On Wed, Apr 16, 2025 at 08:34:21PM +0530, Manivannan Sadhasivam wrote:
> I don't think it is possible to get rid of the powerpc version. It has
> its own pci_dev::sysdata pointing to 'struct pci_controller' pointer
> which is internal to powerpc arch code. And the generic code would need
> 'struct pci_host_bridge' to access the callback.
Below is my proposal to convert powerpc to the new ->slot_reset() callback.
Compile-tested only.
Feel free to include this in your series, alternatively I can submit it
to powerpc maintainers once your series has landed. Thanks!
-- >8 --
From: Lukas Wunner <lu...@wunner.de>
Subject: [PATCH] powerpc/powernv/pci: Migrate to pci_host_bridge::reset_slot
callback
struct pci_host_bridge has just been amended with a ->reset_slot()
callback to allow for a per-host-bridge Secondary Bus Reset procedure.
PowerNV needs a platform-specific reset procedure and has historically
implemented it by overriding pcibios_reset_secondary_bus().
Migrate PowerNV to the new ->reset_slot() callback for simplicity and
cleanliness. Assign the callback as soon as the pci_host_bridge is
allocated through the following call chain:
pcibios_init()
pcibios_scan_phb()
pci_create_root_bus()
pci_register_host_bridge()
pcibios_root_bridge_prepare()
The powerpc-specific implementation of pcibios_reset_secondary_bus() can
thus be deleted and the remaining default implementation in the PCI core
can be made private. The ->reset_secondary_bus() callback in struct
pci_controller_ops likewise becomes obsolete and can be deleted.
Signed-off-by: Lukas Wunner <lu...@wunner.de>
---
arch/powerpc/include/asm/pci-bridge.h | 1 -
arch/powerpc/kernel/pci-common.c | 12 ------------
arch/powerpc/platforms/powernv/eeh-powernv.c | 14 +++++++++-----
arch/powerpc/platforms/powernv/pci-ioda.c | 9 +++++++--
arch/powerpc/platforms/powernv/pci.h | 3 ++-
drivers/pci/pci.c | 2 +-
include/linux/pci.h | 1 -
7 files changed, 19 insertions(+), 23 deletions(-)
diff --git a/arch/powerpc/include/asm/pci-bridge.h
b/arch/powerpc/include/asm/pci-bridge.h
index 2aa3a091ef20..0de09fc90641 100644
--- a/arch/powerpc/include/asm/pci-bridge.h
+++ b/arch/powerpc/include/asm/pci-bridge.h
@@ -36,7 +36,6 @@ struct pci_controller_ops {
unsigned long type);
void (*setup_bridge)(struct pci_bus *bus,
unsigned long type);
- void (*reset_secondary_bus)(struct pci_dev *pdev);
#ifdef CONFIG_PCI_MSI
int (*setup_msi_irqs)(struct pci_dev *pdev,
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index eac84d687b53..dad15fbec4e0 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -233,18 +233,6 @@ void pcibios_setup_bridge(struct pci_bus *bus, unsigned
long type)
hose->controller_ops.setup_bridge(bus, type);
}
-void pcibios_reset_secondary_bus(struct pci_dev *dev)
-{
- struct pci_controller *phb = pci_bus_to_host(dev->bus);
-
- if (phb->controller_ops.reset_secondary_bus) {
- phb->controller_ops.reset_secondary_bus(dev);
- return;
- }
-
- pci_reset_secondary_bus(dev);
-}
-
resource_size_t pcibios_default_alignment(void)
{
if (ppc_md.pcibios_default_alignment)
diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c
b/arch/powerpc/platforms/powernv/eeh-powernv.c
index db3370d1673c..9b9517cb6ab7 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
@@ -890,18 +890,22 @@ static int pnv_eeh_bridge_reset(struct pci_dev *pdev, int
option)
return (rc == OPAL_SUCCESS) ? 0 : -EIO;
}
-void pnv_pci_reset_secondary_bus(struct pci_dev *dev)
+int pnv_pci_reset_secondary_bus(struct pci_host_bridge *host,
+ struct pci_dev *dev)
{
struct pci_controller *hose;
+ int rc_hot, rc_dea;
if (pci_is_root_bus(dev->bus)) {
hose = pci_bus_to_host(dev->bus);
- pnv_eeh_root_reset(hose, EEH_RESET_HOT);
- pnv_eeh_root_reset(hose, EEH_RESET_DEACTIVATE);
+ rc_hot = pnv_eeh_root_reset(hose, EEH_RESET_HOT);
+ rc_dea = pnv_eeh_root_reset(hose, EEH_RESET_DEACTIVATE);
} else {
- pnv_eeh_bridge_reset(dev, EEH_RESET_HOT);
- pnv_eeh_bridge_reset(dev, EEH_RESET_DEACTIVATE);
+ rc_hot = pnv_eeh_bridge_reset(dev, EEH_RESET_HOT);
+ rc_dea = pnv_eeh_bridge_reset(dev, EEH_RESET_DEACTIVATE);
}
+
+ return rc_hot ? : rc_dea ? : 0;
}
static void pnv_eeh_wait_for_pending(struct pci_dn *pdn, const char *type,
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c
b/arch/powerpc/platforms/powernv/pci-ioda.c
index ae4b549b5ca0..e1b75a4bc681 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -2145,6 +2145,12 @@ static void pnv_pci_ioda_fixup(void)
#endif
}
+static int pnv_pci_root_bridge_prepare(struct pci_host_bridge *bridge)
+{
+ bridge->reset_slot = pnv_pci_reset_secondary_bus;
+ return 0;
+}
+
/*
* Returns the alignment for I/O or memory windows for P2P
* bridges. That actually depends on how PEs are segmented.
