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

From: okaya
Date: Tue Jun 05 2018 - 07:58:19 EST

On 2018-06-05 05:12, Andy Shevchenko wrote:
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.

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


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