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* Re: [PATCH net-next v2 9/9] ibmvnic: Do not replenish RX buffers after every polling loop
From: Thomas Falcon @ 2020-11-19 20:58 UTC (permalink / raw)
  To: ljp
  Cc: cforno12, netdev, ricklind, dnbanerg, Linuxppc-dev, drt, brking,
	kuba, sukadev, linuxppc-dev
In-Reply-To: <7853649c6c1f2f4ce6d8bf9643cd1a43@linux.vnet.ibm.com>

On 11/19/20 2:38 PM, ljp wrote:
> On 2020-11-19 14:26, Thomas Falcon wrote:
>> On 11/19/20 3:43 AM, ljp wrote:
>>
>>> On 2020-11-18 19:12, Thomas Falcon wrote:
>>>
>>>> From: "Dwip N. Banerjee" <dnbanerg@us.ibm.com>
>>>>
>>>> Reduce the amount of time spent replenishing RX buffers by
>>>> only doing so once available buffers has fallen under a certain
>>>> threshold, in this case half of the total number of buffers, or
>>>> if the polling loop exits before the packets processed is less
>>>> than its budget.
>>>>
>>>> Signed-off-by: Dwip N. Banerjee <dnbanerg@us.ibm.com>
>>>> ---
>>>> drivers/net/ethernet/ibm/ibmvnic.c | 5 ++++-
>>>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/net/ethernet/ibm/ibmvnic.c
>>>> b/drivers/net/ethernet/ibm/ibmvnic.c
>>>> index 96df6d8fa277..9fe43ab0496d 100644
>>>> --- a/drivers/net/ethernet/ibm/ibmvnic.c
>>>> +++ b/drivers/net/ethernet/ibm/ibmvnic.c
>>>> @@ -2537,7 +2537,10 @@ static int ibmvnic_poll(struct napi_struct
>>>>
>>>> *napi, int budget)
>>>> frames_processed++;
>>>> }
>>>>
>>>> - if (adapter->state != VNIC_CLOSING)
>>>> + if (adapter->state != VNIC_CLOSING &&
>>>> + ((atomic_read(&adapter->rx_pool[scrq_num].available) <
>>>> + adapter->req_rx_add_entries_per_subcrq / 2) ||
>>>> + frames_processed < budget))
>>>
>>> 1/2 seems a simple and good algorithm.
>>> Explaining why "frames_process < budget" is necessary in the commit
>>> message
>>> or source code also helps.
>>
>> Hello, Lijun. The patch author, Dwip Banerjee, suggested the modified
>> commit message below:
>>
>> Reduce the amount of time spent replenishing RX buffers by
>>  only doing so once available buffers has fallen under a certain
>>  threshold, in this case half of the total number of buffers, or
>>  if the polling loop exits before the packets processed is less
>>  than its budget. Non-exhaustion of NAPI budget implies lower
>>  incoming packet pressure, allowing the leeway to refill the buffers
>>  in preparation for any impending burst.
>
> It looks good to me.
>
>>
>> Would such an update require a v3?
>
> I assume you ask Jakub, right?
>
>
Yes. There was an issue with my mail client in my earlier response, so I 
am posting Dwip's modified commit message again below.

Reduce the amount of time spent replenishing RX buffers by only doing so 
once available buffers has fallen under a certain threshold, in this 
case half of the total number of buffers, or if the polling loop exits 
before the packets processed is less than its budget. Non-exhaustion of 
NAPI budget implies lower incoming packet pressure, allowing the leeway 
to refill the buffers in preparation for any impending burst.

>>>> replenish_rx_pool(adapter, &adapter->rx_pool[scrq_num]);
>>>> if (frames_processed < budget) {
>>>> if (napi_complete_done(napi, frames_processed)) {

^ permalink raw reply

* Re: [PATCH v3 23/23] mtd: devices: powernv_flash: Add function names to headers and fix 'dev'
From: Miquel Raynal @ 2020-11-19 21:07 UTC (permalink / raw)
  To: Lee Jones
  Cc: Vignesh Raghavendra, Richard Weinberger, Miquel Raynal,
	linux-kernel, Paul Mackerras, linux-mtd, linuxppc-dev
In-Reply-To: <20201109182206.3037326-24-lee.jones@linaro.org>

On Mon, 2020-11-09 at 18:22:06 UTC, Lee Jones wrote:
> Fixes the following W=1 kernel build warning(s):
> 
>  drivers/mtd/devices/powernv_flash.c:129: warning: Cannot understand  * @mtd: the device
>  drivers/mtd/devices/powernv_flash.c:145: warning: Cannot understand  * @mtd: the device
>  drivers/mtd/devices/powernv_flash.c:161: warning: Cannot understand  * @mtd: the device
>  drivers/mtd/devices/powernv_flash.c:184: warning: Function parameter or member 'dev' not described in 'powernv_flash_set_driver_info'
> 
> Cc: Miquel Raynal <miquel.raynal@bootlin.com>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Vignesh Raghavendra <vigneshr@ti.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linux-mtd@lists.infradead.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Lee Jones <lee.jones@linaro.org>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next, thanks.

Miquel

^ permalink raw reply

* Re: [PATCH v3 2/2] powerpc/ptrace: Hard wire PT_SOFTE value to 1 in gpr_get() too
From: Christophe Leroy @ 2020-11-19 21:10 UTC (permalink / raw)
  To: Oleg Nesterov
  Cc: Christophe Leroy, Madhavan Srinivasan, linuxppc-dev,
	Nicholas Piggin, linux-kernel, Paul Mackerras, Al Viro,
	Aneesh Kumar K.V, Jan Kratochvil
In-Reply-To: <20201119160247.GB5188@redhat.com>


Quoting Oleg Nesterov <oleg@redhat.com>:

> The commit a8a4b03ab95f ("powerpc: Hard wire PT_SOFTE value to 1 in
> ptrace & signals") changed ptrace_get_reg(PT_SOFTE) to report 0x1,
> but PTRACE_GETREGS still copies pt_regs->softe as is.
>
> This is not consistent and this breaks the user-regs-peekpoke test
> from https://sourceware.org/systemtap/wiki/utrace/tests/
>
> Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> ---
>  arch/powerpc/kernel/ptrace/ptrace-tm.c   | 8 +++++++-
>  arch/powerpc/kernel/ptrace/ptrace-view.c | 8 +++++++-
>  2 files changed, 14 insertions(+), 2 deletions(-)
>

I think the following should work, and not require the first patch  
(compile tested only).

diff --git a/arch/powerpc/kernel/ptrace/ptrace-tm.c  
b/arch/powerpc/kernel/ptrace/ptrace-tm.c
index 54f2d076206f..f779b3bc0279 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-tm.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-tm.c
@@ -104,8 +104,14 @@ int tm_cgpr_get(struct task_struct *target, const  
struct user_regset *regset,
  		     offsetof(struct pt_regs, msr) + sizeof(long));

  	membuf_write(&to, &target->thread.ckpt_regs.orig_gpr3,
-			sizeof(struct user_pt_regs) -
-			offsetof(struct pt_regs, orig_gpr3));
+		     offsetof(struct pt_regs, softe) - offsetof(struct pt_regs,  
orig_gpr3));
+	membuf_store(&to, 1UL);
+
+	BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
+		     offsetof(struct pt_regs, softe) + sizeof(long));
+
+	membuf_write(&to, &target->thread.ckpt_regs.trap,
+		     sizeof(struct user_pt_regs) - offsetof(struct pt_regs, trap));
  	return membuf_zero(&to, ELF_NGREG * sizeof(unsigned long) -
  			sizeof(struct user_pt_regs));
  }
diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c  
b/arch/powerpc/kernel/ptrace/ptrace-view.c
index 7e6478e7ed07..736bfbf33890 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-view.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-view.c
@@ -234,9 +234,21 @@ static int gpr_get(struct task_struct *target,  
const struct user_regset *regset,
  	BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
  		     offsetof(struct pt_regs, msr) + sizeof(long));

+#ifdef CONFIG_PPC64
+	membuf_write(&to, &target->thread.regs->orig_gpr3,
+		     offsetof(struct pt_regs, softe) - offsetof(struct pt_regs,  
orig_gpr3));
+	membuf_store(&to, 1UL);
+
+	BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
+		     offsetof(struct pt_regs, softe) + sizeof(long));
+
+	membuf_write(&to, &target->thread.regs->trap,
+		     sizeof(struct user_pt_regs) - offsetof(struct pt_regs, trap));
+#else
  	membuf_write(&to, &target->thread.regs->orig_gpr3,
  			sizeof(struct user_pt_regs) -
  			offsetof(struct pt_regs, orig_gpr3));
+#endif
  	return membuf_zero(&to, ELF_NGREG * sizeof(unsigned long) -
  				 sizeof(struct user_pt_regs));
  }
---
Christophe

^ permalink raw reply related

* Re: [PATCH v2 2/2] kbuild: Disable CONFIG_LD_ORPHAN_WARN for ld.lld 10.0.1
From: Nick Desaulniers @ 2020-11-19 21:13 UTC (permalink / raw)
  To: Nathan Chancellor
  Cc: Michal Marek, Kees Cook, kernelci . org bot,
	Linux Kbuild mailing list, Mark Brown, Catalin Marinas,
	Masahiro Yamada, maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT),
	Russell King, LKML, linuxppc-dev, Arvind Sankar, Ingo Molnar,
	Borislav Petkov, clang-built-linux, Thomas Gleixner, Will Deacon,
	Linux ARM
In-Reply-To: <20201119204656.3261686-2-natechancellor@gmail.com>

On Thu, Nov 19, 2020 at 12:57 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> ld.lld 10.0.1 spews a bunch of various warnings about .rela sections,
> along with a few others. Newer versions of ld.lld do not have these
> warnings. As a result, do not add '--orphan-handling=warn' to
> LDFLAGS_vmlinux if ld.lld's version is not new enough.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1187
> Link: https://github.com/ClangBuiltLinux/linux/issues/1193
> Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
> Reported-by: kernelci.org bot <bot@kernelci.org>
> Reported-by: Mark Brown <broonie@kernel.org>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

Thanks for the additions in v2.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>
> v1 -> v2:
>
> * Add condition as a depends on line (Kees Cook)
>
> * Capture output of "$* --version" to avoid invoking linker twice (Nick
>   Desaulniers)
>
> * Improve documentation of script in comments (Nick Desaulniers)
>
> * Pick up review tag from Kees
>
>  MAINTAINERS            |  1 +
>  init/Kconfig           |  5 +++++
>  scripts/lld-version.sh | 20 ++++++++++++++++++++
>  3 files changed, 26 insertions(+)
>  create mode 100755 scripts/lld-version.sh
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e451dcce054f..e6f74f130ae1 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4284,6 +4284,7 @@ B:        https://github.com/ClangBuiltLinux/linux/issues
>  C:     irc://chat.freenode.net/clangbuiltlinux
>  F:     Documentation/kbuild/llvm.rst
>  F:     scripts/clang-tools/
> +F:     scripts/lld-version.sh
>  K:     \b(?i:clang|llvm)\b
>
>  CLEANCACHE API
> diff --git a/init/Kconfig b/init/Kconfig
> index 92c58b45abb8..b9037d6c5ab3 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -47,6 +47,10 @@ config CLANG_VERSION
>         int
>         default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
>
> +config LLD_VERSION
> +       int
> +       default $(shell,$(srctree)/scripts/lld-version.sh $(LD))
> +
>  config CC_CAN_LINK
>         bool
>         default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
> @@ -1351,6 +1355,7 @@ config LD_DEAD_CODE_DATA_ELIMINATION
>  config LD_ORPHAN_WARN
>         def_bool y
>         depends on ARCH_WANT_LD_ORPHAN_WARN
> +       depends on !LD_IS_LLD || LLD_VERSION >= 110000
>         depends on $(ld-option,--orphan-handling=warn)
>
>  config SYSCTL
> diff --git a/scripts/lld-version.sh b/scripts/lld-version.sh
> new file mode 100755
> index 000000000000..d70edb4d8a4f
> --- /dev/null
> +++ b/scripts/lld-version.sh
> @@ -0,0 +1,20 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Usage: $ ./scripts/lld-version.sh ld.lld
> +#
> +# Print the linker version of `ld.lld' in a 5 or 6-digit form
> +# such as `100001' for ld.lld 10.0.1 etc.
> +
> +linker_string="$($* --version)"
> +
> +if ! ( echo $linker_string | grep -q LLD ); then
> +       echo 0
> +       exit 1
> +fi
> +
> +VERSION=$(echo $linker_string | cut -d ' ' -f 2)
> +MAJOR=$(echo $VERSION | cut -d . -f 1)
> +MINOR=$(echo $VERSION | cut -d . -f 2)
> +PATCHLEVEL=$(echo $VERSION | cut -d . -f 3)
> +printf "%d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL
> --
> 2.29.2
>


-- 
Thanks,
~Nick Desaulniers

^ permalink raw reply

* Re: [PATCH v3 2/2] powerpc/ptrace: Hard wire PT_SOFTE value to 1 in gpr_get() too
From: Oleg Nesterov @ 2020-11-19 22:43 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Christophe Leroy, Madhavan Srinivasan, linuxppc-dev,
	Nicholas Piggin, linux-kernel, Paul Mackerras, Al Viro,
	Aneesh Kumar K.V, Jan Kratochvil
In-Reply-To: <20201119221033.Horde.be-msjDTeIW4XeXARjUu7g1@messagerie.c-s.fr>

On 11/19, Christophe Leroy wrote:
>
> I think the following should work, and not require the first patch (compile
> tested only).
>
> --- a/arch/powerpc/kernel/ptrace/ptrace-view.c
> +++ b/arch/powerpc/kernel/ptrace/ptrace-view.c
> @@ -234,9 +234,21 @@ static int gpr_get(struct task_struct *target, const
> struct user_regset *regset,
>  	BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
>  		     offsetof(struct pt_regs, msr) + sizeof(long));
> 
> +#ifdef CONFIG_PPC64
> +	membuf_write(&to, &target->thread.regs->orig_gpr3,
> +		     offsetof(struct pt_regs, softe) - offsetof(struct pt_regs,
> orig_gpr3));
> +	membuf_store(&to, 1UL);
> +
> +	BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
> +		     offsetof(struct pt_regs, softe) + sizeof(long));
> +
> +	membuf_write(&to, &target->thread.regs->trap,
> +		     sizeof(struct user_pt_regs) - offsetof(struct pt_regs, trap));
> +#else
>  	membuf_write(&to, &target->thread.regs->orig_gpr3,
>  			sizeof(struct user_pt_regs) -
>  			offsetof(struct pt_regs, orig_gpr3));
> +#endif
>  	return membuf_zero(&to, ELF_NGREG * sizeof(unsigned long) -
>  				 sizeof(struct user_pt_regs));
>  }

Probably yes.

This mirrors the previous patch I sent (https://lore.kernel.org/lkml/20190917143753.GA12300@redhat.com/)
and this is exactly what I tried to avoid, we can make a simpler fix now.

But let me repeat, I agree with any fix even if imp my version simplifies the code, just
commit this change and lets forget this problem.

Oleg.


^ permalink raw reply

* [PATCH 0/7] CVE-2020-4788: Speculation on incompletely validated data on IBM Power9
From: Daniel Axtens @ 2020-11-19 23:13 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: dja, cmr, spoorts2, npiggin

IBM Power9 processors can speculatively operate on data in the L1
cache before it has been completely validated, via a way-prediction
mechanism. It is not possible for an attacker to determine the
contents of impermissible memory using this method, since these
systems implement a combination of hardware and software security
measures to prevent scenarios where protected data could be leaked.

