From 9edb4da273705735361bf7153ef2141d3147066b Mon Sep 17 00:00:00 2001 From: Tony Truong Date: Wed, 7 Dec 2016 11:41:54 -0800 Subject: [PATCH] msm: pcie: add mutex for PCIe enumeration PCIe bus driver supports a few ways for clients to trigger enumeration. To prevent race conditions, add a mutex to secure the enumeration process. Change-Id: Ifa4f6d2b4edee85e750e6e44626c89ec0de966cf Signed-off-by: Tony Truong --- drivers/pci/host/pci-msm.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/pci/host/pci-msm.c b/drivers/pci/host/pci-msm.c index 9a6f1aed82e8..7c8b5e3e57a1 100644 --- a/drivers/pci/host/pci-msm.c +++ b/drivers/pci/host/pci-msm.c @@ -589,6 +589,7 @@ struct msm_pcie_dev_t { bool cfg_access; spinlock_t cfg_lock; unsigned long irqsave_flags; + struct mutex enumerate_lock; struct mutex setup_lock; struct irq_domain *irq_domain; @@ -4964,12 +4965,15 @@ int msm_pcie_enumerate(u32 rc_idx) int ret = 0, bus_ret = 0, scan_ret = 0; struct msm_pcie_dev_t *dev = &msm_pcie_dev[rc_idx]; + mutex_lock(&dev->enumerate_lock); + PCIE_DBG(dev, "Enumerate RC%d\n", rc_idx); if (!dev->drv_ready) { PCIE_DBG(dev, "RC%d has not been successfully probed yet\n", rc_idx); - return -EPROBE_DEFER; + ret = -EPROBE_DEFER; + goto out; } if (!dev->enumerated) { @@ -4996,8 +5000,7 @@ int msm_pcie_enumerate(u32 rc_idx) PCIE_ERR(dev, "PCIe: failed to get host bridge resources for RC%d: %d\n", dev->rc_idx, ret); - - return ret; + goto out; } bus = pci_create_root_bus(&dev->pdev->dev, 0, @@ -5008,8 +5011,8 @@ int msm_pcie_enumerate(u32 rc_idx) PCIE_ERR(dev, "PCIe: failed to create root bus for RC%d\n", dev->rc_idx); - - return -ENOMEM; + ret = -ENOMEM; + goto out; } scan_ret = pci_scan_child_bus(bus); @@ -5057,7 +5060,8 @@ int msm_pcie_enumerate(u32 rc_idx) PCIE_ERR(dev, "PCIe: Did not find PCI device for RC%d.\n", dev->rc_idx); - return -ENODEV; + ret = -ENODEV; + goto out; } bus_ret = bus_for_each_dev(&pci_bus_type, NULL, dev, @@ -5067,7 +5071,8 @@ int msm_pcie_enumerate(u32 rc_idx) PCIE_ERR(dev, "PCIe: Failed to set up device table for RC%d\n", dev->rc_idx); - return -ENODEV; + ret = -ENODEV; + goto out; } } else { PCIE_ERR(dev, "PCIe: failed to enable RC%d.\n", @@ -5078,6 +5083,9 @@ int msm_pcie_enumerate(u32 rc_idx) dev->rc_idx); } +out: + mutex_unlock(&dev->enumerate_lock); + return ret; } EXPORT_SYMBOL(msm_pcie_enumerate); @@ -6436,6 +6444,7 @@ int __init pcie_init(void) rc_name, i); spin_lock_init(&msm_pcie_dev[i].cfg_lock); msm_pcie_dev[i].cfg_access = true; + mutex_init(&msm_pcie_dev[i].enumerate_lock); mutex_init(&msm_pcie_dev[i].setup_lock); mutex_init(&msm_pcie_dev[i].recovery_lock); spin_lock_init(&msm_pcie_dev[i].linkdown_lock);