From 3d2606f42984613d324ad3047cf503bcddc3880a Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Fri, 20 May 2011 09:46:54 +0200 Subject: [PATCH] oprofile, x86: Enable preemption during pci device setup in IBS init IBS initialization is a mix of per-core register access and per-node pci device setup. Register access should be pinned to the cpu, but pci setup must run with preemption enabled. This patch better separates the code into non-/preemptible sections and fixes sleeping with preemption disabled. See bug message below. Fixes also freeing the eilvt entry by introducing put_eilvt(). BUG: sleeping function called from invalid context at mm/slub.c:824 in_atomic(): 1, irqs_disabled(): 0, pid: 32357, name: modprobe INFO: lockdep is turned off. Pid: 32357, comm: modprobe Not tainted 2.6.39-rc7+ #14 Call Trace: [] __might_sleep+0x112/0x117 [] kmem_cache_alloc_trace+0x4b/0xe7 [] kzalloc.constprop.0+0x29/0x2b [] pci_get_subsys+0x36/0x78 [] ? setup_APIC_eilvt+0xfb/0x139 [] pci_get_device+0x16/0x18 [] op_amd_init+0xd3/0x211 [oprofile] [] ? 0xffffffffa064cfff [] op_nmi_init+0x21e/0x26a [oprofile] [] oprofile_arch_init+0xe/0x26 [oprofile] [] oprofile_init+0x10/0x42 [oprofile] [] do_one_initcall+0x7f/0x13a [] sys_init_module+0x132/0x281 [] system_call_fastpath+0x16/0x1b Reported-by: Dave Jones Cc: [2.6.37.x] Signed-off-by: Robert Richter --- arch/x86/oprofile/op_model_amd.c | 95 ++++++++++++++++++-------------- 1 file changed, 54 insertions(+), 41 deletions(-) diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c index c3b8e24f2b16..9fd8a567fe1e 100644 --- a/arch/x86/oprofile/op_model_amd.c +++ b/arch/x86/oprofile/op_model_amd.c @@ -316,16 +316,23 @@ static void op_amd_stop_ibs(void) wrmsrl(MSR_AMD64_IBSOPCTL, 0); } -static inline int eilvt_is_available(int offset) +static inline int get_eilvt(int offset) { - /* check if we may assign a vector */ return !setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 1); } +static inline int put_eilvt(int offset) +{ + return !setup_APIC_eilvt(offset, 0, 0, 1); +} + static inline int ibs_eilvt_valid(void) { int offset; u64 val; + int valid = 0; + + preempt_disable(); rdmsrl(MSR_AMD64_IBSCTL, val); offset = val & IBSCTL_LVT_OFFSET_MASK; @@ -333,16 +340,20 @@ static inline int ibs_eilvt_valid(void) if (!(val & IBSCTL_LVT_OFFSET_VALID)) { pr_err(FW_BUG "cpu %d, invalid IBS interrupt offset %d (MSR%08X=0x%016llx)\n", smp_processor_id(), offset, MSR_AMD64_IBSCTL, val); - return 0; + goto out; } - if (!eilvt_is_available(offset)) { + if (!get_eilvt(offset)) { pr_err(FW_BUG "cpu %d, IBS interrupt offset %d not available (MSR%08X=0x%016llx)\n", smp_processor_id(), offset, MSR_AMD64_IBSCTL, val); - return 0; + goto out; } - return 1; + valid = 1; +out: + preempt_enable(); + + return valid; } static inline int get_ibs_offset(void) @@ -600,67 +611,69 @@ static int setup_ibs_ctl(int ibs_eilvt_off) static int force_ibs_eilvt_setup(void) { - int i; + int offset; int ret; - /* find the next free available EILVT entry */ - for (i = 1; i < 4; i++) { - if (!eilvt_is_available(i)) - continue; - ret = setup_ibs_ctl(i); - if (ret) - return ret; - pr_err(FW_BUG "using offset %d for IBS interrupts\n", i); - return 0; + /* + * find the next free available EILVT entry, skip offset 0, + * pin search to this cpu + */ + preempt_disable(); + for (offset = 1; offset < APIC_EILVT_NR_MAX; offset++) { + if (get_eilvt(offset)) + break; } + preempt_enable(); - printk(KERN_DEBUG "No EILVT entry available\n"); - - return -EBUSY; -} - -static int __init_ibs_nmi(void) -{ - int ret; - - if (ibs_eilvt_valid()) - return 0; + if (offset == APIC_EILVT_NR_MAX) { + printk(KERN_DEBUG "No EILVT entry available\n"); + return -EBUSY; + } - ret = force_ibs_eilvt_setup(); + ret = setup_ibs_ctl(offset); if (ret) - return ret; + goto out; - if (!ibs_eilvt_valid()) - return -EFAULT; + if (!ibs_eilvt_valid()) { + ret = -EFAULT; + goto out; + } + pr_err(FW_BUG "using offset %d for IBS interrupts\n", offset); pr_err(FW_BUG "workaround enabled for IBS LVT offset\n"); return 0; +out: + preempt_disable(); + put_eilvt(offset); + preempt_enable(); + return ret; } /* * check and reserve APIC extended interrupt LVT offset for IBS if * available - * - * init_ibs() preforms implicitly cpu-local operations, so pin this - * thread to its current CPU */ static void init_ibs(void) { - preempt_disable(); - ibs_caps = get_ibs_caps(); + if (!ibs_caps) + return; + + if (ibs_eilvt_valid()) goto out; - if (__init_ibs_nmi() < 0) - ibs_caps = 0; - else - printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n", ibs_caps); + if (!force_ibs_eilvt_setup()) + goto out; + + /* Failed to setup ibs */ + ibs_caps = 0; + return; out: - preempt_enable(); + printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n", ibs_caps); } static int (*create_arch_files)(struct super_block *sb, struct dentry *root); -- GitLab