However these measures don't address the scenario where an attacker
induces the operating system to speculatively execute instructions
using data that the attacker controls. This can be used for example to
speculatively bypass "kernel user access prevention" techniques, as
discovered by Anthony Steinhauser of Google's Safeside Project. This
is not an attack by itself, but there is a possibility it could be
used in conjunction with side-channels or other weaknesses in the
privileged code to construct an attack.

This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This series flushes the cache on kernel entry and
after kernel user accesses.

Thanks to Nick Piggin, Russell Currey, Christopher M. Riedl, Michael
Ellerman and Spoorthy S for their work in developing, optimising,
testing and backporting these fixes, and to the many others who helped
behind the scenes.

Daniel Axtens (3):
  selftests/powerpc: entry flush test
  selftests/powerpc: refactor entry and rfi_flush tests
  powerpc/64s: rename pnv|pseries_setup_rfi_flush to
    _setup_security_mitigations

Michael Ellerman (1):
  powerpc: Only include kup-radix.h for 64-bit Book3S

Nicholas Piggin (2):
  powerpc/64s: flush L1D on kernel entry
  powerpc/64s: flush L1D after user accesses

Russell Currey (1):
  selftests/powerpc: rfi_flush: disable entry flush if present

 .../admin-guide/kernel-parameters.txt         |   7 +
 .../powerpc/include/asm/book3s/64/kup-radix.h |  66 ++++++---
 arch/powerpc/include/asm/exception-64s.h      |  12 +-
 arch/powerpc/include/asm/feature-fixups.h     |  19 +++
 arch/powerpc/include/asm/kup.h                |  26 +++-
 arch/powerpc/include/asm/security_features.h  |   7 +
 arch/powerpc/include/asm/setup.h              |   4 +
 arch/powerpc/kernel/exceptions-64s.S          |  80 +++++-----
 arch/powerpc/kernel/setup_64.c                | 122 ++++++++++++++-
 arch/powerpc/kernel/syscall_64.c              |   2 +-
 arch/powerpc/kernel/vmlinux.lds.S             |  14 ++
 arch/powerpc/lib/feature-fixups.c             | 104 +++++++++++++
 arch/powerpc/platforms/powernv/setup.c        |  24 ++-
 arch/powerpc/platforms/pseries/mobility.c     |   4 +-
 arch/powerpc/platforms/pseries/pseries.h      |   2 +-
 arch/powerpc/platforms/pseries/setup.c        |  15 +-
 .../testing/selftests/powerpc/include/utils.h |   5 +
 .../selftests/powerpc/security/.gitignore     |   1 +
 .../selftests/powerpc/security/Makefile       |   4 +-
 .../selftests/powerpc/security/entry_flush.c  | 139 ++++++++++++++++++
 .../selftests/powerpc/security/flush_utils.c  |  70 +++++++++
 .../selftests/powerpc/security/flush_utils.h  |  17 +++
 .../selftests/powerpc/security/rfi_flush.c    |  96 ++++--------
 23 files changed, 693 insertions(+), 147 deletions(-)
 create mode 100644 tools/testing/selftests/powerpc/security/entry_flush.c
 create mode 100644 tools/testing/selftests/powerpc/security/flush_utils.c
 create mode 100644 tools/testing/selftests/powerpc/security/flush_utils.h

-- 
2.25.1


^ permalink raw reply

* [PATCH 1/7] selftests/powerpc: rfi_flush: disable entry flush if present
From: Daniel Axtens @ 2020-11-19 23:13 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: dja, cmr, spoorts2, npiggin
In-Reply-To: <20201119231333.361771-1-dja@axtens.net>

From: Russell Currey <ruscur@russell.cc>

We are about to add an entry flush. The rfi (exit) flush test measures
the number of L1D flushes over a syscall with the RFI flush enabled and
disabled. But if the entry flush is also enabled, the effect of enabling
and disabling the RFI flush is masked.

If there is a debugfs entry for the entry flush, disable it during the RFI
flush and restore it later.

Reported-by: Spoorthy S <spoorts2@in.ibm.com>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
 .../selftests/powerpc/security/rfi_flush.c    | 35 +++++++++++++++----
 1 file changed, 29 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/powerpc/security/rfi_flush.c b/tools/testing/selftests/powerpc/security/rfi_flush.c
index 93a65bd1f231..4e7b2776c367 100644
--- a/tools/testing/selftests/powerpc/security/rfi_flush.c
+++ b/tools/testing/selftests/powerpc/security/rfi_flush.c
@@ -85,19 +85,33 @@ int rfi_flush_test(void)
 	__u64 l1d_misses_total = 0;
 	unsigned long iterations = 100000, zero_size = 24 * 1024;
 	unsigned long l1d_misses_expected;
-	int rfi_flush_org, rfi_flush;
+	int rfi_flush_orig, rfi_flush;
+	int have_entry_flush, entry_flush_orig;
 
 	SKIP_IF(geteuid() != 0);
 
 	// The PMU event we use only works on Power7 or later
 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
 
-	if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_org)) {
+	if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
 		perror("Unable to read powerpc/rfi_flush debugfs file");
 		SKIP_IF(1);
 	}
 
-	rfi_flush = rfi_flush_org;
+	if (read_debugfs_file("powerpc/entry_flush", &entry_flush_orig) < 0) {
+		have_entry_flush = 0;
+	} else {
+		have_entry_flush = 1;
+
+		if (entry_flush_orig != 0) {
+			if (write_debugfs_file("powerpc/entry_flush", 0) < 0) {
+				perror("error writing to powerpc/entry_flush debugfs file");
+				return 1;
+			}
+		}
+	}
+
+	rfi_flush = rfi_flush_orig;
 
 	fd = perf_event_open_counter(PERF_TYPE_RAW, /* L1d miss */ 0x400f0, -1);
 	FAIL_IF(fd < 0);
@@ -106,6 +120,7 @@ int rfi_flush_test(void)
 
 	FAIL_IF(perf_event_enable(fd));
 
+	// disable L1 prefetching
 	set_dscr(1);
 
 	iter = repetitions;
@@ -147,8 +162,8 @@ again:
 		       repetitions * l1d_misses_expected / 2,
 		       passes, repetitions);
 
-	if (rfi_flush == rfi_flush_org) {
-		rfi_flush = !rfi_flush_org;
+	if (rfi_flush == rfi_flush_orig) {
+		rfi_flush = !rfi_flush_orig;
 		if (write_debugfs_file("powerpc/rfi_flush", rfi_flush) < 0) {
 			perror("error writing to powerpc/rfi_flush debugfs file");
 			return 1;
@@ -164,11 +179,19 @@ again:
 
 	set_dscr(0);
 
-	if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_org) < 0) {
+	if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_orig) < 0) {
 		perror("unable to restore original value of powerpc/rfi_flush debugfs file");
 		return 1;
 	}
 
+	if (have_entry_flush) {
+		if (write_debugfs_file("powerpc/entry_flush", entry_flush_orig) < 0) {
+			perror("unable to restore original value of powerpc/entry_flush "
+			       "debugfs file");
+			return 1;
+		}
+	}
+
 	return rc;
 }
 
-- 
2.25.1


^ permalink raw reply related

* [PATCH 2/7] powerpc/64s: flush L1D on kernel entry
From: Daniel Axtens @ 2020-11-19 23:13 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: dja, cmr, spoorts2, npiggin
In-Reply-To: <20201119231333.361771-1-dja@axtens.net>

From: Nicholas Piggin <npiggin@gmail.com>

IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.

However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.

This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache on kernel entry.

This is part of the fix for CVE-2020-4788.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
 .../admin-guide/kernel-parameters.txt         |  3 +
 arch/powerpc/include/asm/exception-64s.h      |  9 ++-
 arch/powerpc/include/asm/feature-fixups.h     | 10 ++++
 arch/powerpc/include/asm/security_features.h  |  4 ++
 arch/powerpc/include/asm/setup.h              |  3 +
 arch/powerpc/kernel/exceptions-64s.S          | 37 ++++++++++++
 arch/powerpc/kernel/setup_64.c                | 60 ++++++++++++++++++-
 arch/powerpc/kernel/vmlinux.lds.S             |  7 +++
 arch/powerpc/lib/feature-fixups.c             | 54 +++++++++++++++++
 arch/powerpc/platforms/powernv/setup.c        | 11 ++++
 arch/powerpc/platforms/pseries/setup.c        |  4 ++
 11 files changed, 200 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index af4ec2a8f32a..282789cfa1dc 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2875,6 +2875,7 @@
 					       mds=off [X86]
 					       tsx_async_abort=off [X86]
 					       kvm.nx_huge_pages=off [X86]
+					       no_entry_flush [PPC]
 
 				Exceptions:
 					       This does not have any effect on
@@ -3203,6 +3204,8 @@
 
 	noefi		Disable EFI runtime services support.
 
+	no_entry_flush  [PPC] Don't flush the L1-D cache when entering the kernel.
+
 	noexec		[IA-64]
 
 	noexec		[X86]
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index ebe95aa04d53..83fa88bc9935 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -57,11 +57,18 @@
 	nop;								\
 	nop
 
+#define ENTRY_FLUSH_SLOT						\
+	ENTRY_FLUSH_FIXUP_SECTION;					\
+	nop;								\
+	nop;								\
+	nop;
+
 /*
  * r10 must be free to use, r13 must be paca
  */
 #define INTERRUPT_TO_KERNEL						\
-	STF_ENTRY_BARRIER_SLOT
+	STF_ENTRY_BARRIER_SLOT;						\
+	ENTRY_FLUSH_SLOT
 
 /*
  * Macros for annotating the expected destination of (h)rfid
diff --git a/arch/powerpc/include/asm/feature-fixups.h b/arch/powerpc/include/asm/feature-fixups.h
index b0af97add751..06a48219bbf2 100644
--- a/arch/powerpc/include/asm/feature-fixups.h
+++ b/arch/powerpc/include/asm/feature-fixups.h
@@ -205,6 +205,14 @@ label##3:					       	\
 	FTR_ENTRY_OFFSET 955b-956b;			\
 	.popsection;
 
+#define ENTRY_FLUSH_FIXUP_SECTION			\
+957:							\
+	.pushsection __entry_flush_fixup,"a";		\
+	.align 2;					\
+958:							\
+	FTR_ENTRY_OFFSET 957b-958b;			\
+	.popsection;
+
 #define RFI_FLUSH_FIXUP_SECTION				\
 951:							\
 	.pushsection __rfi_flush_fixup,"a";		\
@@ -237,8 +245,10 @@ label##3:					       	\
 #include <linux/types.h>
 
 extern long stf_barrier_fallback;
+extern long entry_flush_fallback;
 extern long __start___stf_entry_barrier_fixup, __stop___stf_entry_barrier_fixup;
 extern long __start___stf_exit_barrier_fixup, __stop___stf_exit_barrier_fixup;
+extern long __start___entry_flush_fixup, __stop___entry_flush_fixup;
 extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup;
 extern long __start___barrier_nospec_fixup, __stop___barrier_nospec_fixup;
 extern long __start__btb_flush_fixup, __stop__btb_flush_fixup;
diff --git a/arch/powerpc/include/asm/security_features.h b/arch/powerpc/include/asm/security_features.h
index fbb8fa32150f..9e7459d2edca 100644
--- a/arch/powerpc/include/asm/security_features.h
+++ b/arch/powerpc/include/asm/security_features.h
@@ -86,12 +86,16 @@ static inline bool security_ftr_enabled(u64 feature)
 // Software required to flush link stack on context switch
 #define SEC_FTR_FLUSH_LINK_STACK	0x0000000000001000ull
 
+// The L1-D cache should be flushed when entering the kernel
+#define SEC_FTR_L1D_FLUSH_ENTRY		0x0000000000004000ull
+
 
 // Features enabled by default
 #define SEC_FTR_DEFAULT \
 	(SEC_FTR_L1D_FLUSH_HV | \
 	 SEC_FTR_L1D_FLUSH_PR | \
 	 SEC_FTR_BNDS_CHK_SPEC_BAR | \
+	 SEC_FTR_L1D_FLUSH_ENTRY | \
 	 SEC_FTR_FAVOUR_SECURITY)
 
 #endif /* _ASM_POWERPC_SECURITY_FEATURES_H */
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 9efbddee2bca..e2fcd3e874f8 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -52,12 +52,15 @@ enum l1d_flush_type {
 };
 
 void setup_rfi_flush(enum l1d_flush_type, bool enable);
+void setup_entry_flush(bool enable);
+void setup_uaccess_flush(bool enable);
 void do_rfi_flush_fixups(enum l1d_flush_type types);
 #ifdef CONFIG_PPC_BARRIER_NOSPEC
 void setup_barrier_nospec(void);
 #else
 static inline void setup_barrier_nospec(void) { };
 #endif
+void do_entry_flush_fixups(enum l1d_flush_type types);
 void do_barrier_nospec_fixups(bool enable);
 extern bool barrier_nospec_enabled;
 
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index f7d748b88705..5577dd887d37 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2951,6 +2951,43 @@ TRAMP_REAL_BEGIN(stf_barrier_fallback)
 	.endr
 	blr
 
+TRAMP_REAL_BEGIN(entry_flush_fallback)
+	std	r9,PACA_EXRFI+EX_R9(r13)
+	std	r10,PACA_EXRFI+EX_R10(r13)
+	std	r11,PACA_EXRFI+EX_R11(r13)
+	mfctr	r9
+	ld	r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
+	ld	r11,PACA_L1D_FLUSH_SIZE(r13)
+	srdi	r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
+	mtctr	r11
+	DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
+
+	/* order ld/st prior to dcbt stop all streams with flushing */
+	sync
+
+	/*
+	 * The load addresses are at staggered offsets within cachelines,
+	 * which suits some pipelines better (on others it should not
+	 * hurt).
+	 */
+1:
+	ld	r11,(0x80 + 8)*0(r10)
+	ld	r11,(0x80 + 8)*1(r10)
+	ld	r11,(0x80 + 8)*2(r10)
+	ld	r11,(0x80 + 8)*3(r10)
+	ld	r11,(0x80 + 8)*4(r10)
+	ld	r11,(0x80 + 8)*5(r10)
+	ld	r11,(0x80 + 8)*6(r10)
+	ld	r11,(0x80 + 8)*7(r10)
+	addi	r10,r10,0x80*8
+	bdnz	1b
+
+	mtctr	r9
+	ld	r9,PACA_EXRFI+EX_R9(r13)
+	ld	r10,PACA_EXRFI+EX_R10(r13)
+	ld	r11,PACA_EXRFI+EX_R11(r13)
+	blr
+
 TRAMP_REAL_BEGIN(rfi_flush_fallback)
 	SET_SCRATCH0(r13);
 	GET_PACA(r13);
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index bb9cab3641d7..7d447b43ad13 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -945,7 +945,9 @@ early_initcall(disable_hardlockup_detector);
 static enum l1d_flush_type enabled_flush_types;
 static void *l1d_flush_fallback_area;
 static bool no_rfi_flush;
+static bool no_entry_flush;
 bool rfi_flush;
+bool entry_flush;
 
 static int __init handle_no_rfi_flush(char *p)
 {
@@ -955,6 +957,14 @@ static int __init handle_no_rfi_flush(char *p)
 }
 early_param("no_rfi_flush", handle_no_rfi_flush);
 
