book3s64's ioremap_range() is almost same as fallback ioremap_range(),
except that it calls radix__ioremap_range() when radix is enabled.
radix__ioremap_range() is also very similar to the other ones, expect
that it calls ioremap_page_range when slab is available.
PPC32 __ioremap_caller() have a loop doing the same thing as
ioremap_range() so use it on PPC32 as well.
Lets keep only one version of ioremap_range() which calls
ioremap_page_range() on all platforms when slab is available.
At the same time, drop the nid parameter which is not used.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4b1dca7096b01823b101be7338983578641547f1.1566309263.git.christophe.leroy@c-s.fr
Create ioremap_32.c and ioremap_64.c and move respective ioremap
functions out of pgtable_32.c and pgtable_64.c
In the meantime, fix a few comments and changes a printk() to
pr_warn(). Also fix a few oversplitted lines.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b5c8b02ccefd4ede64c61b53cf64fb5dacb35740.1566309263.git.christophe.leroy@c-s.fr
Drop multiple definitions of ioremap_bot and make one common to
all subarches.
Only CONFIG_PPC_BOOK3E_64 had a global static init value for
ioremap_bot. Now ioremap_bot is set in early_init_mmu_global().
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/920eebfd9f36f14c79d1755847f5bf7c83703bdd.1566309262.git.christophe.leroy@c-s.fr
ppc_md.ioremap() is only used for I/O workaround on CELL platform,
so indirect function call can be avoided.
This patch reworks the io-workaround and ioremap() functions to
use the global 'io_workaround_inited' flag for the activation
of io-workaround.
When CONFIG_PPC_IO_WORKAROUNDS or CONFIG_PPC_INDIRECT_MMIO are not
selected, the I/O workaround ioremap() voids and the global flag is
not used.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5fa3ef069fbd0f152512afaae19e7a60161454cf.1566309262.git.christophe.leroy@c-s.fr
ppc_md.iounmap() is never set, drop it.
Once ppc_md.iounmap() is gone, iounmap() remains the only user of
__iounmap() and iounmap() does nothing else than calling __iounmap().
So drop iounmap() and make __iounmap() the new iounmap().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d73ba92bb7a387cc58cc34666d7f5158a45851b0.1566309262.git.christophe.leroy@c-s.fr
__ioremap() is similar to ioremap_prot() except that ioremap_prot()
does a few sanity changes in addition.
The flags used by PS3 are not impacted by those changes so for
PS3 both functions are equivalent.
At the same time, drop parts of the comment that have been invalid
since commit e58e87adc8 ("powerpc/mm: Update _PAGE_KERNEL_RO")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/36bff5d875ff562889c5e12dab63e5d7c5d1fbd8.1566309262.git.christophe.leroy@c-s.fr
Add support for disabling the kernel implemented spectre v2 mitigation
(count cache flush on context switch) via the nospectre_v2 and
mitigations=off cmdline options.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190524024647.381-1-cmr@informatik.wtf
While reviewing lockdown patches, I discovered that we still enable
/dev/port (CONFIG_DEVPORT) in skiroot.
/dev/port is used for old x86 style IO accesses. It's set up in
drivers/char/mem.c, and is only created if arch_has_dev_port() returns
true. Per arch/powerpc/include/asm/io.h, on PPC64 with PCI, this is
only true if there's a legacy ISA bridge.
Even if a system has a legacy ISA bridge installed, we have no
business accessing it in skiroot.
Deselect CONFIG_DEVPORT for skiroot.
Signed-off-by: Daniel Axtens <dja@axtens.net>
[mpe: Incorporate emailed comments into the change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190627053008.29315-1-dja@axtens.net
If a PCI device is removed during eeh_pe_report_edev(), between the
calls to device_lock() and device_unlock(), edev->pdev will change and
cause a crash as the wrong mutex is released.
To correct this, hold the PCI rescan/remove lock while taking a copy
of edev->pdev and performing a get_device() on it. Use this value to
release the mutex, but also pass it through to the device driver's EEH
handlers so that they always see the same device.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3c590579a0faa24d20c826dcd26c739eb4d454e6.1565930772.git.sbobroff@linux.ibm.com
Convert existing messages, where appropriate, to use the eeh_edev_*
logging macros.
The only effect should be minor adjustments to the log messages, apart
from:
- A new message in pseries_eeh_probe() "Probing device" to match the
powernv case.
