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Date:   Tue, 05 Jun 2018 07:58:09 -0400
From:   okaya@codeaurora.org
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     linux-pci@vger.kernel.org, Timur Tabi <timur@codeaurora.org>,
        linux-arm-msm@vger.kernel.org,
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        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
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        Kai-Heng Feng <kai.heng.feng@canonical.com>,
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Subject: Re: [PATCH V4] PCI: move early dump functionality from x86 arch into
 the common code
In-Reply-To: <CAHp75VdD0Ds6dFdYWF8YpY04hiKY-LmfOU7+dPs7PkTOjbRKbw@mail.gmail.com>
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 <CAHp75VdD0Ds6dFdYWF8YpY04hiKY-LmfOU7+dPs7PkTOjbRKbw@mail.gmail.com>
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On 2018-06-05 05:12, Andy Shevchenko wrote:
> On Tue, Jun 5, 2018 at 5:16 AM, Sinan Kaya <okaya@codeaurora.org> 
> wrote:
>> Move early dump functionality into common code so that it is available 
>> for
>> all archtiectures. No need to carry arch specific reads around as the 
>> read
>> hooks are already initialized by the time pci_setup_device() is 
>> getting
>> called during scan.
>> 
> 
> Makes sense.
> 
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> 
> One style comment below, though.
> 
> If you wait a bit, I perhaps would be able to test on x86.

Sure, no rush. This is a nice to have feature with no urgency.

> 
>> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
>> ---
>>  Documentation/admin-guide/kernel-parameters.txt |  2 +-
>>  arch/x86/include/asm/pci-direct.h               |  4 ---
>>  arch/x86/kernel/setup.c                         |  5 ---
>>  arch/x86/pci/common.c                           |  4 ---
>>  arch/x86/pci/early.c                            | 44 
>> -------------------------
>>  drivers/pci/pci.c                               |  5 +++
>>  drivers/pci/pci.h                               |  1 +
>>  drivers/pci/probe.c                             | 19 +++++++++++
>>  8 files changed, 26 insertions(+), 58 deletions(-)
>> 
>> diff --git a/Documentation/admin-guide/kernel-parameters.txt 
>> b/Documentation/admin-guide/kernel-parameters.txt
>> index e490902..e64f1d8 100644
>> --- a/Documentation/admin-guide/kernel-parameters.txt
>> +++ b/Documentation/admin-guide/kernel-parameters.txt
>> @@ -2995,7 +2995,7 @@
>>                         See also Documentation/blockdev/paride.txt.
>> 
>>         pci=option[,option...]  [PCI] various PCI subsystem options:
>> -               earlydump       [X86] dump PCI config space before the 
>> kernel
>> +               earlydump       dump PCI config space before the 
>> kernel
>>                                 changes anything
>>                 off             [X86] don't probe for the PCI bus
>>                 bios            [X86-32] force use of PCI BIOS, don't 
>> access
>> diff --git a/arch/x86/include/asm/pci-direct.h 
>> b/arch/x86/include/asm/pci-direct.h
>> index e1084f7..94597a3 100644
>> --- a/arch/x86/include/asm/pci-direct.h
>> +++ b/arch/x86/include/asm/pci-direct.h
>> @@ -15,8 +15,4 @@ extern void write_pci_config_byte(u8 bus, u8 slot, 
>> u8 func, u8 offset, u8 val);
>>  extern void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, 
>> u16 val);
>> 
>>  extern int early_pci_allowed(void);
>> -
>> -extern unsigned int pci_early_dump_regs;
>> -extern void early_dump_pci_device(u8 bus, u8 slot, u8 func);
>> -extern void early_dump_pci_devices(void);
>>  #endif /* _ASM_X86_PCI_DIRECT_H */
>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>> index 2f86d88..480f250 100644
>> --- a/arch/x86/kernel/setup.c
>> +++ b/arch/x86/kernel/setup.c
>> @@ -991,11 +991,6 @@ void __init setup_arch(char **cmdline_p)
>>                 setup_clear_cpu_cap(X86_FEATURE_APIC);
>>         }
>> 
>> -#ifdef CONFIG_PCI
>> -       if (pci_early_dump_regs)
>> -               early_dump_pci_devices();
>> -#endif
>> -
>>         e820__reserve_setup_data();
>>         e820__finish_early_params();
>> 
>> diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
>> index 563049c..d4ec117 100644
>> --- a/arch/x86/pci/common.c
>> +++ b/arch/x86/pci/common.c
>> @@ -22,7 +22,6 @@
>>  unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | 
>> PCI_PROBE_CONF2 |
>>                                 PCI_PROBE_MMCONF;
>> 
>> -unsigned int pci_early_dump_regs;
>>  static int pci_bf_sort;
>>  int pci_routeirq;
>>  int noioapicquirk;
>> @@ -599,9 +598,6 @@ char *__init pcibios_setup(char *str)
>>                 pci_probe |= PCI_BIG_ROOT_WINDOW;
>>                 return NULL;
>>  #endif
>> -       } else if (!strcmp(str, "earlydump")) {
>> -               pci_early_dump_regs = 1;
>> -               return NULL;