+static int __init handle_no_entry_flush(char *p)
+{
+	pr_info("entry-flush: disabled on command line.");
+	no_entry_flush = true;
+	return 0;
+}
+early_param("no_entry_flush", handle_no_entry_flush);
+
 /*
  * The RFI flush is not KPTI, but because users will see doco that says to use
  * nopti we hijack that option here to also disable the RFI flush.
@@ -986,6 +996,18 @@ void rfi_flush_enable(bool enable)
 	rfi_flush = enable;
 }
 
+void entry_flush_enable(bool enable)
+{
+	if (enable) {
+		do_entry_flush_fixups(enabled_flush_types);
+		on_each_cpu(do_nothing, NULL, 1);
+	} else {
+		do_entry_flush_fixups(L1D_FLUSH_NONE);
+	}
+
+	entry_flush = enable;
+}
+
 static void __ref init_fallback_flush(void)
 {
 	u64 l1d_size, limit;
@@ -1044,10 +1066,19 @@ void setup_rfi_flush(enum l1d_flush_type types, bool enable)
 
 	enabled_flush_types = types;
 
-	if (!no_rfi_flush && !cpu_mitigations_off())
+	if (!cpu_mitigations_off() && !no_rfi_flush)
 		rfi_flush_enable(enable);
 }
 
+void setup_entry_flush(bool enable)
+{
+	if (cpu_mitigations_off())
+		return;
+
+	if (!no_entry_flush)
+		entry_flush_enable(enable);
+}
+
 #ifdef CONFIG_DEBUG_FS
 static int rfi_flush_set(void *data, u64 val)
 {
@@ -1075,9 +1106,36 @@ static int rfi_flush_get(void *data, u64 *val)
 
 DEFINE_SIMPLE_ATTRIBUTE(fops_rfi_flush, rfi_flush_get, rfi_flush_set, "%llu\n");
 
+static int entry_flush_set(void *data, u64 val)
+{
+	bool enable;
+
+	if (val == 1)
+		enable = true;
+	else if (val == 0)
+		enable = false;
+	else
+		return -EINVAL;
+
+	/* Only do anything if we're changing state */
+	if (enable != entry_flush)
+		entry_flush_enable(enable);
+
+	return 0;
+}
+
+static int entry_flush_get(void *data, u64 *val)
+{
+	*val = entry_flush ? 1 : 0;
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_entry_flush, entry_flush_get, entry_flush_set, "%llu\n");
+
 static __init int rfi_flush_debugfs_init(void)
 {
 	debugfs_create_file("rfi_flush", 0600, powerpc_debugfs_root, NULL, &fops_rfi_flush);
+	debugfs_create_file("entry_flush", 0600, powerpc_debugfs_root, NULL, &fops_entry_flush);
 	return 0;
 }
 device_initcall(rfi_flush_debugfs_init);
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index e0548b4950de..715ec4d4614a 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -131,6 +131,13 @@ SECTIONS
 		__stop___stf_entry_barrier_fixup = .;
 	}
 
+	. = ALIGN(8);
+	__entry_flush_fixup : AT(ADDR(__entry_flush_fixup) - LOAD_OFFSET) {
+		__start___entry_flush_fixup = .;
+		*(__entry_flush_fixup)
+		__stop___entry_flush_fixup = .;
+	}
+
 	. = ALIGN(8);
 	__stf_exit_barrier_fixup : AT(ADDR(__stf_exit_barrier_fixup) - LOAD_OFFSET) {
 		__start___stf_exit_barrier_fixup = .;
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 4c0a7ee9fa00..70e83cfd74aa 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -234,6 +234,60 @@ void do_stf_barrier_fixups(enum stf_barrier_type types)
 	do_stf_exit_barrier_fixups(types);
 }
 
+void do_entry_flush_fixups(enum l1d_flush_type types)
+{
+	unsigned int instrs[3], *dest;
+	long *start, *end;
+	int i;
+
+	start = PTRRELOC(&__start___entry_flush_fixup);
+	end = PTRRELOC(&__stop___entry_flush_fixup);
+
+	instrs[0] = 0x60000000; /* nop */
+	instrs[1] = 0x60000000; /* nop */
+	instrs[2] = 0x60000000; /* nop */
+
+	i = 0;
+	if (types == L1D_FLUSH_FALLBACK) {
+		instrs[i++] = 0x7d4802a6; /* mflr r10		*/
+		instrs[i++] = 0x60000000; /* branch patched below */
+		instrs[i++] = 0x7d4803a6; /* mtlr r10		*/
+	}
+
+	if (types & L1D_FLUSH_ORI) {
+		instrs[i++] = 0x63ff0000; /* ori 31,31,0 speculation barrier */
+		instrs[i++] = 0x63de0000; /* ori 30,30,0 L1d flush*/
+	}
+
+	if (types & L1D_FLUSH_MTTRIG)
+		instrs[i++] = 0x7c12dba6; /* mtspr TRIG2,r0 (SPR #882) */
+
+	for (i = 0; start < end; start++, i++) {
+		dest = (void *)start + *start;
+
+		pr_devel("patching dest %lx\n", (unsigned long)dest);
+
+		patch_instruction((struct ppc_inst *)dest, ppc_inst(instrs[0]));
+
+		if (types == L1D_FLUSH_FALLBACK)
+			patch_branch((struct ppc_inst *)(dest + 1), (unsigned long)&entry_flush_fallback,
+				     BRANCH_SET_LINK);
+		else
+			patch_instruction((struct ppc_inst *)(dest + 1), ppc_inst(instrs[1]));
+
+		patch_instruction((struct ppc_inst *)(dest + 2), ppc_inst(instrs[2]));
+	}
+
+	printk(KERN_DEBUG "entry-flush: patched %d locations (%s flush)\n", i,
+		(types == L1D_FLUSH_NONE)       ? "no" :
+		(types == L1D_FLUSH_FALLBACK)   ? "fallback displacement" :
+		(types &  L1D_FLUSH_ORI)        ? (types & L1D_FLUSH_MTTRIG)
+							? "ori+mttrig type"
+							: "ori type" :
+		(types &  L1D_FLUSH_MTTRIG)     ? "mttrig type"
+						: "unknown");
+}
+
 void do_rfi_flush_fixups(enum l1d_flush_type types)
 {
 	unsigned int instrs[3], *dest;
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 9acaa0f131b9..d04a085c423d 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -122,12 +122,23 @@ static void pnv_setup_rfi_flush(void)
 			type = L1D_FLUSH_ORI;
 	}
 
+	/*
+	 * If we are non-Power9 bare metal, we don't need to flush on kernel
+	 * entry: it fixes a P9 specific vulnerability.
+	 */
+	if (!pvr_version_is(PVR_POWER9))
+		security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
+
 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \
 		 (security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR)   || \
 		  security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV));
 
 	setup_rfi_flush(type, enable);
 	setup_count_cache_flush();
+
+	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
+		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_ENTRY);
+	setup_entry_flush(enable);
 }
 
 static void __init pnv_check_guarded_cores(void)
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 633c45ec406d..8136c5368ee4 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -579,6 +579,10 @@ void pseries_setup_rfi_flush(void)
 
 	setup_rfi_flush(types, enable);
 	setup_count_cache_flush();
+
+	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
+		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_ENTRY);
+	setup_entry_flush(enable);
 }
 
 #ifdef CONFIG_PCI_IOV
-- 
2.25.1


^ permalink raw reply related

* [PATCH 3/7] powerpc/64s: flush L1D after user accesses
From: Daniel Axtens @ 2020-11-19 23:13 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: dja, cmr, spoorts2, npiggin
In-Reply-To: <20201119231333.361771-1-dja@axtens.net>

From: Nicholas Piggin <npiggin@gmail.com>

IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.

However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.

This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache after user accesses.

This is part of the fix for CVE-2020-4788.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
 .../admin-guide/kernel-parameters.txt         |  4 +
 .../powerpc/include/asm/book3s/64/kup-radix.h | 66 ++++++++------
 arch/powerpc/include/asm/exception-64s.h      |  3 +
 arch/powerpc/include/asm/feature-fixups.h     |  9 ++
 arch/powerpc/include/asm/kup.h                | 19 +++--
 arch/powerpc/include/asm/security_features.h  |  3 +
 arch/powerpc/include/asm/setup.h              |  1 +
 arch/powerpc/kernel/exceptions-64s.S          | 85 ++++++-------------
 arch/powerpc/kernel/setup_64.c                | 62 ++++++++++++++
 arch/powerpc/kernel/vmlinux.lds.S             |  7 ++
 arch/powerpc/lib/feature-fixups.c             | 50 +++++++++++
 arch/powerpc/platforms/powernv/setup.c        | 10 ++-
 arch/powerpc/platforms/pseries/setup.c        |  4 +
 13 files changed, 233 insertions(+), 90 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 282789cfa1dc..d1b417dd1266 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2876,6 +2876,7 @@
 					       tsx_async_abort=off [X86]
 					       kvm.nx_huge_pages=off [X86]
 					       no_entry_flush [PPC]
+					       no_uaccess_flush [PPC]
 
 				Exceptions:
 					       This does not have any effect on
@@ -3255,6 +3256,9 @@
 	nospec_store_bypass_disable
 			[HW] Disable all mitigations for the Speculative Store Bypass vulnerability
 
+	no_uaccess_flush
+	                [PPC] Don't flush the L1-D cache after accessing user data.
+
 	noxsave		[BUGS=X86] Disables x86 extended register state save
 			and restore using xsave. The kernel will fallback to
 			enabling legacy floating-point and sse state.
diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h
index 3ee1ec60be84..97c2394e7dea 100644
--- a/arch/powerpc/include/asm/book3s/64/kup-radix.h
+++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h
@@ -61,6 +61,8 @@
 
 #else /* !__ASSEMBLY__ */
 
+DECLARE_STATIC_KEY_FALSE(uaccess_flush_key);
+
 #ifdef CONFIG_PPC_KUAP
 
 #include <asm/mmu.h>
@@ -103,8 +105,16 @@ static inline void kuap_check_amr(void)
 
 static inline unsigned long get_kuap(void)
 {
+	/*
+	 * We return AMR_KUAP_BLOCKED when we don't support KUAP because
+	 * prevent_user_access_return needs to return AMR_KUAP_BLOCKED to
+	 * cause restore_user_access to do a flush.
+	 *
+	 * This has no effect in terms of actually blocking things on hash,
+	 * so it doesn't break anything.
+	 */
 	if (!early_mmu_has_feature(MMU_FTR_RADIX_KUAP))
-		return 0;
+		return AMR_KUAP_BLOCKED;
 
 	return mfspr(SPRN_AMR);
 }
@@ -123,6 +133,31 @@ static inline void set_kuap(unsigned long value)
 	isync();
 }
 
+static inline bool
+bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	return WARN(mmu_has_feature(MMU_FTR_RADIX_KUAP) &&
+		    (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)),
+		    "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
+}
+#else /* CONFIG_PPC_KUAP */
+static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr) { }
+
+static inline unsigned long kuap_get_and_check_amr(void)
+{
+	return 0UL;
+}
+
+static inline void kuap_check_amr(void) { }
+
+static inline unsigned long get_kuap(void)
+{
+	return AMR_KUAP_BLOCKED;
+}
+
+static inline void set_kuap(unsigned long value) { }
+#endif /* !CONFIG_PPC_KUAP */
+
 static __always_inline void allow_user_access(void __user *to, const void __user *from,
 					      unsigned long size, unsigned long dir)
 {
@@ -142,6 +177,8 @@ static inline void prevent_user_access(void __user *to, const void __user *from,
 				       unsigned long size, unsigned long dir)
 {
 	set_kuap(AMR_KUAP_BLOCKED);
+	if (static_branch_unlikely(&uaccess_flush_key))
+		do_uaccess_flush();
 }
 
 static inline unsigned long prevent_user_access_return(void)
@@ -149,6 +186,8 @@ static inline unsigned long prevent_user_access_return(void)
 	unsigned long flags = get_kuap();
 
 	set_kuap(AMR_KUAP_BLOCKED);
+	if (static_branch_unlikely(&uaccess_flush_key))
+		do_uaccess_flush();
 
 	return flags;
 }
@@ -156,30 +195,9 @@ static inline unsigned long prevent_user_access_return(void)
 static inline void restore_user_access(unsigned long flags)
 {
 	set_kuap(flags);
+	if (static_branch_unlikely(&uaccess_flush_key) && flags == AMR_KUAP_BLOCKED)
+		do_uaccess_flush();
 }
-
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
-{
-	return WARN(mmu_has_feature(MMU_FTR_RADIX_KUAP) &&
-		    (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)),
-		    "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
-}
-#else /* CONFIG_PPC_KUAP */
-static inline void kuap_restore_amr(struct pt_regs *regs, unsigned long amr)
-{
-}
-
-static inline void kuap_check_amr(void)
-{
-}
-
-static inline unsigned long kuap_get_and_check_amr(void)
-{
-	return 0;
-}
-#endif /* CONFIG_PPC_KUAP */
-
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H */
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 83fa88bc9935..1d32b174ab6a 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -144,6 +144,9 @@
 	RFSCV;								\
 	b	rfscv_flush_fallback
 
+#else /* __ASSEMBLY__ */
+/* Prototype for function defined in exceptions-64s.S */
+void do_uaccess_flush(void);
 #endif /* __ASSEMBLY__ */
 
 #endif	/* _ASM_POWERPC_EXCEPTION_H */
diff --git a/arch/powerpc/include/asm/feature-fixups.h b/arch/powerpc/include/asm/feature-fixups.h
index 06a48219bbf2..fbd406cd6916 100644
--- a/arch/powerpc/include/asm/feature-fixups.h
+++ b/arch/powerpc/include/asm/feature-fixups.h
@@ -205,6 +205,14 @@ label##3:					       	\
 	FTR_ENTRY_OFFSET 955b-956b;			\
 	.popsection;
 
+#define UACCESS_FLUSH_FIXUP_SECTION			\
+959:							\
+	.pushsection __uaccess_flush_fixup,"a";		\
+	.align 2;					\
+960:							\
+	FTR_ENTRY_OFFSET 959b-960b;			\
+	.popsection;
+
 #define ENTRY_FLUSH_FIXUP_SECTION			\
 957:							\
 	.pushsection __entry_flush_fixup,"a";		\
@@ -248,6 +256,7 @@ extern long stf_barrier_fallback;
 extern long entry_flush_fallback;
 extern long __start___stf_entry_barrier_fixup, __stop___stf_entry_barrier_fixup;
 extern long __start___stf_exit_barrier_fixup, __stop___stf_exit_barrier_fixup;
+extern long __start___uaccess_flush_fixup, __stop___uaccess_flush_fixup;
 extern long __start___entry_flush_fixup, __stop___entry_flush_fixup;
 extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup;
 extern long __start___barrier_nospec_fixup, __stop___barrier_nospec_fixup;
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 1d0f7d838b2e..0f5c606ae057 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -53,17 +53,26 @@ static inline void setup_kuep(bool disabled) { }
 void setup_kuap(bool disabled);
 #else
 static inline void setup_kuap(bool disabled) { }
+
+static inline bool
+bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+{
+	return false;
+}
+
+/*
+ * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
+ * the L1D cache after user accesses. Only include the empty stubs for other
+ * platforms.
+ */
+#ifndef CONFIG_PPC64
 static inline void allow_user_access(void __user *to, const void __user *from,
 				     unsigned long size, unsigned long dir) { }
 static inline void prevent_user_access(void __user *to, const void __user *from,
 				       unsigned long size, unsigned long dir) { }
 static inline unsigned long prevent_user_access_return(void) { return 0UL; }
 static inline void restore_user_access(unsigned long flags) { }
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
-{
-	return false;
-}
+#endif /* CONFIG_PPC64 */
 #endif /* CONFIG_PPC_KUAP */
 
 static inline void allow_read_from_user(const void __user *from, unsigned long size)
diff --git a/arch/powerpc/include/asm/security_features.h b/arch/powerpc/include/asm/security_features.h
index 9e7459d2edca..b774a4477d5f 100644
--- a/arch/powerpc/include/asm/security_features.h
+++ b/arch/powerpc/include/asm/security_features.h
@@ -89,6 +89,8 @@ static inline bool security_ftr_enabled(u64 feature)
 // The L1-D cache should be flushed when entering the kernel
 #define SEC_FTR_L1D_FLUSH_ENTRY		0x0000000000004000ull
 
