| Message ID | 1462893601-8937-5-git-send-email-tn@semihalf.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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.
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 +} + 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 d2a57f3..d6ea6ce 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1169,6 +1169,7 @@ 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) {