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-rw-r--r--drivers/pci/host/pci-tegra.c33
1 files changed, 21 insertions, 12 deletions
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 0dadb81eca70..b3722b7709df 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -233,8 +233,8 @@ struct tegra_msi {
struct msi_controller chip;
DECLARE_BITMAP(used, INT_PCI_MSI_NR);
struct irq_domain *domain;
- unsigned long pages;
struct mutex lock;
+ u64 phys;
int irq;
};
@@ -1448,9 +1448,8 @@ static int tegra_msi_setup_irq(struct msi_controller *chip,
irq_set_msi_desc(irq, desc);
- msg.address_lo = virt_to_phys((void *)msi->pages);
- /* 32 bit address only */
- msg.address_hi = 0;
+ msg.address_lo = lower_32_bits(msi->phys);
+ msg.address_hi = upper_32_bits(msi->phys);
msg.data = hwirq;
pci_write_msi_msg(irq, &msg);
@@ -1499,7 +1498,6 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie)
const struct tegra_pcie_soc *soc = pcie->soc;
struct tegra_msi *msi = &pcie->msi;
struct device *dev = pcie->dev;
- unsigned long base;
int err;
u32 reg;
@@ -1531,12 +1529,25 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie)
goto err;
}
- /* setup AFI/FPCI range */
- msi->pages = __get_free_pages(GFP_KERNEL, 0);
- base = virt_to_phys((void *)msi->pages);
+ /*
+ * The PCI host bridge on Tegra contains some logic that intercepts
+ * MSI writes, which means that the MSI target address doesn't have
+ * to point to actual physical memory. Rather than allocating one 4
+ * KiB page of system memory that's never used, we can simply pick
+ * an arbitrary address within an area reserved for system memory
+ * in the FPCI address map.
+ *
+ * However, in order to avoid confusion, we pick an address that
+ * doesn't map to physical memory. The FPCI address map reserves a
+ * 1012 GiB region for system memory and memory-mapped I/O. Since
+ * none of the Tegra SoCs that contain this PCI host bridge can
+ * address more than 16 GiB of system memory, the last 4 KiB of
+ * these 1012 GiB is a good candidate.
+ */
+ msi->phys = 0xfcfffff000;
- afi_writel(pcie, base >> soc->msi_base_shift, AFI_MSI_FPCI_BAR_ST);
- afi_writel(pcie, base, AFI_MSI_AXI_BAR_ST);
+ afi_writel(pcie, msi->phys >> soc->msi_base_shift, AFI_MSI_FPCI_BAR_ST);
+ afi_writel(pcie, msi->phys, AFI_MSI_AXI_BAR_ST);
/* this register is in 4K increments */
afi_writel(pcie, 1, AFI_MSI_BAR_SZ);
@@ -1585,8 +1596,6 @@ static int tegra_pcie_disable_msi(struct tegra_pcie *pcie)
afi_writel(pcie, 0, AFI_MSI_EN_VEC6);
afi_writel(pcie, 0, AFI_MSI_EN_VEC7);
- free_pages(msi->pages, 0);
-
if (msi->irq > 0)
free_irq(msi->irq, pcie);