powerpc/cell: Move spu_handle_mm_fault() out of cell platform

Currently spu_handle_mm_fault() is in the cell platform.

This code is generically useful for other non-cell co-processors on powerpc.

This patch moves this function out of the cell platform into arch/powerpc/mm so
that others may use it.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
powerpc/cell: Move data segment faulting code out of cell platform

__spu_trap_data_seg() currently contains code to determine the VSID and ESID
required for a particular EA and mm struct.

This code is generically useful for other co-processors. This moves the code
of the cell platform so it can be used by other powerpc code. It also adds 1TB
segment handling which Cell didn't have.

This also moves the internal struct spu_slb to a generic struct copro_slb which
is now used in the spu and copro code.  We use this new struct instead of the
us passing around esid and vsid parameters.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
powerpc/cell: Make spu_flush_all_slbs() generic

This moves spu_flush_all_slbs() into a generic call copro_flush_all_slbs().

This will be useful when we add cxl which also needs a similar SLB flush call.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
powerpc/msi: Improve IRQ bitmap allocator

Currently msi_bitmap_alloc_hwirqs() will round up any IRQ allocation requests
to the nearest power of 2. eg. ask for 5 IRQs and you'll get 8. This wastes a
lot of IRQs which can be a scarce resource.

For cxl we may require multiple IRQs for every context that is attached to the
accelerator. There may be 1000s of contexts attached, hence we can easily run
out of IRQs, especially if we are needlessly wasting them.

This changes the msi_bitmap_alloc_hwirqs() to allocate only the required number
of IRQs, hence avoiding this wastage. It keeps the natural alignment
requirement though.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
powerpc/mm: Export mmu_kernel_ssize and mmu_linear_psize

Export mmu_kernel_ssize and mmu_linear_psize.  These are needed by the cxl
driver which has it's own MMU.  To setup the MMU cxl need access to these.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
powerpc/powernv: Split out set MSI IRQ chip code

Some of the MSI IRQ code in pnv_pci_ioda_msi_setup() is generically useful so
split it out.

This will be used by some of the cxl PCIe code later.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
cxl: Add new header for call backs and structs

This new header adds callbacks and structs needed by the rest of the kernel to
hook into the cxl infrastructure.

cxl_ctx_get/put/in_use are static inlined here as they are called in tlbie
which we want to be fast (mpe's suggestion).

Empty functions are provided when CONFIG_CXL_BASE is not enabled.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
powerpc/powerpc: Add new PCIe functions for allocating cxl interrupts

This adds a number of functions for allocating IRQs under powernv PCIe for cxl.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
powerpc/mm: Add new hash_page_mm()

This adds a new function hash_page_mm() based on the existing hash_page().
This version allows any struct mm to be passed in, rather than assuming
current. This is useful for servicing co-processor faults which are not in the
context of the current running process.

We need to be careful here as the current hash_page() assumes current in a few
places.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
powerpc/opal: Add PHB to cxl mode call

This adds the OPAL call to change a PHB into cxl mode.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
powerpc/mm: Add hooks for cxl

This add a hook into tlbie() so that we use global invalidations when there are
cxl contexts active.

Normally cxl snoops broadcast tlbie. cxl can have TLB entries invalidated via
MMIO, but we aren't doing that yet. So for now we are just disabling local
tlbies when cxl contexts are active. In future we can make tlbie() local mode
smarter so that it invalidates cxl contexts explicitly when it needs to.

This also adds a hooks for when SLBs are invalidated to ensure any
corresponding SLBs in cxl are also invalidated at the same time.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
cxl: Add base builtin support

This adds the base cxl support that needs to be build into the kernel to use
cxl as a module. This is needed so that the cxl call backs from the core
powerpc mm code always exist irrespective of if the cxl module is loaded or
not. This is similar to how cell works with CONFIG_SPU_BASE.

This adds a cxl_slbia() call (similar to spu_flush_all_slbs()) which checks for
the cxl module being loaded. If the modules is not loaded we return, otherwise
we call into the cxl SLB invalidation code.

This also adds the cxl_ctx_in_use() function for use in the mm code to see if
any cxl contexts are currently in use. This is used by the tlbie() to
determine if it can do local TLB invalidations or not. This also adds get/put
calls for the cxl driver module to refcount the active cxl contexts.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
cxl: Driver code for powernv PCIe based cards for userspace access

This is the core of the cxl driver.

It adds support for using cxl cards in the powernv environment only (ie POWER8
bare metal). It allows access to cxl accelerators by userspace using the
/dev/cxl/afuM.N char devices.

The kernel driver has no knowledge of the function implemented by the
accelerator. It provides services to userspace via the /dev/cxl/afuM.N
devices. When a program opens this device and runs the start work IOCTL, the
accelerator will have coherent access to that processes memory using the same
virtual addresses. That process may mmap the device to access any MMIO space
the accelerator provides.  Also, reads on the device will allow interrupts to
be received. These services are further documented in a later patch in
Documentation/powerpc/cxl.txt.

Documentation of the cxl hardware architecture and userspace API is provided in
subsequent patches.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
cxl: Userspace header file.

This defines structs and magic numbers required for userspace to interact with
the kernel cxl driver via /dev/cxl/afu0.0.

It adds this header file Kbuild so it's exported when doing make
headers_installs.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
cxl: Add driver to Kbuild and Makefiles

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
cxl: Add documentation for userspace APIs

This documentation gives an overview of the hardware architecture, userspace
APIs via /dev/cxl/afu0.0 and the syfs files. It also adds a MAINTAINERS file
entry for cxl.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>