[PATCH v3 2/2] PCI: dwc: Use an address in the driver data for MSI address

[Jisheng Zhang]

There's no need to allocate a page for the MSI address, we could use
an address in the driver data.

One side effect of this patch is fixing the MSI page leakage during
suspend/resume. Take the pcie-tegra194.c for example, it calls
dw_pcie_msi_init() in resume path, thus the previous MSI page is
leaked.

Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support")
Suggested-by: Rob Herring <r...@kernel.org>
Signed-off-by: Jisheng Zhang <jisheng.zh...@synaptics.com>
---
 .../pci/controller/dwc/pcie-designware-host.c | 22 ++-----------------
 drivers/pci/controller/dwc/pcie-designware.h  |  1 -
 2 files changed, 2 insertions(+), 21 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c 
b/drivers/pci/controller/dwc/pcie-designware-host.c
index f08f4d97f321..bf25d783b5c5 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -126,9 +126,7 @@ static void dw_pci_setup_msi_msg(struct irq_data *d, struct 
msi_msg *msg)
 {
        struct pcie_port *pp = irq_data_get_irq_chip_data(d);
        struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
-       u64 msi_target;
-
-       msi_target = (u64)pp->msi_data;
+       u64 msi_target = virt_to_phys(&pp->msi_data);
 
        msg->address_lo = lower_32_bits(msi_target);
        msg->address_hi = upper_32_bits(msi_target);
@@ -287,27 +285,11 @@ void dw_pcie_free_msi(struct pcie_port *pp)
 
        irq_domain_remove(pp->msi_domain);
        irq_domain_remove(pp->irq_domain);
-
-       if (pp->msi_page)
-               __free_page(pp->msi_page);
 }
 
 void dw_pcie_msi_init(struct pcie_port *pp)
 {
-       struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
-       struct device *dev = pci->dev;
-       u64 msi_target;
-
-       pp->msi_page = alloc_page(GFP_KERNEL);
-       pp->msi_data = dma_map_page(dev, pp->msi_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(pp->msi_page);
-               pp->msi_page = NULL;
-               return;
-       }
-       msi_target = (u64)pp->msi_data;
+       u64 msi_target = virt_to_phys(&pp->msi_data);
 
        /* Program the msi_data */
        dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_LO, 4,
diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
b/drivers/pci/controller/dwc/pcie-designware.h
index f911760dcc69..a88e15a09745 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -195,7 +195,6 @@ struct pcie_port {
        struct irq_domain       *irq_domain;
        struct irq_domain       *msi_domain;
        dma_addr_t              msi_data;
-       struct page             *msi_page;
        struct irq_chip         *msi_irq_chip;
        u32                     num_vectors;
        u32                     irq_mask[MAX_MSI_CTRLS];
-- 
2.28.0