On real hardware the ppc hash page table is stored in memory; accordingly
our mmu emulation code can read a hash page table in guest memory. But,
when paravirtualized under PAPR, the real hash page table is in host
memory, accessible to the guest only via hypercalls. We model this by
also allowing the MMU emulation code to access a specially allocated hash
page table outside the guest's memory image. At present these two options
are implemented with some ugly conditionals at each access point in the mmu
emulation code. In the implementation of the PAPR hypercalls, we assume
the external hash table.
This patch cleans things up by adding helpers to load and store from the
hash table for both 32-bit and 64-bit hash mmus. The 64-bit versions
handle both the in-guest-memory and outside guest memory cases. The 32-bit
versions only handle the in-guest-memory case since no 32-bit systems can
have an external hash table at present.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently cpu.h contains a number of definitions relating to the 64-bit
hash MMU. Some are used in the MMU emulation code, but some are only used
in the spapr MMU management hcall implementations.
This patch moves these definitions (except for a few that are needed
more widely) into mmu-hash64.h header, shared between the MMU emulation
code and the spapr hcall code. The MMU emulation code is also updated to
actually use a number of those definitions in place of hard coded
constants.
Similarly, we add new analogous definitions to mmu-hash32.h and use those
in place of many hard-coded constants in mmu-hash32.c
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[agraf: fix 32-bit hosts]
Signed-off-by: Alexander Graf <agraf@suse.de>
mmu_ctx_t is currently defined in cpu.h. However it is used for temporary
information relating to mmu translation, and is only used in mmu_helper.c
and (now) mmu-hash{32,64}.c. Furthermore it contains information which
should be specific to particular MMU types. Therefore, move its definition
to mmu_helper.c. mmu-hash{32,64}.c are converted to use new data types
private to the relevant MMUs (identical to mmu_ctx_t for now, but that will
change in future patches).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
The get_pteg_offset() helper function is currently shared between 32-bit
and 64-bit hash mmus, taking a parameter for the hash pte size. In the
64-bit paths, it's only called in one place, and it's a trivial
calculation. This patch, therefore, open codes it for 64-bit. The
remaining version, which is used in two places is made 32-bit only and
moved to mmu-hash32.c.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
The newly separated paths for hash mmus rely on several helper functions
which are still shared with 32-bit hash mmus: pp_check(), check_prot() and
pte_update_flags(). While these don't have ugly ifdefs on the mmu type,
they're not very well thought out, so sharing them impedes cleaning up the
hash mmu paths. For now, put near-duplicate versions into mmu-hash64.c and
mmu-hash32.c, leaving the old version in mmu_helper.c for 6xx software
loaded tlb implementations. The hash 32 and software loaded
implementations are simplfied slightly, using the fact that no 32-bit CPUs
implement the 3rd page protection bit.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
cpu_get_phys_page_debug() is a trivial wrapper around
get_physical_address(). But even the signature of
get_physical_address() has some things we'd like to clean up on a
per-mmu basis, so this patch moves the test on mmu model out to
cpu_get_phys_page_debug(), moving the version for 64-bit hash MMUs out
to mmu-hash64.c and the version for 32-bit hash MMUs to mmu-hash32.c
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
cpu_ppc_handle_mmu_fault() calls get_physical_address() (whose behaviour
depends on MMU type) then, if that fails, issues an appropriate exception
- which again has a number of dependencies on MMU type.
This patch starts converting cpu_ppc_handle_mmu_fault() to have a
single switch on MMU type, calling MMU specific fault handler
functions which deal with both translation and exception delivery
appropriately for the MMU type. We convert 32-bit and 64-bit hash
MMUs to this new model, but the existing code is left in place for
other MMU types for now.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
Depending on the MSR state, for 64-bit hash MMUs, get_physical_address
can either call check_physical (which has further tests for mmu type)
or get_segment64. Similarly for 32-bit hash MMUs we can either call
check_physucal or get_bat() and get_segment32().
This patch splits off the whole get_physical_addresss() path for hash
MMUs into 32-bit and 64-bit versions, handling real mode correctly for
such MMUs without going to check_physical and rechecking the mmu type.
Correspondingly, the hash MMU specific paths in check_physical() are
removed.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
The poorly named get_segment() function handles most of the address
translation logic for hash-based MMUs. It has many ugly conditionals on
whether the MMU is 32-bit or 64-bit.
This patch splits the function into 32 and 64-bit versions, using the
switch on mmu_type that's already in the caller
(get_physical_address()) to select the right one. Most of the
original function remains in mmu_helper.c to support the 6xx software
loaded TLB implementations (cleaning those up is a project for another
day).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
32-bit and 64-bit hash MMU implementations currently share a find_pte
function. This results in a whole bunch of ugly conditionals in the shared
function, and not all that much actually shared code.
This patch separates out the 32-bit and 64-bit versions, putting then
in mmu-hash64.c and mmu-has32.c, and removes the conditionals from
both versions.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently support for both 32-bit and 64-bit hash MMUs share an
implementation of pte_check. But there are enough differences that this
means the shared function has several very ugly conditionals on "is_64b".
This patch cleans things up by separating out the 64-bit version
(putting it into mmu-hash64.c) and the 32-bit hash version (putting it
in mmu-hash32.c). Another copy remains in mmu_helper.c, which is used
for the 6xx software loaded TLB paths.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
As a first step to disentangling the handling for 64-bit hash MMUs from
the rest, we move the code handling the Segment Lookaside Buffer (SLB)
(which only exists on 64-bit hash MMUs) into a new mmu-hash64.c file.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
