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Subject[PATCH v2 06/17] PCI: designware-ep: Add generic function for raising MSI irq
Date
This function can be used by all DWC based controllers to raise a MSI
irq. However, certain controllers, like DRA7xx, has a special
convenience register for raising MSI irqs that doesn't require you to
explicitly map the MSI address.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
V2:
* New patch in this series. The other changes in the changelog are against
the version that was included in pcie-artpec6.c in V1.
* raise_msi_irq now uses readw/writew instead of masking.
* raise_msi_irq now uses fixed offset for MSI cap in raise_msi, since it is
always at the same offset for this IP.
* raise_msi_irq now uses PCI_MSI_FLAGS_64BIT rather than BIT(7).

drivers/pci/dwc/pcie-designware-ep.c | 34 ++++++++++++++++++++++++++++++++++
drivers/pci/dwc/pcie-designware.h | 9 +++++++++
2 files changed, 43 insertions(+)

diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index 47134a85a342..92b7ca36bae4 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -282,6 +282,40 @@ static const struct pci_epc_ops epc_ops = {
.stop = dw_pcie_ep_stop,
};

+int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep,
+ u8 interrupt_num)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+ struct pci_epc *epc = ep->epc;
+ u16 msg_ctrl, msg_data;
+ u32 msg_addr_lower, msg_addr_upper;
+ u64 msg_addr;
+ bool has_upper;
+ int ret;
+
+ /* Raise MSI per the PCI Local Bus Specification Revision 3.0, 6.8.1. */
+ msg_ctrl = dw_pcie_readw_dbi(pci, MSI_MESSAGE_CONTROL);
+ has_upper = !!(msg_ctrl & PCI_MSI_FLAGS_64BIT);
+ msg_addr_lower = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_L32);
+ if (has_upper) {
+ msg_addr_upper = dw_pcie_readl_dbi(pci, MSI_MESSAGE_ADDR_U32);
+ msg_data = dw_pcie_readw_dbi(pci, MSI_MESSAGE_DATA_64);
+ } else {
+ msg_addr_upper = 0;
+ msg_data = dw_pcie_readw_dbi(pci, MSI_MESSAGE_DATA_32);
+ }
+ msg_addr = ((u64) msg_addr_upper) << 32 | msg_addr_lower;
+ ret = dw_pcie_ep_map_addr(epc, ep->msi_mem_phys, msg_addr, PAGE_SIZE);
+ if (ret)
+ return ret;
+
+ writel(msg_data | (interrupt_num - 1), ep->msi_mem);
+
+ dw_pcie_ep_unmap_addr(epc, ep->msi_mem_phys);
+
+ return 0;
+}
+
void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
{
struct pci_epc *epc = ep->epc;
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index 37dfad8d003f..24edac035160 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -106,6 +106,8 @@
#define MSI_CAP_MME_MASK (7 << MSI_CAP_MME_SHIFT)
#define MSI_MESSAGE_ADDR_L32 0x54
#define MSI_MESSAGE_ADDR_U32 0x58
+#define MSI_MESSAGE_DATA_32 0x58
+#define MSI_MESSAGE_DATA_64 0x5C

/*
* Maximum number of MSI IRQs can be 256 per controller. But keep
@@ -338,6 +340,7 @@ static inline int dw_pcie_host_init(struct pcie_port *pp)
void dw_pcie_ep_linkup(struct dw_pcie_ep *ep);
int dw_pcie_ep_init(struct dw_pcie_ep *ep);
void dw_pcie_ep_exit(struct dw_pcie_ep *ep);
+int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 interrupt_num);
void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar);
#else
static inline void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
@@ -353,6 +356,12 @@ static inline void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
{
}

+static inline int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep,
+ u8 interrupt_num)
+{
+ return 0;
+}
+
static inline void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
{
}
--
2.14.2
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