[PATCH] cpufreq: set value of CPUFREQ_BOOST_FREQ to 0xABABABAB

[PATCH] cpufreq: set value of CPUFREQ_BOOST_FREQ to 0xABABABAB

[Viresh Kumar]

Ideally, .driver_data field of struct cpufreq_frequency_table must not be used
by core at all. But during a recent change if its value is same as
CPUFREQ_BOOST_FREQ macro, then it is treated specially by core.

The value of this macro was set to ~2 earlier, i.e. 0xFFFFFFFD. In case some
driver is using this field for its own data and sets this field to -3, then with
two's complement that value will also become 0xFFFFFFFD.

To fix this issue, lets change value of this flag to a very uncommon value which
shouldn't be used by any driver unless they want to use BOOST feature.

Along with this update comments to make this more clear.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---

Gautham/Vaidy: I hope this fixes the problem we discussed for your patchset.

 include/linux/cpufreq.h | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index c48e595..9f25d9d 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -455,12 +455,18 @@ extern struct cpufreq_governor cpufreq_gov_conservative;
  *                     FREQUENCY TABLE HELPERS                       *
  *********************************************************************/
 
+/* Special Values of .frequency field */
 #define CPUFREQ_ENTRY_INVALID ~0
 #define CPUFREQ_TABLE_END     ~1
-#define CPUFREQ_BOOST_FREQ    ~2
+/* Special Values of .driver_data field */
+#define CPUFREQ_BOOST_FREQ    0xABABABAB
 
 struct cpufreq_frequency_table {
-	unsigned int	driver_data; /* driver specific data, not used by core */
+	/*
+	 * driver specific data, not used by core unless it is set to
+	 * CPUFREQ_BOOST_FREQ.
+	 */
+	unsigned int	driver_data;
 	unsigned int	frequency; /* kHz - doesn't need to be in ascending
 				    * order */
 };
-- 
1.7.12.rc2.18.g61b472e

Re: [PATCH] cpufreq: set value of CPUFREQ_BOOST_FREQ to 0xABABABAB

[Lukasz Majewski]

Hi Viresh,

> Ideally, .driver_data field of struct cpufreq_frequency_table must
> not be used by core at all. But during a recent change if its value
> is same as CPUFREQ_BOOST_FREQ macro, then it is treated specially by
> core.
> 
> The value of this macro was set to ~2 earlier, i.e. 0xFFFFFFFD. In
> case some driver is using this field for its own data and sets this
> field to -3, then with two's complement that value will also become
> 0xFFFFFFFD.
> 
> To fix this issue, lets change value of this flag to a very uncommon
> value which shouldn't be used by any driver unless they want to use
> BOOST feature.
> 
> Along with this update comments to make this more clear.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> 
> Gautham/Vaidy: I hope this fixes the problem we discussed for your
> patchset.
> 

I think that a name of the patchset, for which the current setting
causes problem would be welcome here.

Otherwise, I can only ask why it is not possible to add 
#define SPECIAL_SETTING ~3 ?


>  include/linux/cpufreq.h | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index c48e595..9f25d9d 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -455,12 +455,18 @@ extern struct cpufreq_governor
> cpufreq_gov_conservative;
>   *                     FREQUENCY TABLE HELPERS
> *
> *********************************************************************/ 
> +/* Special Values of .frequency field */
>  #define CPUFREQ_ENTRY_INVALID ~0
>  #define CPUFREQ_TABLE_END     ~1
> -#define CPUFREQ_BOOST_FREQ    ~2
> +/* Special Values of .driver_data field */
> +#define CPUFREQ_BOOST_FREQ    0xABABABAB
>  
>  struct cpufreq_frequency_table {
> -	unsigned int	driver_data; /* driver specific data,
> not used by core */
> +	/*
> +	 * driver specific data, not used by core unless it is set to
> +	 * CPUFREQ_BOOST_FREQ.
> +	 */
> +	unsigned int	driver_data;
>  	unsigned int	frequency; /* kHz - doesn't need to be
> in ascending
>  				    * order */
>  };



-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group

Re: [PATCH] cpufreq: set value of CPUFREQ_BOOST_FREQ to 0xABABABAB

[Viresh Kumar]

On 24 March 2014 13:51, Lukasz Majewski <l.majewski@samsung.com> wrote:
> I think that a name of the patchset, for which the current setting
> causes problem would be welcome here.

I couldn't find a lkml link to the exact message earlier, but it was discussed
here:

https://patchwork.kernel.org/patch/3865481/

> Otherwise, I can only ask why it is not possible to add
> #define SPECIAL_SETTING ~3 ?

Driver wants to use this field for +ve and -ve values and it should be free
to do so.... And ~2 was creating problems when he used -3 for this field..
If we make it ~3, then he will face problem for -4..

So, I used a special value 0xABABABAB here whose integer value is:
-1414812757

The only other option we have is to add another field "bool boost" in
cpufreq_frequency_table, which is the last thing I wanted to do.

And that's the point Gautham was trying to make in one of our IRC
chats as well..

Re: [PATCH] cpufreq: set value of CPUFREQ_BOOST_FREQ to 0xABABABAB

[Gautham R Shenoy]

On Mon, Mar 24, 2014 at 12:18:14PM +0530, Viresh Kumar wrote:
> Ideally, .driver_data field of struct cpufreq_frequency_table must not be used
> by core at all. But during a recent change if its value is same as
> CPUFREQ_BOOST_FREQ macro, then it is treated specially by core.
> 
> The value of this macro was set to ~2 earlier, i.e. 0xFFFFFFFD. In case some
> driver is using this field for its own data and sets this field to -3, then with
> two's complement that value will also become 0xFFFFFFFD.
> 
> To fix this issue, lets change value of this flag to a very uncommon value which
> shouldn't be used by any driver unless they want to use BOOST
> feature
> 
> Along with this update comments to make this more clear.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> 
> Gautham/Vaidy: I hope this fixes the problem we discussed for your
> patchset.

Since the type of .driver_data is "unsigned int", the cpufreq core
seems to be assuming that the value cannot be -ve. So, drivers should
be storing -ve values in these fields at their own risk. Because apart
from determining whether the corresponding frequency is a boost
frequency or not, the cpufreq core seems to be using the .driver_data
field in pr_debugs(). The value of .driver_data formatted as "%u" is
not useful in these pr_debugs, if the driver stores -ve value in this
field.

On the other hand, if we change the type of .driver_data to "int" then
restricting the driver to not use specific values is unreasonable
since .driver_data field is supposed to be private to the driver and
the core is not supposed to intepret it. In which case we should
be having a separate field for determining if the frequency is a BOOST
frequency or not.

So while it fixes the problem for us, I don't think this patch fixes
the problem in general for the reasons mentioned above.

