Re: [PATCH V4] PCI: move early dump functionality from x86 arch into the common code

From: Andy Shevchenko
Date: Tue Jun 05 2018 - 05:12:44 EST

On Tue, Jun 5, 2018 at 5:16 AM, Sinan Kaya <okaya@xxxxxxxxxxxxxx> 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@xxxxxxxxx>

One style comment below, though.

If you wait a bit, I perhaps would be able to test on x86.

> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> ---
> 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
>



--
With Best Regards,
Andy Shevchenko