On Tue, May 10, 2016 at 8:49 PM, Tomasz Nowicki tn@semihalf.com wrote:
It is very useful 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 | 24 ++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 25 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index bc0c914..ff97a0b 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" @@ -3167,6 +3168,29 @@ 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));+#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 +}
WARN is not needed here, since we would have already done it in pci_remap_iospace.
Ideally, we should undo the pci_register_io_range as well, but re-registering the same range seems to be fine.
JC.