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| author |   Nathan Lynch <nathanl@linux.ibm.com> | 2022-09-07 17:01:11 -0500 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-09-14 22:43:13 +1000 |
| commit | f88aabad33ea22be2ce1c60d8901942e4e2a9edb (patch) | |
| tree | ba41bd056270ef519fa0db5ce0cd55fcd7d9b1c0 /arch/powerpc/include/asm | |
| parent | powerpc/powernv: add missing of_node_put() in opal_export_attrs() (diff) | |
| download | linux-dev-f88aabad33ea22be2ce1c60d8901942e4e2a9edb.tar.xz linux-dev-f88aabad33ea22be2ce1c60d8901942e4e2a9edb.zip | |
Revert "powerpc/rtas: Implement reentrant rtas call"
At the time this was submitted by Leonardo, I confirmed -- or thought
I had confirmed -- with PowerVM partition firmware development that
the following RTAS functions:
- ibm,get-xive
- ibm,int-off
- ibm,int-on
- ibm,set-xive
were safe to call on multiple CPUs simultaneously, not only with
respect to themselves as indicated by PAPR, but with arbitrary other
RTAS calls:
https://lore.kernel.org/linuxppc-dev/875zcy2v8o.fsf@linux.ibm.com/
Recent discussion with firmware development makes it clear that this
is not true, and that the code in commit b664db8e3f97 ("powerpc/rtas:
Implement reentrant rtas call") is unsafe, likely explaining several
strange bugs we've seen in internal testing involving DLPAR and
LPM. These scenarios use ibm,configure-connector, whose internal state
can be corrupted by the concurrent use of the "reentrant" functions,
leading to symptoms like endless busy statuses from RTAS.
Fixes: b664db8e3f97 ("powerpc/rtas: Implement reentrant rtas call")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220907220111.223267-1-nathanl@linux.ibm.com
Diffstat (limited to 'arch/powerpc/include/asm')
| -rw-r--r-- | arch/powerpc/include/asm/paca.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/rtas.h | 1 |
2 files changed, 0 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index 4d7aaab82702..3537b0500f4d 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -263,7 +263,6 @@ struct paca_struct { u64 l1d_flush_size; #endif #ifdef CONFIG_PPC_PSERIES - struct rtas_args *rtas_args_reentrant; u8 *mce_data_buf; /* buffer to hold per cpu rtas errlog */ #endif /* CONFIG_PPC_PSERIES */ diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h index 00531af17ce0..56319aea646e 100644 --- a/arch/powerpc/include/asm/rtas.h +++ b/arch/powerpc/include/asm/rtas.h @@ -240,7 +240,6 @@ extern struct rtas_t rtas; extern int rtas_token(const char *service); extern int rtas_service_present(const char *service); extern int rtas_call(int token, int, int, int *, ...); -int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...); void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...); extern void __noreturn rtas_restart(char *cmd); |