2024-03-14 07:48:46

by Manivannan Sadhasivam

[permalink] [raw]
Subject: [PATCH v10 0/8] PCI: dwc: ep: Fix DBI access failure for drivers requiring refclk from host

Hello,

This series is the continuation of previous work by Vidya Sagar [1] to fix the
issues related to accessing DBI register space before completing the core
initialization in some EP platforms like Tegra194/234 and Qcom EP.

Since Vidya is busy, I took over the series based on his consent (off-list
discussion).

NOTE
====

Based on the comments received in v7 [2], I've heavily modified the series
to fix several other issues reported by Bjorn and Niklas. One noticeable
change is getting rid of the 'core_init_notifer' flag added to differentiate
between glue drivers requiring refclk from host and drivers getting refclk
locally.

By getting rid of this flag, now both the DWC EP driver and the EPF drivers
can use a single flow and need not distinguish between the glue drivers.

We can also get rid of the 'link_up_notifier' flag in the future by following
the same convention.

Testing
=======

I've tested the series on Qcom SM8450 based dev board that depends on refclk
from host with EPF_MHI driver. It'd be good to test this series on platforms
that generate refclk locally and also with EPF_TEST driver.

- Mani

[1] https://lore.kernel.org/linux-pci/[email protected]/
[2] https://lore.kernel.org/linux-pci/[email protected]/

Changes in v10:
- Reordered the commits by moving the independent fixes/cleanups first (Niklas)
- Addressed several comments from Niklas
- Moved PTM register setting out of dw_pcie_ep_init_non_sticky_registers() (Niklas)
- Addressed the issue that EPF drivers were missing init notification after the
removal of core_init_notifier (Niklas)
- Dropped a few cleanup patches to be clubbed with the follow up series
- Collected review tags
- Dropped the review tags for patch 8/8 as it got changed
- Link to v9: https://lore.kernel.org/r/[email protected]

Changes in v9:
- Incorporated changes for missing drivers (Niklas)
- Reworded the dw_pcie_ep_cleanup() API kdoc (Niklas)
- Reworded the description of patch 6/10 (Frank)
- Collected reviews
- Link to v8: https://lore.kernel.org/r/[email protected]

Changes in v8:

- Rebased on top of v6.8-rc1
- Removed the deinit callback from struct dw_pcie_ep_ops
- Renamed dw_pcie_ep_exit() to dw_pcie_ep_deinit()
- Introduced dw_pcie_ep_cleanup() API for drivers supporting PERST#
- Renamed dw_pcie_ep_init_complete() to dw_pcie_ep_init_registers()
- Called dw_pcie_ep_init_registers() API directly from all glue drivers
- Removed "core_init_notifier" flag
- Added a generic dw_pcie_ep_linkdown() API to handle LINK_DOWN event and used
it in qcom driver
- Added Kernel-doc comments for DWC EP APIs

Changes in v7:

- Rebased on top of v6.7-rc1
- Kept the current dw_pcie_ep_init_complete() API instead of renaming it to
dw_pcie_ep_init_late(), since changing the name causes a slight ambiguity.
- Splitted the change that moves pci_epc_init_notify() inside
dw_pcie_ep_init_notify() to help bisecting and also to avoid build issue.
- Added a new patch that moves pci_epc_init_notify() inside
dw_pcie_ep_init_notify().
- Took over the authorship and dropped the previous Ack as the patches are
heavily modified.

Changes in v6:

- Rebased on top of pci/next (6e2fca71e187)
- removed ep_init_late() callback as it is no longer necessary

For previous changelog, please refer [1].

Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
Manivannan Sadhasivam (8):
PCI: dwc: ep: Fix DBI access failure for drivers requiring refclk from host
PCI: dwc: ep: Add Kernel-doc comments for APIs
PCI: dwc: ep: Remove deinit() callback from struct dw_pcie_ep_ops
PCI: dwc: ep: Rename dw_pcie_ep_exit() to dw_pcie_ep_deinit()
PCI: dwc: ep: Introduce dw_pcie_ep_cleanup() API for drivers supporting PERST#
PCI: dwc: ep: Rename dw_pcie_ep_init_complete() to dw_pcie_ep_init_registers()
PCI: dwc: ep: Call dw_pcie_ep_init_registers() API directly from all glue drivers
PCI: dwc: ep: Remove "core_init_notifier" flag

drivers/pci/controller/dwc/pci-dra7xx.c | 9 +
drivers/pci/controller/dwc/pci-imx6.c | 10 +
drivers/pci/controller/dwc/pci-keystone.c | 11 +
drivers/pci/controller/dwc/pci-layerscape-ep.c | 9 +
drivers/pci/controller/dwc/pcie-artpec6.c | 15 +-
drivers/pci/controller/dwc/pcie-designware-ep.c | 238 +++++++++++++++-------
drivers/pci/controller/dwc/pcie-designware-plat.c | 11 +
drivers/pci/controller/dwc/pcie-designware.h | 14 +-
drivers/pci/controller/dwc/pcie-keembay.c | 18 +-
drivers/pci/controller/dwc/pcie-qcom-ep.c | 4 +-
drivers/pci/controller/dwc/pcie-rcar-gen4.c | 28 ++-
drivers/pci/controller/dwc/pcie-tegra194.c | 5 +-
drivers/pci/controller/dwc/pcie-uniphier-ep.c | 15 +-
drivers/pci/endpoint/functions/pci-epf-test.c | 18 +-
drivers/pci/endpoint/pci-ep-cfs.c | 9 +
drivers/pci/endpoint/pci-epc-core.c | 22 ++
include/linux/pci-epc.h | 7 +-
17 files changed, 332 insertions(+), 111 deletions(-)
---
base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
change-id: 20240224-pci-dbi-rework-b2e99a62930c

Best regards,
--
Manivannan Sadhasivam <[email protected]>



2024-03-14 07:49:04

by Manivannan Sadhasivam

[permalink] [raw]
Subject: [PATCH v10 1/8] PCI: dwc: ep: Fix DBI access failure for drivers requiring refclk from host

The DWC glue drivers requiring an active reference clock from the PCIe host
for initializing their PCIe EP core, set a flag called 'core_init_notifier'
to let DWC driver know that these drivers need a special attention during
initialization. In these drivers, access to the hw registers (like DBI)
before receiving the active refclk from host will result in access failure
and also could cause a whole system hang.

But the current DWC EP driver doesn't honor the requirements of the drivers
setting 'core_init_notifier' flag and tries to access the DBI registers
during dw_pcie_ep_init(). This causes the system hang for glue drivers such
as Tegra194 and Qcom EP as they depend on refclk from host and have set the
above mentioned flag.

To workaround this issue, users of the affected platforms have to maintain
the dependency with the PCIe host by booting the PCIe EP after host boot.
But this won't provide a good user experience, since PCIe EP is _one_ of
the features of those platforms and it doesn't make sense to delay the
whole platform booting due to PCIe requiring active refclk.

So to fix this issue, let's move all the DBI access from
dw_pcie_ep_init() in the DWC EP driver to the dw_pcie_ep_init_complete()
API. This API will only be called by the drivers setting
'core_init_notifier' flag once refclk is received from host. For the rest
of the drivers that gets the refclk locally, this API will be called
within dw_pcie_ep_init().

Fixes: e966f7390da9 ("PCI: dwc: Refactor core initialization code for EP mode")
Co-developed-by: Vidya Sagar <[email protected]>
Signed-off-by: Vidya Sagar <[email protected]>
Reviewed-by: Frank Li <[email protected]>
Reviewed-by: Niklas Cassel <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/controller/dwc/pcie-designware-ep.c | 120 ++++++++++++++----------
1 file changed, 71 insertions(+), 49 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 5befed2dc02b..c05304eabb89 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -602,11 +602,16 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+ struct dw_pcie_ep_func *ep_func;
+ struct device *dev = pci->dev;
+ struct pci_epc *epc = ep->epc;
unsigned int offset, ptm_cap_base;
unsigned int nbars;
u8 hdr_type;
+ u8 func_no;
+ int i, ret;
+ void *addr;
u32 reg;
- int i;

hdr_type = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE) &
PCI_HEADER_TYPE_MASK;
@@ -617,6 +622,58 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
return -EIO;
}

+ dw_pcie_version_detect(pci);
+
+ dw_pcie_iatu_detect(pci);
+
+ ret = dw_pcie_edma_detect(pci);
+ if (ret)
+ return ret;
+
+ if (!ep->ib_window_map) {
+ ep->ib_window_map = devm_bitmap_zalloc(dev, pci->num_ib_windows,
+ GFP_KERNEL);
+ if (!ep->ib_window_map)
+ goto err_remove_edma;
+ }
+
+ if (!ep->ob_window_map) {
+ ep->ob_window_map = devm_bitmap_zalloc(dev, pci->num_ob_windows,
+ GFP_KERNEL);
+ if (!ep->ob_window_map)
+ goto err_remove_edma;
+ }
+
+ if (!ep->outbound_addr) {
+ addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t),
+ GFP_KERNEL);
+ if (!addr)
+ goto err_remove_edma;
+ ep->outbound_addr = addr;
+ }
+
+ for (func_no = 0; func_no < epc->max_functions; func_no++) {
+
+ ep_func = dw_pcie_ep_get_func_from_ep(ep, func_no);
+ if (ep_func)
+ continue;
+
+ ep_func = devm_kzalloc(dev, sizeof(*ep_func), GFP_KERNEL);
+ if (!ep_func)
+ goto err_remove_edma;
+
+ ep_func->func_no = func_no;
+ ep_func->msi_cap = dw_pcie_ep_find_capability(ep, func_no,
+ PCI_CAP_ID_MSI);
+ ep_func->msix_cap = dw_pcie_ep_find_capability(ep, func_no,
+ PCI_CAP_ID_MSIX);
+
+ list_add_tail(&ep_func->list, &ep->func_list);
+ }
+
+ if (ep->ops->init)
+ ep->ops->init(ep);
+
offset = dw_pcie_ep_find_ext_capability(pci, PCI_EXT_CAP_ID_REBAR);
ptm_cap_base = dw_pcie_ep_find_ext_capability(pci, PCI_EXT_CAP_ID_PTM);

@@ -651,14 +708,17 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
dw_pcie_dbi_ro_wr_dis(pci);

return 0;
+
+err_remove_edma:
+ dw_pcie_edma_remove(pci);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete);

int dw_pcie_ep_init(struct dw_pcie_ep *ep)
{
int ret;
- void *addr;
- u8 func_no;
struct resource *res;
struct pci_epc *epc;
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
@@ -666,7 +726,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
struct platform_device *pdev = to_platform_device(dev);
struct device_node *np = dev->of_node;
const struct pci_epc_features *epc_features;
- struct dw_pcie_ep_func *ep_func;

INIT_LIST_HEAD(&ep->func_list);

@@ -684,26 +743,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
if (ep->ops->pre_init)
ep->ops->pre_init(ep);

- dw_pcie_version_detect(pci);
-
- dw_pcie_iatu_detect(pci);
-
- ep->ib_window_map = devm_bitmap_zalloc(dev, pci->num_ib_windows,
- GFP_KERNEL);
- if (!ep->ib_window_map)
- return -ENOMEM;
-
- ep->ob_window_map = devm_bitmap_zalloc(dev, pci->num_ob_windows,
- GFP_KERNEL);
- if (!ep->ob_window_map)
- return -ENOMEM;
-
- addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t),
- GFP_KERNEL);
- if (!addr)
- return -ENOMEM;
- ep->outbound_addr = addr;
-
epc = devm_pci_epc_create(dev, &epc_ops);
if (IS_ERR(epc)) {
dev_err(dev, "Failed to create epc device\n");
@@ -717,23 +756,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
if (ret < 0)
epc->max_functions = 1;

- for (func_no = 0; func_no < epc->max_functions; func_no++) {
- ep_func = devm_kzalloc(dev, sizeof(*ep_func), GFP_KERNEL);
- if (!ep_func)
- return -ENOMEM;
-
- ep_func->func_no = func_no;
- ep_func->msi_cap = dw_pcie_ep_find_capability(ep, func_no,
- PCI_CAP_ID_MSI);
- ep_func->msix_cap = dw_pcie_ep_find_capability(ep, func_no,
- PCI_CAP_ID_MSIX);
-
- list_add_tail(&ep_func->list, &ep->func_list);
- }
-
- if (ep->ops->init)
- ep->ops->init(ep);
-
ret = pci_epc_mem_init(epc, ep->phys_base, ep->addr_size,
ep->page_size);
if (ret < 0) {
@@ -749,25 +771,25 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
goto err_exit_epc_mem;
}

- ret = dw_pcie_edma_detect(pci);
- if (ret)
- goto err_free_epc_mem;
-
if (ep->ops->get_features) {
epc_features = ep->ops->get_features(ep);
if (epc_features->core_init_notifier)
return 0;
}

+ /*
+ * NOTE:- Avoid accessing the hardware (Ex:- DBI space) before this
+ * step as platforms that implement 'core_init_notifier' feature may
+ * not have the hardware ready (i.e. core initialized) for access
+ * (Ex: tegra194). Any hardware access on such platforms result
+ * in system hang.
+ */
ret = dw_pcie_ep_init_complete(ep);
if (ret)
- goto err_remove_edma;
+ goto err_free_epc_mem;

return 0;

-err_remove_edma:
- dw_pcie_edma_remove(pci);
-
err_free_epc_mem:
pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
epc->mem->window.page_size);

--
2.25.1


2024-03-14 07:49:37

by Manivannan Sadhasivam

[permalink] [raw]
Subject: [PATCH v10 2/8] PCI: dwc: ep: Add Kernel-doc comments for APIs

All of the APIs are missing the Kernel-doc comments. Hence, add them.

Reviewed-by: Frank Li <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/controller/dwc/pcie-designware-ep.c | 78 +++++++++++++++++++++++++
1 file changed, 78 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index c05304eabb89..d7e8f2dda6ce 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -14,6 +14,10 @@
#include <linux/pci-epc.h>
#include <linux/pci-epf.h>

+/**
+ * dw_pcie_ep_linkup - Notify EPF drivers about link up event
+ * @ep: DWC EP device
+ */
void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
{
struct pci_epc *epc = ep->epc;
@@ -22,6 +26,11 @@ void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
}
EXPORT_SYMBOL_GPL(dw_pcie_ep_linkup);

+/**
+ * dw_pcie_ep_init_notify - Notify EPF drivers about EPC initialization
+ * complete
+ * @ep: DWC EP device
+ */
void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep)
{
struct pci_epc *epc = ep->epc;
@@ -30,6 +39,14 @@ void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep)
}
EXPORT_SYMBOL_GPL(dw_pcie_ep_init_notify);

+/**
+ * dw_pcie_ep_get_func_from_ep - Get the struct dw_pcie_ep_func corresponding to
+ * the endpoint function
+ * @ep: DWC EP device
+ * @func_no: Function number of the endpoint device
+ *
+ * Return: struct dw_pcie_ep_func if success, NULL otherwise.
+ */
struct dw_pcie_ep_func *
dw_pcie_ep_get_func_from_ep(struct dw_pcie_ep *ep, u8 func_no)
{
@@ -60,6 +77,11 @@ static void __dw_pcie_ep_reset_bar(struct dw_pcie *pci, u8 func_no,
dw_pcie_dbi_ro_wr_dis(pci);
}

+/**
+ * dw_pcie_ep_reset_bar - Reset endpoint BAR
+ * @pci: DWC PCI device
+ * @bar: BAR number of the endpoint
+ */
void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
{
u8 func_no, funcs;
@@ -439,6 +461,13 @@ static const struct pci_epc_ops epc_ops = {
.get_features = dw_pcie_ep_get_features,
};

+/**
+ * dw_pcie_ep_raise_intx_irq - Raise INTx IRQ to the host
+ * @ep: DWC EP device
+ * @func_no: Function number of the endpoint
+ *
+ * Return: 0 if success, errono otherwise.
+ */
int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
@@ -450,6 +479,14 @@ int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
}
EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_intx_irq);

+/**
+ * dw_pcie_ep_raise_msi_irq - Raise MSI IRQ to the host
+ * @ep: DWC EP device
+ * @func_no: Function number of the endpoint
+ * @interrupt_num: Interrupt number to be raised
+ *
+ * Return: 0 if success, errono otherwise.
+ */
int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
u8 interrupt_num)
{
@@ -498,6 +535,15 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
}
EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_msi_irq);

+/**
+ * dw_pcie_ep_raise_msix_irq_doorbell - Raise MSIX to the host using Doorbell
+ * method
+ * @ep: DWC EP device
+ * @func_no: Function number of the endpoint device
+ * @interrupt_num: Interrupt number to be raised
+ *
+ * Return: 0 if success, errno otherwise.
+ */
int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep *ep, u8 func_no,
u16 interrupt_num)
{
@@ -517,6 +563,14 @@ int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

+/**
+ * dw_pcie_ep_raise_msix_irq - Raise MSIX to the host
+ * @ep: DWC EP device
+ * @func_no: Function number of the endpoint device
+ * @interrupt_num: Interrupt number to be raised
+ *
+ * Return: 0 if success, errno otherwise.
+ */
int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
u16 interrupt_num)
{
@@ -564,6 +618,13 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

+/**
+ * dw_pcie_ep_exit - Deinitialize the endpoint device
+ * @ep: DWC EP device
+ *
+ * Deinitialize the endpoint device. EPC device is not destroyed since that will
+ * taken care by Devres.
+ */
void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
@@ -599,6 +660,14 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
return 0;
}

+/**
+ * dw_pcie_ep_init_complete - Complete DWC EP initialization
+ * @ep: DWC EP device
+ *
+ * Complete the initialization of the registers (CSRs) specific to DWC EP. This
+ * API should be called only when the endpoint receives an active refclk (either
+ * from host or generated locally).
+ */
int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
@@ -716,6 +785,15 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
}
EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete);

+/**
+ * dw_pcie_ep_init - Initialize the endpoint device
+ * @ep: DWC EP device
+ *
+ * Initialize the endpoint device. Allocate resources and create the EPC
+ * device with the endpoint framework.
+ *
+ * Return: 0 if success, errno otherwise.
+ */
int dw_pcie_ep_init(struct dw_pcie_ep *ep)
{
int ret;

--
2.25.1


2024-03-14 07:50:55

by Manivannan Sadhasivam

[permalink] [raw]
Subject: [PATCH v10 6/8] PCI: dwc: ep: Rename dw_pcie_ep_init_complete() to dw_pcie_ep_init_registers()

The goal of the dw_pcie_ep_init_complete() API is to initialize the DWC
specific registers post registering the controller with the EP framework.

But the naming doesn't reflect its functionality and causes confusion. So,
let's rename it to dw_pcie_ep_init_registers() to make it clear that it
initializes the DWC specific registers.

