From 24a2fd5908ca39ae2e0c22454ca8b0c8cc3013d7 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 30 Mar 2021 16:11:33 +0100 Subject: [PATCH] UPSTREAM: PCI: rcar: Don't allocate extra memory for the MSI capture address A long cargo-culted behaviour of PCI drivers is to allocate memory to obtain an address that is fed to the controller as the MSI capture address (i.e. the MSI doorbell). But there is no actual requirement for this address to be RAM. All it needs to be is a suitable aligned address that will *not* be DMA'd to. Since the rcar platform already has a requirement that this address should be in the first 4GB of the physical address space, use the controller's own base address as the capture address. Link: https://lore.kernel.org/r/20210330151145.997953-3-maz@kernel.org Tested-by: Yoshihiro Shimoda Signed-off-by: Marc Zyngier Signed-off-by: Lorenzo Pieralisi Reviewed-by: Yoshihiro Shimoda (cherry picked from commit 93cd1bb4862d71298ad5ec86991eac0a119d024d) Signed-off-by: Marc Zyngier Change-Id: Ibf1fd67482a4dc39e4c58a4adfb756e0cf38fc4c Bug: 187801341 --- drivers/pci/controller/pcie-rcar-host.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/drivers/pci/controller/pcie-rcar-host.c b/drivers/pci/controller/pcie-rcar-host.c index 2bee09b16255..623fbabb5053 100644 --- a/drivers/pci/controller/pcie-rcar-host.c +++ b/drivers/pci/controller/pcie-rcar-host.c @@ -36,7 +36,6 @@ struct rcar_msi { DECLARE_BITMAP(used, INT_PCI_MSI_NR); struct irq_domain *domain; struct msi_controller chip; - unsigned long pages; struct mutex lock; int irq1; int irq2; @@ -682,14 +681,15 @@ static void rcar_pcie_unmap_msi(struct rcar_pcie_host *host) static void rcar_pcie_hw_enable_msi(struct rcar_pcie_host *host) { struct rcar_pcie *pcie = &host->pcie; - struct rcar_msi *msi = &host->msi; - unsigned long base; + struct device *dev = pcie->dev; + struct resource res; + + if (WARN_ON(of_address_to_resource(dev->of_node, 0, &res))) + return; /* setup MSI data target */ - base = virt_to_phys((void *)msi->pages); - - rcar_pci_write_reg(pcie, lower_32_bits(base) | MSIFE, PCIEMSIALR); - rcar_pci_write_reg(pcie, upper_32_bits(base), PCIEMSIAUR); + rcar_pci_write_reg(pcie, lower_32_bits(res.start) | MSIFE, PCIEMSIALR); + rcar_pci_write_reg(pcie, upper_32_bits(res.start), PCIEMSIAUR); /* enable all MSI interrupts */ rcar_pci_write_reg(pcie, 0xffffffff, PCIEMSIIER); @@ -737,7 +737,6 @@ static int rcar_pcie_enable_msi(struct rcar_pcie_host *host) } /* setup MSI data target */ - msi->pages = __get_free_pages(GFP_KERNEL | GFP_DMA32, 0); rcar_pcie_hw_enable_msi(host); return 0; @@ -750,7 +749,6 @@ err: static void rcar_pcie_teardown_msi(struct rcar_pcie_host *host) { struct rcar_pcie *pcie = &host->pcie; - struct rcar_msi *msi = &host->msi; /* Disable all MSI interrupts */ rcar_pci_write_reg(pcie, 0, PCIEMSIIER); @@ -758,8 +756,6 @@ static void rcar_pcie_teardown_msi(struct rcar_pcie_host *host) /* Disable address decoding of the MSI interrupt, MSIFE */ rcar_pci_write_reg(pcie, 0, PCIEMSIALR); - free_pages(msi->pages, 0); - rcar_pcie_unmap_msi(host); }