- The "Probing device" message in pnv_eeh_probe() is now generated
slightly later, which will mean that it is no longer emitted for
devices that aren't probed due to the initial checks.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ce505a0a7a4a5b0367f0f40f8b26e7c0a9cf4cb7.1565930772.git.sbobroff@linux.ibm.com
Now that struct eeh_dev includes the BDFN of it's PCI device, make use
of it to replace eeh_edev_info() with a set of dev_dbg()-style macros
that only need a struct edev.
With the BDFN available without the struct pci_dev, eeh_pci_name() is
now unnecessary, so remove it.
While only the "info" level function is used here, the others will be
used in followup work.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f90ae9a53d762be7b0ccbad79e62b5a1b4f4996e.1565930772.git.sbobroff@linux.ibm.com
Preparation for removing pci_dn from the powernv EEH code. The only
thing we really use pci_dn for is to get the bdfn of the device for
config space accesses, so adding that information to eeh_dev reduces
the need to carry around the pci_dn.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[SB: Re-wrapped commit message, fixed whitespace damage.]
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e458eb69a1f591d8a120782f23a8506b15d3c654.1565930772.git.sbobroff@linux.ibm.com
Now that EEH support for all devices (on PowerNV and pSeries) is
provided by the pcibios bus add device hooks, eeh_probe_devices() and
eeh_addr_cache_build() are redundant and can be removed.
Move the EEH enabled message into it's own function so that it can be
called from multiple places.
Note that previously on pSeries, useless EEH sysfs files were created
for some devices that did not have EEH support and this change
prevents them from being created.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/33b0a6339d5ac88693de092d6fba984f2a5add66.1565930772.git.sbobroff@linux.ibm.com
On PowerNV and pSeries, devices currently acquire EEH support from
several different places: Boot-time devices from eeh_probe_devices()
and eeh_addr_cache_build(), Virtual Function devices from the pcibios
bus add device hooks and hot plugged devices from pci_hp_add_devices()
(with other platforms using other methods as well). Unfortunately,
pSeries machines currently discover hot plugged devices using
pci_rescan_bus(), not pci_hp_add_devices(), and so those devices do
not receive EEH support.
Rather than adding another case for pci_rescan_bus(), this change
widens the scope of the pcibios bus add device hooks so that they can
handle all devices. As a side effect this also supports devices
discovered after manually rescanning via /sys/bus/pci/rescan.
Note that on PowerNV, this change allows the EEH subsystem to become
enabled after boot as long as it has not been forced off, which was
not previously possible (it was already possible on pSeries).
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/72ae8ae9c54097158894a52de23690448de38ea9.1565930772.git.sbobroff@linux.ibm.com
The EEH address cache is currently initialized and populated by a
single function: eeh_addr_cache_build(). While the initial population
of the cache can only be done once resources are allocated,
initialization (just setting up a spinlock) could be done much
earlier.
So move the initialization step into a separate function and call it
from a core_initcall (rather than a subsys initcall).
This will allow future work to make use of the cache during boot time
PCI scanning.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0557206741bffee76cdfff042f65321f6f7a5b41.1565930772.git.sbobroff@linux.ibm.com
The EEH_DEV_NO_HANDLER flag is used by the EEH system to prevent the
use of driver callbacks in drivers that have been bound part way
through the recovery process. This is necessary to prevent later stage
handlers from being called when the earlier stage handlers haven't,
which can be confusing for drivers.
However, the flag is set for all devices that are added after boot
time and only cleared at the end of the EEH recovery process. This
results in hot plugged devices erroneously having the flag set during
the first recovery after they are added (causing their driver's
handlers to be incorrectly ignored).
To remedy this, clear the flag at the beginning of recovery
processing. The flag is still cleared at the end of recovery
processing, although it is no longer really necessary.
Also clear the flag during eeh_handle_special_event(), for the same
reasons.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b8ca5629d27de74c957d4f4b250177d1b6fc4bbd.1565930772.git.sbobroff@linux.ibm.com
The pcibios_init() function for PowerPC 64 currently calls
pci_bus_add_devices() before pcibios_resource_survey(). This means
that at boot time, when the pcibios_bus_add_device() hooks are called
by pci_bus_add_devices(), device resources have not been allocated and
they are unable to perform EEH setup, so a separate pass is needed.
This patch adjusts that order so that it will become possible to
consolidate the EEH setup work into a single location.