Reviewed-by: Frank Li <[email protected]>
Reviewed-by: Niklas Cassel <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/controller/dwc/pcie-designware-ep.c | 14 +++++++-------
drivers/pci/controller/dwc/pcie-designware.h | 4 ++--
drivers/pci/controller/dwc/pcie-qcom-ep.c | 2 +-
drivers/pci/controller/dwc/pcie-tegra194.c | 2 +-
4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 4c21a38245b6..9354671644b6 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -673,14 +673,14 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
}

/**
- * dw_pcie_ep_init_complete - Complete DWC EP initialization
+ * dw_pcie_ep_init_registers - Initialize DWC EP specific registers
* @ep: DWC EP device
*
- * Complete the initialization of the registers (CSRs) specific to DWC EP. This
- * API should be called only when the endpoint receives an active refclk (either
- * from host or generated locally).
+ * Initialize the registers (CSRs) specific to DWC EP. This API should be called
+ * only when the endpoint receives an active refclk (either from host or
+ * generated locally).
*/
-int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
+int dw_pcie_ep_init_registers(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
struct dw_pcie_ep_func *ep_func;
@@ -795,7 +795,7 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)

return ret;
}
-EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete);
+EXPORT_SYMBOL_GPL(dw_pcie_ep_init_registers);

/**
* dw_pcie_ep_init - Initialize the endpoint device
@@ -874,7 +874,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
* (Ex: tegra194). Any hardware access on such platforms result
* in system hang.
*/
- ret = dw_pcie_ep_init_complete(ep);
+ ret = dw_pcie_ep_init_registers(ep);
if (ret)
goto err_free_epc_mem;

diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 351d2fe3ea4d..f8e5431a207b 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -669,7 +669,7 @@ static inline void __iomem *dw_pcie_own_conf_map_bus(struct pci_bus *bus,
#ifdef CONFIG_PCIE_DW_EP
void dw_pcie_ep_linkup(struct dw_pcie_ep *ep);
int dw_pcie_ep_init(struct dw_pcie_ep *ep);
-int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep);
+int dw_pcie_ep_init_registers(struct dw_pcie_ep *ep);
void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep);
void dw_pcie_ep_deinit(struct dw_pcie_ep *ep);
void dw_pcie_ep_cleanup(struct dw_pcie_ep *ep);
@@ -693,7 +693,7 @@ static inline int dw_pcie_ep_init(struct dw_pcie_ep *ep)
return 0;
}

-static inline int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
+static inline int dw_pcie_ep_init_registers(struct dw_pcie_ep *ep)
{
return 0;
}
diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 59b1c0110288..3697b4a944cc 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -463,7 +463,7 @@ static int qcom_pcie_perst_deassert(struct dw_pcie *pci)
PARF_INT_ALL_LINK_UP | PARF_INT_ALL_EDMA;
writel_relaxed(val, pcie_ep->parf + PARF_INT_ALL_MASK);

- ret = dw_pcie_ep_init_complete(&pcie_ep->pci.ep);
+ ret = dw_pcie_ep_init_registers(&pcie_ep->pci.ep);
if (ret) {
dev_err(dev, "Failed to complete initialization: %d\n", ret);
goto err_disable_resources;
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 68bfeed3429b..264ee76bf008 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1897,7 +1897,7 @@ static void pex_ep_event_pex_rst_deassert(struct tegra_pcie_dw *pcie)
val = (upper_32_bits(ep->msi_mem_phys) & MSIX_ADDR_MATCH_HIGH_OFF_MASK);
dw_pcie_writel_dbi(pci, MSIX_ADDR_MATCH_HIGH_OFF, val);

- ret = dw_pcie_ep_init_complete(ep);
+ ret = dw_pcie_ep_init_registers(ep);
if (ret) {
dev_err(dev, "Failed to complete initialization: %d\n", ret);
goto fail_init_complete;

--
2.25.1


2024-03-14 07:52:42

by Manivannan Sadhasivam

[permalink] [raw]
Subject: [PATCH v10 8/8] PCI: dwc: ep: Remove "core_init_notifier" flag

"core_init_notifier" flag is set by the glue drivers requiring refclk from
the host to complete the DWC core initialization. Also, those drivers will
send a notification to the EPF drivers once the initialization is fully
completed using the pci_epc_init_notify() API. Only then, the EPF drivers
will start functioning.

For the rest of the drivers generating refclk locally, EPF drivers will
start functioning post binding with them. EPF drivers rely on the
'core_init_notifier' flag to differentiate between the drivers.
Unfortunately, this creates two different flows for the EPF drivers.

So to avoid that, let's get rid of the "core_init_notifier" flag and follow
a single initialization flow for the EPF drivers. This is done by calling
the dw_pcie_ep_init_notify() from all glue drivers after the completion of
dw_pcie_ep_init_registers() API. This will allow all the glue drivers to
send the notification to the EPF drivers once the initialization is fully
completed.

Only difference here is that, the drivers requiring refclk from host will
send the notification once refclk is received, while others will send it
during probe time itself.

But this also requires the EPC core driver to deliver the notification
after EPF driver bind. Because, the glue driver can send the notification
before the EPF drivers bind() and in those cases the EPF drivers will miss
the event. To accommodate this, EPC core is now caching the state of the
EPC initialization in 'init_complete' flag and pci-ep-cfs driver sends the
notification to EPF drivers based on that after each EPF driver bind.

Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/controller/dwc/pci-dra7xx.c | 2 ++
drivers/pci/controller/dwc/pci-imx6.c | 2 ++
drivers/pci/controller/dwc/pci-keystone.c | 2 ++
drivers/pci/controller/dwc/pci-layerscape-ep.c | 2 ++
drivers/pci/controller/dwc/pcie-artpec6.c | 2 ++
drivers/pci/controller/dwc/pcie-designware-plat.c | 2 ++
drivers/pci/controller/dwc/pcie-keembay.c | 2 ++
drivers/pci/controller/dwc/pcie-qcom-ep.c | 1 -
drivers/pci/controller/dwc/pcie-rcar-gen4.c | 2 ++
drivers/pci/controller/dwc/pcie-tegra194.c | 1 -
drivers/pci/controller/dwc/pcie-uniphier-ep.c | 2 ++
drivers/pci/endpoint/functions/pci-epf-test.c | 18 +++++-------------
drivers/pci/endpoint/pci-ep-cfs.c | 9 +++++++++
drivers/pci/endpoint/pci-epc-core.c | 22 ++++++++++++++++++++++
include/linux/pci-epc.h | 7 ++++---
15 files changed, 58 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-dra7xx.c b/drivers/pci/controller/dwc/pci-dra7xx.c
index 395042b29ffc..d2d17d37d3e0 100644
--- a/drivers/pci/controller/dwc/pci-dra7xx.c
+++ b/drivers/pci/controller/dwc/pci-dra7xx.c
@@ -474,6 +474,8 @@ static int dra7xx_add_pcie_ep(struct dra7xx_pcie *dra7xx,
return ret;
}

+ dw_pcie_ep_init_notify(ep);
+
return 0;
}

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index bfcafa440ddb..894b5de76e3a 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1144,6 +1144,8 @@ static int imx6_add_pcie_ep(struct imx6_pcie *imx6_pcie,
return ret;
}

+ dw_pcie_ep_init_notify(ep);
+
/* Start LTSSM. */
imx6_pcie_ltssm_enable(dev);

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index 093dbb725e41..b7b30470b394 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -1293,6 +1293,8 @@ static int ks_pcie_probe(struct platform_device *pdev)
goto err_ep_init;
}

+ dw_pcie_ep_init_notify(&pci->ep);
+
break;
default:
dev_err(dev, "INVALID device type %d\n", mode);
diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c
index b712fdd06549..c513598a46d7 100644
--- a/drivers/pci/controller/dwc/pci-layerscape-ep.c
+++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c
@@ -283,6 +283,8 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev)
return ret;
}

+ dw_pcie_ep_init_notify(&pci->ep);
+
return ls_pcie_ep_interrupt_init(pcie, pdev);
}

diff --git a/drivers/pci/controller/dwc/pcie-artpec6.c b/drivers/pci/controller/dwc/pcie-artpec6.c
index a6095561db4a..a4630b92489b 100644
--- a/drivers/pci/controller/dwc/pcie-artpec6.c
+++ b/drivers/pci/controller/dwc/pcie-artpec6.c
@@ -452,6 +452,8 @@ static int artpec6_pcie_probe(struct platform_device *pdev)
return ret;
}

+ dw_pcie_ep_init_notify(&pci->ep);
+
break;
default:
dev_err(dev, "INVALID device type %d\n", artpec6_pcie->mode);
diff --git a/drivers/pci/controller/dwc/pcie-designware-plat.c b/drivers/pci/controller/dwc/pcie-designware-plat.c
index ca9b22e654cd..8490c5d6ff9f 100644
--- a/drivers/pci/controller/dwc/pcie-designware-plat.c
+++ b/drivers/pci/controller/dwc/pcie-designware-plat.c
@@ -154,6 +154,8 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
dw_pcie_ep_deinit(&pci->ep);
}

+ dw_pcie_ep_init_notify(&pci->ep);
+
break;
default:
dev_err(dev, "INVALID device type %d\n", dw_plat_pcie->mode);
diff --git a/drivers/pci/controller/dwc/pcie-keembay.c b/drivers/pci/controller/dwc/pcie-keembay.c
index 250d6acf16dc..9fa9354a5f48 100644
--- a/drivers/pci/controller/dwc/pcie-keembay.c
+++ b/drivers/pci/controller/dwc/pcie-keembay.c
@@ -438,6 +438,8 @@ static int keembay_pcie_probe(struct platform_device *pdev)
return ret;
}

+ dw_pcie_ep_init_notify(&pci->ep);
+
break;
default:
dev_err(dev, "Invalid device type %d\n", pcie->mode);
diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 3697b4a944cc..2fb8c15e7a91 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -775,7 +775,6 @@ static void qcom_pcie_ep_init_debugfs(struct qcom_pcie_ep *pcie_ep)

static const struct pci_epc_features qcom_pcie_epc_features = {
.linkup_notifier = true,
- .core_init_notifier = true,
.msi_capable = true,
.msix_capable = false,
.align = SZ_4K,
diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index fb7c03639a53..0448928017f3 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -435,6 +435,8 @@ static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
rcar_gen4_pcie_ep_deinit(rcar);
}

+ dw_pcie_ep_init_notify(ep);
+
return ret;
}

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 264ee76bf008..e02deb31a72d 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -2006,7 +2006,6 @@ static int tegra_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,

static const struct pci_epc_features tegra_pcie_epc_features = {
.linkup_notifier = true,
- .core_init_notifier = true,
.msi_capable = false,
.msix_capable = false,
.reserved_bar = 1 << BAR_2 | 1 << BAR_3 | 1 << BAR_4 | 1 << BAR_5,
diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
index 82ccaea089be..eb1d79fdb1f1 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
@@ -410,6 +410,8 @@ static int uniphier_pcie_ep_probe(struct platform_device *pdev)
return ret;
}

+ dw_pcie_ep_init_notify(&priv->pci.ep);
+
return 0;
}

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 18c80002d3bd..fc0282b0d626 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -753,6 +753,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
const struct pci_epc_features *epc_features;
struct pci_epc *epc = epf->epc;
struct device *dev = &epf->dev;
+ bool linkup_notifier = false;
bool msix_capable = false;
bool msi_capable = true;
int ret;
@@ -795,6 +796,10 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
}
}

+ linkup_notifier = epc_features->linkup_notifier;
+ if (!linkup_notifier)
+ queue_work(kpcitest_workqueue, &epf_test->cmd_handler.work);
+
return 0;
}

