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authorHaren Myneni <haren@us.ibm.com>2006-07-27 14:29:00 -0700
committerPaul Mackerras <paulus@samba.org>2006-08-08 16:00:11 +1000
commit81b73dd92b97423b8f5324a59044da478c04f4c4 (patch)
tree032f8415eb980d7f231e8e2490fba3c5356aadf9
parentdcc42f483d6808ba4d04af9da35e7e47b711f6c2 (diff)
downloadlinux-bcache-81b73dd92b97423b8f5324a59044da478c04f4c4.tar.zst
[POWERPC] Fix might-sleep warning on removing cpus
Noticing the following might_sleep warning (dump_stack()) during kdump testing when CONFIG_DEBUG_SPINLOCK_SLEEP is enabled. All secondary CPUs will be calling rtas_set_indicator with interrupts disabled to remove them from global interrupt queue. BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:463 in_atomic():1, irqs_disabled():1 Call Trace: [C00000000FFFB970] [C000000000010234] .show_stack+0x68/0x1b0 (unreliable) [C00000000FFFBA10] [C000000000059354] .__might_sleep+0xd8/0xf4 [C00000000FFFBA90] [C00000000001D1BC] .rtas_busy_delay+0x20/0x5c [C00000000FFFBB20] [C00000000001D8A8] .rtas_set_indicator+0x6c/0xcc [C00000000FFFBBC0] [C000000000048BF4] .xics_teardown_cpu+0x118/0x134 [C00000000FFFBC40] [C00000000004539C] .pseries_kexec_cpu_down_xics+0x74/0x8c [C00000000FFFBCC0] [C00000000002DF08] .crash_ipi_callback+0x15c/0x188 [C00000000FFFBD50] [C0000000000296EC] .smp_message_recv+0x84/0xdc [C00000000FFFBDC0] [C000000000048E08] .xics_ipi_dispatch+0xf0/0x130 [C00000000FFFBE50] [C00000000009EF10] .handle_IRQ_event+0x7c/0xf8 [C00000000FFFBF00] [C0000000000A0A14] .handle_percpu_irq+0x90/0x10c [C00000000FFFBF90] [C00000000002659C] .call_handle_irq+0x1c/0x2c [C00000000058B9C0] [C00000000000CA10] .do_IRQ+0xf4/0x1a4 [C00000000058BA50] [C0000000000044EC] hardware_interrupt_entry+0xc/0x10 --- Exception: 501 at .plpar_hcall_norets+0x14/0x1c LR = .pseries_dedicated_idle_sleep+0x190/0x1d4 [C00000000058BD40] [C00000000058BDE0] 0xc00000000058bde0 (unreliable) [C00000000058BDF0] [C00000000001270C] .cpu_idle+0x10c/0x1e0 [C00000000058BE70] [C000000000009274] .rest_init+0x44/0x5c To fix this issue, rtas_set_indicator_fast() is added so that will not wait for RTAS 'busy' delay and this new function is used for kdump (in xics_teardown_cpu()) and for CPU hotplug ( xics_migrate_irqs_away() and xics_setup_cpu()). Note that the platform architecture spec says that set-indicator on the indicator we're using here is not permitted to return the busy or extended busy status codes. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
-rw-r--r--arch/powerpc/kernel/rtas.c21
-rw-r--r--arch/powerpc/platforms/pseries/xics.c6
-rw-r--r--include/asm-powerpc/rtas.h1
3 files changed, 25 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 4a4cb5598402..77f1e06d208d 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -569,6 +569,27 @@ int rtas_set_indicator(int indicator, int index, int new_value)
}
EXPORT_SYMBOL(rtas_set_indicator);
+/*
+ * Ignoring RTAS extended delay
+ */
+int rtas_set_indicator_fast(int indicator, int index, int new_value)
+{
+ int rc;
+ int token = rtas_token("set-indicator");
+
+ if (token == RTAS_UNKNOWN_SERVICE)
+ return -ENOENT;
+
+ rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
+
+ WARN_ON(rc == -2 || (rc >= 9900 && rc <= 9905));
+
+ if (rc < 0)
+ return rtas_error_rc(rc);
+
+ return rc;
+}
+
void rtas_restart(char *cmd)
{
if (rtas_flash_term_hook)
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
index 2d0da6f9e244..e98863025721 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -467,7 +467,7 @@ void xics_setup_cpu(void)
*
* XXX: undo of teardown on kexec needs this too, as may hotplug
*/
- rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
+ rtas_set_indicator_fast(GLOBAL_INTERRUPT_QUEUE,
(1UL << interrupt_server_size) - 1 - default_distrib_server, 1);
}
@@ -796,7 +796,7 @@ void xics_teardown_cpu(int secondary)
* so leave the master cpu in the group.
*/
if (secondary)
- rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
+ rtas_set_indicator_fast(GLOBAL_INTERRUPT_QUEUE,
(1UL << interrupt_server_size) - 1 -
default_distrib_server, 0);
}
@@ -813,7 +813,7 @@ void xics_migrate_irqs_away(void)
xics_set_cpu_priority(cpu, 0);
/* remove ourselves from the global interrupt queue */
- status = rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
+ status = rtas_set_indicator_fast(GLOBAL_INTERRUPT_QUEUE,
(1UL << interrupt_server_size) - 1 - default_distrib_server, 0);
WARN_ON(status < 0);
diff --git a/include/asm-powerpc/rtas.h b/include/asm-powerpc/rtas.h
index a33c6acffa61..82a27e9a041f 100644
--- a/include/asm-powerpc/rtas.h
+++ b/include/asm-powerpc/rtas.h
@@ -170,6 +170,7 @@ extern int rtas_get_sensor(int sensor, int index, int *state);
extern int rtas_get_power_level(int powerdomain, int *level);
extern int rtas_set_power_level(int powerdomain, int level, int *setlevel);
extern int rtas_set_indicator(int indicator, int index, int new_value);
+extern int rtas_set_indicator_fast(int indicator, int index, int new_value);
extern void rtas_progress(char *s, unsigned short hex);
extern void rtas_initialize(void);