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| author | Nathan Lynch <nathanl@linux.ibm.com> | 2023-02-10 21:42:08 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-02-13 14:35:03 +0300 |
| commit | 08273c9f619cb32fb041935724f576e607101f3b (patch) | |
| tree | 49017ed6ba9e8a9dec74342d86a4fe425d6a3303 /arch/powerpc/xmon | |
| parent | 716bfc97bd5fb7b442cdd06081f49df097f2e27b (diff) | |
| download | linux-08273c9f619cb32fb041935724f576e607101f3b.tar.xz | |
powerpc/rtas: arch-wide function token lookup conversions
With the tokens for all implemented RTAS functions now available via
rtas_function_token(), which is optimal and safe for arbitrary
contexts, there is no need to use rtas_token() or cache its result.
Most conversions are trivial, but a few are worth describing in more
detail:
* Error injection token comparisons for lockdown purposes are
consolidated into a simple predicate: token_is_restricted_errinjct().
* A couple of special cases in block_rtas_call() do not use
rtas_token() but perform string comparisons against names in the
function table. These are converted to compare against token values
instead, which is logically equivalent but less expensive.
* The lookup for the ibm,os-term token can be deferred until needed,
instead of caching it at boot to avoid device tree traversal during
panic.
* Since rtas_function_token() accesses a read-only data structure
without taking any locks, xmon's lookup of set-indicator can be
performed as needed instead of cached at startup.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-20-26929c8cce78@linux.ibm.com
Diffstat (limited to 'arch/powerpc/xmon')
| -rw-r--r-- | arch/powerpc/xmon/xmon.c | 16 |
1 files changed, 3 insertions, 13 deletions
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 0da66bc4823d..73c620c2a3a1 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -76,9 +76,6 @@ static cpumask_t xmon_batch_cpus = CPU_MASK_NONE; #define xmon_owner 0 #endif /* CONFIG_SMP */ -#ifdef CONFIG_PPC_PSERIES -static int set_indicator_token = RTAS_UNKNOWN_SERVICE; -#endif static unsigned long in_xmon __read_mostly = 0; static int xmon_on = IS_ENABLED(CONFIG_XMON_DEFAULT); static bool xmon_is_ro = IS_ENABLED(CONFIG_XMON_DEFAULT_RO_MODE); @@ -398,6 +395,7 @@ static inline void disable_surveillance(void) #ifdef CONFIG_PPC_PSERIES /* Since this can't be a module, args should end up below 4GB. */ static struct rtas_args args; + const s32 token = rtas_function_token(RTAS_FN_SET_INDICATOR); /* * At this point we have got all the cpus we can into @@ -406,10 +404,10 @@ static inline void disable_surveillance(void) * If we did try to take rtas.lock there would be a * real possibility of deadlock. */ - if (set_indicator_token == RTAS_UNKNOWN_SERVICE) + if (token == RTAS_UNKNOWN_SERVICE) return; - rtas_call_unlocked(&args, set_indicator_token, 3, 1, NULL, + rtas_call_unlocked(&args, token, 3, 1, NULL, SURVEILLANCE_TOKEN, 0, 0); #endif /* CONFIG_PPC_PSERIES */ @@ -3976,14 +3974,6 @@ static void xmon_init(int enable) __debugger_iabr_match = xmon_iabr_match; __debugger_break_match = xmon_break_match; __debugger_fault_handler = xmon_fault_handler; - -#ifdef CONFIG_PPC_PSERIES - /* - * Get the token here to avoid trying to get a lock - * during the crash, causing a deadlock. - */ - set_indicator_token = rtas_token("set-indicator"); -#endif } else { __debugger = NULL; __debugger_ipi = NULL; |