@@ -901,8 +906,6 @@ static int pci_epf_test_bind(struct pci_epf *epf)
const struct pci_epc_features *epc_features;
enum pci_barno test_reg_bar = BAR_0;
struct pci_epc *epc = epf->epc;
- bool linkup_notifier = false;
- bool core_init_notifier = false;

if (WARN_ON_ONCE(!epc))
return -EINVAL;
@@ -913,8 +916,6 @@ static int pci_epf_test_bind(struct pci_epf *epf)
return -EOPNOTSUPP;
}

- linkup_notifier = epc_features->linkup_notifier;
- core_init_notifier = epc_features->core_init_notifier;
test_reg_bar = pci_epc_get_first_free_bar(epc_features);
if (test_reg_bar < 0)
return -EINVAL;
@@ -927,21 +928,12 @@ static int pci_epf_test_bind(struct pci_epf *epf)
if (ret)
return ret;

- if (!core_init_notifier) {
- ret = pci_epf_test_core_init(epf);
- if (ret)
- return ret;
- }
-
epf_test->dma_supported = true;

ret = pci_epf_test_init_dma_chan(epf_test);
if (ret)
epf_test->dma_supported = false;

- if (!linkup_notifier && !core_init_notifier)
- queue_work(kpcitest_workqueue, &epf_test->cmd_handler.work);
-
return 0;
}

diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
index 0ea64e24ed61..3b21e28f9b59 100644
--- a/drivers/pci/endpoint/pci-ep-cfs.c
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -64,6 +64,9 @@ static int pci_secondary_epc_epf_link(struct config_item *epf_item,
return ret;
}

+ /* Send any pending EPC initialization complete to the EPF driver */
+ pci_epc_notify_pending_init(epc, epf);
+
return 0;
}

@@ -125,6 +128,9 @@ static int pci_primary_epc_epf_link(struct config_item *epf_item,
return ret;
}

+ /* Send any pending EPC initialization complete to the EPF driver */
+ pci_epc_notify_pending_init(epc, epf);
+
return 0;
}

@@ -230,6 +236,9 @@ static int pci_epc_epf_link(struct config_item *epc_item,
return ret;
}

+ /* Send any pending EPC initialization complete to the EPF driver */
+ pci_epc_notify_pending_init(epc, epf);
+
return 0;
}

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index dcd4e66430c1..ba2ff037dfa6 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -753,10 +753,32 @@ void pci_epc_init_notify(struct pci_epc *epc)
epf->event_ops->core_init(epf);
mutex_unlock(&epf->lock);
}
+ epc->init_complete = true;
mutex_unlock(&epc->list_lock);
}
EXPORT_SYMBOL_GPL(pci_epc_init_notify);

+/**
+ * pci_epc_notify_pending_init() - Notify the pending EPC device initialization
+ * complete to the EPF device
+ * @epc: the EPC device whose core initialization is pending to be notified
+ * @epf: the EPF device to be notified
+ *
+ * Invoke to notify the pending EPC device initialization complete to the EPF
+ * device. This is used to deliver the notification if the EPC initialization
+ * got completed before the EPF driver bind.
+ */
+void pci_epc_notify_pending_init(struct pci_epc *epc, struct pci_epf *epf)
+{
+ if (epc->init_complete) {
+ mutex_lock(&epf->lock);
+ if (epf->event_ops && epf->event_ops->core_init)
+ epf->event_ops->core_init(epf);
+ mutex_unlock(&epf->lock);
+ }
+}
+EXPORT_SYMBOL_GPL(pci_epc_notify_pending_init);
+
/**
* pci_epc_bme_notify() - Notify the EPF device that the EPC device has received
* the BME event from the Root complex
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 40ea18f5aa02..adee6dbe4e45 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -128,6 +128,8 @@ struct pci_epc_mem {
* @group: configfs group representing the PCI EPC device
* @lock: mutex to protect pci_epc ops
* @function_num_map: bitmap to manage physical function number
+ * @init_complete: flag to indicate whether the EPC initialization is complete
+ * or not
*/
struct pci_epc {
struct device dev;
@@ -143,13 +145,12 @@ struct pci_epc {
/* mutex to protect against concurrent access of EP controller */
struct mutex lock;
unsigned long function_num_map;
+ bool init_complete;
};

/**
* struct pci_epc_features - features supported by a EPC device per function
* @linkup_notifier: indicate if the EPC device can notify EPF driver on link up
- * @core_init_notifier: indicate cores that can notify about their availability
- * for initialization
* @msi_capable: indicate if the endpoint function has MSI capability
* @msix_capable: indicate if the endpoint function has MSI-X capability
* @reserved_bar: bitmap to indicate reserved BAR unavailable to function driver
@@ -159,7 +160,6 @@ struct pci_epc {
*/
struct pci_epc_features {
unsigned int linkup_notifier : 1;
- unsigned int core_init_notifier : 1;
unsigned int msi_capable : 1;
unsigned int msix_capable : 1;
u8 reserved_bar;
@@ -198,6 +198,7 @@ int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
void pci_epc_linkup(struct pci_epc *epc);
void pci_epc_linkdown(struct pci_epc *epc);
void pci_epc_init_notify(struct pci_epc *epc);
+void pci_epc_notify_pending_init(struct pci_epc *epc, struct pci_epf *epf);
void pci_epc_bme_notify(struct pci_epc *epc);
void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
enum pci_epc_interface_type type);

--
2.25.1


2024-03-14 07:52:51

by Manivannan Sadhasivam

[permalink] [raw]
Subject: [PATCH v10 4/8] PCI: dwc: ep: Rename dw_pcie_ep_exit() to dw_pcie_ep_deinit()

dw_pcie_ep_exit() API is undoing what the dw_pcie_ep_init() API has done
already (at least partly). But the API name dw_pcie_ep_exit() is not quite
reflecting that. So let's rename it to dw_pcie_ep_deinit() to make the
purpose of this API clear. This also aligns with the DWC host driver.

Reviewed-by: Frank Li <[email protected]>
Reviewed-by: Niklas Cassel <[email protected]>
Reviewed-by: Yoshihiro Shimoda <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/controller/dwc/pcie-designware-ep.c | 6 +++---
drivers/pci/controller/dwc/pcie-designware.h | 4 ++--
drivers/pci/controller/dwc/pcie-rcar-gen4.c | 2 +-
3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index e59e35fd7251..fa7b26da8718 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -619,13 +619,13 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
}

/**
- * dw_pcie_ep_exit - Deinitialize the endpoint device
+ * dw_pcie_ep_deinit - Deinitialize the endpoint device
* @ep: DWC EP device
*
* Deinitialize the endpoint device. EPC device is not destroyed since that will
* taken care by Devres.
*/
-void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
+void dw_pcie_ep_deinit(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
struct pci_epc *epc = ep->epc;
@@ -637,7 +637,7 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)

pci_epc_mem_exit(epc);
}
-EXPORT_SYMBOL_GPL(dw_pcie_ep_exit);
+EXPORT_SYMBOL_GPL(dw_pcie_ep_deinit);

static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
{
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index ab7431a37209..61465203bb60 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -671,7 +671,7 @@ void dw_pcie_ep_linkup(struct dw_pcie_ep *ep);
int dw_pcie_ep_init(struct dw_pcie_ep *ep);
int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep);
void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep);
-void dw_pcie_ep_exit(struct dw_pcie_ep *ep);
+void dw_pcie_ep_deinit(struct dw_pcie_ep *ep);
int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no);
int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
u8 interrupt_num);
@@ -701,7 +701,7 @@ static inline void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep)
{
}

-static inline void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
+static inline void dw_pcie_ep_deinit(struct dw_pcie_ep *ep)
{
}

diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index ac97d594ea47..9d9d22e367bb 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -430,7 +430,7 @@ static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)

static void rcar_gen4_remove_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
{
- dw_pcie_ep_exit(&rcar->dw.ep);
+ dw_pcie_ep_deinit(&rcar->dw.ep);
rcar_gen4_pcie_ep_deinit(rcar);
}


--
2.25.1


2024-03-14 07:53:10

by Manivannan Sadhasivam

[permalink] [raw]
Subject: [PATCH v10 5/8] PCI: dwc: ep: Introduce dw_pcie_ep_cleanup() API for drivers supporting PERST#

For DWC glue drivers supporting PERST# (currently Qcom and Tegra194), some
of the DWC resources like eDMA should be cleaned up during the PERST#
assert time.

So let's introduce a dw_pcie_ep_cleanup() API that could be called by these
drivers to cleanup the DWC specific resources. Currently, it just removes
eDMA.

Reported-by: Niklas Cassel <[email protected]>
Closes: https://lore.kernel.org/linux-pci/ZWYmX8Y%2F7Q9WMxES@x1-carbon
Reviewed-by: Frank Li <[email protected]>
Reviewed-by: Niklas Cassel <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/controller/dwc/pcie-designware-ep.c | 19 +++++++++++++++++--
drivers/pci/controller/dwc/pcie-designware.h | 5 +++++
drivers/pci/controller/dwc/pcie-qcom-ep.c | 1 +
drivers/pci/controller/dwc/pcie-tegra194.c | 2 ++
4 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index fa7b26da8718..4c21a38245b6 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -618,6 +618,22 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
return 0;
}

+/**
+ * dw_pcie_ep_cleanup - Cleanup DWC EP resources after fundamental reset
+ * @ep: DWC EP device
+ *
+ * Cleans up the DWC EP specific resources like eDMA etc... after fundamental
+ * reset like PERST#. Note that this API is only applicable for drivers
+ * supporting PERST# or any other methods of fundamental reset.
+ */
+void dw_pcie_ep_cleanup(struct dw_pcie_ep *ep)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+ dw_pcie_edma_remove(pci);
+}
+EXPORT_SYMBOL_GPL(dw_pcie_ep_cleanup);
+
/**
* dw_pcie_ep_deinit - Deinitialize the endpoint device
* @ep: DWC EP device
@@ -627,10 +643,9 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
*/
void dw_pcie_ep_deinit(struct dw_pcie_ep *ep)
{
- struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
struct pci_epc *epc = ep->epc;

