The existing code relied on the hardware definition (<arch/chip.h>)
to specify how much VA and PA space was available.  It's convenient
to allow customizing this for some configurations, so provide symbols
MAX_PA_WIDTH and MAX_VA_WIDTH in <asm/page.h> that can be modified
if desired.

Additionally, move away from the MEM_XX_INTRPT nomenclature to
define the start of various regions within the VA space.  In fact
the cleaner symbol is, for example, MEM_SV_START, to indicate the
start of the area used for supervisor code; the actual address of the
interrupt vectors is not as important, and can be changed if desired.
As part of this change, convert from "intrpt1" nomenclature (which
built in the old privilege-level 1 model) to a simple "intrpt".

Also strip out some tilepro-specific code supporting modifying the
PL the kernel could run at, since we don't actually support using
different PLs in tilepro, only tilegx.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

Previously, we used a special-purpose register (SPR_SYSTEM_SAVE_K_0)
to hold the CPU number and the top of the current kernel stack
by using the low bits to hold the CPU number, and using the high
bits to hold the address of the page just above where we'd want
the kernel stack to be.  That way we could initialize a new SP
when first entering the kernel by just masking the SPR value and
subtracting a couple of words.

However, it's actually more useful to be able to place an arbitrary
kernel-top value in the SPR.  This allows us to create a new stack
context (e.g. for virtualization) with an arbitrary top-of-stack VA.
To make this work, we now store the CPU number in the high bits,
above the highest legal VA bit (42 bits in the current tilegx
microarchitecture).  The full 42 bits are thus available to store the
top of stack value.  Getting the current cpu (a relatively common
operation) is still fast; it's now a shift rather than a mask.

We make this change only for tilegx, since tilepro has too few SPR
bits to do this, and we don't need this support on tilepro anyway.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This change adds infrastructure (CONFIG_TILE_HVGLUE_TRACE) that
provides C code wrappers for the calls the kernel makes to the Tilera
hypervisor.  This allows standard kernel infrastructure like FTRACE to
be able to instrument hypervisor calls.

To allow direct calls to the true API, we export their names with a
leading underscore as well.  This is important for the few contexts
where we need to make hypervisor calls without touching the stack.

As part of this change, we also switch from creating the symbols
with linker magic to creating them with assembler magic.  This lets
us provide a symbol type and generally make them appear more as symbols
and less as just random values in the Elf namespace.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The "inv" (invalidate) instruction is generally less safe than "finv"
(flush and invalidate), as it will drop dirty data from the cache.
It turns out we have almost no need for "inv" (other than for the
older 32-bit architecture in some limited cases), so convert to
"finv" where possible and delete the extra "inv" infrastructure.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The Tilera hypervisor shipped in releases up through MDE 4.1 launches
the client operating system (i.e. Linux) at privilege level 1 (PL1).
Starting with MDE 4.2, as part of the work to enable KVM, the
Tilera hypervisor launches Linux at PL2 instead.

This commit makes the KERNEL_PL option default to 2 for tilegx, while
still saying at 1 for tilepro, which doesn't have an updated hypervisor.
It also explains how and when you might want to choose another value.
In addition, we change a small buglet in the on-chip Ethernet driver,
where we were failing to use the KERNEL_PL constant in an API call.

To make the transition cleaner, this change also provides the updated
hv_init() API for the new hypervisor that supports announcing Linux's
compiled-in PL, so the hypervisor can generate a suitable error in the
case of a mismatched hypervisor and Linux binary.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
Cc: stable@vger.linux.org

This change introduces new flags for the hv_install_context()
API that passes a page table pointer to the hypervisor.  Clients
can explicitly request 4K, 16K, or 64K small pages when they
install a new context.  In practice, the page size is fixed at
kernel compile time and the same size is always requested every
time a new page table is installed.

The <hv/hypervisor.h> header changes so that it provides more abstract
macros for managing "page" things like PFNs and page tables.  For
example there is now a HV_DEFAULT_PAGE_SIZE_SMALL instead of the old
HV_PAGE_SIZE_SMALL.  The various PFN routines have been eliminated and
only PA- or PTFN-based ones remain (since PTFNs are always expressed
in fixed 2KB "page" size).  The page-table management macros are
renamed with a leading underscore and take page-size arguments with
the presumption that clients will use those macros in some single
place to provide the "real" macros they will use themselves.

I happened to notice the old hv_set_caching() API was totally broken
(it assumed 4KB pages) so I changed it so it would nominally work
correctly with other page sizes.

Tag modules with the page size so you can't load a module built with
a conflicting page size.  (And add a test for SMP while we're at it.)
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This change supports building the kernel with newer binutils where
a shift of greater than the word size is no longer interpreted
silently as modulo the word size, but instead generates a warning.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

The convention changed to, e.g., ".data..page_aligned".  This commit
fixes the places in the tile architecture that were still using the
old convention.  One tile-specific section (.init.page) was dropped
in favor of just using an "aligned" attribute.

Sam Ravnborg <sam@ravnborg.org> pointed out __PAGE_ALIGNED_BSS, etc.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

While not a port to KVM (yet), this change modifies the kernel
to be able to build either at PL1 or at PL2 with a suitable
config switch.  Pushing up this change avoids handling branch
merge issues going forward with the KVM work.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.

This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: NPaul Mundt <lethal@linux-sh.org>