--
Thanks and Regards
gautham.

> 
>  include/linux/cpufreq.h | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index c48e595..9f25d9d 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -455,12 +455,18 @@ extern struct cpufreq_governor cpufreq_gov_conservative;
>   *                     FREQUENCY TABLE HELPERS                       *
>   *********************************************************************/
> 
> +/* Special Values of .frequency field */
>  #define CPUFREQ_ENTRY_INVALID ~0
>  #define CPUFREQ_TABLE_END     ~1
> -#define CPUFREQ_BOOST_FREQ    ~2
> +/* Special Values of .driver_data field */
> +#define CPUFREQ_BOOST_FREQ    0xABABABAB
> 
>  struct cpufreq_frequency_table {
> -	unsigned int	driver_data; /* driver specific data, not used by core */
> +	/*
> +	 * driver specific data, not used by core unless it is set to
> +	 * CPUFREQ_BOOST_FREQ.
> +	 */
> +	unsigned int	driver_data;
>  	unsigned int	frequency; /* kHz - doesn't need to be in ascending
>  				    * order */
>  };
> -- 
> 1.7.12.rc2.18.g61b472e
> 

[PATCH] cpufreq: create another field .flags in cpufreq_frequency_table

[Viresh Kumar]

Currently cpufreq frequency table has two fields: frequency and driver_data.
driver_data is only for driver's internal use and cpufreq core shouldn't use it
at all. But with the introduction of BOOST frequencies, this assumption was
broken and we started using it as a flag instead.

There are two problems due to this:
- It is against the description of this field, as driver's data is used by core
  now.
- if drivers fill it with -3 for any frequency, then those frequencies are never
  considered by cpufreq core as it is exactly same as value of
  CPUFREQ_BOOST_FREQ, i.e. ~2.

The best way to get this fixed is by creating another field flags which will be
used for such flags. This patch does that. Along with that various drivers need
modifications due to the change of struct cpufreq_frequency_table.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
I have sent following patch earlier for fixing the issues mentioned above:
https://lkml.org/lkml/2014/3/24/44

Please discard that now.

I always knew that the best way to get this fixed was to add another field but
was running away from that as I wasn't very keen on adding another field into
this struct.

But after some rethinking, it becomes more and more obvious that we are inviting
more trouble in future if we don't add another field here.

So with the pain of 150+- changes, here is a patch to get things cleaned up. I
have grepped for cpufreq_frequency_table and did all modifications here. I have
compiled it only for few ARM platforms. To make sure I haven't broken anything
else, I have pushed this for getting tested by 'kbuild test robot'..

So, by the time it get tested here it is for all of you to review.

--
viresh

 arch/mips/loongson/lemote-2f/clock.c   | 20 ++++++++++----------
 drivers/cpufreq/cris-artpec3-cpufreq.c |  6 +++---
 drivers/cpufreq/cris-etraxfs-cpufreq.c |  6 +++---
 drivers/cpufreq/elanfreq.c             | 18 +++++++++---------
 drivers/cpufreq/exynos4210-cpufreq.c   | 12 ++++++------
 drivers/cpufreq/exynos4x12-cpufreq.c   | 30 +++++++++++++++---------------
 drivers/cpufreq/exynos5250-cpufreq.c   | 34 +++++++++++++++++-----------------
 drivers/cpufreq/freq_table.c           |  4 ++--
 drivers/cpufreq/kirkwood-cpufreq.c     |  6 +++---
 drivers/cpufreq/maple-cpufreq.c        |  6 +++---
 drivers/cpufreq/p4-clockmod.c          | 20 ++++++++++----------
 drivers/cpufreq/pasemi-cpufreq.c       | 12 ++++++------
 drivers/cpufreq/pmac32-cpufreq.c       |  6 +++---
 drivers/cpufreq/pmac64-cpufreq.c       |  6 +++---
 drivers/cpufreq/powernow-k6.c          | 18 +++++++++---------
 drivers/cpufreq/ppc_cbe_cpufreq.c      | 18 +++++++++---------
 drivers/cpufreq/s3c2416-cpufreq.c      | 20 ++++++++++----------
 drivers/cpufreq/s3c64xx-cpufreq.c      | 26 +++++++++++++-------------
 drivers/cpufreq/s5pv210-cpufreq.c      | 12 ++++++------
 drivers/cpufreq/sc520_freq.c           |  6 +++---
 drivers/cpufreq/speedstep-ich.c        |  6 +++---
 drivers/cpufreq/speedstep-smi.c        |  6 +++---
 include/linux/cpufreq.h                |  9 ++++++---
 23 files changed, 155 insertions(+), 152 deletions(-)

diff --git a/arch/mips/loongson/lemote-2f/clock.c b/arch/mips/loongson/lemote-2f/clock.c
index aed32b8..e1f427f 100644
--- a/arch/mips/loongson/lemote-2f/clock.c
+++ b/arch/mips/loongson/lemote-2f/clock.c
@@ -28,16 +28,16 @@ enum {
 };
 
 struct cpufreq_frequency_table loongson2_clockmod_table[] = {
-	{DC_RESV, CPUFREQ_ENTRY_INVALID},
-	{DC_ZERO, CPUFREQ_ENTRY_INVALID},
-	{DC_25PT, 0},
-	{DC_37PT, 0},
-	{DC_50PT, 0},
-	{DC_62PT, 0},
-	{DC_75PT, 0},
-	{DC_87PT, 0},
-	{DC_DISABLE, 0},
-	{DC_RESV, CPUFREQ_TABLE_END},
+	{0, DC_RESV, CPUFREQ_ENTRY_INVALID},
+	{0, DC_ZERO, CPUFREQ_ENTRY_INVALID},
+	{0, DC_25PT, 0},
+	{0, DC_37PT, 0},
+	{0, DC_50PT, 0},
+	{0, DC_62PT, 0},
+	{0, DC_75PT, 0},
+	{0, DC_87PT, 0},
+	{0, DC_DISABLE, 0},
+	{0, DC_RESV, CPUFREQ_TABLE_END},
 };
 EXPORT_SYMBOL_GPL(loongson2_clockmod_table);
 
diff --git a/drivers/cpufreq/cris-artpec3-cpufreq.c b/drivers/cpufreq/cris-artpec3-cpufreq.c
index d457303..601b88c 100644
--- a/drivers/cpufreq/cris-artpec3-cpufreq.c
+++ b/drivers/cpufreq/cris-artpec3-cpufreq.c
@@ -15,9 +15,9 @@ static struct notifier_block cris_sdram_freq_notifier_block = {
 };
 
