[PATCH V8 3/9] pci: Add new function to unmap IO resources.

Tomasz Nowicki
2016-05-30T15:18:39Z

We need to release I/O resources so that the same I/O resources
can be allocated again (pci_remap_iospace), like in PCI hotplug removal
scenario. Therefore this patch implements new pci_unmap_iospace call which
unmaps I/O space as the symmetry to pci_remap_iospace.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
---
drivers/pci/pci.c | 18 ++++++++++++++++++
include/linux/pci.h | 1 +
2 files changed, 19 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c8b4dbd..eb431b5 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -25,6 +25,7 @@
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <linux/pci_hotplug.h>
+#include <linux/vmalloc.h>
#include <asm/setup.h>
#include <linux/aer.h>
#include "pci.h"
@@ -3165,6 +3166,23 @@ 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
+ * @res: resource to be unmapped
+ *
+ * Unmap the CPU virtual address @res from virtual address space.
+ * Only architectures that have memory mapped IO functions defined
+ * (and the PCI_IOBASE value defined) should call this function.
+ */
+void 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));
+#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 b67e4df..12349de 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1167,6 +1167,7 @@ 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)
{
--
1.9.1