linux/arch/arm/include/asm/xen/page.h

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#ifndef _ASM_ARM_XEN_PAGE_H
#define _ASM_ARM_XEN_PAGE_H
#include <asm/page.h>
#include <asm/pgtable.h>
#include <linux/pfn.h>
#include <linux/types.h>
xen/arm,arm64: enable SWIOTLB_XEN Xen on arm and arm64 needs SWIOTLB_XEN: when running on Xen we need to program the hardware with mfns rather than pfns for dma addresses. Remove SWIOTLB_XEN dependency on X86 and PCI and make XEN select SWIOTLB_XEN on arm and arm64. At the moment always rely on swiotlb-xen, but when Xen starts supporting hardware IOMMUs we'll be able to avoid it conditionally on the presence of an IOMMU on the platform. Implement xen_create_contiguous_region on arm and arm64: for the moment we assume that dom0 has been mapped 1:1 (physical addresses == machine addresses) therefore we don't need to call XENMEM_exchange. Simply return the physical address as dma address. Initialize the xen-swiotlb from xen_early_init (before the native dma_ops are initialized), set xen_dma_ops to &xen_swiotlb_dma_ops. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Changes in v8: - assume dom0 is mapped 1:1, no need to call XENMEM_exchange. Changes in v7: - call __set_phys_to_machine_multi from xen_create_contiguous_region and xen_destroy_contiguous_region to update the P2M; - don't call XENMEM_unpin, it has been removed; - call XENMEM_exchange instead of XENMEM_exchange_and_pin; - set nr_exchanged to 0 before calling the hypercall. Changes in v6: - introduce and export xen_dma_ops; - call xen_mm_init from as arch_initcall. Changes in v4: - remove redefinition of DMA_ERROR_CODE; - update the code to use XENMEM_exchange_and_pin and XENMEM_unpin; - add a note about hardware IOMMU in the commit message. Changes in v3: - code style changes; - warn on XENMEM_put_dma_buf failures.
2013-10-10 13:40:44 +00:00
#include <linux/dma-mapping.h>
#include <xen/xen.h>
#include <xen/interface/grant_table.h>
#define phys_to_machine_mapping_valid(pfn) (1)
/* Xen machine address */
typedef struct xmaddr {
phys_addr_t maddr;
} xmaddr_t;
/* Xen pseudo-physical address */
typedef struct xpaddr {
phys_addr_t paddr;
} xpaddr_t;
#define XMADDR(x) ((xmaddr_t) { .maddr = (x) })
#define XPADDR(x) ((xpaddr_t) { .paddr = (x) })
#define INVALID_P2M_ENTRY (~0UL)
/*
* The pseudo-physical frame (pfn) used in all the helpers is always based
* on Xen page granularity (i.e 4KB).
*
* A Linux page may be split across multiple non-contiguous Xen page so we
* have to keep track with frame based on 4KB page granularity.
*
* PV drivers should never make a direct usage of those helpers (particularly
* pfn_to_gfn and gfn_to_pfn).
*/
unsigned long __pfn_to_mfn(unsigned long pfn);
extern struct rb_root phys_to_mach;
/* Pseudo-physical <-> Guest conversion */
static inline unsigned long pfn_to_gfn(unsigned long pfn)
{
return pfn;
}
static inline unsigned long gfn_to_pfn(unsigned long gfn)
{
return gfn;
}
xen: Make clear that swiotlb and biomerge are dealing with DMA address The swiotlb is required when programming a DMA address on ARM when a device is not protected by an IOMMU. In this case, the DMA address should always be equal to the machine address. For DOM0 memory, Xen ensure it by have an identity mapping between the guest address and host address. However, when mapping a foreign grant reference, the 1:1 model doesn't work. For ARM guest, most of the callers of pfn_to_mfn expects to get a GFN (Guest Frame Number), i.e a PFN (Page Frame Number) from the Linux point of view given that all ARM guest are auto-translated. Even though the name pfn_to_mfn is misleading, we need to ensure that those caller get a GFN and not by mistake a MFN. In pratical, I haven't seen error related to this but we should fix it for the sake of correctness. In order to fix the implementation of pfn_to_mfn on ARM in a follow-up patch, we have to introduce new helpers to return the DMA from a PFN and the invert. On x86, the new helpers will be an alias of pfn_to_mfn and mfn_to_pfn. The helpers will be used in swiotlb and xen_biovec_phys_mergeable. This is necessary in the latter because we have to ensure that the biovec code will not try to merge a biovec using foreign page and another using Linux memory. Lastly, the helper mfn_to_local_pfn has been renamed to bfn_to_local_pfn given that the only usage was in swiotlb. Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-07 16:34:35 +00:00
/* Pseudo-physical <-> BUS conversion */
static inline unsigned long pfn_to_bfn(unsigned long pfn)
{
unsigned long mfn;
if (phys_to_mach.rb_node != NULL) {
mfn = __pfn_to_mfn(pfn);
if (mfn != INVALID_P2M_ENTRY)
return mfn;
}
return pfn;
}
static inline unsigned long bfn_to_pfn(unsigned long bfn)
{
return bfn;
}
#define bfn_to_local_pfn(bfn) bfn_to_pfn(bfn)
/* VIRT <-> GUEST conversion */
#define virt_to_gfn(v) (pfn_to_gfn(virt_to_phys(v) >> XEN_PAGE_SHIFT))
#define gfn_to_virt(m) (__va(gfn_to_pfn(m) << XEN_PAGE_SHIFT))
/* Only used in PV code. But ARM guests are always HVM. */
static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr)
{
BUG();
}
/* TODO: this shouldn't be here but it is because the frontend drivers
* are using it (its rolled in headers) even though we won't hit the code path.
