x86/pci: Add MCFG debug logging

MCFG handling is a frequent source of problems.  Add more logging to aid in
debugging.

Enable the logging with CONFIG_DYNAMIC_DEBUG=y and the kernel boot
parameter 'dyndbg="file arch/x86/pci +p"'.

Link: https://lore.kernel.org/r/20231121183643.249006-4-helgaas@kernel.org
Tested-by: Tomasz Pala <gotar@polanet.pl>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index ea2eb2ec90e2bc96368090bb0478a2c8f591df0e..55c4b07ec1f6319bb781071453d034c9efa9ed65 100644 (file)
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -283,6 +283,9 @@ static int setup_mcfg_map(struct acpi_pci_root_info *ci)
        info->mcfg_added = false;
        seg = info->sd.domain;
 
+       dev_dbg(dev, "%s(%04x %pR ECAM %pa)\n", __func__, seg,
+               &root->secondary, &root->mcfg_addr);
+
        /* return success if MMCFG is not in use */
        if (raw_pci_ext_ops && raw_pci_ext_ops != &pci_mmcfg)
                return 0;

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 64c39a23d37af6f53e1e0fb031b71591be5698cd..bc1312d920da403f8a7976a83ee5df4b02279cfd 100644 (file)
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -579,7 +579,8 @@ static void __init pci_mmcfg_reject_broken(int early)
 
        list_for_each_entry(cfg, &pci_mmcfg_list, list) {
                if (pci_mmcfg_check_reserved(NULL, cfg, early) == 0) {
-                       pr_info(PREFIX "not using MMCONFIG\n");
+                       pr_info(PREFIX "not using MMCONFIG (%pR not reserved)\n",
+                               &cfg->res);
                        free_all_mmcfg();
                        return;
                }
@@ -676,6 +677,8 @@ static int pci_mmcfg_for_each_region(int (*func)(__u64 start, __u64 size,
 
 static void __init __pci_mmcfg_init(int early)
 {
+       pr_debug(PREFIX "%s(%s)\n", __func__, early ? "early" : "late");
+
        pci_mmcfg_reject_broken(early);
        if (list_empty(&pci_mmcfg_list))
                return;
@@ -702,6 +705,8 @@ static int __initdata known_bridge;
 
 void __init pci_mmcfg_early_init(void)
 {
+       pr_debug(PREFIX "%s() pci_probe %#x\n", __func__, pci_probe);
+
        if (pci_probe & PCI_PROBE_MMCONF) {
                if (pci_mmcfg_check_hostbridge())
                        known_bridge = 1;
@@ -715,6 +720,8 @@ void __init pci_mmcfg_early_init(void)
 
 void __init pci_mmcfg_late_init(void)
 {
+       pr_debug(PREFIX "%s() pci_probe %#x\n", __func__, pci_probe);
+
        /* MMCONFIG disabled */
        if ((pci_probe & PCI_PROBE_MMCONF) == 0)
                return;
@@ -735,6 +742,8 @@ static int __init pci_mmcfg_late_insert_resources(void)
 
        pci_mmcfg_running_state = true;
 
+       pr_debug(PREFIX "%s() pci_probe %#x\n", __func__, pci_probe);
+
        /* If we are not using MMCONFIG, don't insert the resources. */
        if ((pci_probe & PCI_PROBE_MMCONF) == 0)
                return 1;
@@ -744,9 +753,12 @@ static int __init pci_mmcfg_late_insert_resources(void)
         * marked so it won't cause request errors when __request_region is
         * called.
         */
-       list_for_each_entry(cfg, &pci_mmcfg_list, list)
-               if (!cfg->res.parent)
+       list_for_each_entry(cfg, &pci_mmcfg_list, list) {
+               if (!cfg->res.parent) {
+                       pr_debug(PREFIX "%s() insert %pR\n", __func__, &cfg->res);
                        insert_resource(&iomem_resource, &cfg->res);
+               }
+       }
 
        return 0;
 }
@@ -766,6 +778,8 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
        struct resource *tmp = NULL;
        struct pci_mmcfg_region *cfg;
 
+       dev_dbg(dev, "%s(%04x [bus %02x-%02x])\n", __func__, seg, start, end);
+
        if (!(pci_probe & PCI_PROBE_MMCONF) || pci_mmcfg_arch_init_failed)
                return -ENODEV;
 
@@ -810,8 +824,7 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
                                 "%s %pR\n",
                                 &cfg->res, tmp->name, tmp);
                } else if (pci_mmcfg_arch_map(cfg)) {
-                       dev_warn(dev, "fail to map MMCONFIG %pR.\n",
-                                &cfg->res);
+                       dev_warn(dev, "fail to map MMCONFIG %pR\n", &cfg->res);
                } else {
                        list_add_sorted(cfg);
                        dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",