linux-stable.git/arch/powerpc, branch linux-3.16.y

of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc

2020-05-22T20:19:39+00:00

commit dabf6b36b83a18d57e3d4b9d50544ed040d86255 upstream.

There's an OF helper called of_dma_is_coherent(), which checks if a
device has a "dma-coherent" property to see if the device is coherent
for DMA.

But on some platforms devices are coherent by default, and on some
platforms it's not possible to update existing device trees to add the
"dma-coherent" property.

So add a Kconfig symbol to allow arch code to tell
of_dma_is_coherent() that devices are coherent by default, regardless
of the presence of the property.

Select that symbol on powerpc when NOT_COHERENT_CACHE is not set, ie.
when the system has a coherent cache.

Fixes: 92ea637edea3 ("of: introduce of_dma_is_coherent() helper")
Reported-by: Christian Zigotzky 
Tested-by: Christian Zigotzky 
Signed-off-by: Michael Ellerman 
Reviewed-by: Ulf Hansson 
Signed-off-by: Rob Herring 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

KVM: PPC: Book3S PR: Free shared page if mmu initialization fails

2020-05-22T20:19:33+00:00

commit cb10bf9194f4d2c5d830eddca861f7ca0fecdbb4 upstream.

Explicitly free the shared page if kvmppc_mmu_init() fails during
kvmppc_core_vcpu_create(), as the page is freed only in
kvmppc_core_vcpu_free(), which is not reached via kvm_vcpu_uninit().

Fixes: 96bc451a15329 ("KVM: PPC: Introduce shared page")
Reviewed-by: Greg Kurz 
Signed-off-by: Sean Christopherson 
Acked-by: Paul Mackerras 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Ben Hutchings

KVM: PPC: Book3S HV: Uninit vCPU if vcore creation fails

2020-05-22T20:19:33+00:00

commit 1a978d9d3e72ddfa40ac60d26301b154247ee0bc upstream.

Call kvm_vcpu_uninit() if vcore creation fails to avoid leaking any
resources allocated by kvm_vcpu_init(), i.e. the vcpu->run page.

Fixes: 371fefd6f2dc4 ("KVM: PPC: Allow book3s_hv guests to use SMT processor modes")
Reviewed-by: Greg Kurz 
Signed-off-by: Sean Christopherson 
Acked-by: Paul Mackerras 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Ben Hutchings

powerpc/irq: fix stack overflow verification

2020-04-28T18:03:03+00:00

commit 099bc4812f09155da77eeb960a983470249c9ce1 upstream.

Before commit 0366a1c70b89 ("powerpc/irq: Run softirqs off the top of
the irq stack"), check_stack_overflow() was called by do_IRQ(), before
switching to the irq stack.
In that commit, do_IRQ() was renamed __do_irq(), and is now executing
on the irq stack, so check_stack_overflow() has just become almost
useless.

Move check_stack_overflow() call in do_IRQ() to do the check while
still on the current stack.

Fixes: 0366a1c70b89 ("powerpc/irq: Run softirqs off the top of the irq stack")
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/e033aa8116ab12b7ca9a9c75189ad0741e3b9b5f.1575872340.git.christophe.leroy@c-s.fr
Signed-off-by: Ben Hutchings

powerpc: Fix vDSO clock_getres()

2020-02-11T20:03:55+00:00

commit 552263456215ada7ee8700ce022d12b0cffe4802 upstream.

clock_getres in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().

In particular, posix_get_hrtimer_res() does:
    sec = 0;
    ns = hrtimer_resolution;
and hrtimer_resolution depends on the enablement of the high
resolution timers that can happen either at compile or at run time.

Fix the powerpc vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.

Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel")
Signed-off-by: Vincenzo Frascino 
Reviewed-by: Christophe Leroy 
Acked-by: Shuah Khan 
[chleroy: changed CLOCK_REALTIME_RES to CLOCK_HRTIMER_RES]
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/a55eca3a5e85233838c2349783bcb5164dae1d09.1575273217.git.christophe.leroy@c-s.fr
[bwh: Backported to 3.16:
 - In asm-offsets.c, use DEFINE() instead of OFFSET()
 - Adjust context]
Signed-off-by: Ben Hutchings

powerpc: Allow 64bit VDSO __kernel_sync_dicache to work across ranges >4GB

2020-02-11T20:03:34+00:00

commit f9ec11165301982585e5e5f606739b5bae5331f3 upstream.