+// The L1-D cache should be flushed after user accesses from the kernel
+#define SEC_FTR_L1D_FLUSH_UACCESS	0x0000000000008000ull
 
 // Features enabled by default
 #define SEC_FTR_DEFAULT \
@@ -96,6 +98,7 @@ static inline bool security_ftr_enabled(u64 feature)
 	 SEC_FTR_L1D_FLUSH_PR | \
 	 SEC_FTR_BNDS_CHK_SPEC_BAR | \
 	 SEC_FTR_L1D_FLUSH_ENTRY | \
+	 SEC_FTR_L1D_FLUSH_UACCESS | \
 	 SEC_FTR_FAVOUR_SECURITY)
 
 #endif /* _ASM_POWERPC_SECURITY_FEATURES_H */
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index e2fcd3e874f8..a466749703f1 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -60,6 +60,7 @@ void setup_barrier_nospec(void);
 #else
 static inline void setup_barrier_nospec(void) { };
 #endif
+void do_uaccess_flush_fixups(enum l1d_flush_type types);
 void do_entry_flush_fixups(enum l1d_flush_type types);
 void do_barrier_nospec_fixups(bool enable);
 extern bool barrier_nospec_enabled;
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 5577dd887d37..f63a3d3bca3d 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2951,11 +2951,8 @@ TRAMP_REAL_BEGIN(stf_barrier_fallback)
 	.endr
 	blr
 
-TRAMP_REAL_BEGIN(entry_flush_fallback)
-	std	r9,PACA_EXRFI+EX_R9(r13)
-	std	r10,PACA_EXRFI+EX_R10(r13)
-	std	r11,PACA_EXRFI+EX_R11(r13)
-	mfctr	r9
+/* Clobbers r10, r11, ctr */
+.macro L1D_DISPLACEMENT_FLUSH
 	ld	r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
 	ld	r11,PACA_L1D_FLUSH_SIZE(r13)
 	srdi	r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
@@ -2981,7 +2978,14 @@ TRAMP_REAL_BEGIN(entry_flush_fallback)
 	ld	r11,(0x80 + 8)*7(r10)
 	addi	r10,r10,0x80*8
 	bdnz	1b
+.endm
 
+TRAMP_REAL_BEGIN(entry_flush_fallback)
+	std	r9,PACA_EXRFI+EX_R9(r13)
+	std	r10,PACA_EXRFI+EX_R10(r13)
+	std	r11,PACA_EXRFI+EX_R11(r13)
+	mfctr	r9
+	L1D_DISPLACEMENT_FLUSH
 	mtctr	r9
 	ld	r9,PACA_EXRFI+EX_R9(r13)
 	ld	r10,PACA_EXRFI+EX_R10(r13)
@@ -2997,32 +3001,7 @@ TRAMP_REAL_BEGIN(rfi_flush_fallback)
 	std	r10,PACA_EXRFI+EX_R10(r13)
 	std	r11,PACA_EXRFI+EX_R11(r13)
 	mfctr	r9
-	ld	r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
-	ld	r11,PACA_L1D_FLUSH_SIZE(r13)
-	srdi	r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
-	mtctr	r11
-	DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
-
-	/* order ld/st prior to dcbt stop all streams with flushing */
-	sync
-
-	/*
-	 * The load adresses are at staggered offsets within cachelines,
-	 * which suits some pipelines better (on others it should not
-	 * hurt).
-	 */
-1:
-	ld	r11,(0x80 + 8)*0(r10)
-	ld	r11,(0x80 + 8)*1(r10)
-	ld	r11,(0x80 + 8)*2(r10)
-	ld	r11,(0x80 + 8)*3(r10)
-	ld	r11,(0x80 + 8)*4(r10)
-	ld	r11,(0x80 + 8)*5(r10)
-	ld	r11,(0x80 + 8)*6(r10)
-	ld	r11,(0x80 + 8)*7(r10)
-	addi	r10,r10,0x80*8
-	bdnz	1b
-
+	L1D_DISPLACEMENT_FLUSH
 	mtctr	r9
 	ld	r9,PACA_EXRFI+EX_R9(r13)
 	ld	r10,PACA_EXRFI+EX_R10(r13)
@@ -3040,32 +3019,7 @@ TRAMP_REAL_BEGIN(hrfi_flush_fallback)
 	std	r10,PACA_EXRFI+EX_R10(r13)
 	std	r11,PACA_EXRFI+EX_R11(r13)
 	mfctr	r9
-	ld	r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
-	ld	r11,PACA_L1D_FLUSH_SIZE(r13)
-	srdi	r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
-	mtctr	r11
-	DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
-
-	/* order ld/st prior to dcbt stop all streams with flushing */
-	sync
-
-	/*
-	 * The load adresses are at staggered offsets within cachelines,
-	 * which suits some pipelines better (on others it should not
-	 * hurt).
-	 */
-1:
-	ld	r11,(0x80 + 8)*0(r10)
-	ld	r11,(0x80 + 8)*1(r10)
-	ld	r11,(0x80 + 8)*2(r10)
-	ld	r11,(0x80 + 8)*3(r10)
-	ld	r11,(0x80 + 8)*4(r10)
-	ld	r11,(0x80 + 8)*5(r10)
-	ld	r11,(0x80 + 8)*6(r10)
-	ld	r11,(0x80 + 8)*7(r10)
-	addi	r10,r10,0x80*8
-	bdnz	1b
-
+	L1D_DISPLACEMENT_FLUSH
 	mtctr	r9
 	ld	r9,PACA_EXRFI+EX_R9(r13)
 	ld	r10,PACA_EXRFI+EX_R10(r13)
@@ -3116,8 +3070,21 @@ TRAMP_REAL_BEGIN(rfscv_flush_fallback)
 	RFSCV
 
 USE_TEXT_SECTION()
-	MASKED_INTERRUPT
-	MASKED_INTERRUPT hsrr=1
+
+_GLOBAL(do_uaccess_flush)
+	UACCESS_FLUSH_FIXUP_SECTION
+	nop
+	nop
+	nop
+	blr
+	L1D_DISPLACEMENT_FLUSH
+	blr
+_ASM_NOKPROBE_SYMBOL(do_uaccess_flush)
+EXPORT_SYMBOL(do_uaccess_flush)
+
+
+MASKED_INTERRUPT
+MASKED_INTERRUPT hsrr=1
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 kvmppc_skip_interrupt:
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 7d447b43ad13..74fd47f46fa5 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -946,8 +946,12 @@ static enum l1d_flush_type enabled_flush_types;
 static void *l1d_flush_fallback_area;
 static bool no_rfi_flush;
 static bool no_entry_flush;
+static bool no_uaccess_flush;
 bool rfi_flush;
 bool entry_flush;
+bool uaccess_flush;
+DEFINE_STATIC_KEY_FALSE(uaccess_flush_key);
+EXPORT_SYMBOL(uaccess_flush_key);
 
 static int __init handle_no_rfi_flush(char *p)
 {
@@ -965,6 +969,14 @@ static int __init handle_no_entry_flush(char *p)
 }
 early_param("no_entry_flush", handle_no_entry_flush);
 
+static int __init handle_no_uaccess_flush(char *p)
+{
+	pr_info("uaccess-flush: disabled on command line.");
+	no_uaccess_flush = true;
+	return 0;
+}
+early_param("no_uaccess_flush", handle_no_uaccess_flush);
+
 /*
  * The RFI flush is not KPTI, but because users will see doco that says to use
  * nopti we hijack that option here to also disable the RFI flush.
@@ -1008,6 +1020,20 @@ void entry_flush_enable(bool enable)
 	entry_flush = enable;
 }
 
+void uaccess_flush_enable(bool enable)
+{
+	if (enable) {
+		do_uaccess_flush_fixups(enabled_flush_types);
+		static_branch_enable(&uaccess_flush_key);
+		on_each_cpu(do_nothing, NULL, 1);
+	} else {
+		static_branch_disable(&uaccess_flush_key);
+		do_uaccess_flush_fixups(L1D_FLUSH_NONE);
+	}
+
+	uaccess_flush = enable;
+}
+
 static void __ref init_fallback_flush(void)
 {
 	u64 l1d_size, limit;
@@ -1079,6 +1105,15 @@ void setup_entry_flush(bool enable)
 		entry_flush_enable(enable);
 }
 
+void setup_uaccess_flush(bool enable)
+{
+	if (cpu_mitigations_off())
+		return;
+
+	if (!no_uaccess_flush)
+		uaccess_flush_enable(enable);
+}
+
 #ifdef CONFIG_DEBUG_FS
 static int rfi_flush_set(void *data, u64 val)
 {
@@ -1132,10 +1167,37 @@ static int entry_flush_get(void *data, u64 *val)
 
 DEFINE_SIMPLE_ATTRIBUTE(fops_entry_flush, entry_flush_get, entry_flush_set, "%llu\n");
 
+static int uaccess_flush_set(void *data, u64 val)
+{
+	bool enable;
+
+	if (val == 1)
+		enable = true;
+	else if (val == 0)
+		enable = false;
+	else
+		return -EINVAL;
+
+	/* Only do anything if we're changing state */
+	if (enable != uaccess_flush)
+		uaccess_flush_enable(enable);
+
+	return 0;
+}
+
+static int uaccess_flush_get(void *data, u64 *val)
+{
+	*val = uaccess_flush ? 1 : 0;
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_uaccess_flush, uaccess_flush_get, uaccess_flush_set, "%llu\n");
+
 static __init int rfi_flush_debugfs_init(void)
 {
 	debugfs_create_file("rfi_flush", 0600, powerpc_debugfs_root, NULL, &fops_rfi_flush);
 	debugfs_create_file("entry_flush", 0600, powerpc_debugfs_root, NULL, &fops_entry_flush);
+	debugfs_create_file("uaccess_flush", 0600, powerpc_debugfs_root, NULL, &fops_uaccess_flush);
 	return 0;
 }
 device_initcall(rfi_flush_debugfs_init);
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 715ec4d4614a..6db90cdf11da 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -131,6 +131,13 @@ SECTIONS
 		__stop___stf_entry_barrier_fixup = .;
 	}
 
+	. = ALIGN(8);
+	__uaccess_flush_fixup : AT(ADDR(__uaccess_flush_fixup) - LOAD_OFFSET) {
+		__start___uaccess_flush_fixup = .;
+		*(__uaccess_flush_fixup)
+		__stop___uaccess_flush_fixup = .;
+	}
+
 	. = ALIGN(8);
 	__entry_flush_fixup : AT(ADDR(__entry_flush_fixup) - LOAD_OFFSET) {
 		__start___entry_flush_fixup = .;
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 70e83cfd74aa..321c12a9ef6b 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -234,6 +234,56 @@ void do_stf_barrier_fixups(enum stf_barrier_type types)
 	do_stf_exit_barrier_fixups(types);
 }
 
+void do_uaccess_flush_fixups(enum l1d_flush_type types)
+{
+	unsigned int instrs[4], *dest;
+	long *start, *end;
+	int i;
+
+	start = PTRRELOC(&__start___uaccess_flush_fixup);
+	end = PTRRELOC(&__stop___uaccess_flush_fixup);
+
+	instrs[0] = 0x60000000; /* nop */
+	instrs[1] = 0x60000000; /* nop */
+	instrs[2] = 0x60000000; /* nop */
+	instrs[3] = 0x4e800020; /* blr */
+
+	i = 0;
+	if (types == L1D_FLUSH_FALLBACK) {
+		instrs[3] = 0x60000000; /* nop */
+		/* fallthrough to fallback flush */
+	}
+
+	if (types & L1D_FLUSH_ORI) {
+		instrs[i++] = 0x63ff0000; /* ori 31,31,0 speculation barrier */
+		instrs[i++] = 0x63de0000; /* ori 30,30,0 L1d flush*/
+	}
+
+	if (types & L1D_FLUSH_MTTRIG)
+		instrs[i++] = 0x7c12dba6; /* mtspr TRIG2,r0 (SPR #882) */
+
+	for (i = 0; start < end; start++, i++) {
+		dest = (void *)start + *start;
+
+		pr_devel("patching dest %lx\n", (unsigned long)dest);
+
+		patch_instruction((struct ppc_inst *)dest, ppc_inst(instrs[0]));
+
+		patch_instruction((struct ppc_inst *)(dest + 1), ppc_inst(instrs[1]));
+		patch_instruction((struct ppc_inst *)(dest + 2), ppc_inst(instrs[2]));
+		patch_instruction((struct ppc_inst *)(dest + 3), ppc_inst(instrs[3]));
+	}
+
+	printk(KERN_DEBUG "uaccess-flush: patched %d locations (%s flush)\n", i,
+		(types == L1D_FLUSH_NONE)       ? "no" :
+		(types == L1D_FLUSH_FALLBACK)   ? "fallback displacement" :
+		(types &  L1D_FLUSH_ORI)        ? (types & L1D_FLUSH_MTTRIG)
+							? "ori+mttrig type"
+							: "ori type" :
+		(types &  L1D_FLUSH_MTTRIG)     ? "mttrig type"
+						: "unknown");
+}
+
 void do_entry_flush_fixups(enum l1d_flush_type types)
 {
 	unsigned int instrs[3], *dest;
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index d04a085c423d..087ec92acfc4 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -124,10 +124,12 @@ static void pnv_setup_rfi_flush(void)
 
 	/*
 	 * If we are non-Power9 bare metal, we don't need to flush on kernel
-	 * entry: it fixes a P9 specific vulnerability.
+	 * entry or after user access: they fix a P9 specific vulnerability.
 	 */
-	if (!pvr_version_is(PVR_POWER9))
+	if (!pvr_version_is(PVR_POWER9)) {
 		security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
+		security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);
+	}
 
 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \
 		 (security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR)   || \
@@ -139,6 +141,10 @@ static void pnv_setup_rfi_flush(void)
 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
 		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_ENTRY);
 	setup_entry_flush(enable);
+
+	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
+		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_UACCESS);
+	setup_uaccess_flush(enable);
 }
 
 static void __init pnv_check_guarded_cores(void)
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 8136c5368ee4..3617cdb079f6 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -583,6 +583,10 @@ void pseries_setup_rfi_flush(void)
 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
 		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_ENTRY);
 	setup_entry_flush(enable);
+
+	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
+		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_UACCESS);
+	setup_uaccess_flush(enable);
 }
 
 #ifdef CONFIG_PCI_IOV
-- 
2.25.1


^ permalink raw reply related

* [PATCH 4/7] powerpc: Only include kup-radix.h for 64-bit Book3S
From: Daniel Axtens @ 2020-11-19 23:13 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: dja, cmr, spoorts2, npiggin
In-Reply-To: <20201119231333.361771-1-dja@axtens.net>

From: Michael Ellerman <mpe@ellerman.id.au>

In kup.h we currently include kup-radix.h for all 64-bit builds, which
includes Book3S and Book3E. The latter doesn't make sense, Book3E
never uses the Radix MMU.

