1 files changed, 87 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c
new file mode 100644
index 000000000..3f32e2759
--- /dev/null
+++ b/arch/xtensa/kernel/pci.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * arch/xtensa/kernel/pci.c
+ *
+ * PCI bios-type initialisation for PCI machines
+ *
+ * Copyright (C) 2001-2005 Tensilica Inc.
+ *
+ * Based largely on work from Cort (ppc/kernel/pci.c)
+ * IO functions copied from sparc.
+ *
+ * Chris Zankel <chris@zankel.net>
+ */
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/memblock.h>
+
+#include <asm/pci-bridge.h>
+#include <asm/platform.h>
+
+/*
+ * We need to avoid collisions with `mirrored' VGA ports
+ * and other strange ISA hardware, so we always want the
+ * addresses to be allocated in the 0x000-0x0ff region
+ * modulo 0x400.
+ *
+ * Why? Because some silly external IO cards only decode
+ * the low 10 bits of the IO address. The 0x00-0xff region
+ * is reserved for motherboard devices that decode all 16
+ * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
+ * but we want to try to avoid allocating at 0x2900-0x2bff
+ * which might have be mirrored at 0x0100-0x03ff..
+ */
+resource_size_t
+pcibios_align_resource(void *data, const struct resource *res,
+		       resource_size_t size, resource_size_t align)
+{
+	struct pci_dev *dev = data;
+	resource_size_t start = res->start;
+
+	if (res->flags & IORESOURCE_IO) {
+		if (size > 0x100) {
+			pr_err("PCI: I/O Region %s/%d too large (%u bytes)\n",
+					pci_name(dev), dev->resource - res,
+					size);
+		}
+
+		if (start & 0x300)
+			start = (start + 0x3ff) & ~0x3ff;
+	}
+
+	return start;
+}
+
+void pcibios_fixup_bus(struct pci_bus *bus)
+{
+	if (bus->parent) {
+		/* This is a subordinate bridge */
+		pci_read_bridge_bases(bus);
+	}
+}
+
+/*
+ * Platform support for /proc/bus/pci/X/Y mmap()s.
+ *  -- paulus.
+ */
+
+int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma)
+{
+	struct pci_controller *pci_ctrl = (struct pci_controller*) pdev->sysdata;
+	resource_size_t ioaddr = pci_resource_start(pdev, bar);
+
+	if (pci_ctrl == 0)
+		return -EINVAL;		/* should never happen */
+
+	/* Convert to an offset within this PCI controller */
+	ioaddr -= (unsigned long)pci_ctrl->io_space.base;
+
+	vma->vm_pgoff += (ioaddr + pci_ctrl->io_space.start) >> PAGE_SHIFT;
+	return 0;
+}