 static struct cpufreq_frequency_table cris_freq_table[] = {
-	{0x01,	6000},
-	{0x02,	200000},
-	{0,	CPUFREQ_TABLE_END},
+	{0, 0x01, 6000},
+	{0, 0x02, 200000},
+	{0, 0, CPUFREQ_TABLE_END},
 };
 
 static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu)
diff --git a/drivers/cpufreq/cris-etraxfs-cpufreq.c b/drivers/cpufreq/cris-etraxfs-cpufreq.c
index 13c3361..22b2cdd 100644
--- a/drivers/cpufreq/cris-etraxfs-cpufreq.c
+++ b/drivers/cpufreq/cris-etraxfs-cpufreq.c
@@ -15,9 +15,9 @@ static struct notifier_block cris_sdram_freq_notifier_block = {
 };
 
 static struct cpufreq_frequency_table cris_freq_table[] = {
-	{0x01, 6000},
-	{0x02, 200000},
-	{0, CPUFREQ_TABLE_END},
+	{0, 0x01, 6000},
+	{0, 0x02, 200000},
+	{0, 0, CPUFREQ_TABLE_END},
 };
 
 static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu)
diff --git a/drivers/cpufreq/elanfreq.c b/drivers/cpufreq/elanfreq.c
index c987e94..7f5d2a6 100644
--- a/drivers/cpufreq/elanfreq.c
+++ b/drivers/cpufreq/elanfreq.c
@@ -56,15 +56,15 @@ static struct s_elan_multiplier elan_multiplier[] = {
 };
 
 static struct cpufreq_frequency_table elanfreq_table[] = {
-	{0,	1000},
-	{1,	2000},
-	{2,	4000},
-	{3,	8000},
-	{4,	16000},
-	{5,	33000},
-	{6,	66000},
-	{7,	99000},
-	{0,	CPUFREQ_TABLE_END},
+	{0, 0,	1000},
+	{0, 1,	2000},
+	{0, 2,	4000},
+	{0, 3,	8000},
+	{0, 4,	16000},
+	{0, 5,	33000},
+	{0, 6,	66000},
+	{0, 7,	99000},
+	{0, 0,	CPUFREQ_TABLE_END},
 };
 
 
diff --git a/drivers/cpufreq/exynos4210-cpufreq.c b/drivers/cpufreq/exynos4210-cpufreq.c
index 40d84c4..6384e5b 100644
--- a/drivers/cpufreq/exynos4210-cpufreq.c
+++ b/drivers/cpufreq/exynos4210-cpufreq.c
@@ -29,12 +29,12 @@ static unsigned int exynos4210_volt_table[] = {
 };
 
 static struct cpufreq_frequency_table exynos4210_freq_table[] = {
-	{L0, 1200 * 1000},
-	{L1, 1000 * 1000},
-	{L2,  800 * 1000},
-	{L3,  500 * 1000},
-	{L4,  200 * 1000},
-	{0, CPUFREQ_TABLE_END},
+	{0, L0, 1200 * 1000},
+	{0, L1, 1000 * 1000},
+	{0, L2,  800 * 1000},
+	{0, L3,  500 * 1000},
+	{0, L4,  200 * 1000},
+	{0, 0, CPUFREQ_TABLE_END},
 };
 
 static struct apll_freq apll_freq_4210[] = {
diff --git a/drivers/cpufreq/exynos4x12-cpufreq.c b/drivers/cpufreq/exynos4x12-cpufreq.c
index 7c11ace..8c4c6a5 100644
--- a/drivers/cpufreq/exynos4x12-cpufreq.c
+++ b/drivers/cpufreq/exynos4x12-cpufreq.c
@@ -30,21 +30,21 @@ static unsigned int exynos4x12_volt_table[] = {
 };
 
 static struct cpufreq_frequency_table exynos4x12_freq_table[] = {
-	{CPUFREQ_BOOST_FREQ, 1500 * 1000},
-	{L1, 1400 * 1000},
-	{L2, 1300 * 1000},
-	{L3, 1200 * 1000},
-	{L4, 1100 * 1000},
-	{L5, 1000 * 1000},
-	{L6,  900 * 1000},
-	{L7,  800 * 1000},
-	{L8,  700 * 1000},
-	{L9,  600 * 1000},
-	{L10, 500 * 1000},
-	{L11, 400 * 1000},
-	{L12, 300 * 1000},
-	{L13, 200 * 1000},
-	{0, CPUFREQ_TABLE_END},
+	{CPUFREQ_BOOST_FREQ, 0, 1500 * 1000},
+	{0, L1, 1400 * 1000},
+	{0, L2, 1300 * 1000},
+	{0, L3, 1200 * 1000},
+	{0, L4, 1100 * 1000},
+	{0, L5, 1000 * 1000},
+	{0, L6,  900 * 1000},
+	{0, L7,  800 * 1000},
+	{0, L8,  700 * 1000},
+	{0, L9,  600 * 1000},
+	{0, L10, 500 * 1000},
+	{0, L11, 400 * 1000},
+	{0, L12, 300 * 1000},
+	{0, L13, 200 * 1000},
+	{0, 0, CPUFREQ_TABLE_END},
 };
 
 static struct apll_freq *apll_freq_4x12;
diff --git a/drivers/cpufreq/exynos5250-cpufreq.c b/drivers/cpufreq/exynos5250-cpufreq.c
index 5f90b82..363a0b3 100644
--- a/drivers/cpufreq/exynos5250-cpufreq.c
+++ b/drivers/cpufreq/exynos5250-cpufreq.c
@@ -34,23 +34,23 @@ static unsigned int exynos5250_volt_table[] = {
 };
 
 static struct cpufreq_frequency_table exynos5250_freq_table[] = {
-	{L0, 1700 * 1000},
-	{L1, 1600 * 1000},
-	{L2, 1500 * 1000},
-	{L3, 1400 * 1000},
-	{L4, 1300 * 1000},
-	{L5, 1200 * 1000},
-	{L6, 1100 * 1000},
-	{L7, 1000 * 1000},
-	{L8,  900 * 1000},
-	{L9,  800 * 1000},
-	{L10, 700 * 1000},
-	{L11, 600 * 1000},
-	{L12, 500 * 1000},
-	{L13, 400 * 1000},
-	{L14, 300 * 1000},
-	{L15, 200 * 1000},
-	{0, CPUFREQ_TABLE_END},
+	{0, L0, 1700 * 1000},
+	{0, L1, 1600 * 1000},
+	{0, L2, 1500 * 1000},
+	{0, L3, 1400 * 1000},
+	{0, L4, 1300 * 1000},
+	{0, L5, 1200 * 1000},
+	{0, L6, 1100 * 1000},
+	{0, L7, 1000 * 1000},
+	{0, L8,  900 * 1000},
+	{0, L9,  800 * 1000},
+	{0, L10, 700 * 1000},
+	{0, L11, 600 * 1000},
+	{0, L12, 500 * 1000},
+	{0, L13, 400 * 1000},
+	{0, L14, 300 * 1000},
+	{0, L15, 200 * 1000},
+	{0, 0, CPUFREQ_TABLE_END},
 };
 
