diff options
| -rw-r--r-- | drivers/pci/host/pci-hyperv.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c index 328c653d7503..58f7eeb79bb4 100644 --- a/drivers/pci/host/pci-hyperv.c +++ b/drivers/pci/host/pci-hyperv.c @@ -553,6 +553,8 @@ static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where, spin_lock_irqsave(&hpdev->hbus->config_lock, flags); /* Choose the function to be read. (See comment above) */ writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); + /* Make sure the function was chosen before we start reading. */ + mb(); /* Read from that function's config space. */ switch (size) { case 1: @@ -565,6 +567,11 @@ static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where, *val = readl(addr); break; } + /* + * Make sure the write was done before we release the spinlock + * allowing consecutive reads/writes. + */ + mb(); spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); } else { dev_err(&hpdev->hbus->hdev->device, @@ -592,6 +599,8 @@ static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where, spin_lock_irqsave(&hpdev->hbus->config_lock, flags); /* Choose the function to be written. (See comment above) */ writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); + /* Make sure the function was chosen before we start writing. */ + wmb(); /* Write to that function's config space. */ switch (size) { case 1: @@ -604,6 +613,11 @@ static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where, writel(val, addr); break; } + /* + * Make sure the write was done before we release the spinlock + * allowing consecutive reads/writes. + */ + mb(); spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); } else { dev_err(&hpdev->hbus->hdev->device, |