cpufreq: fix sleeping in atomic context when realloc freq_table for all_time_in_state

Commit 40cf2f8 (cpufreq: Persist cpufreq time in state data across hotplug)
causes the following call trace to be spit on boot:

BUG: sleeping function called from invalid context at mm/slub.c:936
in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: swapper/0
CPU: 6 PID: 1 Comm: swapper/0 Not tainted 3.10.9-20140624.172707-eng-gd6c0f69-dirty raspberrypi#50
Backtrace:
[<c0012270>] (dump_backtrace+0x0/0x10c) from [<c001256c>] (show_stack+0x18/0x1c)
 r6:ffff1788 r5:c0c020c0 r4:e609c000 r3:00000000
[<c0012554>] (show_stack+0x0/0x1c) from [<c07a2970>] (dump_stack+0x20/0x28)
[<c07a2950>] (dump_stack+0x0/0x28) from [<c0057678>] (__might_sleep+0x104/0x120)
[<c0057574>] (__might_sleep+0x0/0x120) from [<c00ff000>] (__kmalloc_track_caller+0x144/0x274)
 r6:00000000 r5:e609c000 r4:e6802140
[<c00feebc>] (__kmalloc_track_caller+0x0/0x274) from [<c00da098>] (krealloc+0x58/0xb0)
[<c00da040>] (krealloc+0x0/0xb0) from [<c050266c>] (cpufreq_allstats_create+0x120/0x204)
 r8:e4c4ff00 r7:c0d266b8 r6:0013d620 r5:e4c4e600 r4:00000001
r3:e535d6d0
[<c050254c>] (cpufreq_allstats_create+0x0/0x204) from [<c0502e38>] (cpufreq_stat_notifier_policy+0xb8/0xd0)
[<c0502d80>] (cpufreq_stat_notifier_policy+0x0/0xd0) from [<c00517cc>] (notifier_call_chain+0x4c/0x8c)
 r5:00000000 r4:fffffffe
[<c0051780>] (notifier_call_chain+0x0/0x8c) from [<c00519fc>] (__blocking_notifier_call_chain+0x50/0x68)
 r8:c0cd4d00 r7:00000002 r6:e609dd7c r5:ffffffff r4:c0d25a4c
r3:ffffffff
[<c00519ac>] (__blocking_notifier_call_chain+0x0/0x68) from [<c0051a34>] (blocking_notifier_call_chain+0x20/0x28)
 r7:c0e24f30 r6:00000000 r5:e53e1e00 r4:e609dd7c
[<c0051a14>] (blocking_notifier_call_chain+0x0/0x28) from [<c0500fec>] (__cpufreq_set_policy+0xc0/0x1d0)
[<c0500f2c>] (__cpufreq_set_policy+0x0/0x1d0) from [<c0501308>] (cpufreq_add_dev_interface+0x20c/0x270)
 r7:00000008 r6:00000000 r5:e53e1e00 r4:e53e1e58
[<c05010fc>] (cpufreq_add_dev_interface+0x0/0x270) from [<c05016a8>] (cpufreq_add_dev+0x33c/0x420)
[<c050136c>] (cpufreq_add_dev+0x0/0x420) from [<c03604a4>] (subsys_interface_register+0x80/0xbc)
[<c0360424>] (subsys_interface_register+0x0/0xbc) from [<c050035c>] (cpufreq_register_driver+0x8c/0x194)

Change-Id: If77a656d0ea60a8fc4083283d104509fa6c07f8f
Signed-off-by: Minsung Kim <[email protected]>

Author: Minsung Kim

drivers/cpufreq/cpufreq_stats.c

@@ -424,7 +424,7 @@ static void add_all_freq_table(unsigned int freq)
 	unsigned int size;
 	size = sizeof(unsigned int) * (all_freq_table->table_size + 1);
 	all_freq_table->freq_table = krealloc(all_freq_table->freq_table,
-			size, GFP_KERNEL);
+			size, GFP_ATOMIC);
 	if (IS_ERR(all_freq_table->freq_table)) {
 		pr_warn("Could not reallocate memory for freq_table\n");
 		all_freq_table->freq_table = NULL;