 static struct apll_freq apll_freq_5250[] = {
diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index 53ff3c2..08e7bbc 100644
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -33,7 +33,7 @@ int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 			continue;
 		}
 		if (!cpufreq_boost_enabled()
-		    && table[i].driver_data == CPUFREQ_BOOST_FREQ)
+		    && (table[i].flags & CPUFREQ_BOOST_FREQ))
 			continue;
 
 		pr_debug("table entry %u: %u kHz\n", i, freq);
@@ -229,7 +229,7 @@ static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf,
 		 * show_boost = false and driver_data != BOOST freq
 		 * display NON BOOST freqs
 		 */
-		if (show_boost ^ (table[i].driver_data == CPUFREQ_BOOST_FREQ))
+		if (show_boost ^ (table[i].flags & CPUFREQ_BOOST_FREQ))
 			continue;
 
 		count += sprintf(&buf[count], "%d ", table[i].frequency);
diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
index 3d114bc..37a4806 100644
--- a/drivers/cpufreq/kirkwood-cpufreq.c
+++ b/drivers/cpufreq/kirkwood-cpufreq.c
@@ -43,9 +43,9 @@ static struct priv
  * table.
  */
 static struct cpufreq_frequency_table kirkwood_freq_table[] = {
-	{STATE_CPU_FREQ,	0}, /* CPU uses cpuclk */
-	{STATE_DDR_FREQ,	0}, /* CPU uses ddrclk */
-	{0,			CPUFREQ_TABLE_END},
+	{0, STATE_CPU_FREQ,	0}, /* CPU uses cpuclk */
+	{0, STATE_DDR_FREQ,	0}, /* CPU uses ddrclk */
+	{0, 0,			CPUFREQ_TABLE_END},
 };
 
 static unsigned int kirkwood_cpufreq_get_cpu_frequency(unsigned int cpu)
diff --git a/drivers/cpufreq/maple-cpufreq.c b/drivers/cpufreq/maple-cpufreq.c
index c4dfa42..cc3408f 100644
--- a/drivers/cpufreq/maple-cpufreq.c
+++ b/drivers/cpufreq/maple-cpufreq.c
@@ -59,9 +59,9 @@
 #define CPUFREQ_LOW                   1
 
 static struct cpufreq_frequency_table maple_cpu_freqs[] = {
-	{CPUFREQ_HIGH,		0},
-	{CPUFREQ_LOW,		0},
-	{0,			CPUFREQ_TABLE_END},
+	{0, CPUFREQ_HIGH,		0},
+	{0, CPUFREQ_LOW,		0},
+	{0, 0,				CPUFREQ_TABLE_END},
 };
 
 /* Power mode data is an array of the 32 bits PCR values to use for
diff --git a/drivers/cpufreq/p4-clockmod.c b/drivers/cpufreq/p4-clockmod.c
index 74f593e..529cfd9 100644
--- a/drivers/cpufreq/p4-clockmod.c
+++ b/drivers/cpufreq/p4-clockmod.c
@@ -92,16 +92,16 @@ static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate)
 
 
 static struct cpufreq_frequency_table p4clockmod_table[] = {
-	{DC_RESV, CPUFREQ_ENTRY_INVALID},
-	{DC_DFLT, 0},
-	{DC_25PT, 0},
-	{DC_38PT, 0},
-	{DC_50PT, 0},
-	{DC_64PT, 0},
-	{DC_75PT, 0},
-	{DC_88PT, 0},
-	{DC_DISABLE, 0},
-	{DC_RESV, CPUFREQ_TABLE_END},
+	{0, DC_RESV, CPUFREQ_ENTRY_INVALID},
+	{0, DC_DFLT, 0},
+	{0, DC_25PT, 0},
+	{0, DC_38PT, 0},
+	{0, DC_50PT, 0},
+	{0, DC_64PT, 0},
+	{0, DC_75PT, 0},
+	{0, DC_88PT, 0},
+	{0, DC_DISABLE, 0},
+	{0, DC_RESV, CPUFREQ_TABLE_END},
 };
 
 
diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c
index 6a2b7d3..84c84b5 100644
--- a/drivers/cpufreq/pasemi-cpufreq.c
+++ b/drivers/cpufreq/pasemi-cpufreq.c
@@ -60,12 +60,12 @@ static int current_astate;
 
 /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
 static struct cpufreq_frequency_table pas_freqs[] = {
-	{0,	0},
-	{1,	0},
-	{2,	0},
-	{3,	0},
-	{4,	0},
-	{0,	CPUFREQ_TABLE_END},
+	{0, 0,	0},
+	{0, 1,	0},
+	{0, 2,	0},
+	{0, 3,	0},
+	{0, 4,	0},
+	{0, 0,	CPUFREQ_TABLE_END},
 };
 
 /*
diff --git a/drivers/cpufreq/pmac32-cpufreq.c b/drivers/cpufreq/pmac32-cpufreq.c
index cf55d20..80ee398 100644
--- a/drivers/cpufreq/pmac32-cpufreq.c
+++ b/drivers/cpufreq/pmac32-cpufreq.c
@@ -81,9 +81,9 @@ static int is_pmu_based;
 #define CPUFREQ_LOW                   1
 
 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
-	{CPUFREQ_HIGH, 		0},
-	{CPUFREQ_LOW,		0},
-	{0,			CPUFREQ_TABLE_END},
+	{0, CPUFREQ_HIGH, 		0},
+	{0, CPUFREQ_LOW,		0},
+	{0, 0,				CPUFREQ_TABLE_END},
 };
 
 static inline void local_delay(unsigned long ms)
diff --git a/drivers/cpufreq/pmac64-cpufreq.c b/drivers/cpufreq/pmac64-cpufreq.c
index 6a338f8..290efe7 100644
--- a/drivers/cpufreq/pmac64-cpufreq.c
+++ b/drivers/cpufreq/pmac64-cpufreq.c
@@ -65,9 +65,9 @@
 #define CPUFREQ_LOW                   1
 
 static struct cpufreq_frequency_table g5_cpu_freqs[] = {
-	{CPUFREQ_HIGH, 		0},
-	{CPUFREQ_LOW,		0},
-	{0,			CPUFREQ_TABLE_END},
+	{0, CPUFREQ_HIGH, 		0},
+	{0, CPUFREQ_LOW,		0},
+	{0, 0,				CPUFREQ_TABLE_END},
 };
 
