[PATCH v6 1/3] PCI: designware-ep: Fix DBI access before core init
From: Manivannan Sadhasivam
Date: Fri Oct 20 2023 - 02:44:14 EST
From: Vidya Sagar <vidyas@xxxxxxxxxx>
Platforms that cannot support their core initialization without the
reference clock from the host, implement the feature 'core_init_notifier'
to indicate the DesignWare sub-system about when their core is getting
initialized. Any accesses to the core (Ex:- DBI) would the core being
ready result in system hang in such systems (Ex:- tegra194).
This patch moves any access to the core to dw_pcie_ep_init_complete() API
which is effectively called only after the core initialization.
It also introduces .ep_init_late() ops hook to be used for any post init
work that platform drivers may have to do.
Acked-by: Jingoo Han <jingoohan1@xxxxxxxxx>
Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
[mani: rebased and removed ep_init_late() callback]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
.../pci/controller/dwc/pcie-designware-ep.c | 142 +++++++++++-------
drivers/pci/controller/dwc/pcie-designware.h | 9 +-
2 files changed, 87 insertions(+), 64 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index f9182f8d552f..f37c4481e7d0 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -21,14 +21,6 @@ void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
}
EXPORT_SYMBOL_GPL(dw_pcie_ep_linkup);
-void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep)
-{
- struct pci_epc *epc = ep->epc;
-
- pci_epc_init_notify(epc);
-}
-EXPORT_SYMBOL_GPL(dw_pcie_ep_init_notify);
-
struct dw_pcie_ep_func *
dw_pcie_ep_get_func_from_ep(struct dw_pcie_ep *ep, u8 func_no)
{
@@ -641,14 +633,19 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
return 0;
}
-int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
+static int dw_pcie_ep_init_late(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;
@@ -659,6 +656,55 @@ 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);
+ }
+
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);
@@ -693,14 +739,31 @@ 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_notify(struct dw_pcie_ep *ep)
+{
+ struct pci_epc *epc = ep->epc;
+ int ret;
+
+ ret = dw_pcie_ep_init_late(ep);
+ if (ret)
+ return ret;
+
+ pci_epc_init_notify(epc);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dw_pcie_ep_init_notify);
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);
@@ -708,7 +771,6 @@ 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);
@@ -723,26 +785,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
ep->phys_base = res->start;
ep->addr_size = resource_size(res);
- 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");
@@ -756,20 +798,6 @@ 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->ep_init)
ep->ops->ep_init(ep);
@@ -788,25 +816,25 @@ 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;
}
- ret = dw_pcie_ep_init_complete(ep);
+ /*
+ * 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 hard hang.
+ */
+ ret = dw_pcie_ep_init_late(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);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index efb4d4754fc8..9e8e95df320c 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -573,8 +573,7 @@ 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);
-void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep);
+int dw_pcie_ep_init_notify(struct dw_pcie_ep *ep);
void dw_pcie_ep_exit(struct dw_pcie_ep *ep);
int dw_pcie_ep_raise_legacy_irq(struct dw_pcie_ep *ep, u8 func_no);
int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
@@ -596,15 +595,11 @@ 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_notify(struct dw_pcie_ep *ep)
{
return 0;
}
-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)
{
}
--
2.25.1