- dw_pcie_edma_remove(pci);
+ dw_pcie_ep_cleanup(ep);

pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
epc->mem->window.page_size);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 61465203bb60..351d2fe3ea4d 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -672,6 +672,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep);
int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep);
void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep);
void dw_pcie_ep_deinit(struct dw_pcie_ep *ep);
+void dw_pcie_ep_cleanup(struct dw_pcie_ep *ep);
int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no);
int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
u8 interrupt_num);
@@ -705,6 +706,10 @@ static inline void dw_pcie_ep_deinit(struct dw_pcie_ep *ep)
{
}

+static inline void dw_pcie_ep_cleanup(struct dw_pcie_ep *ep)
+{
+}
+
static inline int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
{
return 0;
diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 36e5e80cd22f..59b1c0110288 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -507,6 +507,7 @@ static void qcom_pcie_perst_assert(struct dw_pcie *pci)
return;
}

+ dw_pcie_ep_cleanup(&pci->ep);
qcom_pcie_disable_resources(pcie_ep);
pcie_ep->link_status = QCOM_PCIE_EP_LINK_DISABLED;
}
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 7afa9e9aabe2..68bfeed3429b 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1715,6 +1715,8 @@ static void pex_ep_event_pex_rst_assert(struct tegra_pcie_dw *pcie)
if (ret)
dev_err(pcie->dev, "Failed to go Detect state: %d\n", ret);

+ dw_pcie_ep_cleanup(&pcie->pci.ep);
+
reset_control_assert(pcie->core_rst);

tegra_pcie_disable_phy(pcie);

--
2.25.1


2024-03-14 07:58:56

by Manivannan Sadhasivam

[permalink] [raw]
Subject: [PATCH v10 3/8] PCI: dwc: ep: Remove deinit() callback from struct dw_pcie_ep_ops

deinit() callback was solely introduced for the pcie-rcar-gen4 driver where
it is used to do platform specific resource deallocation. And this callback
is called right at the end of the dw_pcie_ep_exit() API. So it doesn't
matter whether it is called within or outside of dw_pcie_ep_exit() API.

So let's remove this callback and directly call rcar_gen4_pcie_ep_deinit()
in pcie-rcar-gen4 driver to do resource deallocation after the completion
of dw_pcie_ep_exit() API in rcar_gen4_remove_dw_pcie_ep().

This simplifies the DWC layer.

Reviewed-by: Frank Li <[email protected]>
Reviewed-by: Niklas Cassel <[email protected]>
Reviewed-by: Yoshihiro Shimoda <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/controller/dwc/pcie-designware-ep.c | 9 +--------
drivers/pci/controller/dwc/pcie-designware.h | 1 -
drivers/pci/controller/dwc/pcie-rcar-gen4.c | 14 ++++++++------
3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index d7e8f2dda6ce..e59e35fd7251 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -636,9 +636,6 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
epc->mem->window.page_size);

pci_epc_mem_exit(epc);
-
- if (ep->ops->deinit)
- ep->ops->deinit(ep);
}
EXPORT_SYMBOL_GPL(dw_pcie_ep_exit);

@@ -838,7 +835,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
ep->page_size);
if (ret < 0) {
dev_err(dev, "Failed to initialize address space\n");
- goto err_ep_deinit;
+ return ret;
}

ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
@@ -875,10 +872,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
err_exit_epc_mem:
pci_epc_mem_exit(epc);

-err_ep_deinit:
- if (ep->ops->deinit)
- ep->ops->deinit(ep);
-
return ret;
}
EXPORT_SYMBOL_GPL(dw_pcie_ep_init);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 26dae4837462..ab7431a37209 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -333,7 +333,6 @@ struct dw_pcie_rp {
struct dw_pcie_ep_ops {
void (*pre_init)(struct dw_pcie_ep *ep);
void (*init)(struct dw_pcie_ep *ep);
- void (*deinit)(struct dw_pcie_ep *ep);
int (*raise_irq)(struct dw_pcie_ep *ep, u8 func_no,
unsigned int type, u16 interrupt_num);
const struct pci_epc_features* (*get_features)(struct dw_pcie_ep *ep);
diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index e9166619b1f9..ac97d594ea47 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -352,11 +352,8 @@ static void rcar_gen4_pcie_ep_init(struct dw_pcie_ep *ep)
dw_pcie_ep_reset_bar(pci, bar);
}

-static void rcar_gen4_pcie_ep_deinit(struct dw_pcie_ep *ep)
+static void rcar_gen4_pcie_ep_deinit(struct rcar_gen4_pcie *rcar)
{
- struct dw_pcie *dw = to_dw_pcie_from_ep(ep);
- struct rcar_gen4_pcie *rcar = to_rcar_gen4_pcie(dw);
-
writel(0, rcar->base + PCIEDMAINTSTSEN);
rcar_gen4_pcie_common_deinit(rcar);
}
@@ -408,7 +405,6 @@ static unsigned int rcar_gen4_pcie_ep_get_dbi2_offset(struct dw_pcie_ep *ep,
static const struct dw_pcie_ep_ops pcie_ep_ops = {
.pre_init = rcar_gen4_pcie_ep_pre_init,
.init = rcar_gen4_pcie_ep_init,
- .deinit = rcar_gen4_pcie_ep_deinit,
.raise_irq = rcar_gen4_pcie_ep_raise_irq,
.get_features = rcar_gen4_pcie_ep_get_features,
.get_dbi_offset = rcar_gen4_pcie_ep_get_dbi_offset,
@@ -418,18 +414,24 @@ static const struct dw_pcie_ep_ops pcie_ep_ops = {
static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
{
struct dw_pcie_ep *ep = &rcar->dw.ep;
+ int ret;

if (!IS_ENABLED(CONFIG_PCIE_RCAR_GEN4_EP))
return -ENODEV;

ep->ops = &pcie_ep_ops;

- return dw_pcie_ep_init(ep);
+ ret = dw_pcie_ep_init(ep);
+ if (ret)
+ rcar_gen4_pcie_ep_deinit(rcar);
+
+ return ret;
}

static void rcar_gen4_remove_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
{
dw_pcie_ep_exit(&rcar->dw.ep);
+ rcar_gen4_pcie_ep_deinit(rcar);
}

/* Common */

--
2.25.1


2024-03-14 07:59:04

by Manivannan Sadhasivam

[permalink] [raw]
Subject: [PATCH v10 7/8] PCI: dwc: ep: Call dw_pcie_ep_init_registers() API directly from all glue drivers

Currently, dw_pcie_ep_init_registers() API is directly called by the glue
drivers requiring active refclk from host. But for the other drivers, it is
getting called implicitly by dw_pcie_ep_init(). This is due to the fact
that this API initializes DWC EP specific registers and that requires an
active refclk (either from host or generated locally by endpoint itsef).

But, this causes a discrepancy among the glue drivers. So to avoid this
confusion, let's call this API directly from all glue drivers irrespective
of refclk dependency. Only difference here is that the drivers requiring
refclk from host will call this API only after the refclk is received and
other drivers without refclk dependency will call this API right after
dw_pcie_ep_init().

With this change, the check for 'core_init_notifier' flag can now be
dropped from dw_pcie_ep_init() API. This will also allow us to remove the
'core_init_notifier' flag completely in the later commits.

Reviewed-by: Yoshihiro Shimoda <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/controller/dwc/pci-dra7xx.c | 7 +++++++
drivers/pci/controller/dwc/pci-imx6.c | 8 ++++++++
drivers/pci/controller/dwc/pci-keystone.c | 9 +++++++++
drivers/pci/controller/dwc/pci-layerscape-ep.c | 7 +++++++
drivers/pci/controller/dwc/pcie-artpec6.c | 13 ++++++++++++-
drivers/pci/controller/dwc/pcie-designware-ep.c | 22 ----------------------
drivers/pci/controller/dwc/pcie-designware-plat.c | 9 +++++++++
drivers/pci/controller/dwc/pcie-keembay.c | 16 +++++++++++++++-
drivers/pci/controller/dwc/pcie-rcar-gen4.c | 12 +++++++++++-
drivers/pci/controller/dwc/pcie-uniphier-ep.c | 13 ++++++++++++-
10 files changed, 90 insertions(+), 26 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-dra7xx.c b/drivers/pci/controller/dwc/pci-dra7xx.c
index 0e406677060d..395042b29ffc 100644
--- a/drivers/pci/controller/dwc/pci-dra7xx.c
+++ b/drivers/pci/controller/dwc/pci-dra7xx.c
@@ -467,6 +467,13 @@ static int dra7xx_add_pcie_ep(struct dra7xx_pcie *dra7xx,
return ret;
}

+ ret = dw_pcie_ep_init_registers(ep);
+ if (ret) {
+ dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+ dw_pcie_ep_deinit(ep);
+ return ret;
+ }
+
return 0;
}

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index dc2c036ab28c..bfcafa440ddb 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1136,6 +1136,14 @@ static int imx6_add_pcie_ep(struct imx6_pcie *imx6_pcie,
dev_err(dev, "failed to initialize endpoint\n");
return ret;
}
+
+ ret = dw_pcie_ep_init_registers(ep);
+ if (ret) {
+ dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+ dw_pcie_ep_deinit(ep);
+ return ret;
+ }
+
/* Start LTSSM. */
imx6_pcie_ltssm_enable(dev);

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index c0c62533a3f1..093dbb725e41 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -1286,6 +1286,13 @@ static int ks_pcie_probe(struct platform_device *pdev)
ret = dw_pcie_ep_init(&pci->ep);
if (ret < 0)
goto err_get_sync;
+
+ ret = dw_pcie_ep_init_registers(&pci->ep);
+ if (ret) {
+ dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+ goto err_ep_init;
+ }
+
break;
default:
dev_err(dev, "INVALID device type %d\n", mode);
@@ -1295,6 +1302,8 @@ static int ks_pcie_probe(struct platform_device *pdev)

return 0;

+err_ep_init:
+ dw_pcie_ep_deinit(&pci->ep);
err_get_sync:
pm_runtime_put(dev);
pm_runtime_disable(dev);
diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c
index 2e398494e7c0..b712fdd06549 100644
--- a/drivers/pci/controller/dwc/pci-layerscape-ep.c
+++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c
@@ -276,6 +276,13 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev)
if (ret)
return ret;

