All hugetlb range freeing functions have a verification like the following,
which only differs by the mask used, depending on the page table level.
start &= MASK;
if (start < floor)
return;
if (ceiling) {
ceiling &= MASK;
if (! ceiling)
return;
}
if (end - 1 > ceiling - 1)
return;
Refactor that into a helper function which takes the mask as
an argument, returning true when [start;end[ is not fully
contained inside [floor;ceiling[
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/16a571bb32eb6e8cd44bda484c8d81cd8a25e6d7.1604668827.git.christophe.leroy@csgroup.eu
Exception fixup doesn't require the heady full regs saving,
do it from do_page_fault() directly.
For that, split bad_page_fault() in two parts.
As bad_page_fault() can also be called from other places than
handle_page_fault(), it will still perform exception fixup and
fallback on __bad_page_fault().
handle_page_fault() directly calls __bad_page_fault() as the
exception fixup will now be done by do_page_fault()
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bd07d6fef9237614cd6d318d8f19faeeadaa816b.1607491748.git.christophe.leroy@csgroup.eu
search_exception_tables() is an heavy operation, we have to avoid it.
When KUAP is selected, we'll know the fault has been blocked by KUAP.
When it is blocked by KUAP, check whether we are in an expected
userspace access place. If so, emit a warning to spot something is
going work. Otherwise, just remain silent, it will likely Oops soon.
When KUAP is not selected, it behaves just as if the address was
already in the TLBs and no fault was generated.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9870f01e293a5a76c4f4e4ddd4a6b0f63038c591.1607491748.git.christophe.leroy@csgroup.eu
The verification and message introduced by commit 374f3f5979
("powerpc/mm/hash: Handle user access of kernel address gracefully")
applies to all platforms, it should not be limited to BOOK3S.
Make the BOOK3S version of sanity_check_fault() the one for all,
and bail out earlier if not BOOK3S.
Fixes: 374f3f5979 ("powerpc/mm/hash: Handle user access of kernel address gracefully")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fe199d5af3578d3bf80035d203a94d742a7a28af.1607491748.git.christophe.leroy@csgroup.eu
In order to re-enable MMU earlier, ensure ITLB miss exception
cannot clobber SPRN_SPRG_SCRATCH0 and SPRN_SPRG_SCRATCH1.
Do so by using SPRN_SPRG_SCRATCH2 and SPRN_M_TW instead, like
the DTLB miss exception.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/abc78e8e9577d473691ebb9996c6413b37bfd9ca.1606231483.git.christophe.leroy@csgroup.eu
There is no big poing in not pinning kernel text anymore, as now
we can keep pinned TLB even with things like DEBUG_PAGEALLOC.
Remove CONFIG_PIN_TLB_TEXT, making it always right.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Drop ifdef around mmu_pin_tlb() to fix build errors]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/203b89de491e1379f1677a2685211b7c32adfff0.1606231483.git.christophe.leroy@csgroup.eu
Since commit e611939fc8 ("powerpc/mm: Ensure change_page_attr()
doesn't invalidate pinned TLBs"), pinned TLBs are not anymore
invalidated by __kernel_map_pages() when CONFIG_DEBUG_PAGEALLOC is
selected.
Remove the dependency on CONFIG_DEBUG_PAGEALLOC.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e796c5fcb5898de827c803cf1ab8ba1d7a5d4b76.1606231483.git.christophe.leroy@csgroup.eu
When SMC1 is relocated and early debug is selected, the
board hangs is ppc_md.setup_arch(). This is because ones
the microcode has been loaded and SMC1 relocated, early
debug writes in the weed.
To allow smooth continuation, the SMC1 parameter RAM set up
by the bootloader have to be copied into the new location.
Fixes: 43db76f418 ("powerpc/8xx: Add microcode patch to move SMC parameter RAM.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b2f71f39eca543f1e4ec06596f09a8b12235c701.1607076683.git.christophe.leroy@csgroup.eu
On hash 32 bits, handling minor protection faults like unsetting
dirty flag is heavy if done from the normal page_fault processing,
because it implies hash table software lookup for flushing the entry
and then a DSI is taken anyway to add the entry back.
When KUAP was implemented, as explained in commit a68c31fc01
("powerpc/32s: Implement Kernel Userspace Access Protection"),
protection faults has been diverted from hash_page() because
hash_page() was not able to identify a KUAP fault.
Implement KUAP verification in hash_page(), by clearing write
permission when the access is a kernel access and Ks is 1.
This works regardless of the address because kernel segments always
have Ks set to 0 while user segments have Ks set to 0 only
when kernel write to userspace is granted.