The only functional change is to execute pcibios_resource_survey()
(excepting ppc_md.pcibios_fixup(), see below) before
pci_bus_add_devices() instead of after it.
Because pcibios_scan_phb() and pci_bus_add_devices() are called
together in a loop, this must be broken into one loop for each call.
Then the call to pcibios_resource_survey() is moved up in between
them. This changes the ordering but because pcibios_resource_survey()
also calls ppc_md.pcibios_fixup(), that call is extracted out into
pcibios_init() to where pcibios_resource_survey() was, so that it is
not moved.
The only other caller of pcibios_resource_survey() is the PowerPC 32
version of pcibios_init(), and therefore, that is modified to call
ppc_md.pcibios_fixup() right after pcibios_resource_survey() so that
there is no functional change there at all.
The re-arrangement will cause very few side-effects because at this
stage in the boot, pci_bus_add_devices() does very little:
- pci_create_sysfs_dev_files() does nothing (no sysfs yet)
- pci_proc_attach_device() does nothing (no proc yet)
- device_attach() does nothing (no drivers yet)
This leaves only the pci_final_fixup calls, D3 support, and marking
the device as added. Of those, only the pci_final_fixup calls have the
potential to be affected by resource allocation.
The only pci_final_fixup handlers that touch resources seem to be one
for x86 (pci_amd_enable_64bit_bar()), and a PowerPC 32 platform driver
(quirk_final_uli1575()), neither of which use this pcibios_init()
function. Even if they did, it would almost certainly be a bug, under
the current ordering, to rely on or make changes to resources before
they were allocated.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4506b0489eabd0921a3587d90bd44c7683f3472d.1565930772.git.sbobroff@linux.ibm.com
The KBUILD_ARFLAGS addition in arch/powerpc/Makefile has never worked
in a useful way because it is always overridden by the following code
in the top Makefile:
# use the deterministic mode of AR if available
KBUILD_ARFLAGS := $(call ar-option,D)
The code in the top Makefile was added in 2011, by commit 40df759e2b
("kbuild: Fix build with binutils <= 2.19").
The KBUILD_ARFLAGS addition for ppc has always been dead code from the
beginning.
Nobody has reported a problem since 43c9127d94 ("powerpc: Add option
to use thin archives"), so this code was unneeded.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190713032106.8509-1-yamada.masahiro@socionext.com
The pmem infrastructure uses memcpy_mcsafe in the pmem layer so as to
convert machine check exceptions into a return value on failure in case
a machine check exception is encountered during the memcpy. The return
value is the number of bytes remaining to be copied.
This patch largely borrows from the copyuser_power7 logic and does not add
the VMX optimizations, largely to keep the patch simple. If needed those
optimizations can be folded in.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[arbab@linux.ibm.com: Added symbol export]
Co-developed-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-7-santosh@fossix.org
If we take a UE on one of the instructions with a fixup entry, set nip
to continue execution at the fixup entry. Stop processing the event
further or print it.
Co-developed-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-6-santosh@fossix.org
The function doesn't get used outside this file, so make it static.
Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-4-santosh@fossix.org
The current code would fail on huge pages addresses, since the shift would
be incorrect. Use the correct page shift value returned by
__find_linux_pte() to get the correct physical address. The code is more
generic and can handle both regular and compound pages.
Fixes: ba41e1e1cc ("powerpc/mce: Hookup derror (load/store) UE errors")
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[arbab@linux.ibm.com: Fixup pseries_do_memory_failure()]
Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Tested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-3-santosh@fossix.org
After a partition migration, pseries_devicetree_update() processes
changes to the device tree communicated from the platform to
Linux. This is a relatively heavyweight operation, with multiple
device tree searches, memory allocations, and conversations with
partition firmware.
There's a few levels of nested loops which are bounded only by
decisions made by the platform, outside of Linux's control, and indeed
we have seen RCU stalls on large systems while executing this call
graph. Use cond_resched() in these loops so that the cpu is yielded
when needed.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802192926.19277-4-nathanl@linux.ibm.com
rtas_cpu_state_change_mask() potentially operates on scores of cpus,
so explicitly allow rescheduling in the loop body.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802192926.19277-3-nathanl@linux.ibm.com
The LPAR migration implementation and userspace-initiated cpu hotplug
can interleave their executions like so:
1. Set cpu 7 offline via sysfs.
2. Begin a partition migration, whose implementation requires the OS
to ensure all present cpus are online; cpu 7 is onlined:
rtas_ibm_suspend_me -> rtas_online_cpus_mask -> cpu_up
This sets cpu 7 online in all respects except for the cpu's
corresponding struct device; dev->offline remains true.