This has worked up until now, but almost by accident, and the recent
uaccess flush changes introduced a build breakage on Book3E because of
the bad structure of the code.

So disentangle things so that we only use kup-radix.h for Book3S. This
requires some more stubs in kup.h and fixing an include in
syscall_64.c.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/book3s/64/kup-radix.h |  4 ++--
 arch/powerpc/include/asm/kup.h                 | 11 ++++++++---
 arch/powerpc/kernel/syscall_64.c               |  2 +-
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h
index 97c2394e7dea..28716e2f13e3 100644
--- a/arch/powerpc/include/asm/book3s/64/kup-radix.h
+++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h
@@ -27,6 +27,7 @@
 #endif
 .endm
 
+#ifdef CONFIG_PPC_KUAP
 .macro kuap_check_amr gpr1, gpr2
 #ifdef CONFIG_PPC_KUAP_DEBUG
 	BEGIN_MMU_FTR_SECTION_NESTED(67)
@@ -38,6 +39,7 @@
 	END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_RADIX_KUAP, 67)
 #endif
 .endm
+#endif
 
 .macro kuap_save_amr_and_lock gpr1, gpr2, use_cr, msr_pr_cr
 #ifdef CONFIG_PPC_KUAP
@@ -148,8 +150,6 @@ static inline unsigned long kuap_get_and_check_amr(void)
 	return 0UL;
 }
 
-static inline void kuap_check_amr(void) { }
-
 static inline unsigned long get_kuap(void)
 {
 	return AMR_KUAP_BLOCKED;
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 0f5c606ae057..0d93331d0fab 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -14,7 +14,7 @@
 #define KUAP_CURRENT_WRITE	8
 #define KUAP_CURRENT		(KUAP_CURRENT_READ | KUAP_CURRENT_WRITE)
 
-#ifdef CONFIG_PPC64
+#ifdef CONFIG_PPC_BOOK3S_64
 #include <asm/book3s/64/kup-radix.h>
 #endif
 #ifdef CONFIG_PPC_8xx
@@ -35,6 +35,9 @@
 .macro kuap_check	current, gpr
 .endm
 
+.macro kuap_check_amr	gpr1, gpr2
+.endm
+
 #endif
 
 #else /* !__ASSEMBLY__ */
@@ -60,19 +63,21 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 	return false;
 }
 
+static inline void kuap_check_amr(void) { }
+
 /*
  * book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
  * the L1D cache after user accesses. Only include the empty stubs for other
  * platforms.
  */
-#ifndef CONFIG_PPC64
+#ifndef CONFIG_PPC_BOOK3S_64
 static inline void allow_user_access(void __user *to, const void __user *from,
 				     unsigned long size, unsigned long dir) { }
 static inline void prevent_user_access(void __user *to, const void __user *from,
 				       unsigned long size, unsigned long dir) { }
 static inline unsigned long prevent_user_access_return(void) { return 0UL; }
 static inline void restore_user_access(unsigned long flags) { }
-#endif /* CONFIG_PPC64 */
+#endif /* CONFIG_PPC_BOOK3S_64 */
 #endif /* CONFIG_PPC_KUAP */
 
 static inline void allow_read_from_user(const void __user *from, unsigned long size)
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 8e50818aa50b..310bcd768cd5 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -2,7 +2,7 @@
 
 #include <linux/err.h>
 #include <asm/asm-prototypes.h>
-#include <asm/book3s/64/kup-radix.h>
+#include <asm/kup.h>
 #include <asm/cputime.h>
 #include <asm/hw_irq.h>
 #include <asm/kprobes.h>
-- 
2.25.1


^ permalink raw reply related

* [PATCH 5/7] selftests/powerpc: entry flush test
From: Daniel Axtens @ 2020-11-19 23:13 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: dja, cmr, spoorts2, npiggin
In-Reply-To: <20201119231333.361771-1-dja@axtens.net>

Add a test modelled on the RFI flush test which counts the number
of L1D misses doing a simple syscall with the entry flush on and off.

For simplicity of backporting, this test duplicates a lot of code from
rfi_flush. We clean that up in the next patch.

Signed-off-by: Daniel Axtens <dja@axtens.net>
---
 .../selftests/powerpc/security/.gitignore     |   1 +
 .../selftests/powerpc/security/Makefile       |   2 +-
 .../selftests/powerpc/security/entry_flush.c  | 198 ++++++++++++++++++
 3 files changed, 200 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/powerpc/security/entry_flush.c

diff --git a/tools/testing/selftests/powerpc/security/.gitignore b/tools/testing/selftests/powerpc/security/.gitignore
index f795e06f5ae3..4257a1f156bb 100644
--- a/tools/testing/selftests/powerpc/security/.gitignore
+++ b/tools/testing/selftests/powerpc/security/.gitignore
@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
 rfi_flush
+entry_flush
diff --git a/tools/testing/selftests/powerpc/security/Makefile b/tools/testing/selftests/powerpc/security/Makefile
index eadbbff50be6..921152caf1dc 100644
--- a/tools/testing/selftests/powerpc/security/Makefile
+++ b/tools/testing/selftests/powerpc/security/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0+
 
-TEST_GEN_PROGS := rfi_flush spectre_v2
+TEST_GEN_PROGS := rfi_flush entry_flush spectre_v2
 top_srcdir = ../../../../..
 
 CFLAGS += -I../../../../../usr/include
diff --git a/tools/testing/selftests/powerpc/security/entry_flush.c b/tools/testing/selftests/powerpc/security/entry_flush.c
new file mode 100644
index 000000000000..7ae7e37204c5
--- /dev/null
+++ b/tools/testing/selftests/powerpc/security/entry_flush.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2018 IBM Corporation.
+ */
+
+#define __SANE_USERSPACE_TYPES__
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <malloc.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include "utils.h"
+
+#define CACHELINE_SIZE 128
+
+struct perf_event_read {
+	__u64 nr;
+	__u64 l1d_misses;
+};
+
+static inline __u64 load(void *addr)
+{
+	__u64 tmp;
+
+	asm volatile("ld %0,0(%1)" : "=r"(tmp) : "b"(addr));
+
+	return tmp;
+}
+
+static void syscall_loop(char *p, unsigned long iterations,
+			 unsigned long zero_size)
+{
+	for (unsigned long i = 0; i < iterations; i++) {
+		for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
+			load(p + j);
+		getppid();
+	}
+}
+
+static void sigill_handler(int signr, siginfo_t *info, void *unused)
+{
+	static int warned;
+	ucontext_t *ctx = (ucontext_t *)unused;
+	unsigned long *pc = &UCONTEXT_NIA(ctx);
+
+	/* mtspr 3,RS to check for move to DSCR below */
+	if ((*((unsigned int *)*pc) & 0xfc1fffff) == 0x7c0303a6) {
+		if (!warned++)
+			printf("WARNING: Skipping over dscr setup. Consider running 'ppc64_cpu --dscr=1' manually.\n");
+		*pc += 4;
+	} else {
+		printf("SIGILL at %p\n", pc);
+		abort();
+	}
+}
+
+static void set_dscr(unsigned long val)
+{
+	static int init;
+	struct sigaction sa;
+
+	if (!init) {
+		memset(&sa, 0, sizeof(sa));
+		sa.sa_sigaction = sigill_handler;
+		sa.sa_flags = SA_SIGINFO;
+		if (sigaction(SIGILL, &sa, NULL))
+			perror("sigill_handler");
+		init = 1;
+	}
+
+	asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
+}
+
+int entry_flush_test(void)
+{
+	char *p;
+	int repetitions = 10;
+	int fd, passes = 0, iter, rc = 0;
+	struct perf_event_read v;
+	__u64 l1d_misses_total = 0;
+	unsigned long iterations = 100000, zero_size = 24 * 1024;
+	unsigned long l1d_misses_expected;
+	int rfi_flush_orig;
+	int entry_flush, entry_flush_orig;
+
+	SKIP_IF(geteuid() != 0);
+
+	// The PMU event we use only works on Power7 or later
+	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
+
+	if (read_debugfs_file("powerpc/rfi_flush", &rfi_flush_orig) < 0) {
+		perror("Unable to read powerpc/rfi_flush debugfs file");
+		SKIP_IF(1);
+	}
+
+	if (read_debugfs_file("powerpc/entry_flush", &entry_flush_orig) < 0) {
+		perror("Unable to read powerpc/entry_flush debugfs file");
+		SKIP_IF(1);
+	}
+
+	if (rfi_flush_orig != 0) {
+		if (write_debugfs_file("powerpc/rfi_flush", 0) < 0) {
+			perror("error writing to powerpc/rfi_flush debugfs file");
+			FAIL_IF(1);
+		}
+	}
+
+	entry_flush = entry_flush_orig;
+
+	fd = perf_event_open_counter(PERF_TYPE_RAW, /* L1d miss */ 0x400f0, -1);
+	FAIL_IF(fd < 0);
+
+	p = (char *)memalign(zero_size, CACHELINE_SIZE);
+
+	FAIL_IF(perf_event_enable(fd));
+
+	// disable L1 prefetching
+	set_dscr(1);
+
+	iter = repetitions;
+
+	/*
+	 * We expect to see l1d miss for each cacheline access when entry_flush
+	 * is set. Allow a small variation on this.
+	 */
+	l1d_misses_expected = iterations * (zero_size / CACHELINE_SIZE - 2);
+
+again:
+	FAIL_IF(perf_event_reset(fd));
+
+	syscall_loop(p, iterations, zero_size);
+
+	FAIL_IF(read(fd, &v, sizeof(v)) != sizeof(v));
+
+	if (entry_flush && v.l1d_misses >= l1d_misses_expected)
+		passes++;
+	else if (!entry_flush && v.l1d_misses < (l1d_misses_expected / 2))
+		passes++;
+
+	l1d_misses_total += v.l1d_misses;
+
+	while (--iter)
+		goto again;
+
+	if (passes < repetitions) {
+		printf("FAIL (L1D misses with entry_flush=%d: %llu %c %lu) [%d/%d failures]\n",
+		       entry_flush, l1d_misses_total, entry_flush ? '<' : '>',
+		       entry_flush ? repetitions * l1d_misses_expected :
+		       repetitions * l1d_misses_expected / 2,
+		       repetitions - passes, repetitions);
+		rc = 1;
+	} else {
+		printf("PASS (L1D misses with entry_flush=%d: %llu %c %lu) [%d/%d pass]\n",
+		       entry_flush, l1d_misses_total, entry_flush ? '>' : '<',
+		       entry_flush ? repetitions * l1d_misses_expected :
+		       repetitions * l1d_misses_expected / 2,
+		       passes, repetitions);
+	}
+
+	if (entry_flush == entry_flush_orig) {
+		entry_flush = !entry_flush_orig;
+		if (write_debugfs_file("powerpc/entry_flush", entry_flush) < 0) {
+			perror("error writing to powerpc/entry_flush debugfs file");
+			return 1;
+		}
+		iter = repetitions;
+		l1d_misses_total = 0;
+		passes = 0;
+		goto again;
+	}
+
+	perf_event_disable(fd);
+	close(fd);
+
+	set_dscr(0);
+
+	if (write_debugfs_file("powerpc/rfi_flush", rfi_flush_orig) < 0) {
+		perror("unable to restore original value of powerpc/rfi_flush debugfs file");
+		return 1;
+	}
+
+	if (write_debugfs_file("powerpc/entry_flush", entry_flush_orig) < 0) {
+		perror("unable to restore original value of powerpc/entry_flush debugfs file");
+		return 1;
+	}
+
+	return rc;
+}
+
+int main(int argc, char *argv[])
+{
+	return test_harness(entry_flush_test, "entry_flush_test");
+}
-- 
2.25.1


^ permalink raw reply related

* [PATCH 6/7] selftests/powerpc: refactor entry and rfi_flush tests
From: Daniel Axtens @ 2020-11-19 23:13 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: dja, cmr, spoorts2, npiggin
In-Reply-To: <20201119231333.361771-1-dja@axtens.net>

For simplicity in backporting, the original entry_flush test contained
a lot of duplicated code from the rfi_flush test. De-duplicate that code.

Signed-off-by: Daniel Axtens <dja@axtens.net>
---
 .../testing/selftests/powerpc/include/utils.h |  5 ++
 .../selftests/powerpc/security/Makefile       |  2 +
 .../selftests/powerpc/security/entry_flush.c  | 61 +---------------
 .../selftests/powerpc/security/flush_utils.c  | 70 +++++++++++++++++++
 .../selftests/powerpc/security/flush_utils.h  | 17 +++++
 .../selftests/powerpc/security/rfi_flush.c    | 61 +---------------
 6 files changed, 96 insertions(+), 120 deletions(-)
 create mode 100644 tools/testing/selftests/powerpc/security/flush_utils.c
 create mode 100644 tools/testing/selftests/powerpc/security/flush_utils.h

diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index 052b5a775dc2..b7d188fc87c7 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -42,6 +42,11 @@ int perf_event_enable(int fd);
 int perf_event_disable(int fd);
 int perf_event_reset(int fd);
 
+struct perf_event_read {
+	__u64 nr;
+	__u64 l1d_misses;
+};
+
 #if !defined(__GLIBC_PREREQ) || !__GLIBC_PREREQ(2, 30)
 #include <unistd.h>
 #include <sys/syscall.h>
diff --git a/tools/testing/selftests/powerpc/security/Makefile b/tools/testing/selftests/powerpc/security/Makefile
index 921152caf1dc..f25e854fe370 100644
--- a/tools/testing/selftests/powerpc/security/Makefile
+++ b/tools/testing/selftests/powerpc/security/Makefile
@@ -11,3 +11,5 @@ $(TEST_GEN_PROGS): ../harness.c ../utils.c
 