@@ -2504,7 +2510,6 @@ static const struct pci_controller_ops
pnv_pci_ioda_controller_ops = {
.release_device = pnv_pci_release_device,
.window_alignment = pnv_pci_window_alignment,
.setup_bridge = pnv_pci_fixup_bridge_resources,
- .reset_secondary_bus = pnv_pci_reset_secondary_bus,
.shutdown = pnv_pci_ioda_shutdown,
#ifdef CONFIG_IOMMU_API
.device_group = pnv_pci_device_group,
@@ -2515,7 +2520,6 @@ static const struct pci_controller_ops
pnv_npu_ocapi_ioda_controller_ops = {
.enable_device_hook = pnv_ocapi_enable_device_hook,
.release_device = pnv_pci_release_device,
.window_alignment = pnv_pci_window_alignment,
- .reset_secondary_bus = pnv_pci_reset_secondary_bus,
.shutdown = pnv_pci_ioda_shutdown,
};
@@ -2724,6 +2728,7 @@ static void __init pnv_pci_init_ioda_phb(struct
device_node *np,
}
ppc_md.pcibios_default_alignment = pnv_pci_default_alignment;
+ ppc_md.pcibios_root_bridge_prepare = pnv_pci_root_bridge_prepare;
#ifdef CONFIG_PCI_IOV
ppc_md.pcibios_fixup_sriov = pnv_pci_ioda_fixup_iov;
diff --git a/arch/powerpc/platforms/powernv/pci.h
b/arch/powerpc/platforms/powernv/pci.h
index 42075501663b..44e8969c7729 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -275,7 +275,8 @@ extern struct iommu_table *pnv_pci_table_alloc(int nid);
extern void pnv_pci_init_ioda2_phb(struct device_node *np);
extern void pnv_pci_init_npu2_opencapi_phb(struct device_node *np);
-extern void pnv_pci_reset_secondary_bus(struct pci_dev *dev);
+extern int pnv_pci_reset_secondary_bus(struct pci_host_bridge *host,
+ struct pci_dev *dev);
extern int pnv_eeh_phb_reset(struct pci_controller *hose, int option);
extern struct pnv_ioda_pe *pnv_pci_bdfn_to_pe(struct pnv_phb *phb, u16 bdfn);
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 13709bb898a9..fe66d69c6429 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4980,7 +4980,7 @@ void pci_reset_secondary_bus(struct pci_dev *dev)
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl);
}
-void __weak pcibios_reset_secondary_bus(struct pci_dev *dev)
+static void pcibios_reset_secondary_bus(struct pci_dev *dev)
{
struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
int ret;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 76e977af2d52..43d952361e84 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1398,7 +1398,6 @@ int pci_probe_reset_slot(struct pci_slot *slot);
int pci_probe_reset_bus(struct pci_bus *bus);
int pci_reset_bus(struct pci_dev *dev);
void pci_reset_secondary_bus(struct pci_dev *dev);
-void pcibios_reset_secondary_bus(struct pci_dev *dev);
void pci_update_resource(struct pci_dev *dev, int resno);
int __must_check pci_assign_resource(struct pci_dev *dev, int i);
void pci_release_resource(struct pci_dev *dev, int resno);
--
2.43.0