 /* Power mode data is an array of the 32 bits PCR values to use for
diff --git a/drivers/cpufreq/powernow-k6.c b/drivers/cpufreq/powernow-k6.c
index 62c6f2e..49f120e 100644
--- a/drivers/cpufreq/powernow-k6.c
+++ b/drivers/cpufreq/powernow-k6.c
@@ -37,15 +37,15 @@ MODULE_PARM_DESC(bus_frequency, "Bus frequency in kHz");
 
 /* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
 static struct cpufreq_frequency_table clock_ratio[] = {
-	{60,  /* 110 -> 6.0x */ 0},
-	{55,  /* 011 -> 5.5x */ 0},
-	{50,  /* 001 -> 5.0x */ 0},
-	{45,  /* 000 -> 4.5x */ 0},
-	{40,  /* 010 -> 4.0x */ 0},
-	{35,  /* 111 -> 3.5x */ 0},
-	{30,  /* 101 -> 3.0x */ 0},
-	{20,  /* 100 -> 2.0x */ 0},
-	{0, CPUFREQ_TABLE_END}
+	{0, 60,  /* 110 -> 6.0x */ 0},
+	{0, 55,  /* 011 -> 5.5x */ 0},
+	{0, 50,  /* 001 -> 5.0x */ 0},
+	{0, 45,  /* 000 -> 4.5x */ 0},
+	{0, 40,  /* 010 -> 4.0x */ 0},
+	{0, 35,  /* 111 -> 3.5x */ 0},
+	{0, 30,  /* 101 -> 3.0x */ 0},
+	{0, 20,  /* 100 -> 2.0x */ 0},
+	{0, 0, CPUFREQ_TABLE_END}
 };
 
 static const u8 index_to_register[8] = { 6, 3, 1, 0, 2, 7, 5, 4 };
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq.c b/drivers/cpufreq/ppc_cbe_cpufreq.c
index af7b1ca..5be8a48 100644
--- a/drivers/cpufreq/ppc_cbe_cpufreq.c
+++ b/drivers/cpufreq/ppc_cbe_cpufreq.c
@@ -32,15 +32,15 @@
 
 /* the CBE supports an 8 step frequency scaling */
 static struct cpufreq_frequency_table cbe_freqs[] = {
-	{1,	0},
-	{2,	0},
-	{3,	0},
-	{4,	0},
-	{5,	0},
-	{6,	0},
-	{8,	0},
-	{10,	0},
-	{0,	CPUFREQ_TABLE_END},
+	{0, 1,	0},
+	{0, 2,	0},
+	{0, 3,	0},
+	{0, 4,	0},
+	{0, 5,	0},
+	{0, 6,	0},
+	{0, 8,	0},
+	{0, 10,	0},
+	{0, 0,	CPUFREQ_TABLE_END},
 };
 
 /*
diff --git a/drivers/cpufreq/s3c2416-cpufreq.c b/drivers/cpufreq/s3c2416-cpufreq.c
index 826b8be..4626f90 100644
--- a/drivers/cpufreq/s3c2416-cpufreq.c
+++ b/drivers/cpufreq/s3c2416-cpufreq.c
@@ -72,19 +72,19 @@ static struct s3c2416_dvfs s3c2416_dvfs_table[] = {
 #endif
 
 static struct cpufreq_frequency_table s3c2416_freq_table[] = {
-	{ SOURCE_HCLK, FREQ_DVS },
-	{ SOURCE_ARMDIV, 133333 },
-	{ SOURCE_ARMDIV, 266666 },
-	{ SOURCE_ARMDIV, 400000 },
-	{ 0, CPUFREQ_TABLE_END },
+	{ 0, SOURCE_HCLK, FREQ_DVS },
+	{ 0, SOURCE_ARMDIV, 133333 },
+	{ 0, SOURCE_ARMDIV, 266666 },
+	{ 0, SOURCE_ARMDIV, 400000 },
+	{ 0, 0, CPUFREQ_TABLE_END },
 };
 
 static struct cpufreq_frequency_table s3c2450_freq_table[] = {
-	{ SOURCE_HCLK, FREQ_DVS },
-	{ SOURCE_ARMDIV, 133500 },
-	{ SOURCE_ARMDIV, 267000 },
-	{ SOURCE_ARMDIV, 534000 },
-	{ 0, CPUFREQ_TABLE_END },
+	{ 0, SOURCE_HCLK, FREQ_DVS },
+	{ 0, SOURCE_ARMDIV, 133500 },
+	{ 0, SOURCE_ARMDIV, 267000 },
+	{ 0, SOURCE_ARMDIV, 534000 },
+	{ 0, 0, CPUFREQ_TABLE_END },
 };
 
 static unsigned int s3c2416_cpufreq_get_speed(unsigned int cpu)
diff --git a/drivers/cpufreq/s3c64xx-cpufreq.c b/drivers/cpufreq/s3c64xx-cpufreq.c
index c4226de..ff7d3ec 100644
--- a/drivers/cpufreq/s3c64xx-cpufreq.c
+++ b/drivers/cpufreq/s3c64xx-cpufreq.c
@@ -37,19 +37,19 @@ static struct s3c64xx_dvfs s3c64xx_dvfs_table[] = {
 };
 
 static struct cpufreq_frequency_table s3c64xx_freq_table[] = {
-	{ 0,  66000 },
-	{ 0, 100000 },
-	{ 0, 133000 },
-	{ 1, 200000 },
-	{ 1, 222000 },
-	{ 1, 266000 },
-	{ 2, 333000 },
-	{ 2, 400000 },
-	{ 2, 532000 },
-	{ 2, 533000 },
-	{ 3, 667000 },
-	{ 4, 800000 },
-	{ 0, CPUFREQ_TABLE_END },
+	{ 0, 0,  66000 },
+	{ 0, 0, 100000 },
+	{ 0, 0, 133000 },
+	{ 0, 1, 200000 },
+	{ 0, 1, 222000 },
+	{ 0, 1, 266000 },
+	{ 0, 2, 333000 },
+	{ 0, 2, 400000 },
+	{ 0, 2, 532000 },
+	{ 0, 2, 533000 },
+	{ 0, 3, 667000 },
+	{ 0, 4, 800000 },
+	{ 0, 0, CPUFREQ_TABLE_END },
 };
 #endif
 
diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
index 7242153..ab2c1a4 100644
--- a/drivers/cpufreq/s5pv210-cpufreq.c
+++ b/drivers/cpufreq/s5pv210-cpufreq.c
@@ -64,12 +64,12 @@ enum s5pv210_dmc_port {
 };
 