+ ret = dw_pcie_ep_init_registers(&pci->ep);
+ if (ret) {
+ dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+ dw_pcie_ep_deinit(&pci->ep);
+ return ret;
+ }
+
return ls_pcie_ep_interrupt_init(pcie, pdev);
}

diff --git a/drivers/pci/controller/dwc/pcie-artpec6.c b/drivers/pci/controller/dwc/pcie-artpec6.c
index 9ed0a9ba7619..a6095561db4a 100644
--- a/drivers/pci/controller/dwc/pcie-artpec6.c
+++ b/drivers/pci/controller/dwc/pcie-artpec6.c
@@ -441,7 +441,18 @@ static int artpec6_pcie_probe(struct platform_device *pdev)

pci->ep.ops = &pcie_ep_ops;

- return dw_pcie_ep_init(&pci->ep);
+ ret = dw_pcie_ep_init(&pci->ep);
+ if (ret)
+ return ret;
+
+ ret = dw_pcie_ep_init_registers(&pci->ep);
+ if (ret) {
+ dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+ dw_pcie_ep_deinit(&pci->ep);
+ return ret;
+ }
+
+ break;
default:
dev_err(dev, "INVALID device type %d\n", artpec6_pcie->mode);
}
diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 9354671644b6..3893a8c1a11c 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -815,7 +815,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
struct device *dev = pci->dev;
struct platform_device *pdev = to_platform_device(dev);
struct device_node *np = dev->of_node;
- const struct pci_epc_features *epc_features;

INIT_LIST_HEAD(&ep->func_list);

@@ -861,29 +860,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
goto err_exit_epc_mem;
}

- if (ep->ops->get_features) {
- epc_features = ep->ops->get_features(ep);
- if (epc_features->core_init_notifier)
- return 0;
- }
-
- /*
- * NOTE:- Avoid accessing the hardware (Ex:- DBI space) before this
- * step as platforms that implement 'core_init_notifier' feature may
- * not have the hardware ready (i.e. core initialized) for access
- * (Ex: tegra194). Any hardware access on such platforms result
- * in system hang.
- */
- ret = dw_pcie_ep_init_registers(ep);
- if (ret)
- goto err_free_epc_mem;
-
return 0;

-err_free_epc_mem:
- pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
- epc->mem->window.page_size);
-
err_exit_epc_mem:
pci_epc_mem_exit(epc);

diff --git a/drivers/pci/controller/dwc/pcie-designware-plat.c b/drivers/pci/controller/dwc/pcie-designware-plat.c
index 778588b4be70..ca9b22e654cd 100644
--- a/drivers/pci/controller/dwc/pcie-designware-plat.c
+++ b/drivers/pci/controller/dwc/pcie-designware-plat.c
@@ -145,6 +145,15 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)

pci->ep.ops = &pcie_ep_ops;
ret = dw_pcie_ep_init(&pci->ep);
+ if (ret)
+ return ret;
+
+ ret = dw_pcie_ep_init_registers(&pci->ep);
+ if (ret) {
+ dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+ dw_pcie_ep_deinit(&pci->ep);
+ }
+
break;
default:
dev_err(dev, "INVALID device type %d\n", dw_plat_pcie->mode);
diff --git a/drivers/pci/controller/dwc/pcie-keembay.c b/drivers/pci/controller/dwc/pcie-keembay.c
index 208d3b0ba196..250d6acf16dc 100644
--- a/drivers/pci/controller/dwc/pcie-keembay.c
+++ b/drivers/pci/controller/dwc/pcie-keembay.c
@@ -392,6 +392,7 @@ static int keembay_pcie_probe(struct platform_device *pdev)
struct keembay_pcie *pcie;
struct dw_pcie *pci;
enum dw_pcie_device_mode mode;
+ int ret;

data = device_get_match_data(dev);
if (!data)
@@ -426,11 +427,24 @@ static int keembay_pcie_probe(struct platform_device *pdev)
return -ENODEV;

pci->ep.ops = &keembay_pcie_ep_ops;
- return dw_pcie_ep_init(&pci->ep);
+ ret = dw_pcie_ep_init(&pci->ep);
+ if (ret)
+ return ret;
+
+ ret = dw_pcie_ep_init_registers(&pci->ep);
+ if (ret) {
+ dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+ dw_pcie_ep_deinit(&pci->ep);
+ return ret;
+ }
+
+ break;
default:
dev_err(dev, "Invalid device type %d\n", pcie->mode);
return -ENODEV;
}
+
+ return 0;
}

static const struct keembay_pcie_of_data keembay_pcie_rc_of_data = {
diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
index 9d9d22e367bb..fb7c03639a53 100644
--- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
+++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
@@ -414,6 +414,7 @@ static const struct dw_pcie_ep_ops pcie_ep_ops = {
static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
{
struct dw_pcie_ep *ep = &rcar->dw.ep;
+ struct device *dev = rcar->dw.dev;
int ret;

if (!IS_ENABLED(CONFIG_PCIE_RCAR_GEN4_EP))
@@ -422,8 +423,17 @@ static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
ep->ops = &pcie_ep_ops;

ret = dw_pcie_ep_init(ep);
- if (ret)
+ if (ret) {
rcar_gen4_pcie_ep_deinit(rcar);
+ return ret;
+ }
+
+ ret = dw_pcie_ep_init_registers(ep);
+ if (ret) {
+ dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+ dw_pcie_ep_deinit(ep);
+ rcar_gen4_pcie_ep_deinit(rcar);
+ }

return ret;
}
diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
index 3fced0d3e851..82ccaea089be 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
@@ -399,7 +399,18 @@ static int uniphier_pcie_ep_probe(struct platform_device *pdev)
return ret;

priv->pci.ep.ops = &uniphier_pcie_ep_ops;
- return dw_pcie_ep_init(&priv->pci.ep);
+ ret = dw_pcie_ep_init(&priv->pci.ep);
+ if (ret)
+ return ret;
+
+ ret = dw_pcie_ep_init_registers(&priv->pci.ep);
+ if (ret) {
+ dev_err(dev, "Failed to initialize DWC endpoint registers\n");
+ dw_pcie_ep_deinit(&priv->pci.ep);
+ return ret;
+ }
+
+ return 0;
}

static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = {

--
2.25.1


2024-03-22 11:03:17

by Niklas Cassel

[permalink] [raw]
Subject: Re: [PATCH v10 2/8] PCI: dwc: ep: Add Kernel-doc comments for APIs

On Thu, Mar 14, 2024 at 01:18:00PM +0530, Manivannan Sadhasivam wrote:
> All of the APIs are missing the Kernel-doc comments. Hence, add them.
>
> Reviewed-by: Frank Li <[email protected]>
> Signed-off-by: Manivannan Sadhasivam <[email protected]>
> ---
> drivers/pci/controller/dwc/pcie-designware-ep.c | 78 +++++++++++++++++++++++++
> 1 file changed, 78 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index c05304eabb89..d7e8f2dda6ce 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -14,6 +14,10 @@
> #include <linux/pci-epc.h>
> #include <linux/pci-epf.h>
>
> +/**
> + * dw_pcie_ep_linkup - Notify EPF drivers about link up event
> + * @ep: DWC EP device
> + */
> void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
> {
> struct pci_epc *epc = ep->epc;
> @@ -22,6 +26,11 @@ void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
> }
> EXPORT_SYMBOL_GPL(dw_pcie_ep_linkup);
>
> +/**
> + * dw_pcie_ep_init_notify - Notify EPF drivers about EPC initialization
> + * complete

Nit: "complete" can be on previous line without exceeding 80 chars.


> + * @ep: DWC EP device
> + */
> void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep)
> {
> struct pci_epc *epc = ep->epc;
> @@ -30,6 +39,14 @@ void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep)
> }
> EXPORT_SYMBOL_GPL(dw_pcie_ep_init_notify);
>
> +/**
> + * dw_pcie_ep_get_func_from_ep - Get the struct dw_pcie_ep_func corresponding to
> + * the endpoint function
> + * @ep: DWC EP device
> + * @func_no: Function number of the endpoint device
> + *
> + * Return: struct dw_pcie_ep_func if success, NULL otherwise.
> + */
> struct dw_pcie_ep_func *
> dw_pcie_ep_get_func_from_ep(struct dw_pcie_ep *ep, u8 func_no)
> {
> @@ -60,6 +77,11 @@ static void __dw_pcie_ep_reset_bar(struct dw_pcie *pci, u8 func_no,
> dw_pcie_dbi_ro_wr_dis(pci);
> }
>
> +/**
> + * dw_pcie_ep_reset_bar - Reset endpoint BAR
> + * @pci: DWC PCI device
> + * @bar: BAR number of the endpoint
> + */
> void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
> {
> u8 func_no, funcs;
> @@ -439,6 +461,13 @@ static const struct pci_epc_ops epc_ops = {
> .get_features = dw_pcie_ep_get_features,
> };
>
> +/**
> + * dw_pcie_ep_raise_intx_irq - Raise INTx IRQ to the host
> + * @ep: DWC EP device
> + * @func_no: Function number of the endpoint
> + *
> + * Return: 0 if success, errono otherwise.
> + */
> int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
> {
> struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> @@ -450,6 +479,14 @@ int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
> }
> EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_intx_irq);
>
> +/**
> + * dw_pcie_ep_raise_msi_irq - Raise MSI IRQ to the host
> + * @ep: DWC EP device
> + * @func_no: Function number of the endpoint
> + * @interrupt_num: Interrupt number to be raised
> + *
> + * Return: 0 if success, errono otherwise.
> + */
> int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
> u8 interrupt_num)
> {
> @@ -498,6 +535,15 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
> }
> EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_msi_irq);
>
> +/**
> + * dw_pcie_ep_raise_msix_irq_doorbell - Raise MSIX to the host using Doorbell

Nit: s/MSIX/MSI-X/


> + * method
> + * @ep: DWC EP device
> + * @func_no: Function number of the endpoint device
> + * @interrupt_num: Interrupt number to be raised
> + *
> + * Return: 0 if success, errno otherwise.
> + */
> int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep *ep, u8 func_no,
> u16 interrupt_num)
> {
> @@ -517,6 +563,14 @@ int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep *ep, u8 func_no,
> return 0;
> }
>
> +/**
> + * dw_pcie_ep_raise_msix_irq - Raise MSIX to the host

Nit: s/MSIX/MSI-X/


> + * @ep: DWC EP device
> + * @func_no: Function number of the endpoint device
> + * @interrupt_num: Interrupt number to be raised
> + *
> + * Return: 0 if success, errno otherwise.
> + */
> int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
> u16 interrupt_num)
> {
> @@ -564,6 +618,13 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
> return 0;
> }
>
> +/**
> + * dw_pcie_ep_exit - Deinitialize the endpoint device
> + * @ep: DWC EP device
> + *
> + * Deinitialize the endpoint device. EPC device is not destroyed since that will
> + * taken care by Devres.