3. Set cpu 7 online via sysfs. _cpu_up() determines that cpu 7 is
already online and returns success. The driver core (device_online)
sets dev->offline = false.
4. The migration completes and restores cpu 7 to offline state:
rtas_ibm_suspend_me -> rtas_offline_cpus_mask -> cpu_down
This leaves cpu7 in a state where the driver core considers the cpu
device online, but in all other respects it is offline and
unused. Attempts to online the cpu via sysfs appear to succeed but the
driver core actually does not pass the request to the lower-level
cpuhp support code. This makes the cpu unusable until the cpu device
is manually set offline and then online again via sysfs.
Instead of directly calling cpu_up/cpu_down, the migration code should
use the higher-level device core APIs to maintain consistent state and
serialize operations.
Fixes: 120496ac2d ("powerpc: Bring all threads online prior to migration/hibernation")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802192926.19277-2-nathanl@linux.ibm.com
If a page is already mapped RW without the DIRTY flag, the DIRTY
flag is never set and a TLB store miss exception is taken forever.
This is easily reproduced with the following app:
void main(void)
{
volatile char *ptr = mmap(0, 4096, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
*ptr = *ptr;
}
When DIRTY flag is not set, bail out of TLB miss handler and take
a minor page fault which will set the DIRTY flag.
Fixes: f8b58c64ea ("powerpc/603: let's handle PAGE_DIRTY directly")
Cc: stable@vger.kernel.org # v5.1+
Reported-by: Doug Crawford <doug.crawford@intelight-its.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/80432f71194d7ee75b2f5043ecf1501cf1cca1f3.1566196646.git.christophe.leroy@c-s.fr
pfn_pte is never given a pte above the addressable physical memory
limit, so the masking is redundant. In case of a software bug, it
is not obviously better to silently truncate the pfn than to corrupt
the pte (either one will result in memory corruption or crashes),
so there is no reason to add this to the fast path.
Add VM_BUG_ON to catch cases where the pfn is invalid. These would
catch the create_section_mapping bug fixed by a previous commit.
[16885.256466] ------------[ cut here ]------------
[16885.256492] kernel BUG at arch/powerpc/include/asm/book3s/64/pgtable.h:612!
cpu 0x0: Vector: 700 (Program Check) at [c0000000ee0a36d0]
pc: c000000000080738: __map_kernel_page+0x248/0x6f0
lr: c000000000080ac0: __map_kernel_page+0x5d0/0x6f0
sp: c0000000ee0a3960
msr: 9000000000029033
current = 0xc0000000ec63b400
paca = 0xc0000000017f0000 irqmask: 0x03 irq_happened: 0x01
pid = 85, comm = sh
kernel BUG at arch/powerpc/include/asm/book3s/64/pgtable.h:612!
Linux version 5.3.0-rc1-00001-g0fe93e5f3394
enter ? for help
[c0000000ee0a3a00] c000000000d37378 create_physical_mapping+0x260/0x360
[c0000000ee0a3b10] c000000000d370bc create_section_mapping+0x1c/0x3c
[c0000000ee0a3b30] c000000000071f54 arch_add_memory+0x74/0x130
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
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/20190724084638.24982-5-npiggin@gmail.com
Ensure __va is given a physical address below PAGE_OFFSET, and __pa is
given a virtual address above PAGE_OFFSET.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
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/20190724084638.24982-4-npiggin@gmail.com
The alloc_pages_node return value should be tested for failure
before being passed to page_address.
Tested-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
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/20190724084638.24982-3-npiggin@gmail.com
create_physical_mapping expects physical addresses, but splitting
these mapping on hot unplug is supplying virtual (effective)
addresses.
Fixes: 4dd5f8a99e ("powerpc/mm/radix: Split linear mapping on hot-unplug")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
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/20190724084638.24982-2-npiggin@gmail.com
create_physical_mapping expects physical addresses, but creating and
splitting these mappings after boot is supplying virtual (effective)
addresses. This can be irritated by booting with mem= to limit memory
then probing an unused physical memory range:
echo <addr> > /sys/devices/system/memory/probe
This mostly works by accident, firstly because __va(__va(x)) == __va(x)
so the virtual address does not get corrupted. Secondly because pfn_pte
masks out the upper bits of the pfn beyond the physical address limit,
so a pfn constructed with a 0xc000000000000000 virtual linear address
will be masked back to the correct physical address in the pte.
