diff mbox

[V7,04/11] pci: Add new function to unmap IO resources.

Message ID 1462893601-8937-5-git-send-email-tn@semihalf.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Tomasz Nowicki May 10, 2016, 3:19 p.m. UTC
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(+)

Comments

Jayachandran C. May 23, 2016, 8:28 a.m. UTC | #1
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.
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diff mbox

Patch

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)
 {