[PATCH 02/18] powerpc/{powernv,pseries}: Move PHB discovery

From: Oliver O'Halloran <oohall@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Oliver O'Halloran <oohall@gmail.com>
Subject: [PATCH 02/18] powerpc/{powernv,pseries}: Move PHB discovery
Date: Tue,  3 Nov 2020 15:35:07 +1100	[thread overview]
Message-ID: <20201103043523.916109-2-oohall@gmail.com> (raw)
In-Reply-To: <20201103043523.916109-1-oohall@gmail.com>

Make powernv and pseries use ppc_mc.discover_phbs. These two platforms need
to be done together because they both depends on pci_dn's being created
from the DT. The pci_dn contains a pointer to the relevant pci_controller
so they need to be created after the pci_controller structures are
available, but before  and before PCI devices are scanned. Currently this
ordering is provided by initcalls and the sequence is:

1. PHBs are discovered (setup_arch) (early boot, pre-initcalls)
2. pci_dn are created from the unflattended DT (core initcall)
3. PHBs are scanned pcibios_init() (subsys initcall)

The new ppc_md.discover_phbs() function is also a core_initcall so we can't
guarantee ordering between the creations of pci_controllers and the
creation of pci_dn's which require a pci_controller. We could use the
postcore, or core_sync initcall levels, but it's cleaner to just move the
pci_dn setup into the per-PHB inits which occur inside of .discover_phb()
for these platforms. This brings the boot-time path in line with the PHB
hotplug path that is used for pseries DLPAR operations too.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
---
 arch/powerpc/kernel/pci_dn.c              | 22 ----------------------
 arch/powerpc/platforms/powernv/pci-ioda.c |  3 +++
 arch/powerpc/platforms/powernv/setup.c    |  4 +---
 arch/powerpc/platforms/pseries/setup.c    |  7 +++++--
 4 files changed, 9 insertions(+), 27 deletions(-)

diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
index 54e240597fd9..61571ae23953 100644
--- a/arch/powerpc/kernel/pci_dn.c
+++ b/arch/powerpc/kernel/pci_dn.c
@@ -481,28 +481,6 @@ void pci_devs_phb_init_dynamic(struct pci_controller *phb)
 	pci_traverse_device_nodes(dn, add_pdn, phb);
 }
 
-/** 
- * pci_devs_phb_init - Initialize phbs and pci devs under them.
- * 
- * This routine walks over all phb's (pci-host bridges) on the
- * system, and sets up assorted pci-related structures 
- * (including pci info in the device node structs) for each
- * pci device found underneath.  This routine runs once,
- * early in the boot sequence.
- */
-static int __init pci_devs_phb_init(void)
-{
-	struct pci_controller *phb, *tmp;
-
-	/* This must be done first so the device nodes have valid pci info! */
-	list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
-		pci_devs_phb_init_dynamic(phb);
-
-	return 0;
-}
-
-core_initcall(pci_devs_phb_init);
-
 static void pci_dev_pdn_setup(struct pci_dev *pdev)
 {
 	struct pci_dn *pdn;
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 2b4ceb5e6ce4..d6815f03fee3 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -3176,6 +3176,9 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 	/* Remove M64 resource if we can't configure it successfully */
 	if (!phb->init_m64 || phb->init_m64(phb))
 		hose->mem_resources[1].flags = 0;
+
+	/* create pci_dn's for DT nodes under this PHB */
+	pci_devs_phb_init_dynamic(hose);
 }
 
 void __init pnv_pci_init_ioda2_phb(struct device_node *np)
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 9acaa0f131b9..92f5fa827909 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -162,9 +162,6 @@ static void __init pnv_setup_arch(void)
 	/* Initialize SMP */
 	pnv_smp_init();
 
-	/* Setup PCI */
-	pnv_pci_init();
-
 	/* Setup RTC and NVRAM callbacks */
 	if (firmware_has_feature(FW_FEATURE_OPAL))
 		opal_nvram_init();
@@ -524,6 +521,7 @@ define_machine(powernv) {
 	.init_IRQ		= pnv_init_IRQ,
 	.show_cpuinfo		= pnv_show_cpuinfo,
 	.get_proc_freq          = pnv_get_proc_freq,
+	.discover_phbs		= pnv_pci_init,
 	.progress		= pnv_progress,
 	.machine_shutdown	= pnv_shutdown,
 	.power_save             = NULL,
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 633c45ec406d..e88b30d4b6cd 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -463,7 +463,7 @@ void pseries_little_endian_exceptions(void)
 }
 #endif
 
-static void __init find_and_init_phbs(void)
+static void __init pSeries_discover_phbs(void)
 {
 	struct device_node *node;
 	struct pci_controller *phb;
@@ -481,6 +481,9 @@ static void __init find_and_init_phbs(void)
 		pci_process_bridge_OF_ranges(phb, node, 0);
 		isa_bridge_find_early(phb);
 		phb->controller_ops = pseries_pci_controller_ops;
+
+		/* create pci_dn's for DT nodes under this PHB */
+		pci_devs_phb_init_dynamic(phb);
 	}
 
 	of_node_put(root);
@@ -777,7 +780,6 @@ static void __init pSeries_setup_arch(void)
 
 	/* Find and initialize PCI host bridges */
 	init_pci_config_tokens();
-	find_and_init_phbs();
 	of_reconfig_notifier_register(&pci_dn_reconfig_nb);
 
 	pSeries_nvram_init();
@@ -1041,6 +1043,7 @@ define_machine(pseries) {
 	.init_IRQ		= pseries_init_irq,
 	.show_cpuinfo		= pSeries_show_cpuinfo,
 	.log_error		= pSeries_log_error,
+	.discover_phbs		= pSeries_discover_phbs,
 	.pcibios_fixup		= pSeries_final_fixup,
 	.restart		= rtas_restart,
 	.halt			= rtas_halt,
-- 
2.26.2