 static struct cpufreq_frequency_table s5pv210_freq_table[] = {
-	{L0, 1000*1000},
-	{L1, 800*1000},
-	{L2, 400*1000},
-	{L3, 200*1000},
-	{L4, 100*1000},
-	{0, CPUFREQ_TABLE_END},
+	{0, L0, 1000*1000},
+	{0, L1, 800*1000},
+	{0, L2, 400*1000},
+	{0, L3, 200*1000},
+	{0, L4, 100*1000},
+	{0, 0, CPUFREQ_TABLE_END},
 };
 
 static struct regulator *arm_regulator;
diff --git a/drivers/cpufreq/sc520_freq.c b/drivers/cpufreq/sc520_freq.c
index 69371bf..ac84e48 100644
--- a/drivers/cpufreq/sc520_freq.c
+++ b/drivers/cpufreq/sc520_freq.c
@@ -33,9 +33,9 @@ static __u8 __iomem *cpuctl;
 #define PFX "sc520_freq: "
 
 static struct cpufreq_frequency_table sc520_freq_table[] = {
-	{0x01,	100000},
-	{0x02,	133000},
-	{0,	CPUFREQ_TABLE_END},
+	{0, 0x01,	100000},
+	{0, 0x02,	133000},
+	{0, 0,	CPUFREQ_TABLE_END},
 };
 
 static unsigned int sc520_freq_get_cpu_frequency(unsigned int cpu)
diff --git a/drivers/cpufreq/speedstep-ich.c b/drivers/cpufreq/speedstep-ich.c
index 394ac15..1a07b59 100644
--- a/drivers/cpufreq/speedstep-ich.c
+++ b/drivers/cpufreq/speedstep-ich.c
@@ -49,9 +49,9 @@ static u32 pmbase;
  * are in kHz for the time being.
  */
 static struct cpufreq_frequency_table speedstep_freqs[] = {
-	{SPEEDSTEP_HIGH,	0},
-	{SPEEDSTEP_LOW,		0},
-	{0,			CPUFREQ_TABLE_END},
+	{0, SPEEDSTEP_HIGH,	0},
+	{0, SPEEDSTEP_LOW,	0},
+	{0, 0,			CPUFREQ_TABLE_END},
 };
 
 
diff --git a/drivers/cpufreq/speedstep-smi.c b/drivers/cpufreq/speedstep-smi.c
index db5d274..8635eec 100644
--- a/drivers/cpufreq/speedstep-smi.c
+++ b/drivers/cpufreq/speedstep-smi.c
@@ -42,9 +42,9 @@ static enum speedstep_processor speedstep_processor;
  * are in kHz for the time being.
  */
 static struct cpufreq_frequency_table speedstep_freqs[] = {
-	{SPEEDSTEP_HIGH,	0},
-	{SPEEDSTEP_LOW,		0},
-	{0,			CPUFREQ_TABLE_END},
+	{0, SPEEDSTEP_HIGH,	0},
+	{0, SPEEDSTEP_LOW,	0},
+	{0, 0,			CPUFREQ_TABLE_END},
 };
 
 #define GET_SPEEDSTEP_OWNER 0
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index c48e595..1e8f07d 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -455,11 +455,14 @@ extern struct cpufreq_governor cpufreq_gov_conservative;
  *                     FREQUENCY TABLE HELPERS                       *
  *********************************************************************/
 
-#define CPUFREQ_ENTRY_INVALID ~0
-#define CPUFREQ_TABLE_END     ~1
-#define CPUFREQ_BOOST_FREQ    ~2
+/* Special Values of .frequency field */
+#define CPUFREQ_ENTRY_INVALID	~0
+#define CPUFREQ_TABLE_END	~1
+/* Special Values of .flags field */
+#define CPUFREQ_BOOST_FREQ	0x1
 
 struct cpufreq_frequency_table {
+	unsigned int	flags;
 	unsigned int	driver_data; /* driver specific data, not used by core */
 	unsigned int	frequency; /* kHz - doesn't need to be in ascending
 				    * order */
-- 
1.7.12.rc2.18.g61b472e

[PATCH] cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table

[Viresh Kumar]

Few drivers are using kmalloc() to allocate memory for frequency tables and once
we have an additional field '.flags' in 'struct cpufreq_frequency_table', these
might become unstable. Better get these fixed by replacing kmalloc() by
kzalloc() instead.

Along with that we also remove use of .driver_data from SPEAr driver as it
doesn't use it at all. Also, writing zero to .driver_data is not required for
powernow-k8 as it is already zero.

Reported-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
@Rafael: Please apply this one before:

http://permalink.gmane.org/gmane.linux.kernel/1673994

so that git bisect doesn't break. Though the chances of this field getting
initialized to a value equal to BOOST, i.e. 0x1 are very rare.

 drivers/cpufreq/acpi-cpufreq.c      | 2 +-
 drivers/cpufreq/ia64-acpi-cpufreq.c | 2 +-
 drivers/cpufreq/longhaul.c          | 2 +-
 drivers/cpufreq/powernow-k8.c       | 5 ++---
 drivers/cpufreq/s3c24xx-cpufreq.c   | 4 ++--
 drivers/cpufreq/spear-cpufreq.c     | 7 ++-----
 6 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index d5eaedb..000e4e0 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -754,7 +754,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 		goto err_unreg;
 	}
 
-	data->freq_table = kmalloc(sizeof(*data->freq_table) *
+	data->freq_table = kzalloc(sizeof(*data->freq_table) *
 		    (perf->state_count+1), GFP_KERNEL);
 	if (!data->freq_table) {
 		result = -ENOMEM;
diff --git a/drivers/cpufreq/ia64-acpi-cpufreq.c b/drivers/cpufreq/ia64-acpi-cpufreq.c
index beb191b..c30aaa6 100644
--- a/drivers/cpufreq/ia64-acpi-cpufreq.c
+++ b/drivers/cpufreq/ia64-acpi-cpufreq.c
@@ -254,7 +254,7 @@ acpi_cpufreq_cpu_init (
 	}
 
 	/* alloc freq_table */
-	data->freq_table = kmalloc(sizeof(*data->freq_table) *
+	data->freq_table = kzalloc(sizeof(*data->freq_table) *
 	                           (data->acpi_data.state_count + 1),
 	                           GFP_KERNEL);
 	if (!data->freq_table) {
diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c
index 5c440f8..d00e5d1 100644
--- a/drivers/cpufreq/longhaul.c
+++ b/drivers/cpufreq/longhaul.c
@@ -475,7 +475,7 @@ static int longhaul_get_ranges(void)
 		return -EINVAL;
 	}
 