* So for right now just punt with this.
*/
static inline pte_t *lookup_address(unsigned long address, unsigned int *level)
{
BUG();
return NULL;
}
extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count);
extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count);
bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn,
unsigned long nr_pages);
static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
{
return __set_phys_to_machine(pfn, mfn);
}
Features: - FIFO event channels. Key advantages: support for over 100,000 events (2^17), 16 different event priorities, improved fairness in event latency through the use of FIFOs. - Xen PVH support. "It’s a fully PV kernel mode, running with paravirtualized disk and network, paravirtualized interrupts and timers, no emulated devices of any kind (and thus no qemu), no BIOS or legacy boot — but instead of requiring PV MMU, it uses the HVM hardware extensions to virtualize the pagetables, as well as system calls and other privileged operations." (from "The Paravirtualization Spectrum, Part 2: From poles to a spectrum") Bug-fixes: - Fixes in balloon driver (refactor and make it work under ARM) - Allow xenfb to be used in HVM guests. - Allow xen_platform_pci=0 to work properly. - Refactors in event channels. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAABAgAGBQJS4BmLAAoJEFjIrFwIi8fJ4SAH/iNGESowgMhfW64vRA8pBWq+ NRJpUjYjjwmbxpwoNl6NPwn15cIXFyc3sMtvvrDD3taRDyko2RFuT+NTjpO05xPh d/cRpRXpXERHoiFgPf/WTp7ONBDhvPtHG0+BzJKwgqEIOUYXdbhD+gEjaVlFJScS CAY68OLmk7XYMSZBNzPfKNbSCyhVgZF7wpaimK9lxZBKsFRCDIq6jIyrAsC8epIL 6V/V4l2S6lk/uUeGB6ULphYeINjI2kkpbSfCd1vyenLfWpVscc2o8uWEYFcZMAxy V4HpsoseuqrfdDqgPfud3VgogdISvbkCvDfW85rzfDP4MWxei2mVHFtJ/gSBV+g= =ToNG -----END PGP SIGNATURE----- Merge tag 'stable/for-linus-3.14-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen updates from Konrad Rzeszutek Wilk: "Two major features that Xen community is excited about: The first is event channel scalability by David Vrabel - we switch over from an two-level per-cpu bitmap of events (IRQs) - to an FIFO queue with priorities. This lets us be able to handle more events, have lower latency, and better scalability. Good stuff. The other is PVH by Mukesh Rathor. In short, PV is a mode where the kernel lets the hypervisor program page-tables, segments, etc. With EPT/NPT capabilities in current processors, the overhead of doing this in an HVM (Hardware Virtual Machine) container is much lower than the hypervisor doing it for us. In short we let a PV guest run without doing page-table, segment, syscall, etc updates through the hypervisor - instead it is all done within the guest container. It is a "hybrid" PV - hence the 'PVH' name - a PV guest within an HVM container. The major benefits are less code to deal with - for example we only use one function from the the pv_mmu_ops (which has 39 function calls); faster performance for syscall (no context switches into the hypervisor); less traps on various operations; etc. It is still being baked - the ABI is not yet set in stone. But it is pretty awesome and we are excited about it. Lastly, there are some changes to ARM code - you should get a simple conflict which has been resolved in #linux-next. In short, this pull has awesome features. Features: - FIFO event channels. Key advantages: support for over 100,000 events (2^17), 16 different event priorities, improved fairness in event latency through the use of FIFOs. - Xen PVH support. "It’s a fully PV kernel mode, running with paravirtualized disk and network, paravirtualized interrupts and timers, no emulated devices of any kind (and thus no qemu), no BIOS or legacy boot — but instead of requiring PV MMU, it uses the HVM hardware extensions to virtualize the pagetables, as well as system calls and other privileged operations." (from "The Paravirtualization Spectrum, Part 2: From poles to a spectrum") Bug-fixes: - Fixes in balloon driver (refactor and make it work under ARM) - Allow xenfb to be used in HVM guests. - Allow xen_platform_pci=0 to work properly. - Refactors in event channels" * tag 'stable/for-linus-3.14-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (52 commits) xen/pvh: Set X86_CR0_WP and others in CR0 (v2) MAINTAINERS: add git repository for Xen xen/pvh: Use 'depend' instead of 'select'. xen: delete new instances of __cpuinit usage xen/fb: allow xenfb initialization for hvm guests xen/evtchn_fifo: fix error return code in evtchn_fifo_setup() xen-platform: fix error return code in platform_pci_init() xen/pvh: remove duplicated include from enlighten.c xen/pvh: Fix compile issues with xen_pvh_domain() xen: Use dev_is_pci() to check whether it is pci device xen/grant-table: Force to use v1 of grants. xen/pvh: Support ParaVirtualized Hardware extensions (v3). xen/pvh: Piggyback on PVHVM XenBus. xen/pvh: Piggyback on PVHVM for grant driver (v4) xen/grant: Implement an grant frame array struct (v3). xen/grant-table: Refactor gnttab_init xen/grants: Remove gnttab_max_grant_frames dependency on gnttab_init. xen/pvh: Piggyback on PVHVM for event channels (v2) xen/pvh: Update E820 to work with PVH (v2) xen/pvh: Secondary VCPU bringup (non-bootup CPUs) ...
2014-01-23 06:00:18 +00:00
#define xen_remap(cookie, size) ioremap_cache((cookie), (size))
#define xen_unmap(cookie) iounmap((cookie))
bool xen_arch_need_swiotlb(struct device *dev,
phys_addr_t phys,
dma_addr_t dev_addr);
unsigned long xen_get_swiotlb_free_pages(unsigned int order);
#endif /* _ASM_ARM_XEN_PAGE_H */