From 032c3851f51141e30de02ed0bc50a7743dfd776d Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Wed, 24 Oct 2012 16:42:20 +0800 Subject: [PATCH] perf/x86/uncore: Handle pci_read_config_dword() errors MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This, beyond handling corner cases, also fixes some build warnings: arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function ‘snbep_uncore_pci_disable_box’: arch/x86/kernel/cpu/perf_event_intel_uncore.c:124:9: warning: ‘config’ is used uninitialized in this function [-Wuninitialized] arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function ‘snbep_uncore_pci_enable_box’: arch/x86/kernel/cpu/perf_event_intel_uncore.c:135:9: warning: ‘config’ is used uninitialized in this function [-Wuninitialized] arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function ‘snbep_uncore_pci_read_counter’: arch/x86/kernel/cpu/perf_event_intel_uncore.c:164:2: warning: ‘count’ is used uninitialized in this function [-Wuninitialized] Signed-off-by: Yan, Zheng Cc: a.p.zijlstra@chello.nl Link: http://lkml.kernel.org/r/1351068140-13456-1-git-send-email-zheng.z.yan@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel_uncore.c | 43 ++++++++++++------- 1 file changed, 28 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c index 5df8d32ba91e..6f874771ee65 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -118,22 +118,24 @@ static void snbep_uncore_pci_disable_box(struct intel_uncore_box *box) { struct pci_dev *pdev = box->pci_dev; int box_ctl = uncore_pci_box_ctl(box); - u32 config; + u32 config = 0; - pci_read_config_dword(pdev, box_ctl, &config); - config |= SNBEP_PMON_BOX_CTL_FRZ; - pci_write_config_dword(pdev, box_ctl, config); + if (!pci_read_config_dword(pdev, box_ctl, &config)) { + config |= SNBEP_PMON_BOX_CTL_FRZ; + pci_write_config_dword(pdev, box_ctl, config); + } } static void snbep_uncore_pci_enable_box(struct intel_uncore_box *box) { struct pci_dev *pdev = box->pci_dev; int box_ctl = uncore_pci_box_ctl(box); - u32 config; + u32 config = 0; - pci_read_config_dword(pdev, box_ctl, &config); - config &= ~SNBEP_PMON_BOX_CTL_FRZ; - pci_write_config_dword(pdev, box_ctl, config); + if (!pci_read_config_dword(pdev, box_ctl, &config)) { + config &= ~SNBEP_PMON_BOX_CTL_FRZ; + pci_write_config_dword(pdev, box_ctl, config); + } } static void snbep_uncore_pci_enable_event(struct intel_uncore_box *box, struct perf_event *event) @@ -156,7 +158,7 @@ static u64 snbep_uncore_pci_read_counter(struct intel_uncore_box *box, struct pe { struct pci_dev *pdev = box->pci_dev; struct hw_perf_event *hwc = &event->hw; - u64 count; + u64 count = 0; pci_read_config_dword(pdev, hwc->event_base, (u32 *)&count); pci_read_config_dword(pdev, hwc->event_base + 4, (u32 *)&count + 1); @@ -603,11 +605,12 @@ static struct pci_driver snbep_uncore_pci_driver = { /* * build pci bus to socket mapping */ -static void snbep_pci2phy_map_init(void) +static int snbep_pci2phy_map_init(void) { struct pci_dev *ubox_dev = NULL; int i, bus, nodeid; - u32 config; + int err = 0; + u32 config = 0; while (1) { /* find the UBOX device */ @@ -618,10 +621,14 @@ static void snbep_pci2phy_map_init(void) break; bus = ubox_dev->bus->number; /* get the Node ID of the local register */ - pci_read_config_dword(ubox_dev, 0x40, &config); + err = pci_read_config_dword(ubox_dev, 0x40, &config); + if (err) + break; nodeid = config; /* get the Node ID mapping */ - pci_read_config_dword(ubox_dev, 0x54, &config); + err = pci_read_config_dword(ubox_dev, 0x54, &config); + if (err) + break; /* * every three bits in the Node ID mapping register maps * to a particular node. @@ -633,7 +640,11 @@ static void snbep_pci2phy_map_init(void) } } }; - return; + + if (ubox_dev) + pci_dev_put(ubox_dev); + + return err ? pcibios_err_to_errno(err) : 0; } /* end of Sandy Bridge-EP uncore support */ @@ -2578,9 +2589,11 @@ static int __init uncore_pci_init(void) switch (boot_cpu_data.x86_model) { case 45: /* Sandy Bridge-EP */ + ret = snbep_pci2phy_map_init(); + if (ret) + return ret; pci_uncores = snbep_pci_uncores; uncore_pci_driver = &snbep_uncore_pci_driver; - snbep_pci2phy_map_init(); break; default: return 0;