-	longhaul_table = kmalloc((numscales + 1) * sizeof(*longhaul_table),
+	longhaul_table = kzalloc((numscales + 1) * sizeof(*longhaul_table),
 			GFP_KERNEL);
 	if (!longhaul_table)
 		return -ENOMEM;
diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c
index 770a9e1..1b6ae6b 100644
--- a/drivers/cpufreq/powernow-k8.c
+++ b/drivers/cpufreq/powernow-k8.c
@@ -623,7 +623,7 @@ static int fill_powernow_table(struct powernow_k8_data *data,
 	if (check_pst_table(data, pst, maxvid))
 		return -EINVAL;
 
-	powernow_table = kmalloc((sizeof(*powernow_table)
+	powernow_table = kzalloc((sizeof(*powernow_table)
 		* (data->numps + 1)), GFP_KERNEL);
 	if (!powernow_table) {
 		printk(KERN_ERR PFX "powernow_table memory alloc failure\n");
@@ -793,7 +793,7 @@ static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
 	}
 
 	/* fill in data->powernow_table */
-	powernow_table = kmalloc((sizeof(*powernow_table)
+	powernow_table = kzalloc((sizeof(*powernow_table)
 		* (data->acpi_data.state_count + 1)), GFP_KERNEL);
 	if (!powernow_table) {
 		pr_debug("powernow_table memory alloc failure\n");
@@ -810,7 +810,6 @@ static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
 
 	powernow_table[data->acpi_data.state_count].frequency =
 		CPUFREQ_TABLE_END;
-	powernow_table[data->acpi_data.state_count].driver_data = 0;
 	data->powernow_table = powernow_table;
 
 	if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
diff --git a/drivers/cpufreq/s3c24xx-cpufreq.c b/drivers/cpufreq/s3c24xx-cpufreq.c
index a3dc192..be1b2b5 100644
--- a/drivers/cpufreq/s3c24xx-cpufreq.c
+++ b/drivers/cpufreq/s3c24xx-cpufreq.c
@@ -586,7 +586,7 @@ static int s3c_cpufreq_build_freq(void)
 	size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
 	size++;
 
-	ftab = kmalloc(sizeof(*ftab) * size, GFP_KERNEL);
+	ftab = kzalloc(sizeof(*ftab) * size, GFP_KERNEL);
 	if (!ftab) {
 		printk(KERN_ERR "%s: no memory for tables\n", __func__);
 		return -ENOMEM;
@@ -664,7 +664,7 @@ int __init s3c_plltab_register(struct cpufreq_frequency_table *plls,
 
 	size = sizeof(*vals) * (plls_no + 1);
 
-	vals = kmalloc(size, GFP_KERNEL);
+	vals = kzalloc(size, GFP_KERNEL);
 	if (vals) {
 		memcpy(vals, plls, size);
 		pll_reg = vals;
diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c
index 4cfdcff..3867839 100644
--- a/drivers/cpufreq/spear-cpufreq.c
+++ b/drivers/cpufreq/spear-cpufreq.c
@@ -195,18 +195,15 @@ static int spear_cpufreq_probe(struct platform_device *pdev)
 	cnt = prop->length / sizeof(u32);
 	val = prop->value;
 
-	freq_tbl = kmalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL);
+	freq_tbl = kzalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL);
 	if (!freq_tbl) {
 		ret = -ENOMEM;
 		goto out_put_node;
 	}
 
-	for (i = 0; i < cnt; i++) {
-		freq_tbl[i].driver_data = i;
+	for (i = 0; i < cnt; i++)
 		freq_tbl[i].frequency = be32_to_cpup(val++);
-	}
 
-	freq_tbl[i].driver_data = i;
 	freq_tbl[i].frequency = CPUFREQ_TABLE_END;
 
 	spear_cpufreq.freq_tbl = freq_tbl;
-- 
1.7.12.rc2.18.g61b472e

Re: [PATCH] cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table

[Gautham R Shenoy]

On Fri, Mar 28, 2014 at 03:44:24PM +0530, Viresh Kumar wrote:
> Few drivers are using kmalloc() to allocate memory for frequency tables and once
> we have an additional field '.flags' in 'struct cpufreq_frequency_table', these
> might become unstable. Better get these fixed by replacing kmalloc() by
> kzalloc() instead.
> 
> Along with that we also remove use of .driver_data from SPEAr driver as it
> doesn't use it at all. Also, writing zero to .driver_data is not required for
> powernow-k8 as it is already zero.
> 
> Reported-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>

