Re: [PATCH v2] perf/x86/uncore: fix compilation warning in snb_uncore_imc_init_box()

From: Stephane Eranian
Date: Wed Apr 16 2014 - 11:10:42 EST

On Tue, Apr 15, 2014 at 1:35 PM, Kirill A. Shutemov
<kirill@xxxxxxxxxxxxx> wrote:
> On Wed, Mar 12, 2014 at 12:53:30AM +0100, Stephane Eranian wrote:
>>
>> This patch fixes a compilation problem (unused variable) with the
>> new SNB/IVB/HSW uncore IMC code.
>>
>> In V2, we simplify the fix as suggested by Peter Zjilstra.
>>
>> Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
>> Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
>> --
>>
>> diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
>> index 3e5b240..d614f6b 100644
>> --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
>> +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
>> @@ -1722,15 +1722,16 @@ static struct attribute_group snb_uncore_imc_format_group = {
>> static void snb_uncore_imc_init_box(struct intel_uncore_box *box)
>> {
>> struct pci_dev *pdev = box->pci_dev;
>> - u32 addr_lo, addr_hi;
>> + int where = SNB_UNCORE_PCI_IMC_BAR_OFFSET;
>> + u32 pci_dword;
>> resource_size_t addr;
>>
>> - pci_read_config_dword(pdev, SNB_UNCORE_PCI_IMC_BAR_OFFSET, &addr_lo);
>> - addr = addr_lo;
>> + pci_read_config_dword(pdev, where, &pci_dword);
>> + addr = pci_dword;
>>
>> #ifdef CONFIG_PHYS_ADDR_T_64BIT
>> - pci_read_config_dword(pdev, SNB_UNCORE_PCI_IMC_BAR_OFFSET+4, &addr_hi);
>> - addr = ((resource_size_t)addr_hi << 32) | addr_lo;
>> + pci_read_config_dword(pdev, where + 4, &pci_dword);
>> + addr |= ((resource_size_t)pci_dword << 32);
>> #endif
>>
>> addr &= ~(PAGE_SIZE - 1);
>
> I see the warning on my laptop (X1 Carbon), which probably related to the commit:
>
> [ 0.559204] ------------[ cut here ]------------
> [ 0.559216] WARNING: CPU: 2 PID: 1 at /home/kas/git/public/linux/arch/x86/mm/ioremap.c:171 __ioremap_caller+0x2e3/0x390()
> [ 0.559225] Info: mapping multiple BARs. Your kernel is fine.
> [ 0.559230] Modules linked in:
>
Yes, this is the same warning.
No solution at this point. It seems to affect only Lenovo laptops.

> [ 0.559238] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 3.15.0-rc1-00012-g55101e2d6ce1 #38
> [ 0.559246] Hardware name: LENOVO 3460CC6/3460CC6, BIOS G6ET93WW (2.53 ) 02/04/2013
> [ 0.559254] 0000000000000009 ffff8801182f3b60 ffffffff81a2274e ffff8801182f3ba8
> [ 0.559264] ffff8801182f3b98 ffffffff810db97d ffffc90000658000 00000000fed16000
> [ 0.559274] ffffc90000658000 ffffc90000658000 0000000000006000 ffff8801182f3bf8
> [ 0.559284] Call Trace:
> [ 0.559293] [<ffffffff81a2274e>] dump_stack+0x4d/0x6f
> [ 0.559300] [<ffffffff810db97d>] warn_slowpath_common+0x7d/0xa0
> [ 0.559307] [<ffffffff810db9ec>] warn_slowpath_fmt+0x4c/0x50
> [ 0.559316] [<ffffffff810e39dc>] ? iomem_map_sanity_check+0xac/0xe0
> [ 0.559324] [<ffffffff810a8823>] __ioremap_caller+0x2e3/0x390
> [ 0.559332] [<ffffffff810a88e7>] ioremap_nocache+0x17/0x20
> [ 0.559339] [<ffffffff81083845>] snb_uncore_imc_init_box+0x65/0x90
> [ 0.559348] [<ffffffff810827c8>] uncore_pci_probe+0xd8/0x1b0
> [ 0.559356] [<ffffffff8140f255>] local_pci_probe+0x45/0xa0
> [ 0.559364] [<ffffffff8140e9c5>] ? pci_match_device+0xc5/0xd0
> [ 0.559371] [<ffffffff8140f389>] pci_device_probe+0xd9/0x130
> [ 0.559379] [<ffffffff81598987>] driver_probe_device+0x87/0x390
> [ 0.559385] [<ffffffff81598d63>] __driver_attach+0x93/0xa0
> [ 0.559392] [<ffffffff81598cd0>] ? __device_attach+0x40/0x40
> [ 0.559401] [<ffffffff815968bb>] bus_for_each_dev+0x6b/0xb0
> [ 0.559408] [<ffffffff815983ae>] driver_attach+0x1e/0x20
> [ 0.559415] [<ffffffff81597f88>] bus_add_driver+0x188/0x260
> [ 0.559425] [<ffffffff8237e179>] ? uncore_pmu_register+0xdb/0xdb
> [ 0.559432] [<ffffffff815993c4>] driver_register+0x64/0xf0
> [ 0.559439] [<ffffffff8237e179>] ? uncore_pmu_register+0xdb/0xdb
> [ 0.559446] [<ffffffff8140eb30>] __pci_register_driver+0x60/0x70
> [ 0.559454] [<ffffffff8237e2ee>] intel_uncore_init+0x175/0x42b
> [ 0.559461] [<ffffffff8237e179>] ? uncore_pmu_register+0xdb/0xdb
> [ 0.559470] [<ffffffff8100216a>] do_one_initcall+0xfa/0x1b0
> [ 0.559479] [<ffffffff811035e5>] ? parse_args+0x225/0x3f0
> [ 0.559487] [<ffffffff8236e17c>] kernel_init_freeable+0x1da/0x25f
> [ 0.559495] [<ffffffff8236d8e5>] ? do_early_param+0x88/0x88
> [ 0.559504] [<ffffffff81a13060>] ? rest_init+0x140/0x140
> [ 0.559511] [<ffffffff81a1306e>] kernel_init+0xe/0xf0
> [ 0.559519] [<ffffffff81a380bc>] ret_from_fork+0x7c/0xb0
> [ 0.559526] [<ffffffff81a13060>] ? rest_init+0x140/0x140
> [ 0.559538] ---[ end trace 2d7d94a103087769 ]---
>
> --
> Kirill A. Shutemov
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