Currently, the event channel rebind code is gated with the presence of
the vector callback.
The virtual interrupt controller on ARM has the concept of per-CPU
interrupt (PPI) which allow us to support per-VCPU event channel.
Therefore there is no need of vector callback for ARM.
Xen is already using a free PPI to notify the guest VCPU of an event.
Furthermore, the xen code initialization in Linux (see
arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ.
Introduce new helper xen_support_evtchn_rebind to allow architecture
decide whether rebind an event is support or not. It will always return
true on ARM and keep the same behavior on x86.
This is also allow us to drop the usage of xen_have_vector_callback
entirely in the ARM code.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Merge xen/mm32.c into xen/mm.c.
As a consequence the code gets compiled on arm64 too.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
dev_addr is the machine address of the page.
The new parameter can be used by the ARM and ARM64 implementations of
xen_dma_map_page to find out if the page is a local page (pfn == mfn) or
a foreign page (pfn != mfn).
dev_addr could be retrieved again from the physical address, using
pfn_to_mfn, but it requires accessing an rbtree. Since we already have
the dev_addr in our hands at the call site there is no need to get the
mfn twice.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
On arm64 the dma_map_ops implementation is based on the swiotlb.
swiotlb-xen, used by default in dom0 on Xen, is also based on the
swiotlb.
Avoid calling into the default arm64 dma_map_ops functions from
xen_dma_map_page, xen_dma_unmap_page, xen_dma_sync_single_for_cpu, and
xen_dma_sync_single_for_device otherwise we end up calling into the
swiotlb twice.
When arm64 gets a non-swiotlb based implementation of dma_map_ops, we'll
probably have to reintroduce dma_map_ops calls in page-coherent.h.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: catalin.marinas@arm.com
CC: Will.Deacon@arm.com
CC: Ian.Campbell@citrix.com
Introduce xen_dma_map_page, xen_dma_unmap_page,
xen_dma_sync_single_for_cpu and xen_dma_sync_single_for_device.
They have empty implementations on x86 and ia64 but they call the
corresponding platform dma_ops function on arm and arm64.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Changes in v9:
- xen_dma_map_page return void, avoid page_to_phys.
xen_swiotlb_alloc_coherent needs to allocate a coherent buffer for cpu
and devices. On native x86 is sufficient to call __get_free_pages in
order to get a coherent buffer, while on ARM (and potentially ARM64) we
need to call the native dma_ops->alloc implementation.
Introduce xen_alloc_coherent_pages to abstract the arch specific buffer
allocation.
Similarly introduce xen_free_coherent_pages to free a coherent buffer:
on x86 is simply a call to free_pages while on ARM and ARM64 is
arm_dma_ops.free.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Changes in v7:
- rename __get_dma_ops to __generic_dma_ops;
- call __generic_dma_ops(hwdev)->alloc/free on arm64 too.
Changes in v6:
- call __get_dma_ops to get the native dma_ops pointer on arm.
asm/xen/hypercall.h, asm/xen/hypervisor.h, asm/xen/interface.h and
asm/xen/page.h are identical so to avoid code duplication we are just
including the original arm header files here.
asm/xen/events.h is slightly different, so introduce a different file
here (use xchg to implement xchg_xen_ulong and pass regs->pstate to
raw_irqs_disabled_flags).
Also introduce asm/hypervisor.h and asm/sync_bitops.h.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>