Commit 111111a7 authored by Niklas Cassel's avatar Niklas Cassel Committed by Lorenzo Pieralisi

PCI: dwc: Use the DMA-API to get the MSI address

Use the DMA-API to get the MSI address. This address will be written to
our PCI config space and to the register which determines which AXI
address the DWC IP will spoof for incoming MSI irqs.

Since it is a PCIe endpoint device, rather than the CPU, that is supposed
to write to the MSI address, the proper way to get the MSI address is by
using the DMA API, not by using virt_to_phys().

Using virt_to_phys() might work on some systems, but using the DMA API
should work on all systems.

This is essentially the same thing as allocating a buffer in a driver
to which the endpoint will write to. To do this, we use the DMA API.
Tested-by: default avatarGustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: default avatarNiklas Cassel <niklas.cassel@axis.com>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: default avatarJoao Pinto <jpinto@synopsys.com>
parent 4751fac7
......@@ -83,10 +83,19 @@ irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
void dw_pcie_msi_init(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
struct device *dev = pci->dev;
struct page *page;
u64 msi_target;
pp->msi_data = __get_free_pages(GFP_KERNEL, 0);
msi_target = virt_to_phys((void *)pp->msi_data);
page = alloc_page(GFP_KERNEL);
pp->msi_data = dma_map_page(dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
if (dma_mapping_error(dev, pp->msi_data)) {
dev_err(dev, "failed to map MSI data\n");
__free_page(page);
return;
}
msi_target = (u64)pp->msi_data;
/* program the msi_data */
dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_LO, 4,
......@@ -187,7 +196,7 @@ static void dw_msi_setup_msg(struct pcie_port *pp, unsigned int irq, u32 pos)
if (pp->ops->get_msi_addr)
msi_target = pp->ops->get_msi_addr(pp);
else
msi_target = virt_to_phys((void *)pp->msi_data);
msi_target = (u64)pp->msi_data;
msg.address_lo = (u32)(msi_target & 0xffffffff);
msg.address_hi = (u32)(msi_target >> 32 & 0xffffffff);
......
......@@ -14,6 +14,7 @@
#ifndef _PCIE_DESIGNWARE_H
#define _PCIE_DESIGNWARE_H
#include <linux/dma-mapping.h>
#include <linux/irq.h>
#include <linux/msi.h>
#include <linux/pci.h>
......@@ -168,7 +169,7 @@ struct pcie_port {
const struct dw_pcie_host_ops *ops;
int msi_irq;
struct irq_domain *irq_domain;
unsigned long msi_data;
dma_addr_t msi_data;
DECLARE_BITMAP(msi_irq_in_use, MAX_MSI_IRQS);
};
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment