linux-toradex.git/arch/powerpc/Kconfig.debug, branch v6.7

Merge branch 'topic/ppc-kvm' into next

2023-10-27T09:58:03+00:00

Merge our KVM topic branch, this has been independently included in linux-next
for most of the development cycle.

powerpc: Use shared font data

2023-10-01T12:09:02+00:00

PowerPC has a 'btext' font used for the console which is almost identical
to the shared font_sun8x16, so use it rather than duplicating the data.

They were actually identical until about a decade ago when
   commit bcfbeecea11c ("drivers: console: font_: Change a glyph from
                        "broken bar" to "vertical line"")

which changed the | in the shared font to be a solid
bar rather than a broken bar.  That's the only difference.

This was originally spotted by the PMF source code analyser, which
noticed that sparc does the same thing with the same data, and they
also share a bunch of functions to manipulate the data.  I've previously
posted a near identical patch for sparc.

Tested very lightly with a boot without FS in qemu.

Signed-off-by: "Dr. David Alan Gilbert" 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230825142754.1487900-1-linux@treblig.org

KVM: PPC: Add helper library for Guest State Buffers

2023-09-14T12:04:24+00:00

The PAPR "Nestedv2" guest API introduces the concept of a Guest State
Buffer for communication about L2 guests between L1 and L0 hosts.

In the new API, the L0 manages the L2 on behalf of the L1. This means
that if the L1 needs to change L2 state (e.g. GPRs, SPRs, partition
table...), it must request the L0 perform the modification. If the
nested host needs to read L2 state likewise this request must
go through the L0.

The Guest State Buffer is a Type-Length-Value style data format defined
in the PAPR which assigns all relevant partition state a unique
identity. Unlike a typical TLV format the length is redundant as the
length of each identity is fixed but is included for checking
correctness.

A guest state buffer consists of an element count followed by a stream
of elements, where elements are composed of an ID number, data length,
then the data:

  Header:

   <---4 bytes--->
  +----------------+-----
  | Element Count  | Elements...
  +----------------+-----

  Element:

   <----2 bytes---> <-2 bytes-> <-Length bytes->
  +----------------+-----------+----------------+
  | Guest State ID |  Length   |      Data      |
  +----------------+-----------+----------------+

Guest State IDs have other attributes defined in the PAPR such as
whether they are per thread or per guest, or read-only.

Introduce a library for using guest state buffers. This includes support
for actions such as creating buffers, adding elements to buffers,
reading the value of elements and parsing buffers. This will be used
later by the nestedv2 guest support.

Signed-off-by: Jordan Niethe 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230914030600.16993-9-jniethe5@gmail.com

powerpc: allow PPC_EARLY_DEBUG_CPM only when SERIAL_CPM=y

2023-07-03T06:07:55+00:00

In a randconfig with CONFIG_SERIAL_CPM=m and
CONFIG_PPC_EARLY_DEBUG_CPM=y, there is a build error:
ERROR: modpost: "udbg_putc" [drivers/tty/serial/cpm_uart/cpm_uart.ko] undefined!

Prevent the build error by allowing PPC_EARLY_DEBUG_CPM only when
SERIAL_CPM=y.

Fixes: c374e00e17f1 ("[POWERPC] Add early debug console for CPM serial ports.")
Signed-off-by: Randy Dunlap 
Reviewed-by: Pali Rohár 
Reviewed-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230701054714.30512-1-rdunlap@infradead.org

powerpc: Add support for early debugging via Serial 16550 console

2022-09-28T09:22:09+00:00

Currently powerpc early debugging contains lot of platform specific
options, but does not support standard UART / serial 16550 console.

Later legacy_serial.c code supports registering UART as early debug console
from device tree but it is not early during booting, but rather later after
machine description code finishes.

So for real early debugging via UART is current code unsuitable.

Add support for new early debugging option CONFIG_PPC_EARLY_DEBUG_16550
which enable Serial 16550 console on address defined by new option
CONFIG_PPC_EARLY_DEBUG_16550_PHYSADDR and by stride by option
CONFIG_PPC_EARLY_DEBUG_16550_STRIDE.

With this change it is possible to debug powerpc machine descriptor code.
For example this early debugging code can print on serial console also
"No suitable machine description found" error which is done before
legacy_serial.c code.

Signed-off-by: Pali Rohár 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220822231501.16827-1-pali@kernel.org

powerpc: Kconfig.debug: Remove extra empty line

2022-06-29T09:43:16+00:00

Remove a stray extra empty line.

