2017-10-30 12:48:20

by Niklas Cassel

[permalink] [raw]
Subject: [PATCH v2 04/17] PCI: designware-ep: Pre-allocate memory for MSI in dw_pcie_ep_init

Certain SoCs need to map the MSI address in raise_irq.
To map an address, you first need to call pci_epc_mem_alloc_addr,
however, pci_epc_mem_alloc_addr calls ioremap (which can sleep).

Since raise_irq is only called from atomic context, we can't call
pci_epc_mem_alloc_addr from raise_irq, instead we pre-allocate
a page in dw_pcie_ep_init, so this page can later be used to map/unmap
the MSI address in raise_irq.

Signed-off-by: Niklas Cassel <[email protected]>
---
V2:
* No change.

drivers/pci/dwc/pcie-designware-ep.c | 8 ++++++++
drivers/pci/dwc/pcie-designware.h | 2 ++
2 files changed, 10 insertions(+)

diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index 3fb34be99715..c291da2a10ba 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -286,6 +286,8 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
{
struct pci_epc *epc = ep->epc;

+ pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem, PAGE_SIZE);
+
pci_epc_mem_exit(epc);
}

@@ -341,6 +343,12 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
return ret;
}

+ ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys, PAGE_SIZE);
+ if (!ep->msi_mem) {
+ dev_err(dev, "Failed to reserve memory for MSI\n");
+ return -ENOMEM;
+ }
+
ep->epc = epc;
epc_set_drvdata(epc, ep);
dw_pcie_setup(pci);
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index 9aaf0cd04dd6..5a1da459eda5 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -198,6 +198,8 @@ struct dw_pcie_ep {
unsigned long ob_window_map;
u32 num_ib_windows;
u32 num_ob_windows;
+ void __iomem *msi_mem;
+ phys_addr_t msi_mem_phys;
};

struct dw_pcie_ops {
--
2.14.2


From 1584224533391673986@xxx Thu Nov 16 12:10:48 +0000 2017
X-GM-THRID: 1584224533391673986
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread