linux.git/arch/powerpc/kernel/rtas.c, branch v2.6.18

[POWERPC] Fix might-sleep warning on removing cpus

2006-08-08T06:00:11+00:00

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 
Signed-off-by: Paul Mackerras

[POWERPC] Add udbg support for RTAS console

2006-06-28T01:59:48+00:00

Add udbg hooks for the RTAS console, based on the RTAS put-term-char
and get-term-char calls. Along with my previous patches, this should
enable debugging as soon as early_init_dt_scan_rtas() is called.

Signed-off-by: Michael Ellerman 
Signed-off-by: Paul Mackerras

[POWERPC] Setup RTAS values earlier, to enable rtas_call() earlier

2006-06-28T01:59:48+00:00

Althought RTAS is instantiated when we enter the kernel, we can't actually
call into it until we know its entry point address. Currently we grab that
in rtas_initialize(), however that's quite late in the boot sequence.

To enable rtas_call() earlier, we can grab the RTAS entry etc. values while
we're scanning the flattened device tree. There's existing code to retrieve
the values from /chosen, however we don't store them there anymore, so remove
that code.

Signed-off-by: Michael Ellerman 
Signed-off-by: Paul Mackerras

[POWERPC] Move RTAS exports next to their declarations

2006-06-28T01:59:47+00:00

Move RTAS exports next to their declarations.

Signed-off-by: Michael Ellerman 
Signed-off-by: Paul Mackerras

[POWERPC] Make rtas_call() safe if RTAS hasn't been initialised

2006-06-28T01:59:47+00:00

Currently it's unsafe to call rtas_call() prior to rtas_initialize(). This
is because the rtas.entry value hasn't been setup and so we don't know
where to enter, but we just try anyway.

We can't do anything intelligent without rtas.entry, so if it's not set, just
return. Code that calls rtas_call() early needs to be aware that the call
might fail.

Signed-off-by: Michael Ellerman 
Signed-off-by: Paul Mackerras

[POWERPC] RTAS delay, fix module build breaks

2006-06-21T05:01:27+00:00

Export both news RTAS delay functions, and change the scanlog module to
use the new delay functions.

Signed-off-by: John Rose 
Signed-off-by: Paul Mackerras

[POWERPC] check firmware state before suspending

2006-06-15T09:31:27+00:00

Currently the kernel blindly halts all the processors and calls the
ibm,suspend-me rtas call.  If the firmware is not in the correct
state, we then re-start all the processors and return.  It is much
smarter to first check the firmware state, and only if it is waiting,
call the ibm,suspend-me call.

Signed-off-by: Paul Mackerras

[PATCH] powerpc: reorg RTAS delay code

2006-06-09T11:21:06+00:00

This patch attempts to handle RTAS "busy" return codes in a more simple
and consistent manner.  Typical callers of RTAS shouldn't have to
manage wait times and delay calls.

This patch also changes the kernel to use msleep() rather than udelay()
when a runtime delay is necessary.  This will avoid CPU soft lockups
for extended delay conditions.

Signed-off-by: John Rose 
Signed-off-by: Paul Mackerras

[PATCH] powerpc/pseries: Change H_StudlyCaps to H_SHOUTING_CAPS

2006-04-01T11:36:57+00:00

Also cleans up some nearby whitespace problems.

Signed-off-by: Segher Boessenkool 
Signed-off-by: Paul Mackerras

[PATCH] for_each_possible_cpu: powerpc

2006-03-29T02:44:15+00:00

for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.

Signed-off-by: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Paul Mackerras