When calling __kernel_sync_dicache with a size >4GB, we were masking
off the upper 32 bits, so we would incorrectly flush a range smaller
than intended.

This patch replaces the 32 bit shifts with 64 bit ones, so that
the full size is accounted for.

Signed-off-by: Alastair D'Silva 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20191104023305.9581-3-alastair@au1.ibm.com
Signed-off-by: Ben Hutchings

powerpc: Allow flush_icache_range to work across ranges >4GB

2020-02-11T20:03:34+00:00

commit 29430fae82073d39b1b881a3cd507416a56a363f upstream.

When calling flush_icache_range with a size >4GB, we were masking
off the upper 32 bits, so we would incorrectly flush a range smaller
than intended.

This patch replaces the 32 bit shifts with 64 bit ones, so that
the full size is accounted for.

Signed-off-by: Alastair D'Silva 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20191104023305.9581-2-alastair@au1.ibm.com
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

USB: rio500: Remove Rio 500 kernel driver

2019-12-19T15:57:59+00:00

commit 015664d15270a112c2371d812f03f7c579b35a73 upstream.

The Rio500 kernel driver has not been used by Rio500 owners since 2001
not long after the rio500 project added support for a user-space USB stack
through the very first versions of usbdevfs and then libusb.

Support for the kernel driver was removed from the upstream utilities
in 2008:
https://gitlab.freedesktop.org/hadess/rio500/commit/943f624ab721eb8281c287650fcc9e2026f6f5db

Cc: Cesar Miquel 
Signed-off-by: Bastien Nocera 
Link: https://lore.kernel.org/r/6251c17584d220472ce882a3d9c199c401a51a71.camel@hadess.net
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.16:
 - Also delete CONFIG_USB_RIO500 from arch/powerpc/configs/c2k_defconfig
 - Drop change to arch/arm/configs/pxa_defconfig
 - Adjust filename, content]
Signed-off-by: Ben Hutchings

powerpc/pseries: correctly track irq state in default idle

2019-12-10T18:01:21+00:00

commit 92c94dfb69e350471473fd3075c74bc68150879e upstream.

prep_irq_for_idle() is intended to be called before entering
H_CEDE (and it is used by the pseries cpuidle driver). However the
default pseries idle routine does not call it, leading to mismanaged
lazy irq state when the cpuidle driver isn't in use. Manifestations of
this include:

* Dropped IPIs in the time immediately after a cpu comes
  online (before it has installed the cpuidle handler), making the
  online operation block indefinitely waiting for the new cpu to
  respond.

* Hitting this WARN_ON in arch_local_irq_restore():
	/*
	 * We should already be hard disabled here. We had bugs
	 * where that wasn't the case so let's dbl check it and
	 * warn if we are wrong. Only do that when IRQ tracing
	 * is enabled as mfmsr() can be costly.
	 */
	if (WARN_ON_ONCE(mfmsr() & MSR_EE))
		__hard_irq_disable();

Call prep_irq_for_idle() from pseries_lpar_idle() and honor its
result.

Fixes: 363edbe2614a ("powerpc: Default arch idle could cede processor on pseries")
Signed-off-by: Nathan Lynch 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20190910225244.25056-1-nathanl@linux.ibm.com
Signed-off-by: Ben Hutchings

powerpc/rtas: use device model APIs and serialization during LPM

2019-12-10T18:01:13+00:00

commit a6717c01ddc259f6f73364779df058e2c67309f8 upstream.

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: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation")
Signed-off-by: Nathan Lynch 
Reviewed-by: Gautham R. Shenoy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20190802192926.19277-2-nathanl@linux.ibm.com
Signed-off-by: Ben Hutchings