>>         } else if (!strcmp(str, "routeirq")) {
>>                 pci_routeirq = 1;
>>                 return NULL;
>> diff --git a/arch/x86/pci/early.c b/arch/x86/pci/early.c
>> index e5f753c..f5fc953 100644
>> --- a/arch/x86/pci/early.c
>> +++ b/arch/x86/pci/early.c
>> @@ -57,47 +57,3 @@ int early_pci_allowed(void)
>>                         PCI_PROBE_CONF1;
>>  }
>> 
>> -void early_dump_pci_device(u8 bus, u8 slot, u8 func)
>> -{
>> -       u32 value[256 / 4];
>> -       int i;
>> -
>> -       pr_info("pci 0000:%02x:%02x.%d config space:\n", bus, slot, 
>> func);
>> -
>> -       for (i = 0; i < 256; i += 4)
>> -               value[i / 4] = read_pci_config(bus, slot, func, i);
>> -
>> -       print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 1, 
>> value, 256, false);
>> -}
>> -
>> -void early_dump_pci_devices(void)
>> -{
>> -       unsigned bus, slot, func;
>> -
>> -       if (!early_pci_allowed())
>> -               return;
>> -
>> -       for (bus = 0; bus < 256; bus++) {
>> -               for (slot = 0; slot < 32; slot++) {
>> -                       for (func = 0; func < 8; func++) {
>> -                               u32 class;
>> -                               u8 type;
>> -
>> -                               class = read_pci_config(bus, slot, 
>> func,
>> -                                                       
>> PCI_CLASS_REVISION);
>> -                               if (class == 0xffffffff)
>> -                                       continue;
>> -
>> -                               early_dump_pci_device(bus, slot, 
>> func);
>> -
>> -                               if (func == 0) {
>> -                                       type = 
>> read_pci_config_byte(bus, slot,
>> -                                                                   
>> func,
>> -                                                              
>> PCI_HEADER_TYPE);
>> -                                       if (!(type & 0x80))
>> -                                               break;
>> -                               }
>> -                       }
>> -               }
>> -       }
>> -}
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index 97acba7..04052dc 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -115,6 +115,9 @@ static bool pcie_ari_disabled;
>>  /* If set, the PCIe ATS capability will not be used. */
>>  static bool pcie_ats_disabled;
>> 
>> +/* If set, the PCI config space of each device is printed during 
>> boot. */
>> +bool pci_early_dump;
>> +
>>  bool pci_ats_disabled(void)
>>  {
>>         return pcie_ats_disabled;
>> @@ -5805,6 +5808,8 @@ static int __init pci_setup(char *str)
>>                                 pcie_ats_disabled = true;
>>                         } else if (!strcmp(str, "noaer")) {
>>                                 pci_no_aer();
>> +                       } else if (!strcmp(str, "earlydump")) {
>> +                               pci_early_dump = true;
>>                         } else if (!strncmp(str, "realloc=", 8)) {
>>                                 pci_realloc_get_opt(str + 8);
>>                         } else if (!strncmp(str, "realloc", 7)) {
>> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
>> index c358e7a0..c33265e 100644
>> --- a/drivers/pci/pci.h
>> +++ b/drivers/pci/pci.h
>> @@ -7,6 +7,7 @@
>>  #define PCI_VSEC_ID_INTEL_TBT  0x1234  /* Thunderbolt */
>> 
>>  extern const unsigned char pcie_link_speed[];
>> +extern bool pci_early_dump;
>> 
>>  bool pcie_cap_has_lnkctl(const struct pci_dev *dev);
>> 
>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>> index 56771f3..3678f0a 100644
>> --- a/drivers/pci/probe.c
>> +++ b/drivers/pci/probe.c
>> @@ -1545,6 +1545,23 @@ static int pci_intx_mask_broken(struct pci_dev 
>> *dev)
>>         return 0;
>>  }
>> 
>> +static void early_dump_pci_device(struct pci_dev *pdev)
>> +{
>> +       u32 value[256 / 4];
>> +       int i;
>> +
>> +       if (!pci_early_dump)
>> +               return;
>> +
>> +       pci_info(pdev, "config space:\n");
>> +
>> +       for (i = 0; i < 256; i += 4)
>> +               pci_read_config_dword(pdev, i, &value[i / 4]);
>> +
> 
>> +       print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 1, 
>> value,
>> +                      256, false);
> 
> Logically better either to move value to second line, or move 256 on
> the first line.
> 
>> +}
>> +
>>  /**
>>   * pci_setup_device - Fill in class and map information of a device
>>   * @dev: the device structure to fill
>> @@ -1594,6 +1611,8 @@ int pci_setup_device(struct pci_dev *dev)
>>         pci_printk(KERN_DEBUG, dev, "[%04x:%04x] type %02x class 
>> %#08x\n",
>>                    dev->vendor, dev->device, dev->hdr_type, 
>> dev->class);
>> 
>> +       early_dump_pci_device(dev);
>> +
>>         /* Need to have dev->class ready */
>>         dev->cfg_size = pci_cfg_space_size(dev);
>> 
>> --
>> 2.7.4
>>