linux-stable.git/drivers/of, branch v4.19.3

of, numa: Validate some distance map rules

2018-11-21T08:19:19+00:00

commit 89c38422e072bb453e3045b8f1b962a344c3edea upstream.

Currently the NUMA distance map parsing does not validate the distance
table for the distance-matrix rules 1-2 in [1].

However the arch NUMA code may enforce some of these rules, but not all.
Such is the case for the arm64 port, which does not enforce the rule that
the distance between separates nodes cannot equal LOCAL_DISTANCE.

The patch adds the following rules validation:
- distance of node to self equals LOCAL_DISTANCE
- distance of separate nodes > LOCAL_DISTANCE

This change avoids a yet-unresolved crash reported in [2].

A note on dealing with symmetrical distances between nodes:

Validating symmetrical distances between nodes is difficult. If it were
mandated in the bindings that every distance must be recorded in the
table, then it would be easy. However, it isn't.

In addition to this, it is also possible to record [b, a] distance only
(and not [a, b]). So, when processing the table for [b, a], we cannot
assert that current distance of [a, b] != [b, a] as invalid, as [a, b]
distance may not be present in the table and current distance would be
default at REMOTE_DISTANCE.

As such, we maintain the policy that we overwrite distance [a, b] = [b, a]
for b > a. This policy is different to kernel ACPI SLIT validation, which
allows non-symmetrical distances (ACPI spec SLIT rules allow it). However,
the distance debug message is dropped as it may be misleading (for a distance
which is later overwritten).

Some final notes on semantics:

- It is implied that it is the responsibility of the arch NUMA code to
  reset the NUMA distance map for an error in distance map parsing.

- It is the responsibility of the FW NUMA topology parsing (whether OF or
  ACPI) to enforce NUMA distance rules, and not arch NUMA code.

[1] Documents/devicetree/bindings/numa.txt
[2] https://www.spinics.net/lists/arm-kernel/msg683304.html

Cc: stable@vger.kernel.org # 4.7
Signed-off-by: John Garry 
Acked-by: Will Deacon 
Signed-off-by: Rob Herring 
Signed-off-by: Greg Kroah-Hartman

of: Add missing exports of node name compare functions

2018-11-13T19:08:32+00:00

[ Upstream commit 173ee3962959a1985a109f81539a403b5cd07ae7 ]

Commit f42b0e18f2e5 ("of: add node name compare helper functions")
failed to add the module exports to of_node_name_eq() and
of_node_name_prefix(). Add them now.

Fixes: f42b0e18f2e5 ("of: add node name compare helper functions")
Signed-off-by: Rob Herring 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'devicetree-fixes-for-4.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

2018-10-10T20:09:02+00:00

Rob writes:
  "Devicetree fixes for 4.19, part 3:

   - Fix DT unittest on Oldworld MAC systems"

* tag 'devicetree-fixes-for-4.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of: unittest: Disable interrupt node tests for old world MAC systems

of: unittest: Disable interrupt node tests for old world MAC systems

2018-10-10T11:43:37+00:00

On systems with OF_IMAP_OLDWORLD_MAC set in of_irq_workarounds, the
devicetree interrupt parsing code is different, causing unit tests of
devicetree interrupt nodes to fail. Due to a bug in unittest code, which
tries to dereference an uninitialized pointer, this results in a crash.

OF: /testcase-data/phandle-tests/consumer-a: arguments longer than property
Unable to handle kernel paging request for data at address 0x00bc616e
Faulting instruction address: 0xc08e9468
Oops: Kernel access of bad area, sig: 11 [#1]
BE PREEMPT PowerMac
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.14.72-rc1-yocto-standard+ #1
task: cf8e0000 task.stack: cf8da000
NIP:  c08e9468 LR: c08ea5bc CTR: c08ea5ac
REGS: cf8dbb50 TRAP: 0300   Not tainted  (4.14.72-rc1-yocto-standard+)
MSR:  00001032   CR: 82004044  XER: 00000000
DAR: 00bc616e DSISR: 40000000
GPR00: c08ea5bc cf8dbc00 cf8e0000 c13ca517 c13ca517 c13ca8a0 00000066 00000002
GPR08: 00000063 00bc614e c0b05865 000affff 82004048 00000000 c00047f0 00000000
GPR16: c0a80000 c0a9cc34 c13ca517 c0ad1134 05ffffff 000affff c0b05860 c0abeef8
GPR24: cecec278 cecec278 c0a8c4d0 c0a885e0 c13ca8a0 05ffffff c13ca8a0 c13ca517

NIP [c08e9468] device_node_gen_full_name+0x30/0x15c
LR [c08ea5bc] device_node_string+0x190/0x3c8
Call Trace:
[cf8dbc00] [c007f670] trace_hardirqs_on_caller+0x118/0x1fc (unreliable)
[cf8dbc40] [c08ea5bc] device_node_string+0x190/0x3c8
[cf8dbcb0] [c08eb794] pointer+0x25c/0x4d0
[cf8dbd00] [c08ebcbc] vsnprintf+0x2b4/0x5ec
[cf8dbd60] [c08ec00c] vscnprintf+0x18/0x48
[cf8dbd70] [c008e268] vprintk_store+0x4c/0x22c
[cf8dbda0] [c008ecac] vprintk_emit+0x94/0x130
[cf8dbdd0] [c008ff54] printk+0x5c/0x6c
[cf8dbe10] [c0b8ddd4] of_unittest+0x2220/0x26f8
[cf8dbea0] [c0004434] do_one_initcall+0x4c/0x184
[cf8dbf00] [c0b4534c] kernel_init_freeable+0x13c/0x1d8
[cf8dbf30] [c0004814] kernel_init+0x24/0x118
[cf8dbf40] [c0013398] ret_from_kernel_thread+0x5c/0x64

The problem was observed when running a qemu test for the g3beige machine
with devicetree unittests enabled.