Then protection faults can be handled by hash_page() even for KUAP.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8a4ffe4798e9ea32aaaccdf85e411bb1beed3500.1605542955.git.christophe.leroy@csgroup.eu
book3s/32 has two main families:
- CPU with 603 cores that don't have HASH PTE table and
perform SW TLB loading.
- Other CPUs based on 604+ cores that have HASH PTE table.
This leads to some complex logic and additionnal code to
support both. This makes sense for distribution kernels
that aim at running on any CPU, but when you are fine
tuning a kernel for an embedded 603 based board you
don't need all the HASH logic.
Allow selection of support for each family, in order to opt
out unneeded parts of code. At least one must be selected.
Note that some of the CPU supporting HASH also support SW TLB
loading, however it is not supported by Linux kernel at the
time being, because they do not have alternate registers in
the TLB miss exception handlers.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8dde0cdb629a71abc29b0d85a52a86e920376cb6.1603348103.git.christophe.leroy@csgroup.eu
flush_range() handle both the MMU_FTR_HPTE_TABLE case and
the other case.
The non MMU_FTR_HPTE_TABLE case is trivial as it is only a call
to _tlbie()/_tlbia() which is not worth a dedicated function.
Make flush_range() a hash specific and call it from tlbflush.h based
on mmu_has_feature(MMU_FTR_HPTE_TABLE).
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/132ab19aae52abc8e06ab524ec86d4229b5b9c3d.1603348103.git.christophe.leroy@csgroup.eu
flush_tlb_mm() and flush_tlb_page() handle both the MMU_FTR_HPTE_TABLE
case and the other case.
The non MMU_FTR_HPTE_TABLE case is trivial as it is only a call
to _tlbie()/_tlbia() which is not worth a dedicated function.
Make flush_tlb_mm() and flush_tlb_page() hash specific and call
them from tlbflush.h based on mmu_has_feature(MMU_FTR_HPTE_TABLE).
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/11e932ded41ba6d9b251d89b7afa33cc060d3aa4.1603348103.git.christophe.leroy@csgroup.eu
_tlbie() and _tlbia() are used only on 603 cores while the
other functions are used only on cores having a hash table.
Move them into a new file named nohash_low.S
Add mmu_hash_lock var is used by both, it needs to go
in a common file.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9a265b1b17a64153463d361280cb4b43eb1266a4.1603348103.git.christophe.leroy@csgroup.eu
We now have an early hash table on hash MMU, so no need to check
Hash var to know if the Hash table is set of not.
Use mmu_has_feature(MMU_FTR_HPTE_TABLE) instead. This will allow
optimisation via jump_label.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f1766631a9e014b6433f1a3c12c726ddfce34220.1603348103.git.christophe.leroy@csgroup.eu
Commit bd59380c5b ("powerpc/rtas: Restrict RTAS requests from userspace")
introduced the following error when invoking the errinjct userspace
tool:
[root@ltcalpine2-lp5 librtas]# errinjct open
[327884.071171] sys_rtas: RTAS call blocked - exploit attempt?
[327884.071186] sys_rtas: token=0x26, nargs=0 (called by errinjct)
errinjct: Could not open RTAS error injection facility
errinjct: librtas: open: Unexpected I/O error
The entry for ibm,open-errinjct in rtas_filter array has a typo where
the "j" is omitted in the rtas call name. After fixing this typo the
errinjct tool functions again as expected.
[root@ltcalpine2-lp5 linux]# errinjct open
RTAS error injection facility open, token = 1
Fixes: bd59380c5b ("powerpc/rtas: Restrict RTAS requests from userspace")
Cc: stable@vger.kernel.org
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201208195434.8289-1-tyreld@linux.ibm.com
low_sleep_handler() can't restore the context from standard
stack because the stack can hardly be accessed with MMU OFF.
Store everything in a global storage area instead of storing
a pointer to the stack in that global storage area.
To avoid a complete churn of the function, still use r1 as
the pointer to the storage area during restore.
Fixes: cd08f109e2 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
Reported-by: Giuseppe Sacco <giuseppe@sguazz.it>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Giuseppe Sacco <giuseppe@sguazz.it>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e3e0d8042a3ba75cb4a9546c19c408b5b5b28994.1607404931.git.christophe.leroy@csgroup.eu
In pseries_devicetree_update(), with each call to ibm,update-nodes the
partition firmware communicates the node to be deleted or updated by
placing its phandle in the work buffer. Each of delete_dt_node(),
update_dt_node(), and add_dt_node() have duplicate lookups using the
phandle value and corresponding refcount management.
