79 lines
2.2 KiB
Diff
79 lines
2.2 KiB
Diff
From 9cfa64ddaba49975b420ce5e5020efc3301061ac Mon Sep 17 00:00:00 2001
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From: Gabor Juhos <juhosg@openwrt.org>
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Date: Tue, 26 Jun 2012 10:19:46 +0200
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Subject: [PATCH 01/34] MIPS: pci-ar724x: avoid data bus error due to a missing PCIe module
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If the controller has no PCIe module attached,
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accessing of the device configuration space
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causes a data bus error. Avoid this by checking
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the status of the PCIe link in advance, and
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indicate an error if the link is down.
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Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
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---
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arch/mips/pci/pci-ar724x.c | 22 ++++++++++++++++++++++
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1 files changed, 22 insertions(+), 0 deletions(-)
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--- a/arch/mips/pci/pci-ar724x.c
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+++ b/arch/mips/pci/pci-ar724x.c
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@@ -23,9 +23,12 @@
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#define AR724X_PCI_MEM_BASE 0x10000000
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#define AR724X_PCI_MEM_SIZE 0x08000000
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+#define AR724X_PCI_REG_RESET 0x18
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#define AR724X_PCI_REG_INT_STATUS 0x4c
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#define AR724X_PCI_REG_INT_MASK 0x50
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+#define AR724X_PCI_RESET_LINK_UP BIT(0)
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+
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#define AR724X_PCI_INT_DEV0 BIT(14)
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#define AR724X_PCI_IRQ_COUNT 1
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@@ -38,6 +41,15 @@ static void __iomem *ar724x_pci_ctrl_bas
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static u32 ar724x_pci_bar0_value;
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static bool ar724x_pci_bar0_is_cached;
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+static bool ar724x_pci_link_up;
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+
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+static inline bool ar724x_pci_check_link(void)
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+{
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+ u32 reset;
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+
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+ reset = __raw_readl(ar724x_pci_ctrl_base + AR724X_PCI_REG_RESET);
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+ return reset & AR724X_PCI_RESET_LINK_UP;
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+}
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static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
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int size, uint32_t *value)
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@@ -46,6 +58,9 @@ static int ar724x_pci_read(struct pci_bu
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void __iomem *base;
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u32 data;
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+ if (!ar724x_pci_link_up)
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+ return PCIBIOS_DEVICE_NOT_FOUND;
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+
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if (devfn)
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return PCIBIOS_DEVICE_NOT_FOUND;
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@@ -96,6 +111,9 @@ static int ar724x_pci_write(struct pci_b
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u32 data;
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int s;
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+ if (!ar724x_pci_link_up)
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+ return PCIBIOS_DEVICE_NOT_FOUND;
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+
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if (devfn)
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return PCIBIOS_DEVICE_NOT_FOUND;
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@@ -280,6 +298,10 @@ int __init ar724x_pcibios_init(int irq)
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if (ar724x_pci_ctrl_base == NULL)
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goto err_unmap_devcfg;
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+ ar724x_pci_link_up = ar724x_pci_check_link();
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+ if (!ar724x_pci_link_up)
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+ pr_warn("ar724x: PCIe link is down\n");
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+
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ar724x_pci_irq_init(irq);
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register_pci_controller(&ar724x_pci_controller);
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