 $(OUTPUT)/spectre_v2: CFLAGS += -m64
 $(OUTPUT)/spectre_v2: ../pmu/event.c branch_loops.S
+$(OUTPUT)/rfi_flush: flush_utils.c
+$(OUTPUT)/entry_flush: flush_utils.c
diff --git a/tools/testing/selftests/powerpc/security/entry_flush.c b/tools/testing/selftests/powerpc/security/entry_flush.c
index 7ae7e37204c5..78cf914fa321 100644
--- a/tools/testing/selftests/powerpc/security/entry_flush.c
+++ b/tools/testing/selftests/powerpc/security/entry_flush.c
@@ -15,66 +15,7 @@
 #include <string.h>
 #include <stdio.h>
 #include "utils.h"
-
-#define CACHELINE_SIZE 128
-
-struct perf_event_read {
-	__u64 nr;
-	__u64 l1d_misses;
-};
-
-static inline __u64 load(void *addr)
-{
-	__u64 tmp;
-
-	asm volatile("ld %0,0(%1)" : "=r"(tmp) : "b"(addr));
-
-	return tmp;
-}
-
-static void syscall_loop(char *p, unsigned long iterations,
-			 unsigned long zero_size)
-{
-	for (unsigned long i = 0; i < iterations; i++) {
-		for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
-			load(p + j);
-		getppid();
-	}
-}
-
-static void sigill_handler(int signr, siginfo_t *info, void *unused)
-{
-	static int warned;
-	ucontext_t *ctx = (ucontext_t *)unused;
-	unsigned long *pc = &UCONTEXT_NIA(ctx);
-
-	/* mtspr 3,RS to check for move to DSCR below */
-	if ((*((unsigned int *)*pc) & 0xfc1fffff) == 0x7c0303a6) {
-		if (!warned++)
-			printf("WARNING: Skipping over dscr setup. Consider running 'ppc64_cpu --dscr=1' manually.\n");
-		*pc += 4;
-	} else {
-		printf("SIGILL at %p\n", pc);
-		abort();
-	}
-}
-
-static void set_dscr(unsigned long val)
-{
-	static int init;
-	struct sigaction sa;
-
-	if (!init) {
-		memset(&sa, 0, sizeof(sa));
-		sa.sa_sigaction = sigill_handler;
-		sa.sa_flags = SA_SIGINFO;
-		if (sigaction(SIGILL, &sa, NULL))
-			perror("sigill_handler");
-		init = 1;
-	}
-
-	asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
-}
+#include "flush_utils.h"
 
 int entry_flush_test(void)
 {
diff --git a/tools/testing/selftests/powerpc/security/flush_utils.c b/tools/testing/selftests/powerpc/security/flush_utils.c
new file mode 100644
index 000000000000..0c3c4c40c7fb
--- /dev/null
+++ b/tools/testing/selftests/powerpc/security/flush_utils.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2018 IBM Corporation.
+ */
+
+#define __SANE_USERSPACE_TYPES__
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include "utils.h"
+#include "flush_utils.h"
+
+static inline __u64 load(void *addr)
+{
+	__u64 tmp;
+
+	asm volatile("ld %0,0(%1)" : "=r"(tmp) : "b"(addr));
+
+	return tmp;
+}
+
+void syscall_loop(char *p, unsigned long iterations,
+		  unsigned long zero_size)
+{
+	for (unsigned long i = 0; i < iterations; i++) {
+		for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
+			load(p + j);
+		getppid();
+	}
+}
+
+static void sigill_handler(int signr, siginfo_t *info, void *unused)
+{
+	static int warned;
+	ucontext_t *ctx = (ucontext_t *)unused;
+	unsigned long *pc = &UCONTEXT_NIA(ctx);
+
+	/* mtspr 3,RS to check for move to DSCR below */
+	if ((*((unsigned int *)*pc) & 0xfc1fffff) == 0x7c0303a6) {
+		if (!warned++)
+			printf("WARNING: Skipping over dscr setup. Consider running 'ppc64_cpu --dscr=1' manually.\n");
+		*pc += 4;
+	} else {
+		printf("SIGILL at %p\n", pc);
+		abort();
+	}
+}
+
+void set_dscr(unsigned long val)
+{
+	static int init;
+	struct sigaction sa;
+
+	if (!init) {
+		memset(&sa, 0, sizeof(sa));
+		sa.sa_sigaction = sigill_handler;
+		sa.sa_flags = SA_SIGINFO;
+		if (sigaction(SIGILL, &sa, NULL))
+			perror("sigill_handler");
+		init = 1;
+	}
+
+	asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
+}
diff --git a/tools/testing/selftests/powerpc/security/flush_utils.h b/tools/testing/selftests/powerpc/security/flush_utils.h
new file mode 100644
index 000000000000..07a5eb301466
--- /dev/null
+++ b/tools/testing/selftests/powerpc/security/flush_utils.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+/*
+ * Copyright 2018 IBM Corporation.
+ */
+
+#ifndef _SELFTESTS_POWERPC_SECURITY_FLUSH_UTILS_H
+#define _SELFTESTS_POWERPC_SECURITY_FLUSH_UTILS_H
+
+#define CACHELINE_SIZE 128
+
+void syscall_loop(char *p, unsigned long iterations,
+		  unsigned long zero_size);
+
+void set_dscr(unsigned long val);
+
+#endif /* _SELFTESTS_POWERPC_SECURITY_FLUSH_UTILS_H */
diff --git a/tools/testing/selftests/powerpc/security/rfi_flush.c b/tools/testing/selftests/powerpc/security/rfi_flush.c
index 4e7b2776c367..7565fd786640 100644
--- a/tools/testing/selftests/powerpc/security/rfi_flush.c
+++ b/tools/testing/selftests/powerpc/security/rfi_flush.c
@@ -10,71 +10,12 @@
 #include <stdint.h>
 #include <malloc.h>
 #include <unistd.h>
-#include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include "utils.h"
+#include "flush_utils.h"
 
-#define CACHELINE_SIZE 128
-
-struct perf_event_read {
-	__u64 nr;
-	__u64 l1d_misses;
-};
-
-static inline __u64 load(void *addr)
-{
-	__u64 tmp;
-
-	asm volatile("ld %0,0(%1)" : "=r"(tmp) : "b"(addr));
-
-	return tmp;
-}
-
-static void syscall_loop(char *p, unsigned long iterations,
-			 unsigned long zero_size)
-{
-	for (unsigned long i = 0; i < iterations; i++) {
-		for (unsigned long j = 0; j < zero_size; j += CACHELINE_SIZE)
-			load(p + j);
-		getppid();
-	}
-}
-
-static void sigill_handler(int signr, siginfo_t *info, void *unused)
-{
-	static int warned = 0;
-	ucontext_t *ctx = (ucontext_t *)unused;
-	unsigned long *pc = &UCONTEXT_NIA(ctx);
-
-	/* mtspr 3,RS to check for move to DSCR below */
-	if ((*((unsigned int *)*pc) & 0xfc1fffff) == 0x7c0303a6) {
-		if (!warned++)
-			printf("WARNING: Skipping over dscr setup. Consider running 'ppc64_cpu --dscr=1' manually.\n");
-		*pc += 4;
-	} else {
-		printf("SIGILL at %p\n", pc);
-		abort();
-	}
-}
-
-static void set_dscr(unsigned long val)
-{
-	static int init = 0;
-	struct sigaction sa;
-
-	if (!init) {
-		memset(&sa, 0, sizeof(sa));
-		sa.sa_sigaction = sigill_handler;
-		sa.sa_flags = SA_SIGINFO;
-		if (sigaction(SIGILL, &sa, NULL))
-			perror("sigill_handler");
-		init = 1;
-	}
-
-	asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
-}
 
 int rfi_flush_test(void)
 {
-- 
2.25.1


^ permalink raw reply related

* [PATCH 7/7] powerpc/64s: rename pnv|pseries_setup_rfi_flush to _setup_security_mitigations
From: Daniel Axtens @ 2020-11-19 23:13 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: dja, cmr, spoorts2, npiggin
In-Reply-To: <20201119231333.361771-1-dja@axtens.net>

pseries|pnv_setup_rfi_flush already does the count cache flush setup, and
we just added entry and uaccess flushes. So the name is not very accurate
any more. In both platforms we then also immediately setup the STF flush.

Rename them to _setup_security_mitigations and fold the STF flush in.

Signed-off-by: Daniel Axtens <dja@axtens.net>
---
 arch/powerpc/platforms/powernv/setup.c    | 7 ++++---
 arch/powerpc/platforms/pseries/mobility.c | 4 ++--
 arch/powerpc/platforms/pseries/pseries.h  | 2 +-
 arch/powerpc/platforms/pseries/setup.c    | 7 ++++---
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 087ec92acfc4..46115231a3b2 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -98,7 +98,7 @@ static void init_fw_feat_flags(struct device_node *np)
 		security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
 }
 
-static void pnv_setup_rfi_flush(void)
+static void pnv_setup_security_mitigations(void)
 {
 	struct device_node *np, *fw_features;
 	enum l1d_flush_type type;
@@ -145,6 +145,8 @@ static void pnv_setup_rfi_flush(void)
 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
 		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_UACCESS);
 	setup_uaccess_flush(enable);
+
+	setup_stf_barrier();
 }
 
 static void __init pnv_check_guarded_cores(void)
@@ -173,8 +175,7 @@ static void __init pnv_setup_arch(void)
 {
 	set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT);
 
-	pnv_setup_rfi_flush();
-	setup_stf_barrier();
+	pnv_setup_security_mitigations();
 
 	/* Initialize SMP */
 	pnv_smp_init();
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index d6f4162478a5..2f73cb5bf12d 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -349,8 +349,8 @@ void post_mobility_fixup(void)
 
 	cpus_read_unlock();
 
-	/* Possibly switch to a new RFI flush type */
-	pseries_setup_rfi_flush();
+	/* Possibly switch to a new L1 flush type */
+	pseries_setup_security_mitigations();
 
 	/* Reinitialise system information for hv-24x7 */
 	read_24x7_sys_info();
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 13fa370a87e4..593840847cd3 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -111,7 +111,7 @@ static inline unsigned long cmo_get_page_size(void)
 
 int dlpar_workqueue_init(void);
 
-void pseries_setup_rfi_flush(void);
+void pseries_setup_security_mitigations(void);
 void pseries_lpar_read_hblkrm_characteristics(void);
 
 #endif /* _PSERIES_PSERIES_H */
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 3617cdb079f6..090c13f6c881 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -542,7 +542,7 @@ static void init_cpu_char_feature_flags(struct h_cpu_char_result *result)
 		security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
 }
 
-void pseries_setup_rfi_flush(void)
+void pseries_setup_security_mitigations(void)
 {
 	struct h_cpu_char_result result;
 	enum l1d_flush_type types;
@@ -587,6 +587,8 @@ void pseries_setup_rfi_flush(void)
 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
 		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_UACCESS);
 	setup_uaccess_flush(enable);
+
+	setup_stf_barrier();
 }
 
 #ifdef CONFIG_PCI_IOV
@@ -776,8 +778,7 @@ static void __init pSeries_setup_arch(void)
 
 	fwnmi_init();
 
-	pseries_setup_rfi_flush();
-	setup_stf_barrier();
+	pseries_setup_security_mitigations();
 	pseries_lpar_read_hblkrm_characteristics();
 
 	/* By default, only probe PCI (can be overridden by rtas_pci) */
-- 
2.25.1


^ permalink raw reply related

* [PATCH] media: fsl-viu: Use proper check for presence of {out, in}_be32()
From: Fabio Estevam @ 2020-11-20  0:15 UTC (permalink / raw)
  To: mchehab; +Cc: hverkuil, paulus, Fabio Estevam, geert, linuxppc-dev, linux-media

From: Geert Uytterhoeven <geert@linux-m68k.org>

When compile-testing on m68k or microblaze:

    drivers/media/platform/fsl-viu.c:41:1: warning: "out_be32" redefined
    drivers/media/platform/fsl-viu.c:42:1: warning: "in_be32" redefined

Fix this by replacing the check for PowerPC by checks for the presence
of {out,in}_be32().

As PowerPC implements the be32 accessors using inline functions instead
of macros, identity definions are added for all accessors to make the
above checks work.

Fixes: 29d750686331a1a9 ("media: fsl-viu: allow building it with COMPILE_TEST")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
[fabio: adapt to mainline]
Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
 arch/powerpc/include/asm/io.h    | 14 ++++++++++++++
 drivers/media/platform/fsl-viu.c |  5 +++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index 58635960403c..fcb250db110d 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -194,6 +194,20 @@ static inline void out_be64(volatile u64 __iomem *addr, u64 val)
 #endif
 #endif /* __powerpc64__ */
 
+#define in_be16 in_be16
+#define in_be32 in_be32
+#define in_be64 in_be64
+#define in_le16 in_le16
+#define in_le32 in_le32
+#define in_le64 in_le64
+
+#define out_be16 out_be16
+#define out_be32 out_be32
+#define out_be64 out_be64
+#define out_le16 out_le16
+#define out_le32 out_le32
+#define out_le64 out_le64
+
 /*
  * Low level IO stream instructions are defined out of line for now
  */
diff --git a/drivers/media/platform/fsl-viu.c b/drivers/media/platform/fsl-viu.c
index 4f2a0f992905..bb6c291ed6dc 100644
--- a/drivers/media/platform/fsl-viu.c
+++ b/drivers/media/platform/fsl-viu.c
@@ -31,9 +31,10 @@
 #define DRV_NAME		"fsl_viu"
 #define VIU_VERSION		"0.5.1"
 
-/* Allow building this driver with COMPILE_TEST */
-#if !defined(CONFIG_PPC) && !defined(CONFIG_MICROBLAZE) && !defined(CONFIG_M68K)
+#ifndef out_be32
 #define out_be32(v, a)	iowrite32be(a, (void __iomem *)v)
+#endif
+#ifndef in_be32
 #define in_be32(a)	ioread32be((void __iomem *)a)
 #endif
 
-- 
2.17.1


^ permalink raw reply related

* [PATCH 0/2] powerpc/64s: fix for CPU hotplug vs mm_cpumask bug
From: Nicholas Piggin @ 2020-11-20  2:57 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Peter Zijlstra, Aneesh Kumar K.V, linux-kernel, Nicholas Piggin,
	Anton Vorontsov, Thomas Gleixner

This fixes a race in powerpc mm_cpumask code, I hope the core kernel
patch looks okay and we could take it through the powerpc tree with
an ack from someone (Peter or Thomas, perhaps?)

Thanks,
Nick

Nicholas Piggin (2):
  kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling
  powerpc/64s: Trim offlined CPUs from mm_cpumasks

 arch/powerpc/include/asm/book3s/64/mmu.h     | 12 ++++++++++++
 arch/powerpc/mm/book3s64/mmu_context.c       | 20 ++++++++++++++++++++
 arch/powerpc/platforms/powermac/smp.c        |  2 ++
 arch/powerpc/platforms/powernv/smp.c         |  3 +++
 arch/powerpc/platforms/pseries/hotplug-cpu.c |  3 +++
 kernel/cpu.c                                 |  6 +++++-
 6 files changed, 45 insertions(+), 1 deletion(-)

-- 
2.23.0


^ permalink raw reply

* [PATCH 1/2] kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling
From: Nicholas Piggin @ 2020-11-20  2:57 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Peter Zijlstra, Aneesh Kumar K.V, linux-kernel, Nicholas Piggin,
	Anton Vorontsov, Thomas Gleixner
In-Reply-To: <20201120025757.325930-1-npiggin@gmail.com>

powerpc keeps a counter in the mm which counts bits set in mm_cpumask as
well as other things. This means it can't use generic code to clear bits
out of the mask and doesn't adjust the arch specific counter.

Add an arch override allowing powerpc to use clear_tasks_mm_cpumask().

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 kernel/cpu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 6ff2578ecf17..2b8d7a5db383 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -815,6 +815,10 @@ void __init cpuhp_threads_init(void)
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
+#ifndef arch_clear_mm_cpumask_cpu
+#define arch_clear_mm_cpumask_cpu(cpu, mm) cpumask_clear_cpu(cpu, mm_cpumask(mm))
+#endif
+
 /**
  * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
  * @cpu: a CPU id
@@ -850,7 +854,7 @@ void clear_tasks_mm_cpumask(int cpu)
 		t = find_lock_task_mm(p);
 		if (!t)
 			continue;
-		cpumask_clear_cpu(cpu, mm_cpumask(t->mm));
+		arch_clear_mm_cpumask_cpu(cpu, t->mm);
 		task_unlock(t);
 	}
 	rcu_read_unlock();
-- 
2.23.0


^ permalink raw reply related

* [PATCH 2/2] powerpc/64s: Trim offlined CPUs from mm_cpumasks
From: Nicholas Piggin @ 2020-11-20  2:57 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Peter Zijlstra, Aneesh Kumar K.V, linux-kernel, Nicholas Piggin,
	Anton Vorontsov, Thomas Gleixner
In-Reply-To: <20201120025757.325930-1-npiggin@gmail.com>

When offlining a CPU, powerpc/64s does not flush TLBs, rather it just
leaves the CPU set in mm_cpumasks, so it continues to receive TLBIEs
to manage its TLBs.