Move the lookup and of_node_put() into pseries_devicetree_update(),
and emit a warning on any failed lookups.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-29-nathanl@linux.ibm.com
The pseries hibernate code no longer calls into the original
join/suspend code in kernel/rtas.c, so pseries_prepare_late() and
related code don't accomplish anything now.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-27-nathanl@linux.ibm.com
The pseries hibernate code calls post_mobility_fixup() which is sort
of a dumping ground of fixups that need to run after resuming from
suspend regardless of whether suspend was a hibernation or a
migration. Calling post_mobility_fixup() from
pseries_suspend_enable_irqs() runs this code early in resume with
devices suspended and only one CPU up, while the much more commonly
used migration case runs these fixups in a more typical process
context.
Call post_mobility_fixup() after the suspend core returns a success
status to the hibernate sysfs store method and remove
pseries_suspend_enable_irqs().
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-26-nathanl@linux.ibm.com
Partitions with cache nodes in the device tree can encounter the
following warning on resume:
CPU 0 already accounted in PowerPC,POWER9@0(Data)
WARNING: CPU: 0 PID: 3177 at arch/powerpc/kernel/cacheinfo.c:197 cacheinfo_cpu_online+0x640/0x820
These calls to cacheinfo_cpu_offline/online have been redundant since
commit e610a466d1 ("powerpc/pseries/mobility: rebuild cacheinfo
hierarchy post-migration").
Fixes: e610a466d1 ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-25-nathanl@linux.ibm.com
rtas_suspend_last_cpu() and related code perform a lot of work that
isn't relevant to the hibernation workflow. All other CPUs are offline
when called so there is no need to place them in H_JOIN or prod them
on resume, nor is there need for retries or operations on shared
state.
Call the rtas_ibm_suspend_me() wrapper function directly from
pseries_suspend_enter() instead of using rtas_suspend_last_cpu().
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-23-nathanl@linux.ibm.com
rtas_suspend_cpu() no longer has users; remove it and
__rtas_suspend_cpu() which now becomes unused as well.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-22-nathanl@linux.ibm.com
Since commit 48f6e7f6d9 ("powerpc/pseries: remove cede offline state
for CPUs"), ppc_md.suspend_disable_cpu() is no longer used and all
CPUs (save one) are placed into true offline state as opposed to
H_JOIN. So pseries_suspend_cpu() is effectively unused; remove it.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-20-nathanl@linux.ibm.com
There is no need for the stream id to be a file-global variable; pass
it from hibernate_store() to pseries_suspend_begin() for the
H_VASI_STATE call.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-19-nathanl@linux.ibm.com
There are three ways pseries_suspend_begin() can be reached:
1. When "mem" is written to /sys/power/state:
kobj_attr_store()
-> state_store()
-> pm_suspend()
-> suspend_devices_and_enter()
-> pseries_suspend_begin()
This never works because there is no way to supply a valid stream id
using this interface, and H_VASI_STATE is called with a stream id of
zero. So this call path is useless at best.
2. When a stream id is written to /sys/devices/system/power/hibernate.
pseries_suspend_begin() is polled directly from store_hibernate()
until the stream is in the "Suspending" state (i.e. the platform is
ready for the OS to suspend execution):
dev_attr_store()
-> store_hibernate()
-> pseries_suspend_begin()
3. When a stream id is written to /sys/devices/system/power/hibernate
(continued). After #2, pseries_suspend_begin() is called once again
from the pm core:
dev_attr_store()
-> store_hibernate()
-> pm_suspend()
-> suspend_devices_and_enter()
-> pseries_suspend_begin()
This is redundant because the VASI suspend state is already known to
be Suspending.
The begin() callback of platform_suspend_ops is optional, so we can
simply remove that assignment with no loss of function.
Fixes: 32d8ad4e62 ("powerpc/pseries: Partition hibernation support")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-18-nathanl@linux.ibm.com
rtas_ibm_suspend_me_unsafe() is now unused; remove it and
rtas_percpu_suspend_me() which becomes unused as a result.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-17-nathanl@linux.ibm.com
sys_rtas() cannot call ibm,suspend-me directly in the same way it
handles other inputs. Instead it must dispatch the request to code
that can first perform the H_JOIN sequence before any call to
ibm,suspend-me can succeed. Over time kernel/rtas.c has accreted a fair
amount of platform-specific code to implement this.
Since a different, more robust implementation of the suspend sequence
is now in the pseries platform code, we want to dispatch the request
there.
Note that invoking ibm,suspend-me via the RTAS syscall is all but
deprecated; this change preserves ABI compatibility for old programs
while providing to them the benefit of the new partition suspend
implementation. This is a behavior change in that the kernel performs
the device tree update and firmware activation before returning, but
experimentation indicates this is tolerated fine by legacy user space.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-16-nathanl@linux.ibm.com
