From 19685d5aa79c2f86486b0afee6db4c7a280ea7b3 Mon Sep 17 00:00:00 2001 From: Xiao Wang Date: Mon, 1 Jan 2018 14:00:10 -0800 Subject: [PATCH] igb_uio: allow multi-process access In some case, one device are accessed by different processes via different BARs, so one uio device may be opened by more than one process, for this case we just need to enable interrupt once, and pci_clear_master only when the last process closed. Fixes: 5f6ff30dc507 ("igb_uio: fix interrupt enablement after FLR in VM") Cc: stable@dpdk.org Signed-off-by: Xiao Wang Acked-by: Ferruh Yigit --- lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c index 7f2b4c86dd..9f0fb5eb21 100644 --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c @@ -26,6 +26,8 @@ struct rte_uio_pci_dev { struct uio_info info; struct pci_dev *pdev; enum rte_intr_mode mode; + struct mutex lock; + int refcnt; }; static char *intr_mode; @@ -317,11 +319,18 @@ igbuio_pci_open(struct uio_info *info, struct inode *inode) struct pci_dev *dev = udev->pdev; int err; + mutex_lock(&udev->lock); + if (++udev->refcnt > 1) { + mutex_unlock(&udev->lock); + return 0; + } + /* set bus master, which was cleared by the reset function */ pci_set_master(dev); /* enable interrupts */ err = igbuio_pci_enable_interrupts(udev); + mutex_unlock(&udev->lock); if (err) { dev_err(&dev->dev, "Enable interrupt fails\n"); return err; @@ -335,12 +344,19 @@ igbuio_pci_release(struct uio_info *info, struct inode *inode) struct rte_uio_pci_dev *udev = info->priv; struct pci_dev *dev = udev->pdev; + mutex_lock(&udev->lock); + if (--udev->refcnt > 0) { + mutex_unlock(&udev->lock); + return 0; + } + /* disable interrupts */ igbuio_pci_disable_interrupts(udev); /* stop the device from further DMA */ pci_clear_master(dev); + mutex_unlock(&udev->lock); return 0; } @@ -461,6 +477,7 @@ igbuio_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) if (!udev) return -ENOMEM; + mutex_init(&udev->lock); /* * enable device: ask low-level code to enable I/O and * memory @@ -551,6 +568,7 @@ igbuio_pci_remove(struct pci_dev *dev) { struct rte_uio_pci_dev *udev = pci_get_drvdata(dev); + mutex_destroy(&udev->lock); sysfs_remove_group(&dev->dev.kobj, &dev_attr_grp); uio_unregister_device(&udev->info); igbuio_pci_release_iomem(&udev->info); -- 2.20.1