Disable interrupt node tests on affected systems to avoid both false
unittest failures and the crash.

With this patch in place, unittest on the affected system passes with
the following message.

	dt-test ### end of unittest - 144 passed, 0 failed

Fixes: 53a42093d96ef ("of: Add device tree selftests")
Signed-off-by: Guenter Roeck 
Reviewed-by: Frank Rowand 
Signed-off-by: Rob Herring

Merge tag 'devicetree-fixes-for-4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

2018-09-14T23:03:17+00:00

Pull DeviceTree fix from Rob Herring:
 "One regression for a 20 year old PowerMac:

   - Fix a regression on systems having a DT without any phandles which
     happens on a PowerMac G3"

* tag 'devicetree-fixes-for-4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of: fix phandle cache creation for DTs with no phandles

of: fix phandle cache creation for DTs with no phandles

2018-09-11T16:28:40+00:00

With commit 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of
of_find_node_by_phandle()"), a G3 PowerMac fails to boot. The root cause
is the DT for this system has no phandle properties when booted with
BootX. of_populate_phandle_cache() does not handle the case of no
phandles correctly. The problem is roundup_pow_of_two() for 0 is
undefined. The implementation subtracts 1 underflowing and then things
are in the weeds.

Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
Cc: stable@vger.kernel.org # 4.17+
Reported-by: Finn Thain 
Tested-by: Stan Johnson 
Reviewed-by: Frank Rowand 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Rob Herring

Merge tag 'dma-mapping-4.19-2' of git://git.infradead.org/users/hch/dma-mapping

2018-09-03T03:09:36+00:00

Pull dma-mapping fixes from Christoph Hellwig:
 "A few fixes for the fallout of being a little more pedantic about dma
  masks"

* tag 'dma-mapping-4.19-2' of git://git.infradead.org/users/hch/dma-mapping:
  of/platform: initialise AMBA default DMA masks
  sparc: set a default 32-bit dma mask for OF devices
  kernel/dma/direct: take DMA offset into account in dma_direct_supported

of/platform: initialise AMBA default DMA masks

2018-09-02T08:04:31+00:00

This addresses a v4.19-rc1 regression in the PL111 DRM driver in
drivers/gpu/pl111/*

The driver uses the CMA KMS helpers and will thus at some point call
down to dma_alloc_attrs() to allocate a chunk of contigous DMA memory
for the framebuffer.

It appears that in v4.18, it was OK that this (and other DMA mastering
AMBA devices) left dev->coherent_dma_mask blank (zero).

In v4.19-rc1 the WARN_ON_ONCE(dev && !dev->coherent_dma_mask) in
dma_alloc_attrs() in include/linux/dma-mapping.h is triggered.  The
allocation later fails when get_coherent_dma_mask() is called from
__dma_alloc() and __dma_alloc() returns NULL:

drm-clcd-pl111 dev:20: coherent DMA mask is unset
drm-clcd-pl111 dev:20: [drm:drm_fb_helper_fbdev_setup] *ERROR*
 	       	        Failed to set fbdev configuration

It turns out that in commit 4d8bde883bfb ("OF: Don't set default
coherent DMA mask") the OF core stops setting the default DMA mask on
new devices, especially those lines of the patch:

- if (!dev->coherent_dma_mask)
-               dev->coherent_dma_mask = DMA_BIT_MASK(32);

Robin Murphy solved a similar problem in a5516219b102 ("of/platform:
Initialise default DMA masks") by simply assigning dev.coherent_dma_mask
and the dev.dma_mask to point to the same when creating devices from the
device tree, and introducing the same code into the code path creating
AMBA/PrimeCell devices solved my problem, graphics now come up.

The code simply assumes that the device can access all of the system
memory by setting the coherent DMA mask to 0xffffffff when creating a
device from the device tree, which is crude, but seems to be what kernel
v4.18 assumed.

The AMBA PrimeCells do not differ between coherent and streaming DMA so
we can just assign the same to any DMA mask.

Possibly drivers should augment their coherent DMA mask in accordance
with "dma-ranges" from the device tree if more finegranular masking is
needed.

Reported-by: Russell King 
Fixes: 4d8bde883bfb ("OF: Don't set default coherent DMA mask")
Cc: Russell King 
Cc: Robin Murphy 
Signed-off-by: Linus Walleij 
Signed-off-by: Christoph Hellwig

of: add node name compare helper functions

2018-08-30T18:53:05+00:00

In preparation to remove device_node.name pointer, add helper functions
for node name comparisons which are a common pattern throughout the kernel.

Cc: Frank Rowand 
Signed-off-by: Rob Herring

of: add helper to lookup compatible child node

2018-08-29T13:06:46+00:00

Add of_get_compatible_child() helper that can be used to lookup
compatible child nodes.

Several drivers currently use of_find_compatible_node() to lookup child
nodes while failing to notice that the of_find_ functions search the
entire tree depth-first (from a given start node) and therefore can
match unrelated nodes. The fact that these functions also drop a
reference to the node they start searching from (e.g. the parent node)
is typically also overlooked, something which can lead to use-after-free
bugs.

Signed-off-by: Johan Hovold 
Signed-off-by: Rob Herring