Signed-off-by: Juerg Haefliger 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220526065737.86370-3-juerg.haefliger@canonical.com

powerpc/64e: KASAN Full support for BOOK3E/64

2022-06-29T07:04:15+00:00

We now have memory organised in a way that allows
implementing KASAN.

Unlike book3s/64, book3e always has translation active so the only
thing needed to use KASAN is to setup an early zero shadow mapping
just after setting a stack pointer and before calling early_setup().

The memory layout is now as follows

   +------------------------+  Kernel virtual map end (0xc000200000000000)
   |                        |
   |    16TB of KASAN map   |
   |                        |
   +------------------------+  Kernel KASAN shadow map start
   |                        |
   |    16TB of IO map      |
   |                        |
   +------------------------+  Kernel IO map start
   |                        |
   |    16TB of vmemmap     |
   |                        |
   +------------------------+  Kernel vmemmap start
   |                        |
   |    16TB of vmap        |
   |                        |
   +------------------------+  Kernel virt start (0xc000100000000000)
   |                        |
   |    64TB of linear mem  |
   |                        |
   +------------------------+  Kernel linear (0xc.....)

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/0bef8beda27baf71e3b9e8b13e620fba6e19499b.1656427701.git.christophe.leroy@csgroup.eu

powerpc: Book3S 64-bit outline-only KASAN support

2022-05-22T05:58:29+00:00

Implement a limited form of KASAN for Book3S 64-bit machines running under
the Radix MMU, supporting only outline mode.

 - Enable the compiler instrumentation to check addresses and maintain the
   shadow region. (This is the guts of KASAN which we can easily reuse.)

 - Require kasan-vmalloc support to handle modules and anything else in
   vmalloc space.

 - KASAN needs to be able to validate all pointer accesses, but we can't
   instrument all kernel addresses - only linear map and vmalloc. On boot,
   set up a single page of read-only shadow that marks all iomap and
   vmemmap accesses as valid.

 - Document KASAN in powerpc docs.

Background
----------

KASAN support on Book3S is a bit tricky to get right:

 - It would be good to support inline instrumentation so as to be able to
   catch stack issues that cannot be caught with outline mode.

 - Inline instrumentation requires a fixed offset.

 - Book3S runs code with translations off ("real mode") during boot,
   including a lot of generic device-tree parsing code which is used to
   determine MMU features.

    [ppc64 mm note: The kernel installs a linear mapping at effective
    address c000...-c008.... This is a one-to-one mapping with physical
    memory from 0000... onward. Because of how memory accesses work on
    powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the
    same memory both with translations on (accessing as an 'effective
    address'), and with translations off (accessing as a 'real
    address'). This works in both guests and the hypervisor. For more
    details, see s5.7 of Book III of version 3 of the ISA, in particular
    the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this
    KASAN implementation currently only supports Radix.]

 - Some code - most notably a lot of KVM code - also runs with translations
   off after boot.

 - Therefore any offset has to point to memory that is valid with
   translations on or off.

One approach is just to give up on inline instrumentation. This way
boot-time checks can be delayed until after the MMU is set is up, and we
can just not instrument any code that runs with translations off after
booting. Take this approach for now and require outline instrumentation.

Previous attempts allowed inline instrumentation. However, they came with
some unfortunate restrictions: only physically contiguous memory could be
used and it had to be specified at compile time. Maybe we can do better in
the future.

[paulus@ozlabs.org - Rebased onto 5.17.  Note that a kernel with
 CONFIG_KASAN=y will crash during boot on a machine using HPT
 translation because not all the entry points to the generic
 KASAN code are protected with a call to kasan_arch_is_ready().]

Originally-by: Balbir Singh  # ppc64 out-of-line radix version
Signed-off-by: Daniel Axtens 
Signed-off-by: Paul Mackerras 
[mpe: Update copyright year and comment formatting]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/YoTE69OQwiG7z+Gu@cleo

powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP

2021-08-25T03:35:48+00:00

This patch converts powerpc to the generic PTDUMP implementation.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/03166d569526be70214fe9370a7bad219d2f41c8.1625762907.git.christophe.leroy@csgroup.eu

powerpc: Make PPC_IRQ_SOFT_MASK_DEBUG depend on PPC64

2021-06-24T14:07:09+00:00

32-bit platforms don't have irq soft masking.

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210623032909.826010-1-npiggin@gmail.com