However the exit_flush_lazy_tlbs() function expects that after
returning, all CPUs (except self) have flushed TLBs for that mm, in
which case TLBIEL can be used for this flush. This breaks for offline
CPUs because they don't get the IPI to flush their TLB. This can lead
to stale translations.

Fix this by clearing the CPU from mm_cpumasks, then flushing all TLBs
before going offline.

These offlined CPU bits stuck in the cpumask also prevents the cpumask
from being trimmed back to local mode, which means continual broadcast
IPIs or TLBIEs are needed for TLB flushing. This patch prevents that
situation too.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/book3s/64/mmu.h     | 12 ++++++++++++
 arch/powerpc/mm/book3s64/mmu_context.c       | 20 ++++++++++++++++++++
 arch/powerpc/platforms/powermac/smp.c        |  2 ++
 arch/powerpc/platforms/powernv/smp.c         |  3 +++
 arch/powerpc/platforms/pseries/hotplug-cpu.c |  3 +++
 5 files changed, 40 insertions(+)

diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index e0b52940e43c..750918451dd2 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -242,6 +242,18 @@ extern void radix_init_pseries(void);
 static inline void radix_init_pseries(void) { };
 #endif
 
+#ifdef CONFIG_HOTPLUG_CPU
+#define arch_clear_mm_cpumask_cpu(cpu, mm)				\
+	do {								\
+		if (cpumask_test_cpu(cpu, mm_cpumask(mm))) {		\
+			atomic_dec(&(mm)->context.active_cpus);		\
+			cpumask_clear_cpu(cpu, mm_cpumask(mm));		\
+		}							\
+	} while (0)
+
+void cleanup_cpu_mmu_context(void);
+#endif
+
 static inline int get_user_context(mm_context_t *ctx, unsigned long ea)
 {
 	int index = ea >> MAX_EA_BITS_PER_CONTEXT;
diff --git a/arch/powerpc/mm/book3s64/mmu_context.c b/arch/powerpc/mm/book3s64/mmu_context.c
index 1c54821de7bf..0c8557220ae2 100644
--- a/arch/powerpc/mm/book3s64/mmu_context.c
+++ b/arch/powerpc/mm/book3s64/mmu_context.c
@@ -17,6 +17,7 @@
 #include <linux/export.h>
 #include <linux/gfp.h>
 #include <linux/slab.h>
+#include <linux/cpu.h>
 
 #include <asm/mmu_context.h>
 #include <asm/pgalloc.h>
@@ -307,3 +308,22 @@ void radix__switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
 	isync();
 }
 #endif
+
+/**
+ * cleanup_cpu_mmu_context - Clean up MMU details for this CPU (newly offlined)
+ *
+ * This clears the CPU from mm_cpumask for all processes, and then flushes the
+ * local TLB to ensure TLB coherency in case the CPU is onlined again.
+ *
+ * KVM guest translations are not necessarily flushed here. If KVM started
+ * using mm_cpumask or the Linux APIs which do, this would have to be resolved.
+ */
+#ifdef CONFIG_HOTPLUG_CPU
+void cleanup_cpu_mmu_context(void)
+{
+	int cpu = smp_processor_id();
+
+	clear_tasks_mm_cpumask(cpu);
+	tlbiel_all();
+}
+#endif
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index 74ebe664b016..adae2a6712e1 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -911,6 +911,8 @@ static int smp_core99_cpu_disable(void)
 
 	mpic_cpu_set_priority(0xf);
 
+	cleanup_cpu_mmu_context();
+
 	return 0;
 }
 
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c
index 54c4ba45c7ce..cbb67813cd5d 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -143,6 +143,9 @@ static int pnv_smp_cpu_disable(void)
 		xive_smp_disable_cpu();
 	else
 		xics_migrate_irqs_away();
+
+	cleanup_cpu_mmu_context();
+
 	return 0;
 }
 
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index f2837e33bf5d..a02012f1b04a 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -90,6 +90,9 @@ static int pseries_cpu_disable(void)
 		xive_smp_disable_cpu();
 	else
 		xics_migrate_irqs_away();
+
+	cleanup_cpu_mmu_context();
+
 	return 0;
 }
 
-- 
2.23.0


^ permalink raw reply related

* Re: [PATCH 1/3] ibmvfc: byte swap login_buf.resp values in attribute show functions
From: Martin K. Petersen @ 2020-11-20  3:09 UTC (permalink / raw)
  To: Tyrel Datwyler
  Cc: martin.petersen, linux-scsi, linux-kernel, james.bottomley,
	brking, linuxppc-dev
In-Reply-To: <20201117185031.129939-1-tyreld@linux.ibm.com>


Tyrel,

> Both ibmvfc_show_host_(capabilities|npiv_version) functions retrieve
> values from vhost->login_buf.resp buffer. This is the MAD response
> buffer from the VIOS and as such any multi-byte non-string values are in
> big endian format.

Applied 1-3 to 5.11/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

^ permalink raw reply

* Re: [PATCH v3 0/6] ibmvfc: Protocol definition updates and new targetWWPN Support
From: Martin K. Petersen @ 2020-11-20  3:10 UTC (permalink / raw)
  To: Tyrel Datwyler
  Cc: martin.petersen, linux-scsi, linux-kernel, james.bottomley,
	brking, linuxppc-dev
In-Reply-To: <20201118011104.296999-1-tyreld@linux.ibm.com>


Tyrel,

> Several Management Datagrams (MADs) have been reversioned to add a
> targetWWPN field that is intended to better identify a target over in
> place of the scsi_id.  This patchset adds the new protocol definitions
> and implements support for using the new targetWWPN field and exposing
> the capability to the VIOS. This targetWWPN support is a prerequisuite
> for upcoming channelization/MQ support.

Applied to 5.11/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

^ permalink raw reply

* [PATCH] m68k: Fix WARNING splat in pmac_zilog driver
From: Finn Thain @ 2020-11-20  4:39 UTC (permalink / raw)
  To: Geert Uytterhoeven
  Cc: linuxppc-dev, linux-kernel, stable, linux-m68k, Paul Mackerras,
	linux-serial, Greg Kroah-Hartman, Jiri Slaby, Joshua Thompson

Don't add platform resources that won't be used. This avoids a
recently-added warning from the driver core, that can show up on a
multi-platform kernel when !MACH_IS_MAC.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at drivers/base/platform.c:224 platform_get_irq_optional+0x8e/0xce
0 is an invalid IRQ number
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 5.9.0-multi #1
Stack from 004b3f04:
        004b3f04 00462c2f 00462c2f 004b3f20 0002e128 004754db 004b6ad4 004b3f4c
        0002e19c 004754f7 000000e0 00285ba0 00000009 00000000 004b3f44 ffffffff
        004754db 004b3f64 004b3f74 00285ba0 004754f7 000000e0 00000009 004754db
        004fdf0c 005269e2 004fdf0c 00000000 004b3f88 00285cae 004b6964 00000000
        004fdf0c 004b3fac 0051cc68 004b6964 00000000 004b6964 00000200 00000000
        0051cc3e 0023c18a 004b3fc0 0051cd8a 004fdf0c 00000002 0052b43c 004b3fc8
Call Trace: [<0002e128>] __warn+0xa6/0xd6
 [<0002e19c>] warn_slowpath_fmt+0x44/0x76
 [<00285ba0>] platform_get_irq_optional+0x8e/0xce
 [<00285ba0>] platform_get_irq_optional+0x8e/0xce
 [<00285cae>] platform_get_irq+0x12/0x4c
 [<0051cc68>] pmz_init_port+0x2a/0xa6
 [<0051cc3e>] pmz_init_port+0x0/0xa6
 [<0023c18a>] strlen+0x0/0x22
 [<0051cd8a>] pmz_probe+0x34/0x88
 [<0051cde6>] pmz_console_init+0x8/0x28
 [<00511776>] console_init+0x1e/0x28
 [<0005a3bc>] printk+0x0/0x16
 [<0050a8a6>] start_kernel+0x368/0x4ce
 [<005094f8>] _sinittext+0x4f8/0xc48
random: get_random_bytes called from print_oops_end_marker+0x56/0x80 with crng_init=0
---[ end trace 392d8e82eed68d6c ]---

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Joshua Thompson <funaho@jurai.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: stable@vger.kernel.org # v5.8+
References: commit a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid")
Reported-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
The global platform_device structs provide the equivalent of a direct
search of the OpenFirmware tree, for platforms that don't have OF.
The purpose of that search is discussed in the comments in pmac_zilog.c:

         * First, we need to do a direct OF-based probe pass. We
         * do that because we want serial console up before the
         * macio stuffs calls us back

The actual platform bus matching takes place later, with a module_initcall,
following the usual pattern.
---
 arch/m68k/mac/config.c          | 17 +++++++++--------
 drivers/tty/serial/pmac_zilog.c |  9 ++++-----
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/arch/m68k/mac/config.c b/arch/m68k/mac/config.c
index 0ac53d87493c..2bea1799b8de 100644
--- a/arch/m68k/mac/config.c
+++ b/arch/m68k/mac/config.c
@@ -777,16 +777,12 @@ static struct resource scc_b_rsrcs[] = {
 struct platform_device scc_a_pdev = {
 	.name           = "scc",
 	.id             = 0,
-	.num_resources  = ARRAY_SIZE(scc_a_rsrcs),
-	.resource       = scc_a_rsrcs,
 };
 EXPORT_SYMBOL(scc_a_pdev);
 
 struct platform_device scc_b_pdev = {
 	.name           = "scc",
 	.id             = 1,
-	.num_resources  = ARRAY_SIZE(scc_b_rsrcs),
-	.resource       = scc_b_rsrcs,
 };
 EXPORT_SYMBOL(scc_b_pdev);
 
@@ -813,10 +809,15 @@ static void __init mac_identify(void)
 
 	/* Set up serial port resources for the console initcall. */
 
-	scc_a_rsrcs[0].start = (resource_size_t) mac_bi_data.sccbase + 2;
-	scc_a_rsrcs[0].end   = scc_a_rsrcs[0].start;
-	scc_b_rsrcs[0].start = (resource_size_t) mac_bi_data.sccbase;
-	scc_b_rsrcs[0].end   = scc_b_rsrcs[0].start;
+	scc_a_rsrcs[0].start     = (resource_size_t)mac_bi_data.sccbase + 2;
+	scc_a_rsrcs[0].end       = scc_a_rsrcs[0].start;
+	scc_a_pdev.num_resources = ARRAY_SIZE(scc_a_rsrcs);
+	scc_a_pdev.resource      = scc_a_rsrcs;
+
+	scc_b_rsrcs[0].start     = (resource_size_t)mac_bi_data.sccbase;
+	scc_b_rsrcs[0].end       = scc_b_rsrcs[0].start;
+	scc_b_pdev.num_resources = ARRAY_SIZE(scc_b_rsrcs);
+	scc_b_pdev.resource      = scc_b_rsrcs;
 
 	switch (macintosh_config->scc_type) {
 	case MAC_SCC_PSC:
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index 96e7aa479961..95abdb305d67 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -1697,18 +1697,17 @@ extern struct platform_device scc_a_pdev, scc_b_pdev;
 
 static int __init pmz_init_port(struct uart_pmac_port *uap)
 {
-	struct resource *r_ports;
-	int irq;
+	struct resource *r_ports, *r_irq;
 
 	r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
-	irq = platform_get_irq(uap->pdev, 0);
-	if (!r_ports || irq <= 0)
+	r_irq = platform_get_resource(uap->pdev, IORESOURCE_IRQ, 0);
+	if (!r_ports || !r_irq)
 		return -ENODEV;
 
 	uap->port.mapbase  = r_ports->start;
 	uap->port.membase  = (unsigned char __iomem *) r_ports->start;
 	uap->port.iotype   = UPIO_MEM;
-	uap->port.irq      = irq;
+	uap->port.irq      = r_irq->start;
 	uap->port.uartclk  = ZS_CLOCK;
 	uap->port.fifosize = 1;
 	uap->port.ops      = &pmz_pops;
-- 
2.26.2


^ permalink raw reply related

* [PATCH] macintosh/adb-iop: Always wait for reply message from IOP
From: Finn Thain @ 2020-11-20  4:39 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Michael Ellerman
  Cc: linuxppc-dev, linux-kernel, Joshua Thompson

A recent patch incorrectly altered the adb-iop state machine behaviour
and introduced a regression that can appear intermittently as a
malfunctioning ADB input device. This seems to be caused when reply
packets from different ADB commands become mixed up, especially during
the adb bus scan. Fix this by unconditionally entering the awaiting_reply
state after sending an explicit command, even when the ADB command won't
generate a reply from the ADB device.

Cc: Joshua Thompson <funaho@jurai.org>
Fixes: e2954e5f727f ("macintosh/adb-iop: Implement sending -> idle state transition")
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
 drivers/macintosh/adb-iop.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/macintosh/adb-iop.c b/drivers/macintosh/adb-iop.c
index 6b26b6a2c463..0ee327249150 100644
--- a/drivers/macintosh/adb-iop.c
+++ b/drivers/macintosh/adb-iop.c
@@ -84,10 +84,7 @@ static void adb_iop_complete(struct iop_msg *msg)
 
 	local_irq_save(flags);
 
-	if (current_req->reply_expected)
-		adb_iop_state = awaiting_reply;
-	else
-		adb_iop_done();
+	adb_iop_state = awaiting_reply;
 
 	local_irq_restore(flags);
 }
@@ -95,8 +92,9 @@ static void adb_iop_complete(struct iop_msg *msg)
 /*
  * Listen for ADB messages from the IOP.
  *
- * This will be called when unsolicited messages (usually replies to TALK
- * commands or autopoll packets) are received.
+ * This will be called when unsolicited IOP messages are received.
+ * These IOP messages can carry ADB autopoll responses and also occur
+ * after explicit ADB commands.
  */
 
 static void adb_iop_listen(struct iop_msg *msg)
@@ -123,8 +121,10 @@ static void adb_iop_listen(struct iop_msg *msg)
 		if (adb_iop_state == awaiting_reply) {
 			struct adb_request *req = current_req;
 
-			req->reply_len = amsg->count + 1;
-			memcpy(req->reply, &amsg->cmd, req->reply_len);
+			if (req->reply_expected) {
+				req->reply_len = amsg->count + 1;
+				memcpy(req->reply, &amsg->cmd, req->reply_len);
+			}
 
 			req_done = true;
 		}
-- 
2.26.2


^ permalink raw reply related

* [PATCH] macintosh/adb-iop: Send correct poll command
From: Finn Thain @ 2020-11-20  4:39 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Michael Ellerman
  Cc: linuxppc-dev, linux-kernel, Joshua Thompson

The behaviour of the IOP firmware is not well documented but we do know
that IOP message reply data can be used to issue new ADB commands.
Use the message reply to better control autopoll behaviour by sending
a Talk Register 0 command after every ADB response, not unlike the
algorithm in the via-macii driver. This poll command is addressed to
that device which last received a Talk command (explicit or otherwise).

