n) {
+                                f->bufaddr += n;
+                                put_lba(ahout, f->lba += ahout->scnt);
+                                n = f->bcnt > DEFAULTBCNT ? DEFAULTBCNT : f->bcnt;
+                                ahout->scnt = n >> 9;
+                                if (ahout->aflags & AOEAFL_WRITE)
+                                        skb_fill_page_desc(f->skb, 0, virt_to_page(f->bufaddr),
+                                                offset_in_page(f->bufaddr), n);
+                                skb_get(f->skb);
+                                f->skb->next = NULL;
+                                spin_unlock_irqrestore(&d->lock, flags);
+                                aoenet_xmit(f->skb);
+                                return;
+                        }
+                        if (n > DEFAULTBCNT)
+                                d->lostjumbo = 0;
                         break;
                 case WIN_IDENTIFY:
                         if (skb->len - sizeof *hin - sizeof *ahin < 512) {
@@ -628,9 +669,9 @@ aoecmd_cfg_rsp(struct sk_buff *skb)
         struct aoe_hdr *h;
         struct aoe_cfghdr *ch;
         ulong flags, sysminor, aoemajor;
-        u16 bufcnt;
         struct sk_buff *sl;
         enum { MAXFRAMES = 16 };
+        u16 n;
 
         h = (struct aoe_hdr *) skb->mac.raw;
         ch = (struct aoe_cfghdr *) (h+1);
@@ -654,11 +695,11 @@ aoecmd_cfg_rsp(struct sk_buff *skb)
                 return;
         }
 
-        bufcnt = be16_to_cpu(ch->bufcnt);
-        if (bufcnt > MAXFRAMES) /* keep it reasonable */
-                bufcnt = MAXFRAMES;
+        n = be16_to_cpu(ch->bufcnt);
+        if (n > MAXFRAMES)      /* keep it reasonable */
+                n = MAXFRAMES;
 
-        d = aoedev_by_sysminor_m(sysminor, bufcnt);
+        d = aoedev_by_sysminor_m(sysminor, n);
         if (d == NULL) {
                 printk(KERN_INFO "aoe: aoecmd_cfg_rsp: device sysminor_m failure\n");
                 return;
@@ -669,6 +710,14 @@ aoecmd_cfg_rsp(struct sk_buff *skb)
         /* permit device to migrate mac and network interface */
         d->ifp = skb->dev;
         memcpy(d->addr, h->src, sizeof d->addr);
+        if (!(d->flags & DEVFL_MAXBCNT)) {
+                n = d->ifp->mtu;
+                n -= sizeof (struct aoe_hdr) + sizeof (struct aoe_atahdr);
+                n /= 512;
+                if (n > ch->scnt)
+                        n = ch->scnt;
+                d->maxbcnt = n ? n * 512 : DEFAULTBCNT;
+        }
 
         /* don't change users' perspective */
         if (d->nopen && !(d->flags & DEVFL_PAUSE)) {