Nit: s/will/will be/


> + */
> void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
> {
> struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> @@ -599,6 +660,14 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
> return 0;
> }
>
> +/**
> + * dw_pcie_ep_init_complete - Complete DWC EP initialization
> + * @ep: DWC EP device
> + *
> + * Complete the initialization of the registers (CSRs) specific to DWC EP. This
> + * API should be called only when the endpoint receives an active refclk (either
> + * from host or generated locally).
> + */
> int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
> {
> struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> @@ -716,6 +785,15 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
> }
> EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete);
>
> +/**
> + * dw_pcie_ep_init - Initialize the endpoint device
> + * @ep: DWC EP device
> + *
> + * Initialize the endpoint device. Allocate resources and create the EPC
> + * device with the endpoint framework.
> + *
> + * Return: 0 if success, errno otherwise.
> + */
> int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> {
> int ret;
>
> --
> 2.25.1
>

With nits fixed:
Reviewed-by: Niklas Cassel <[email protected]>

2024-03-22 11:03:51

by Niklas Cassel

[permalink] [raw]
Subject: Re: [PATCH v10 7/8] PCI: dwc: ep: Call dw_pcie_ep_init_registers() API directly from all glue drivers

On Thu, Mar 14, 2024 at 01:18:05PM +0530, Manivannan Sadhasivam wrote:
> Currently, dw_pcie_ep_init_registers() API is directly called by the glue
> drivers requiring active refclk from host. But for the other drivers, it is
> getting called implicitly by dw_pcie_ep_init(). This is due to the fact
> that this API initializes DWC EP specific registers and that requires an
> active refclk (either from host or generated locally by endpoint itsef).
>
> But, this causes a discrepancy among the glue drivers. So to avoid this
> confusion, let's call this API directly from all glue drivers irrespective
> of refclk dependency. Only difference here is that the drivers requiring
> refclk from host will call this API only after the refclk is received and
> other drivers without refclk dependency will call this API right after
> dw_pcie_ep_init().
>
> With this change, the check for 'core_init_notifier' flag can now be
> dropped from dw_pcie_ep_init() API. This will also allow us to remove the
> 'core_init_notifier' flag completely in the later commits.
>
> Reviewed-by: Yoshihiro Shimoda <[email protected]>
> Signed-off-by: Manivannan Sadhasivam <[email protected]>
> ---

Reviewed-by: Niklas Cassel <[email protected]>

2024-03-22 11:57:17

by Niklas Cassel

[permalink] [raw]
Subject: Re: [PATCH v10 8/8] PCI: dwc: ep: Remove "core_init_notifier" flag

On Thu, Mar 14, 2024 at 01:18:06PM +0530, Manivannan Sadhasivam wrote:
> "core_init_notifier" flag is set by the glue drivers requiring refclk from
> the host to complete the DWC core initialization. Also, those drivers will
> send a notification to the EPF drivers once the initialization is fully
> completed using the pci_epc_init_notify() API. Only then, the EPF drivers
> will start functioning.
>
> For the rest of the drivers generating refclk locally, EPF drivers will
> start functioning post binding with them. EPF drivers rely on the
> 'core_init_notifier' flag to differentiate between the drivers.
> Unfortunately, this creates two different flows for the EPF drivers.
>
> So to avoid that, let's get rid of the "core_init_notifier" flag and follow
> a single initialization flow for the EPF drivers. This is done by calling
> the dw_pcie_ep_init_notify() from all glue drivers after the completion of
> dw_pcie_ep_init_registers() API. This will allow all the glue drivers to
> send the notification to the EPF drivers once the initialization is fully
> completed.
>
> Only difference here is that, the drivers requiring refclk from host will
> send the notification once refclk is received, while others will send it
> during probe time itself.
>
> But this also requires the EPC core driver to deliver the notification
> after EPF driver bind. Because, the glue driver can send the notification
> before the EPF drivers bind() and in those cases the EPF drivers will miss
> the event. To accommodate this, EPC core is now caching the state of the
> EPC initialization in 'init_complete' flag and pci-ep-cfs driver sends the
> notification to EPF drivers based on that after each EPF driver bind.
>
> Signed-off-by: Manivannan Sadhasivam <[email protected]>
> ---
> drivers/pci/controller/dwc/pci-dra7xx.c | 2 ++
> drivers/pci/controller/dwc/pci-imx6.c | 2 ++
> drivers/pci/controller/dwc/pci-keystone.c | 2 ++
> drivers/pci/controller/dwc/pci-layerscape-ep.c | 2 ++
> drivers/pci/controller/dwc/pcie-artpec6.c | 2 ++
> drivers/pci/controller/dwc/pcie-designware-plat.c | 2 ++
> drivers/pci/controller/dwc/pcie-keembay.c | 2 ++
> drivers/pci/controller/dwc/pcie-qcom-ep.c | 1 -
> drivers/pci/controller/dwc/pcie-rcar-gen4.c | 2 ++
> drivers/pci/controller/dwc/pcie-tegra194.c | 1 -
> drivers/pci/controller/dwc/pcie-uniphier-ep.c | 2 ++
> drivers/pci/endpoint/functions/pci-epf-test.c | 18 +++++-------------
> drivers/pci/endpoint/pci-ep-cfs.c | 9 +++++++++
> drivers/pci/endpoint/pci-epc-core.c | 22 ++++++++++++++++++++++
> include/linux/pci-epc.h | 7 ++++---
> 15 files changed, 58 insertions(+), 18 deletions(-)

FWIW:
Tested-by: Niklas Cassel <[email protected]>



However, when looking at this, I was surprised that you never call something
that will set:
init_complete = false;
from e.g. dw_pcie_ep_deinit() or dw_pcie_ep_cleanup().

I saw that you do seem to set
init_complete = false;
in your other follow up series that is based on this one.

What will happen if you run with only this series merged (without your
follow up series), on a platform that used to have .core_init_notifier?

If you do remove and recreate the symlink on a platform with external
refclk, since you never set init_complete to false, you could trigger
EPF core_init callback, e.g. pci_epf_test_core_init() to be called,
which will do DBI writes even when there is no refclk.

E.g. (on a platform with external refclk):
1) Create symlink to pci-epf-test in configfs.
2) Start RC, your EPC driver will call ep_init_notifiy() when perst
deasserts.
3) Run pci-epf-test.
4) Remove the pci-epf-test symlink
5) Shutdown RC
6) Create symlink to pci-epf-test in configfs.
This will see that init_complete is true, and will do DBI writes
which will crash your system, since you don't have a refclk.

Perhaps you should move the patch that calls a function that sets
init_complete = false;
to this series, so that this crash is not possible?


