lkml.org 
[lkml]   [2009]   [Apr]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] x86 microcode: revert some work_on_cpu
Revert part of af5c820a3169e81af869c113e18ec7588836cd50
x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c

That change is causing only one Intel CPU's microcode to be updated e.g.
microcode: CPU3 updated from revision 0x9 to 0x17, date = 2005-04-22
where before it announced that also for CPU0 and CPU1 and CPU2.

We cannot use work_on_cpu() in the CONFIG_MICROCODE_OLD_INTERFACE code,
because Intel's request_microcode_user() involves a copy_from_user() from
/sbin/microcode_ctl, which therefore needs to be on that CPU at the time.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
---
This may be not the only problem with that commit: I've seen lockdep
warnings from s2ram when suspending; but I think there have been other
work_on_cpu() lockdep issues, and you may already be on to them?

arch/x86/kernel/microcode_core.c | 33 +++++++++--------------------
1 file changed, 11 insertions(+), 22 deletions(-)

--- 2.6.30-rc1/arch/x86/kernel/microcode_core.c 2009-04-08 18:19:28.000000000 +0100
+++ linux/arch/x86/kernel/microcode_core.c 2009-04-12 23:06:57.000000000 +0100
@@ -108,40 +108,29 @@ struct ucode_cpu_info ucode_cpu_info[NR
EXPORT_SYMBOL_GPL(ucode_cpu_info);

#ifdef CONFIG_MICROCODE_OLD_INTERFACE
-struct update_for_cpu {
- const void __user *buf;
- size_t size;
-};
-
-static long update_for_cpu(void *_ufc)
-{
- struct update_for_cpu *ufc = _ufc;
- int error;
-
- error = microcode_ops->request_microcode_user(smp_processor_id(),
- ufc->buf, ufc->size);
- if (error < 0)
- return error;
- if (!error)
- microcode_ops->apply_microcode(smp_processor_id());
- return error;
-}
-
static int do_microcode_update(const void __user *buf, size_t size)
{
+ cpumask_t old;
int error = 0;
int cpu;
- struct update_for_cpu ufc = { .buf = buf, .size = size };
+
+ old = current->cpus_allowed;

for_each_online_cpu(cpu) {
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

if (!uci->valid)
continue;
- error = work_on_cpu(cpu, update_for_cpu, &ufc);
+
+ set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ error = microcode_ops->request_microcode_user(cpu, buf, size);
if (error < 0)
- break;
+ goto out;
+ if (!error)
+ microcode_ops->apply_microcode(cpu);
}
+out:
+ set_cpus_allowed_ptr(current, &old);
return error;
}


\
 
 \ /
  Last update: 2009-04-14 20:33    [W:0.030 / U:30.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site