[PATCH v2 1/4] arm64: enable pci resource mapping using sysfs

From: David Woodhouse
Date: Wed Mar 15 2017 - 16:42:30 EST


From: Brijesh Singh <brijess@xxxxxxxxxx>

To support PCI resource mapping from userspace, pci_mmap_page_range()
must be implemented and HAVE_PCI_MMAP defined. This support was absent
for arm64.

[dwmw2: Add WC support]
Reviewed-by: Erik Quanstrom <quanstro@xxxxxxxxxx>
Reviewed-by: Anthony Liguori <aliguori@xxxxxxxxxx>
Signed-off-by: Brijesh Singh <brijess@xxxxxxxxxx>
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
---
v2: s/pgprot_uncached/pgprot_device/

arch/arm64/include/asm/pci.h | 4 ++++
arch/arm64/kernel/pci.c | 19 +++++++++++++++++++
2 files changed, 23 insertions(+)

diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h
index b9a7ba9..f73734f 100644
--- a/arch/arm64/include/asm/pci.h
+++ b/arch/arm64/include/asm/pci.h
@@ -37,5 +37,9 @@ static inline int pci_proc_domain(struct pci_bus *bus)
}
#endif /* CONFIG_PCI */

+#define HAVE_PCI_MMAP
+extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
+ enum pci_mmap_state mmap_state, int write_combine);
+
#endif /* __KERNEL__ */
#endif /* __ASM_PCI_H */
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index 4f0e3eb..9a87b2a 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -228,3 +228,22 @@ void pcibios_remove_bus(struct pci_bus *bus)
}

#endif
+
+int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
+ enum pci_mmap_state mmap_state, int write_combine)
+{
+ if (mmap_state == pci_mmap_io)
+ return -EINVAL;
+
+ if (write_combine)
+ vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+ else
+ vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
+
+ if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
+ vma->vm_end - vma->vm_start,
+ vma->vm_page_prot))
+ return -EAGAIN;
+
+ return 0;
+}
--
dwmw2

Attachment: smime.p7s
Description: S/MIME cryptographic signature