>
> diff --git a/drivers/pci/controller/dwc/pci-dra7xx.c b/drivers/pci/controller/dwc/pci-dra7xx.c
> index 395042b29ffc..d2d17d37d3e0 100644
> --- a/drivers/pci/controller/dwc/pci-dra7xx.c
> +++ b/drivers/pci/controller/dwc/pci-dra7xx.c
> @@ -474,6 +474,8 @@ static int dra7xx_add_pcie_ep(struct dra7xx_pcie *dra7xx,
> return ret;
> }
>
> + dw_pcie_ep_init_notify(ep);
> +
> return 0;
> }
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index bfcafa440ddb..894b5de76e3a 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1144,6 +1144,8 @@ static int imx6_add_pcie_ep(struct imx6_pcie *imx6_pcie,
> return ret;
> }
>
> + dw_pcie_ep_init_notify(ep);
> +
> /* Start LTSSM. */
> imx6_pcie_ltssm_enable(dev);
>
> diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
> index 093dbb725e41..b7b30470b394 100644
> --- a/drivers/pci/controller/dwc/pci-keystone.c
> +++ b/drivers/pci/controller/dwc/pci-keystone.c
> @@ -1293,6 +1293,8 @@ static int ks_pcie_probe(struct platform_device *pdev)
> goto err_ep_init;
> }
>
> + dw_pcie_ep_init_notify(&pci->ep);
> +
> break;
> default:
> dev_err(dev, "INVALID device type %d\n", mode);
> diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c
> index b712fdd06549..c513598a46d7 100644
> --- a/drivers/pci/controller/dwc/pci-layerscape-ep.c
> +++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c
> @@ -283,6 +283,8 @@ static int __init ls_pcie_ep_probe(struct platform_device *pdev)
> return ret;
> }
>
> + dw_pcie_ep_init_notify(&pci->ep);
> +
> return ls_pcie_ep_interrupt_init(pcie, pdev);
> }
>
> diff --git a/drivers/pci/controller/dwc/pcie-artpec6.c b/drivers/pci/controller/dwc/pcie-artpec6.c
> index a6095561db4a..a4630b92489b 100644
> --- a/drivers/pci/controller/dwc/pcie-artpec6.c
> +++ b/drivers/pci/controller/dwc/pcie-artpec6.c
> @@ -452,6 +452,8 @@ static int artpec6_pcie_probe(struct platform_device *pdev)
> return ret;
> }
>
> + dw_pcie_ep_init_notify(&pci->ep);
> +
> break;
> default:
> dev_err(dev, "INVALID device type %d\n", artpec6_pcie->mode);
> diff --git a/drivers/pci/controller/dwc/pcie-designware-plat.c b/drivers/pci/controller/dwc/pcie-designware-plat.c
> index ca9b22e654cd..8490c5d6ff9f 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-plat.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-plat.c
> @@ -154,6 +154,8 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
> dw_pcie_ep_deinit(&pci->ep);
> }
>
> + dw_pcie_ep_init_notify(&pci->ep);
> +
> break;
> default:
> dev_err(dev, "INVALID device type %d\n", dw_plat_pcie->mode);
> diff --git a/drivers/pci/controller/dwc/pcie-keembay.c b/drivers/pci/controller/dwc/pcie-keembay.c
> index 250d6acf16dc..9fa9354a5f48 100644
> --- a/drivers/pci/controller/dwc/pcie-keembay.c
> +++ b/drivers/pci/controller/dwc/pcie-keembay.c
> @@ -438,6 +438,8 @@ static int keembay_pcie_probe(struct platform_device *pdev)
> return ret;
> }
>
> + dw_pcie_ep_init_notify(&pci->ep);
> +
> break;
> default:
> dev_err(dev, "Invalid device type %d\n", pcie->mode);
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> index 3697b4a944cc..2fb8c15e7a91 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -775,7 +775,6 @@ static void qcom_pcie_ep_init_debugfs(struct qcom_pcie_ep *pcie_ep)
>
> static const struct pci_epc_features qcom_pcie_epc_features = {
> .linkup_notifier = true,
> - .core_init_notifier = true,
> .msi_capable = true,
> .msix_capable = false,
> .align = SZ_4K,
> diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> index fb7c03639a53..0448928017f3 100644
> --- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> @@ -435,6 +435,8 @@ static int rcar_gen4_add_dw_pcie_ep(struct rcar_gen4_pcie *rcar)
> rcar_gen4_pcie_ep_deinit(rcar);
> }
>
> + dw_pcie_ep_init_notify(ep);
> +
> return ret;
> }
>
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 264ee76bf008..e02deb31a72d 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -2006,7 +2006,6 @@ static int tegra_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
>
> static const struct pci_epc_features tegra_pcie_epc_features = {
> .linkup_notifier = true,
> - .core_init_notifier = true,
> .msi_capable = false,
> .msix_capable = false,
> .reserved_bar = 1 << BAR_2 | 1 << BAR_3 | 1 << BAR_4 | 1 << BAR_5,
> diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
> index 82ccaea089be..eb1d79fdb1f1 100644
> --- a/drivers/pci/controller/dwc/pcie-uniphier-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
> @@ -410,6 +410,8 @@ static int uniphier_pcie_ep_probe(struct platform_device *pdev)
> return ret;
> }
>
> + dw_pcie_ep_init_notify(&priv->pci.ep);
> +
> return 0;
> }
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 18c80002d3bd..fc0282b0d626 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -753,6 +753,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
> const struct pci_epc_features *epc_features;
> struct pci_epc *epc = epf->epc;
> struct device *dev = &epf->dev;
> + bool linkup_notifier = false;
> bool msix_capable = false;
> bool msi_capable = true;
> int ret;
> @@ -795,6 +796,10 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
> }
> }
>
> + linkup_notifier = epc_features->linkup_notifier;
> + if (!linkup_notifier)
> + queue_work(kpcitest_workqueue, &epf_test->cmd_handler.work);
> +
> return 0;
> }
>
> @@ -901,8 +906,6 @@ static int pci_epf_test_bind(struct pci_epf *epf)
> const struct pci_epc_features *epc_features;
> enum pci_barno test_reg_bar = BAR_0;
> struct pci_epc *epc = epf->epc;
> - bool linkup_notifier = false;
> - bool core_init_notifier = false;
>
> if (WARN_ON_ONCE(!epc))
> return -EINVAL;
> @@ -913,8 +916,6 @@ static int pci_epf_test_bind(struct pci_epf *epf)
> return -EOPNOTSUPP;
> }
>
> - linkup_notifier = epc_features->linkup_notifier;
> - core_init_notifier = epc_features->core_init_notifier;
> test_reg_bar = pci_epc_get_first_free_bar(epc_features);
> if (test_reg_bar < 0)
> return -EINVAL;
> @@ -927,21 +928,12 @@ static int pci_epf_test_bind(struct pci_epf *epf)
> if (ret)
> return ret;
>
> - if (!core_init_notifier) {
> - ret = pci_epf_test_core_init(epf);
> - if (ret)
> - return ret;
> - }
> -

While you did fix up all DWC based drivers, the non-DWC EPC drivers that
did not have epc_features->core_init_notifier before this patch:

drivers/pci/controller/cadence/pcie-cadence-ep.c:#include <linux/pci-epc.h>
drivers/pci/controller/pcie-rcar-ep.c:#include <linux/pci-epc.h>
drivers/pci/controller/pcie-rockchip-ep.c:#include <linux/pci-epc.h>

I don't think that they will work with pci-epf-test anymore, since AFAICT,
you did not add a call to: pci_epc_init_notify() or similar in these EPC drivers.
(Like this patch does to all the DWC-based drivers without a core_init_notifier.)


Kind regards,
Niklas

2024-03-25 16:32:59

by Manivannan Sadhasivam

[permalink] [raw]
Subject: Re: [PATCH v10 8/8] PCI: dwc: ep: Remove "core_init_notifier" flag

On Fri, Mar 22, 2024 at 12:53:50PM +0100, Niklas Cassel wrote:
> On Thu, Mar 14, 2024 at 01:18:06PM +0530, Manivannan Sadhasivam wrote:
> > "core_init_notifier" flag is set by the glue drivers requiring refclk from
> > the host to complete the DWC core initialization. Also, those drivers will
> > send a notification to the EPF drivers once the initialization is fully
> > completed using the pci_epc_init_notify() API. Only then, the EPF drivers
> > will start functioning.
> >
> > For the rest of the drivers generating refclk locally, EPF drivers will
> > start functioning post binding with them. EPF drivers rely on the
> > 'core_init_notifier' flag to differentiate between the drivers.
> > Unfortunately, this creates two different flows for the EPF drivers.
> >
> > So to avoid that, let's get rid of the "core_init_notifier" flag and follow
> > a single initialization flow for the EPF drivers. This is done by calling
> > the dw_pcie_ep_init_notify() from all glue drivers after the completion of
> > dw_pcie_ep_init_registers() API. This will allow all the glue drivers to
> > send the notification to the EPF drivers once the initialization is fully
> > completed.
> >
> > Only difference here is that, the drivers requiring refclk from host will
> > send the notification once refclk is received, while others will send it
> > during probe time itself.
> >
> > But this also requires the EPC core driver to deliver the notification
> > after EPF driver bind. Because, the glue driver can send the notification
> > before the EPF drivers bind() and in those cases the EPF drivers will miss
> > the event. To accommodate this, EPC core is now caching the state of the
> > EPC initialization in 'init_complete' flag and pci-ep-cfs driver sends the
> > notification to EPF drivers based on that after each EPF driver bind.
> >
> > Signed-off-by: Manivannan Sadhasivam <[email protected]>
> > ---
> > drivers/pci/controller/dwc/pci-dra7xx.c | 2 ++
> > drivers/pci/controller/dwc/pci-imx6.c | 2 ++
> > drivers/pci/controller/dwc/pci-keystone.c | 2 ++
> > drivers/pci/controller/dwc/pci-layerscape-ep.c | 2 ++
> > drivers/pci/controller/dwc/pcie-artpec6.c | 2 ++
> > drivers/pci/controller/dwc/pcie-designware-plat.c | 2 ++
> > drivers/pci/controller/dwc/pcie-keembay.c | 2 ++
> > drivers/pci/controller/dwc/pcie-qcom-ep.c | 1 -
> > drivers/pci/controller/dwc/pcie-rcar-gen4.c | 2 ++
> > drivers/pci/controller/dwc/pcie-tegra194.c | 1 -
> > drivers/pci/controller/dwc/pcie-uniphier-ep.c | 2 ++
> > drivers/pci/endpoint/functions/pci-epf-test.c | 18 +++++-------------
> > drivers/pci/endpoint/pci-ep-cfs.c | 9 +++++++++
> > drivers/pci/endpoint/pci-epc-core.c | 22 ++++++++++++++++++++++
> > include/linux/pci-epc.h | 7 ++++---
> > 15 files changed, 58 insertions(+), 18 deletions(-)
>
> FWIW:
> Tested-by: Niklas Cassel <[email protected]>
>
>
>
> However, when looking at this, I was surprised that you never call something
> that will set:
> init_complete = false;
> from e.g. dw_pcie_ep_deinit() or dw_pcie_ep_cleanup().
>
> I saw that you do seem to set
> init_complete = false;
> in your other follow up series that is based on this one.
>
> What will happen if you run with only this series merged (without your
> follow up series), on a platform that used to have .core_init_notifier?
>
> If you do remove and recreate the symlink on a platform with external
> refclk, since you never set init_complete to false, you could trigger
> EPF core_init callback, e.g. pci_epf_test_core_init() to be called,
> which will do DBI writes even when there is no refclk.
>
> E.g. (on a platform with external refclk):
> 1) Create symlink to pci-epf-test in configfs.
> 2) Start RC, your EPC driver will call ep_init_notifiy() when perst
> deasserts.
> 3) Run pci-epf-test.
> 4) Remove the pci-epf-test symlink
> 5) Shutdown RC
> 6) Create symlink to pci-epf-test in configfs.
> This will see that init_complete is true, and will do DBI writes
> which will crash your system, since you don't have a refclk.
>
> Perhaps you should move the patch that calls a function that sets
> init_complete = false;
> to this series, so that this crash is not possible?
>

Good catch! But moving that patch to this series requires moving some other
patches as well. So in the meantime, I'll set this flag to false in
dw_pcie_ep_cleanup().

[...]

> > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> > index 18c80002d3bd..fc0282b0d626 100644
> > --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c

[...]

> > - if (!core_init_notifier) {
> > - ret = pci_epf_test_core_init(epf);
> > - if (ret)
> > - return ret;
> > - }
> > -
>
> While you did fix up all DWC based drivers, the non-DWC EPC drivers that
> did not have epc_features->core_init_notifier before this patch:
>
> drivers/pci/controller/cadence/pcie-cadence-ep.c:#include <linux/pci-epc.h>
> drivers/pci/controller/pcie-rcar-ep.c:#include <linux/pci-epc.h>
> drivers/pci/controller/pcie-rockchip-ep.c:#include <linux/pci-epc.h>
>
> I don't think that they will work with pci-epf-test anymore, since AFAICT,
> you did not add a call to: pci_epc_init_notify() or similar in these EPC drivers.
> (Like this patch does to all the DWC-based drivers without a core_init_notifier.)
>

Doh, yeah I completely missed these. Thanks for pointing out. Will add the
notify_init call in next version.

- Mani

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