[PATCH 1/2] pci: add pci_unmap_iospace function for PCI_IOBASE

[Sinan Kaya]

The PCI_IOBASE needs to be released after hotplug removal so that it can be
re-added back by the pci_remap_iospace function during insertion.

Adding unmap function to follow IO remap function.

Signed-off-by: Sinan Kaya <okaya at codeaurora.org>
---
 drivers/pci/pci.c   | 25 +++++++++++++++++++++++++
 include/linux/pci.h |  1 +
 2 files changed, 26 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 3a516c0..f5faed2 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -26,6 +26,7 @@
 #include <linux/device.h>
 #include <linux/pm_runtime.h>
 #include <linux/pci_hotplug.h>
+#include <linux/vmalloc.h>
 #include <asm-generic/pci-bridge.h>
 #include <asm/setup.h>
 #include <linux/aer.h>
@@ -3169,6 +3170,30 @@ int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
 #endif
 }
 
+/**
+ *	pci_unmap_iospace - Unmap the memory mapped I/O space
+ *	@virt_addr: virtual address to be unmapped
+ *	@size: size of the physical address to be unmapped
+ *
+ *	Unmap the CPU virtual address @virt_addr from virtual address space.
+ *	Only architectures that have memory mapped IO functions defined
+ *	(and the PCI_IOBASE value defined) should call this function.
+ */
+void  __weak pci_unmap_iospace(struct resource *res)
+{
+#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
+	unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
+
+	unmap_kernel_range(vaddr, resource_size(res));
+#else
+	/*
+	 * This architecture does not have memory mapped I/O space,
+	 * so this function should never be called.
+	 */
+	WARN_ONCE(1, "This architecture does not support memory mapped I/O\n");
+#endif
+}
+
 static void __pci_set_master(struct pci_dev *dev, bool enable)
 {
 	u16 old_cmd, cmd;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 398ae7e..c6e3f0e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1172,6 +1172,7 @@ int pci_register_io_range(phys_addr_t addr, resource_size_t size);
 unsigned long pci_address_to_pio(phys_addr_t addr);
 phys_addr_t pci_pio_to_address(unsigned long pio);
 int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);
+void pci_unmap_iospace(struct resource *res);
 
 static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar)
 {
-- 
1.8.2.1