Cc: Joshua Thompson <funaho@jurai.org>
Fixes: fa3b5a9929fc ("macintosh/adb-iop: Implement idle -> sending state transition")
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
 drivers/macintosh/adb-iop.c | 40 +++++++++++++++++++++++++++----------
 1 file changed, 30 insertions(+), 10 deletions(-)

diff --git a/drivers/macintosh/adb-iop.c b/drivers/macintosh/adb-iop.c
index f3d1a460fbce..6b26b6a2c463 100644
--- a/drivers/macintosh/adb-iop.c
+++ b/drivers/macintosh/adb-iop.c
@@ -25,6 +25,7 @@
 static struct adb_request *current_req;
 static struct adb_request *last_req;
 static unsigned int autopoll_devs;
+static u8 autopoll_addr;
 
 static enum adb_iop_state {
 	idle,
@@ -41,6 +42,11 @@ static int adb_iop_autopoll(int);
 static void adb_iop_poll(void);
 static int adb_iop_reset_bus(void);
 
+/* ADB command byte structure */
+#define ADDR_MASK       0xF0
+#define OP_MASK         0x0C
+#define TALK            0x0C
+
 struct adb_driver adb_iop_driver = {
 	.name         = "ISM IOP",
 	.probe        = adb_iop_probe,
@@ -96,17 +102,24 @@ static void adb_iop_complete(struct iop_msg *msg)
 static void adb_iop_listen(struct iop_msg *msg)
 {
 	struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
+	u8 addr = (amsg->cmd & ADDR_MASK) >> 4;
+	u8 op = amsg->cmd & OP_MASK;
 	unsigned long flags;
 	bool req_done = false;
 
 	local_irq_save(flags);
 
-	/* Handle a timeout. Timeout packets seem to occur even after
-	 * we've gotten a valid reply to a TALK, presumably because of
-	 * autopolling.
+	/* Responses to Talk commands may be unsolicited as they are
+	 * produced when the IOP polls devices. They are mostly timeouts.
 	 */
-
-	if (amsg->flags & ADB_IOP_EXPLICIT) {
+	if (op == TALK && ((1 << addr) & autopoll_devs))
+		autopoll_addr = addr;
+
+	switch (amsg->flags & (ADB_IOP_EXPLICIT |
+			       ADB_IOP_AUTOPOLL |
+			       ADB_IOP_TIMEOUT)) {
+	case ADB_IOP_EXPLICIT:
+	case ADB_IOP_EXPLICIT | ADB_IOP_TIMEOUT:
 		if (adb_iop_state == awaiting_reply) {
 			struct adb_request *req = current_req;
 
@@ -115,12 +128,16 @@ static void adb_iop_listen(struct iop_msg *msg)
 
 			req_done = true;
 		}
-	} else if (!(amsg->flags & ADB_IOP_TIMEOUT)) {
-		adb_input(&amsg->cmd, amsg->count + 1,
-			  amsg->flags & ADB_IOP_AUTOPOLL);
+		break;
+	case ADB_IOP_AUTOPOLL:
+		if (((1 << addr) & autopoll_devs) &&
+		    amsg->cmd == ADB_READREG(addr, 0))
+			adb_input(&amsg->cmd, amsg->count + 1, 1);
+		break;
 	}
-
-	msg->reply[0] = autopoll_devs ? ADB_IOP_AUTOPOLL : 0;
+	msg->reply[0] = autopoll_addr ? ADB_IOP_AUTOPOLL : 0;
+	msg->reply[1] = 0;
+	msg->reply[2] = autopoll_addr ? ADB_READREG(autopoll_addr, 0) : 0;
 	iop_complete_message(msg);
 
 	if (req_done)
@@ -233,6 +250,9 @@ static void adb_iop_set_ap_complete(struct iop_msg *msg)
 	struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
 
 	autopoll_devs = (amsg->data[1] << 8) | amsg->data[0];
+	if (autopoll_devs & (1 << autopoll_addr))
+		return;
+	autopoll_addr = autopoll_devs ? (ffs(autopoll_devs) - 1) : 0;
 }
 
 static int adb_iop_autopoll(int devs)
-- 
2.26.2


^ permalink raw reply related

* Re: [PATCH] media: fsl-viu: Use proper check for presence of {out, in}_be32()
From: Michael Ellerman @ 2020-11-20  6:25 UTC (permalink / raw)
  To: Fabio Estevam, mchehab
  Cc: linuxppc-dev, hverkuil, paulus, geert, Fabio Estevam, linux-media
In-Reply-To: <20201120001509.15155-1-festevam@gmail.com>

Fabio Estevam <festevam@gmail.com> writes:
> From: Geert Uytterhoeven <geert@linux-m68k.org>
>
> When compile-testing on m68k or microblaze:
>
>     drivers/media/platform/fsl-viu.c:41:1: warning: "out_be32" redefined
>     drivers/media/platform/fsl-viu.c:42:1: warning: "in_be32" redefined
>
> Fix this by replacing the check for PowerPC by checks for the presence
> of {out,in}_be32().
>
> As PowerPC implements the be32 accessors using inline functions instead
> of macros, identity definions are added for all accessors to make the
> above checks work.
>
> Fixes: 29d750686331a1a9 ("media: fsl-viu: allow building it with COMPILE_TEST")
> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
> [fabio: adapt to mainline]
> Signed-off-by: Fabio Estevam <festevam@gmail.com>
> ---
>  arch/powerpc/include/asm/io.h    | 14 ++++++++++++++
>  drivers/media/platform/fsl-viu.c |  5 +++--
>  2 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
> index 58635960403c..fcb250db110d 100644
> --- a/arch/powerpc/include/asm/io.h
> +++ b/arch/powerpc/include/asm/io.h
> @@ -194,6 +194,20 @@ static inline void out_be64(volatile u64 __iomem *addr, u64 val)
>  #endif
>  #endif /* __powerpc64__ */
>  
> +#define in_be16 in_be16
> +#define in_be32 in_be32
> +#define in_be64 in_be64
> +#define in_le16 in_le16
> +#define in_le32 in_le32
> +#define in_le64 in_le64
> +
> +#define out_be16 out_be16
> +#define out_be32 out_be32
> +#define out_be64 out_be64
> +#define out_le16 out_le16
> +#define out_le32 out_le32
> +#define out_le64 out_le64

I'd rather not have to carry this in arch code just for one driver.

> diff --git a/drivers/media/platform/fsl-viu.c b/drivers/media/platform/fsl-viu.c
> index 4f2a0f992905..bb6c291ed6dc 100644
> --- a/drivers/media/platform/fsl-viu.c
> +++ b/drivers/media/platform/fsl-viu.c
> @@ -31,9 +31,10 @@
>  #define DRV_NAME		"fsl_viu"
>  #define VIU_VERSION		"0.5.1"
>  
> -/* Allow building this driver with COMPILE_TEST */
> -#if !defined(CONFIG_PPC) && !defined(CONFIG_MICROBLAZE) && !defined(CONFIG_M68K)
> +#ifndef out_be32
>  #define out_be32(v, a)	iowrite32be(a, (void __iomem *)v)
> +#endif
> +#ifndef in_be32
>  #define in_be32(a)	ioread32be((void __iomem *)a)
>  #endif

Can't the driver just use ioread/write32be() on all platforms?

cheers

^ permalink raw reply

* Re: [PATCH] powerpc/64s/exception: KVM Fix for host DSI being taken in HPT guest MMU context
From: Michael Ellerman @ 2020-11-20  7:00 UTC (permalink / raw)
  To: Nicholas Piggin, linuxppc-dev; +Cc: kvm-ppc
In-Reply-To: <20201117135617.3521127-1-npiggin@gmail.com>

On Tue, 17 Nov 2020 23:56:17 +1000, Nicholas Piggin wrote:
> Commit 2284ffea8f0c ("powerpc/64s/exception: Only test KVM in SRR
> interrupts when PR KVM is supported") removed KVM guest tests from
> interrupts that do not set HV=1, when PR-KVM is not configured.
> 
> This is wrong for HV-KVM HPT guest MMIO emulation case which attempts
> to load the faulting instruction word with MSR[DR]=1 and MSR[HV]=1 with
> the guest MMU context loaded. This can cause host DSI, DSLB interrupts
> which must test for KVM guest. Restore this and add a comment.

Applied to powerpc/fixes.

[1/1] powerpc/64s/exception: KVM Fix for host DSI being taken in HPT guest MMU context
      https://git.kernel.org/powerpc/c/cd81acc600a9684ea4b4d25a47900d38a3890eab

cheers

^ permalink raw reply

* Re: [PATCH] m68k: Fix WARNING splat in pmac_zilog driver
From: Geert Uytterhoeven @ 2020-11-20  7:46 UTC (permalink / raw)
  To: Finn Thain
  Cc: linuxppc-dev, Linux Kernel Mailing List, stable, linux-m68k,
	Paul Mackerras, open list:SERIAL DRIVERS, Greg Kroah-Hartman,
	Jiri Slaby, Joshua Thompson
In-Reply-To: <b39102a332ae92c274fc8651acb4c52cfb9824a1.1605847196.git.fthain@telegraphics.com.au>

Hi Finn,

On Fri, Nov 20, 2020 at 5:51 AM Finn Thain <fthain@telegraphics.com.au> wrote:
> Don't add platform resources that won't be used. This avoids a
> recently-added warning from the driver core, that can show up on a
> multi-platform kernel when !MACH_IS_MAC.
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 0 at drivers/base/platform.c:224 platform_get_irq_optional+0x8e/0xce
> 0 is an invalid IRQ number
> Modules linked in:
> CPU: 0 PID: 0 Comm: swapper Not tainted 5.9.0-multi #1
> Stack from 004b3f04:
>         004b3f04 00462c2f 00462c2f 004b3f20 0002e128 004754db 004b6ad4 004b3f4c
>         0002e19c 004754f7 000000e0 00285ba0 00000009 00000000 004b3f44 ffffffff
>         004754db 004b3f64 004b3f74 00285ba0 004754f7 000000e0 00000009 004754db
>         004fdf0c 005269e2 004fdf0c 00000000 004b3f88 00285cae 004b6964 00000000
>         004fdf0c 004b3fac 0051cc68 004b6964 00000000 004b6964 00000200 00000000
>         0051cc3e 0023c18a 004b3fc0 0051cd8a 004fdf0c 00000002 0052b43c 004b3fc8
> Call Trace: [<0002e128>] __warn+0xa6/0xd6
>  [<0002e19c>] warn_slowpath_fmt+0x44/0x76
>  [<00285ba0>] platform_get_irq_optional+0x8e/0xce
>  [<00285ba0>] platform_get_irq_optional+0x8e/0xce
>  [<00285cae>] platform_get_irq+0x12/0x4c
>  [<0051cc68>] pmz_init_port+0x2a/0xa6
>  [<0051cc3e>] pmz_init_port+0x0/0xa6
>  [<0023c18a>] strlen+0x0/0x22
>  [<0051cd8a>] pmz_probe+0x34/0x88
>  [<0051cde6>] pmz_console_init+0x8/0x28
>  [<00511776>] console_init+0x1e/0x28
>  [<0005a3bc>] printk+0x0/0x16
>  [<0050a8a6>] start_kernel+0x368/0x4ce
>  [<005094f8>] _sinittext+0x4f8/0xc48
> random: get_random_bytes called from print_oops_end_marker+0x56/0x80 with crng_init=0
> ---[ end trace 392d8e82eed68d6c ]---
>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Joshua Thompson <funaho@jurai.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jiri Slaby <jirislaby@kernel.org>
> Cc: stable@vger.kernel.org # v5.8+
> References: commit a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid")
> Reported-by: Laurent Vivier <laurent@vivier.eu>
> Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
> ---
> The global platform_device structs provide the equivalent of a direct
> search of the OpenFirmware tree, for platforms that don't have OF.
> The purpose of that search is discussed in the comments in pmac_zilog.c:
>
>          * First, we need to do a direct OF-based probe pass. We
>          * do that because we want serial console up before the
>          * macio stuffs calls us back
>
> The actual platform bus matching takes place later, with a module_initcall,
> following the usual pattern.

I think it would be good for this explanation to be part of the
actual patch description above.

> --- a/arch/m68k/mac/config.c
> +++ b/arch/m68k/mac/config.c
> @@ -777,16 +777,12 @@ static struct resource scc_b_rsrcs[] = {
>  struct platform_device scc_a_pdev = {
>         .name           = "scc",
>         .id             = 0,
> -       .num_resources  = ARRAY_SIZE(scc_a_rsrcs),
> -       .resource       = scc_a_rsrcs,
>  };
>  EXPORT_SYMBOL(scc_a_pdev);
>
>  struct platform_device scc_b_pdev = {
>         .name           = "scc",
>         .id             = 1,
> -       .num_resources  = ARRAY_SIZE(scc_b_rsrcs),
> -       .resource       = scc_b_rsrcs,
>  };
>  EXPORT_SYMBOL(scc_b_pdev);
>
> @@ -813,10 +809,15 @@ static void __init mac_identify(void)
>
>         /* Set up serial port resources for the console initcall. */
>
> -       scc_a_rsrcs[0].start = (resource_size_t) mac_bi_data.sccbase + 2;
> -       scc_a_rsrcs[0].end   = scc_a_rsrcs[0].start;
> -       scc_b_rsrcs[0].start = (resource_size_t) mac_bi_data.sccbase;
> -       scc_b_rsrcs[0].end   = scc_b_rsrcs[0].start;
> +       scc_a_rsrcs[0].start     = (resource_size_t)mac_bi_data.sccbase + 2;
> +       scc_a_rsrcs[0].end       = scc_a_rsrcs[0].start;
> +       scc_a_pdev.num_resources = ARRAY_SIZE(scc_a_rsrcs);
> +       scc_a_pdev.resource      = scc_a_rsrcs;
> +
> +       scc_b_rsrcs[0].start     = (resource_size_t)mac_bi_data.sccbase;
> +       scc_b_rsrcs[0].end       = scc_b_rsrcs[0].start;
> +       scc_b_pdev.num_resources = ARRAY_SIZE(scc_b_rsrcs);
> +       scc_b_pdev.resource      = scc_b_rsrcs;
>
>         switch (macintosh_config->scc_type) {
>         case MAC_SCC_PSC:
> diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
> index 96e7aa479961..95abdb305d67 100644
> --- a/drivers/tty/serial/pmac_zilog.c
> +++ b/drivers/tty/serial/pmac_zilog.c
> @@ -1697,18 +1697,17 @@ extern struct platform_device scc_a_pdev, scc_b_pdev;
>
>  static int __init pmz_init_port(struct uart_pmac_port *uap)
>  {
> -       struct resource *r_ports;
> -       int irq;
> +       struct resource *r_ports, *r_irq;
>
>         r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
> -       irq = platform_get_irq(uap->pdev, 0);
> -       if (!r_ports || irq <= 0)
> +       r_irq = platform_get_resource(uap->pdev, IORESOURCE_IRQ, 0);
> +       if (!r_ports || !r_irq)
>                 return -ENODEV;
>
>         uap->port.mapbase  = r_ports->start;
>         uap->port.membase  = (unsigned char __iomem *) r_ports->start;
>         uap->port.iotype   = UPIO_MEM;
> -       uap->port.irq      = irq;
> +       uap->port.irq      = r_irq->start;
>         uap->port.uartclk  = ZS_CLOCK;
>         uap->port.fifosize = 1;
>         uap->port.ops      = &pmz_pops;

Given the resources are no longer present on !MAC, just doing

            r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0);
    +       if (!r_ports)
    +               return -ENODEV;
            irq = platform_get_irq(uap->pdev, 0);

should be sufficient?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply


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