Fixes: 6cc27341b2 ("powerpc/mm: add radix__create_section_mapping()")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
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/20190724084638.24982-1-npiggin@gmail.com
current may be cached by the compiler, so remove the volatile asm
restriction. This results in better generated code, as well as being
smaller and fewer dependent loads, it can avoid store-hit-load flushes
like this one that shows up in irq_exit():
preempt_count_sub(HARDIRQ_OFFSET);
if (!in_interrupt() && ...)
Which ends up as:
((struct thread_info *)current)->preempt_count -= HARDIRQ_OFFSET;
if (((struct thread_info *)current)->preempt_count ...
Evaluating current twice presently means it has to be loaded twice, and
here gcc happens to pick a different register each time, then
preempt_count is accessed via that base register:
1058: ld r10,2392(r13) <-- current
105c: lwz r9,0(r10) <-- preempt_count
1060: addis r9,r9,-1
1064: stw r9,0(r10) <-- preempt_count
1068: ld r9,2392(r13) <-- current
106c: lwz r9,0(r9) <-- preempt_count
1070: rlwinm. r9,r9,0,11,23
1074: bne 1090 <irq_exit+0x60>
This can frustrate store-hit-load detection heuristics and cause
flushes. Allowing the compiler to cache current in a reigster with this
patch results in the same base register being used for all accesses,
which is more likely to be detected as an alias:
1058: ld r31,2392(r13)
...
1070: lwz r9,0(r31)
1074: addis r9,r9,-1
1078: stw r9,0(r31)
107c: lwz r9,0(r31)
1080: rlwinm. r9,r9,0,11,23
1084: bne 10a0 <irq_exit+0x60>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190612140317.24490-1-npiggin@gmail.com
copy_page() and clear_page() expect page aligned destination, and
use dcbz instruction to clear entire cache lines based on the
assumption that the destination is cache aligned.
As shown during analysis of a bug in BTRFS filesystem, a misaligned
copy_page() can create bugs that are difficult to locate (see Link).
Add an explicit WARNING when copy_page() or clear_page() are called
with misaligned destination.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=204371
Link: https://lore.kernel.org/r/c6cea38f90480268d439ca44a645647e260fff09.1565941808.git.christophe.leroy@c-s.fr
update_mmu_cache() is only for BOOK3S, and can be simplified for
BOOK3S32.
Move it out of mem.c into respective BOOK3S32 and BOOK3S64 files
containing hash utils.
BOOK3S64 version of hash_preload() is only used locally, declare it
static.
Remove the radix_enabled() stuff in BOOK3S32 version.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/107aaf43583a5f5d09e0d4e84c4c4390ecfcd512.1565933217.git.christophe.leroy@c-s.fr
Only BOOK3S and FSL_BOOK3E have a usefull update_mmu_cache().
For the others, just define it static inline.
In the meantime, simplify the FSL_BOOK3E related ifdef as
book3e_hugetlb_preload() only exists when CONFIG_PPC_FSL_BOOK3E
is selected.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/668aba4db6b9af6d8a151174e11a4289f1a6bbcd.1565933217.git.christophe.leroy@c-s.fr
When KASAN is selected, the definitive hash table has to be
set up later, but there is already an early temporary one.
When KASAN is not selected, there is no early hash table,
so the setup of the definitive hash table cannot be delayed.
Fixes: 72f208c6a8 ("powerpc/32s: move hash code patching out of MMU_init_hw()")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: Jonathan Neuschafer <j.neuschaefer@gmx.net>
Tested-by: Jonathan Neuschafer <j.neuschaefer@gmx.net>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b7860c5e1e784d6b96ba67edf47dd6cbc2e78ab6.1565776892.git.christophe.leroy@c-s.fr
Christophe Leroy
Christoph Hellwig
Christopher M. Riedl
Daniel Axtens
Sam Bobroff
Oliver O'Halloran
Masahiro Yamada
Santosh Sivaraj
Balbir Singh
Reza Arbab
Nathan Lynch
Nicholas Piggin