From: Bryan O'Sullivan Date: Sat, 1 Jul 2006 11:36:15 +0000 (-0700) Subject: [PATCH] IB/ipath: fix a bug that results in addresses near 0 being written via DMA X-Git-Tag: v2.6.18-rc1~212 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=35783ec07c3f7f6902abe4433e7be1b664d0bbaf;p=linux-2.6 [PATCH] IB/ipath: fix a bug that results in addresses near 0 being written via DMA We can't tell for sure if any packets are in the infinipath receive buffer when we shut down a chip port. Normally this is taken care of by orderly shutdown, but when processes are terminated, or sending process has a bug, we can continue to receive packets. So rather than writing zero to the address registers for the closing port, we point it at a dummy memory. Signed-off-by: Dave Olson Signed-off-by: Bryan O'Sullivan Cc: "Michael S. Tsirkin" Cc: Roland Dreier Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c index 4109913c20..f647918db6 100644 --- a/drivers/infiniband/hw/ipath/ipath_driver.c +++ b/drivers/infiniband/hw/ipath/ipath_driver.c @@ -1824,6 +1824,12 @@ static void cleanup_device(struct ipath_devdata *dd) dd->ipath_pioavailregs_phys); dd->ipath_pioavailregs_dma = NULL; } + if (dd->ipath_dummy_hdrq) { + dma_free_coherent(&dd->pcidev->dev, + dd->ipath_pd[0]->port_rcvhdrq_size, + dd->ipath_dummy_hdrq, dd->ipath_dummy_hdrq_phys); + dd->ipath_dummy_hdrq = NULL; + } if (dd->ipath_pageshadow) { struct page **tmpp = dd->ipath_pageshadow; diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c index e89d3a17ac..51a609d470 100644 --- a/drivers/infiniband/hw/ipath/ipath_file_ops.c +++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c @@ -1486,42 +1486,51 @@ static int ipath_close(struct inode *in, struct file *fp) } if (dd->ipath_kregbase) { - ipath_write_kreg_port( - dd, dd->ipath_kregs->kr_rcvhdrtailaddr, - port, 0ULL); - ipath_write_kreg_port( - dd, dd->ipath_kregs->kr_rcvhdraddr, - pd->port_port, 0); + int i; + /* atomically clear receive enable port. */ + clear_bit(INFINIPATH_R_PORTENABLE_SHIFT + port, + &dd->ipath_rcvctrl); + ipath_write_kreg( dd, dd->ipath_kregs->kr_rcvctrl, + dd->ipath_rcvctrl); + /* and read back from chip to be sure that nothing + * else is in flight when we do the rest */ + (void)ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch); /* clean up the pkeys for this port user */ ipath_clean_part_key(pd, dd); - if (port < dd->ipath_cfgports) { - int i = dd->ipath_pbufsport * (port - 1); - ipath_disarm_piobufs(dd, i, dd->ipath_pbufsport); - /* atomically clear receive enable port. */ - clear_bit(INFINIPATH_R_PORTENABLE_SHIFT + port, - &dd->ipath_rcvctrl); - ipath_write_kreg( - dd, - dd->ipath_kregs->kr_rcvctrl, - dd->ipath_rcvctrl); - - if (dd->ipath_pageshadow) - unlock_expected_tids(pd); - ipath_stats.sps_ports--; - ipath_cdbg(PROC, "%s[%u] closed port %u:%u\n", - pd->port_comm, pd->port_pid, - dd->ipath_unit, port); - } + /* + * be paranoid, and never write 0's to these, just use an + * unused part of the port 0 tail page. Of course, + * rcvhdraddr points to a large chunk of memory, so this + * could still trash things, but at least it won't trash + * page 0, and by disabling the port, it should stop "soon", + * even if a packet or two is in already in flight after we + * disabled the port. + */ + ipath_write_kreg_port(dd, + dd->ipath_kregs->kr_rcvhdrtailaddr, port, + dd->ipath_dummy_hdrq_phys); + ipath_write_kreg_port(dd, dd->ipath_kregs->kr_rcvhdraddr, + pd->port_port, dd->ipath_dummy_hdrq_phys); + + i = dd->ipath_pbufsport * (port - 1); + ipath_disarm_piobufs(dd, i, dd->ipath_pbufsport); + + if (dd->ipath_pageshadow) + unlock_expected_tids(pd); + ipath_stats.sps_ports--; + ipath_cdbg(PROC, "%s[%u] closed port %u:%u\n", + pd->port_comm, pd->port_pid, + dd->ipath_unit, port); + + dd->ipath_f_clear_tids(dd, pd->port_port); } pd->port_cnt = 0; pd->port_pid = 0; - dd->ipath_f_clear_tids(dd, pd->port_port); - dd->ipath_pd[pd->port_port] = NULL; /* before releasing mutex */ mutex_unlock(&ipath_mutex); ipath_free_pddata(dd, pd); /* after releasing the mutex */ diff --git a/drivers/infiniband/hw/ipath/ipath_init_chip.c b/drivers/infiniband/hw/ipath/ipath_init_chip.c index 9faa201abe..ff322e5c14 100644 --- a/drivers/infiniband/hw/ipath/ipath_init_chip.c +++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c @@ -647,6 +647,7 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit) u32 val32, kpiobufs; u64 val; struct ipath_portdata *pd = NULL; /* keep gcc4 happy */ + gfp_t gfp_flags = GFP_USER | __GFP_COMP; ret = init_housekeeping(dd, &pd, reinit); if (ret) @@ -834,6 +835,22 @@ int ipath_init_chip(struct ipath_devdata *dd, int reinit) else enable_chip(dd, pd, reinit); + + if (!ret && !reinit) { + /* used when we close a port, for DMA already in flight at close */ + dd->ipath_dummy_hdrq = dma_alloc_coherent( + &dd->pcidev->dev, pd->port_rcvhdrq_size, + &dd->ipath_dummy_hdrq_phys, + gfp_flags); + if (!dd->ipath_dummy_hdrq ) { + dev_info(&dd->pcidev->dev, + "Couldn't allocate 0x%lx bytes for dummy hdrq\n", + pd->port_rcvhdrq_size); + /* fallback to just 0'ing */ + dd->ipath_dummy_hdrq_phys = 0UL; + } + } + /* * cause retrigger of pending interrupts ignored during init, * even if we had errors diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h index 00a6bbdbe9..e9f374fb64 100644 --- a/drivers/infiniband/hw/ipath/ipath_kernel.h +++ b/drivers/infiniband/hw/ipath/ipath_kernel.h @@ -352,6 +352,8 @@ struct ipath_devdata { /* check for stale messages in rcv queue */ /* only allow one intr at a time. */ unsigned long ipath_rcv_pending; + void *ipath_dummy_hdrq; /* used after port close */ + dma_addr_t ipath_dummy_hdrq_phys; /* * Shadow copies of registers; size indicates read access size.