target/arm: Use correct variable for setting 'max' cpu's ID_AA64DFR0

[PATCH] target/arm: Use correct variable for setting 'max' cpu's ID_AA64DFR0

Posted by Peter Maydell 4 years ago

In aarch64_max_initfn() we update both 32-bit and 64-bit ID
registers.  The intended pattern is that for 64-bit ID registers we
use FIELD_DP64 and the uint64_t 't' register, while 32-bit ID
registers use FIELD_DP32 and the uint32_t 'u' register.  For
ID_AA64DFR0 we accidentally used 'u', meaning that the top 32 bits of
this 64-bit ID register would end up always zero.  Luckily at the
moment that's what they should be anyway, so this bug has no visible
effects.

Use the right-sized variable.

Fixes: 3bec78447a958d481991
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/cpu64.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 95d0c8c101a..4c7105ea1a1 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -708,9 +708,9 @@ static void aarch64_max_initfn(Object *obj)
         u = FIELD_DP32(u, ID_MMFR4, CNP, 1); /* TTCNP */
         cpu->isar.id_mmfr4 = u;
 
-        u = cpu->isar.id_aa64dfr0;
-        u = FIELD_DP64(u, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
-        cpu->isar.id_aa64dfr0 = u;
+        t = cpu->isar.id_aa64dfr0;
+        t = FIELD_DP64(t, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
+        cpu->isar.id_aa64dfr0 = t;
 
         u = cpu->isar.id_dfr0;
         u = FIELD_DP32(u, ID_DFR0, PERFMON, 5); /* v8.4-PMU */
-- 
2.20.1

Re: [PATCH] target/arm: Use correct variable for setting 'max' cpu's ID_AA64DFR0

Posted by Laurent Desnogues 4 years ago

On Thu, Apr 23, 2020 at 1:09 PM Peter Maydell <peter.maydell@linaro.org> wrote:
>
> In aarch64_max_initfn() we update both 32-bit and 64-bit ID
> registers.  The intended pattern is that for 64-bit ID registers we
> use FIELD_DP64 and the uint64_t 't' register, while 32-bit ID
> registers use FIELD_DP32 and the uint32_t 'u' register.  For
> ID_AA64DFR0 we accidentally used 'u', meaning that the top 32 bits of
> this 64-bit ID register would end up always zero.  Luckily at the
> moment that's what they should be anyway, so this bug has no visible
> effects.
>
> Use the right-sized variable.
>
> Fixes: 3bec78447a958d481991
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>

Thanks,

Laurent

> ---
>  target/arm/cpu64.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
> index 95d0c8c101a..4c7105ea1a1 100644
> --- a/target/arm/cpu64.c
> +++ b/target/arm/cpu64.c
> @@ -708,9 +708,9 @@ static void aarch64_max_initfn(Object *obj)
>          u = FIELD_DP32(u, ID_MMFR4, CNP, 1); /* TTCNP */
>          cpu->isar.id_mmfr4 = u;
>
> -        u = cpu->isar.id_aa64dfr0;
> -        u = FIELD_DP64(u, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
> -        cpu->isar.id_aa64dfr0 = u;
> +        t = cpu->isar.id_aa64dfr0;
> +        t = FIELD_DP64(t, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
> +        cpu->isar.id_aa64dfr0 = t;
>
>          u = cpu->isar.id_dfr0;
>          u = FIELD_DP32(u, ID_DFR0, PERFMON, 5); /* v8.4-PMU */
> --
> 2.20.1
>
>

Re: [PATCH] target/arm: Use correct variable for setting 'max' cpu's ID_AA64DFR0

Posted by Philippe Mathieu-Daudé 4 years ago

On Thu, Apr 23, 2020 at 1:09 PM Peter Maydell <peter.maydell@linaro.org> wrote:
>
> In aarch64_max_initfn() we update both 32-bit and 64-bit ID
> registers.  The intended pattern is that for 64-bit ID registers we
> use FIELD_DP64 and the uint64_t 't' register, while 32-bit ID
> registers use FIELD_DP32 and the uint32_t 'u' register.

Variable names could be improved...

>  For
> ID_AA64DFR0 we accidentally used 'u', meaning that the top 32 bits of
> this 64-bit ID register would end up always zero.

-Wconversion CPPFLAG helps but there are so many places to fix that we
are not using it:

target/arm/cpu64.c:711:13: error: conversion from ‘uint64_t’ {aka
‘long unsigned int’} to ‘uint32_t’ {aka ‘unsigned int’} may change
value [-Werror=conversion]
  711 |         u = cpu->isar.id_aa64dfr0;
      |             ^~~
target/arm/cpu64.c:712:13: note: in expansion of macro ‘FIELD_DP64’
  712 |         u = FIELD_DP64(u, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
      |             ^~~~~~~~~~

>  Luckily at the
> moment that's what they should be anyway, so this bug has no visible
> effects.
>
> Use the right-sized variable.
>
> Fixes: 3bec78447a958d481991
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---
>  target/arm/cpu64.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
> index 95d0c8c101a..4c7105ea1a1 100644
> --- a/target/arm/cpu64.c
> +++ b/target/arm/cpu64.c
> @@ -708,9 +708,9 @@ static void aarch64_max_initfn(Object *obj)
>          u = FIELD_DP32(u, ID_MMFR4, CNP, 1); /* TTCNP */
>          cpu->isar.id_mmfr4 = u;
>
> -        u = cpu->isar.id_aa64dfr0;
> -        u = FIELD_DP64(u, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
> -        cpu->isar.id_aa64dfr0 = u;
> +        t = cpu->isar.id_aa64dfr0;
> +        t = FIELD_DP64(t, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
> +        cpu->isar.id_aa64dfr0 = t;
>
>          u = cpu->isar.id_dfr0;
>          u = FIELD_DP32(u, ID_DFR0, PERFMON, 5); /* v8.4-PMU */
> --
> 2.20.1
>
>

Re: [PATCH] target/arm: Use correct variable for setting 'max' cpu's ID_AA64DFR0

Posted by no-reply@patchew.org 4 years ago

Patchew URL: https://patchew.org/QEMU/20200423110915.10527-1-peter.maydell@linaro.org/



Hi,

This series seems to have some coding style problems. See output below for
more information:

Subject: [PATCH] target/arm: Use correct variable for setting 'max' cpu's ID_AA64DFR0
Message-id: 20200423110915.10527-1-peter.maydell@linaro.org
Type: series

=== TEST SCRIPT BEGIN ===
#!/bin/bash
git rev-parse base > /dev/null || exit 0
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
error: RPC failed; result=22, HTTP code = 504
fatal: The remote end hung up unexpectedly
error: Could not fetch 3c8cf5a9c21ff8782164d1def7f44bd888713384
Traceback (most recent call last):
  File "patchew-tester/src/patchew-cli", line 521, in test_one
    git_clone_repo(clone, r["repo"], r["head"], logf, True)
  File "patchew-tester/src/patchew-cli", line 48, in git_clone_repo
    stdout=logf, stderr=logf)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/subprocess.py", line 291, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['git', 'remote', 'add', '-f', '--mirror=fetch', '3c8cf5a9c21ff8782164d1def7f44bd888713384', 'https://github.com/patchew-project/qemu']' returned non-zero exit status 1.



The full log is available at
http://patchew.org/logs/20200423110915.10527-1-peter.maydell@linaro.org/testing.checkpatch/?type=message.
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