> ---
> @Rafael: Please apply this one before:
> 
> http://permalink.gmane.org/gmane.linux.kernel/1673994
> 
> so that git bisect doesn't break. Though the chances of this field getting
> initialized to a value equal to BOOST, i.e. 0x1 are very rare.
> 
>  drivers/cpufreq/acpi-cpufreq.c      | 2 +-
>  drivers/cpufreq/ia64-acpi-cpufreq.c | 2 +-
>  drivers/cpufreq/longhaul.c          | 2 +-
>  drivers/cpufreq/powernow-k8.c       | 5 ++---
>  drivers/cpufreq/s3c24xx-cpufreq.c   | 4 ++--
>  drivers/cpufreq/spear-cpufreq.c     | 7 ++-----
>  6 files changed, 9 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
> index d5eaedb..000e4e0 100644
> --- a/drivers/cpufreq/acpi-cpufreq.c
> +++ b/drivers/cpufreq/acpi-cpufreq.c
> @@ -754,7 +754,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
>  		goto err_unreg;
>  	}
> 
> -	data->freq_table = kmalloc(sizeof(*data->freq_table) *
> +	data->freq_table = kzalloc(sizeof(*data->freq_table) *
>  		    (perf->state_count+1), GFP_KERNEL);
>  	if (!data->freq_table) {
>  		result = -ENOMEM;
> diff --git a/drivers/cpufreq/ia64-acpi-cpufreq.c b/drivers/cpufreq/ia64-acpi-cpufreq.c
> index beb191b..c30aaa6 100644
> --- a/drivers/cpufreq/ia64-acpi-cpufreq.c
> +++ b/drivers/cpufreq/ia64-acpi-cpufreq.c
> @@ -254,7 +254,7 @@ acpi_cpufreq_cpu_init (
>  	}
> 
>  	/* alloc freq_table */
> -	data->freq_table = kmalloc(sizeof(*data->freq_table) *
> +	data->freq_table = kzalloc(sizeof(*data->freq_table) *
>  	                           (data->acpi_data.state_count + 1),
>  	                           GFP_KERNEL);
>  	if (!data->freq_table) {
> diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c
> index 5c440f8..d00e5d1 100644
> --- a/drivers/cpufreq/longhaul.c
> +++ b/drivers/cpufreq/longhaul.c
> @@ -475,7 +475,7 @@ static int longhaul_get_ranges(void)
>  		return -EINVAL;
>  	}
> 
> -	longhaul_table = kmalloc((numscales + 1) * sizeof(*longhaul_table),
> +	longhaul_table = kzalloc((numscales + 1) * sizeof(*longhaul_table),
>  			GFP_KERNEL);
>  	if (!longhaul_table)
>  		return -ENOMEM;
> diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c
> index 770a9e1..1b6ae6b 100644
> --- a/drivers/cpufreq/powernow-k8.c
> +++ b/drivers/cpufreq/powernow-k8.c
> @@ -623,7 +623,7 @@ static int fill_powernow_table(struct powernow_k8_data *data,
>  	if (check_pst_table(data, pst, maxvid))
>  		return -EINVAL;
> 
> -	powernow_table = kmalloc((sizeof(*powernow_table)
> +	powernow_table = kzalloc((sizeof(*powernow_table)
>  		* (data->numps + 1)), GFP_KERNEL);
>  	if (!powernow_table) {
>  		printk(KERN_ERR PFX "powernow_table memory alloc failure\n");
> @@ -793,7 +793,7 @@ static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
>  	}
> 
>  	/* fill in data->powernow_table */
> -	powernow_table = kmalloc((sizeof(*powernow_table)
> +	powernow_table = kzalloc((sizeof(*powernow_table)
>  		* (data->acpi_data.state_count + 1)), GFP_KERNEL);
>  	if (!powernow_table) {
>  		pr_debug("powernow_table memory alloc failure\n");
> @@ -810,7 +810,6 @@ static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
> 
>  	powernow_table[data->acpi_data.state_count].frequency =
>  		CPUFREQ_TABLE_END;
> -	powernow_table[data->acpi_data.state_count].driver_data = 0;
>  	data->powernow_table = powernow_table;
> 
>  	if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
> diff --git a/drivers/cpufreq/s3c24xx-cpufreq.c b/drivers/cpufreq/s3c24xx-cpufreq.c
> index a3dc192..be1b2b5 100644
> --- a/drivers/cpufreq/s3c24xx-cpufreq.c
> +++ b/drivers/cpufreq/s3c24xx-cpufreq.c
> @@ -586,7 +586,7 @@ static int s3c_cpufreq_build_freq(void)
>  	size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
>  	size++;
> 
> -	ftab = kmalloc(sizeof(*ftab) * size, GFP_KERNEL);
> +	ftab = kzalloc(sizeof(*ftab) * size, GFP_KERNEL);
>  	if (!ftab) {
>  		printk(KERN_ERR "%s: no memory for tables\n", __func__);
>  		return -ENOMEM;
> @@ -664,7 +664,7 @@ int __init s3c_plltab_register(struct cpufreq_frequency_table *plls,
> 
>  	size = sizeof(*vals) * (plls_no + 1);
> 
> -	vals = kmalloc(size, GFP_KERNEL);
> +	vals = kzalloc(size, GFP_KERNEL);
>  	if (vals) {
>  		memcpy(vals, plls, size);
>  		pll_reg = vals;
> diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c
> index 4cfdcff..3867839 100644
> --- a/drivers/cpufreq/spear-cpufreq.c
> +++ b/drivers/cpufreq/spear-cpufreq.c
> @@ -195,18 +195,15 @@ static int spear_cpufreq_probe(struct platform_device *pdev)
>  	cnt = prop->length / sizeof(u32);
>  	val = prop->value;
> 
> -	freq_tbl = kmalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL);
> +	freq_tbl = kzalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL);
>  	if (!freq_tbl) {
>  		ret = -ENOMEM;
>  		goto out_put_node;
>  	}
> 
> -	for (i = 0; i < cnt; i++) {
> -		freq_tbl[i].driver_data = i;
> +	for (i = 0; i < cnt; i++)
>  		freq_tbl[i].frequency = be32_to_cpup(val++);
> -	}
> 
> -	freq_tbl[i].driver_data = i;
>  	freq_tbl[i].frequency = CPUFREQ_TABLE_END;
> 
>  	spear_cpufreq.freq_tbl = freq_tbl;
> -- 
> 1.7.12.rc2.18.g61b472e
> 

Re: [PATCH] cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table

[Joe Perches]

On Fri, 2014-03-28 at 15:44 +0530, Viresh Kumar wrote:
> Few drivers are using kmalloc() to allocate memory for frequency tables and once
> we have an additional field '.flags' in 'struct cpufreq_frequency_table', these
> might become unstable. Better get these fixed by replacing kmalloc() by
> kzalloc() instead.

There seems to be some sort of bug fix in the
patch at the very end too?

Perhaps a better fix would be to use kcalloc for
all the allocs with a multiply.

> diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
[]
> @@ -754,7 +754,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
[]
> -	data->freq_table = kmalloc(sizeof(*data->freq_table) *
> +	data->freq_table = kzalloc(sizeof(*data->freq_table) *
>  		    (perf->state_count+1), GFP_KERNEL);

> diff --git a/drivers/cpufreq/ia64-acpi-cpufreq.c b/drivers/cpufreq/ia64-acpi-cpufreq.c
[]
> @@ -254,7 +254,7 @@ acpi_cpufreq_cpu_init (
[]
> -	data->freq_table = kmalloc(sizeof(*data->freq_table) *
> +	data->freq_table = kzalloc(sizeof(*data->freq_table) *
>  	                           (data->acpi_data.state_count + 1),
>  	                           GFP_KERNEL);

> diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c
[]
> @@ -475,7 +475,7 @@ static int longhaul_get_ranges(void)
[]
> -	longhaul_table = kmalloc((numscales + 1) * sizeof(*longhaul_table),

> diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c
[]
> @@ -623,7 +623,7 @@ static int fill_powernow_table(struct powernow_k8_data *data,
[]
> -	powernow_table = kmalloc((sizeof(*powernow_table)
> +	powernow_table = kzalloc((sizeof(*powernow_table)
>  		* (data->numps + 1)), GFP_KERNEL);

> diff --git a/drivers/cpufreq/s3c24xx-cpufreq.c b/drivers/cpufreq/s3c24xx-cpufreq.c
[]
> @@ -586,7 +586,7 @@ static int s3c_cpufreq_build_freq(void)
[]
> -	ftab = kmalloc(sizeof(*ftab) * size, GFP_KERNEL);
> +	ftab = kzalloc(sizeof(*ftab) * size, GFP_KERNEL);

> diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c
[]
> @@ -195,18 +195,15 @@ static int spear_cpufreq_probe(struct platform_device *pdev)
[]
> -	freq_tbl = kmalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL);
> +	freq_tbl = kzalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL);
>  	if (!freq_tbl) {
>  		ret = -ENOMEM;
>  		goto out_put_node;
>  	}
>  
> -	for (i = 0; i < cnt; i++) {
> -		freq_tbl[i].driver_data = i;
> +	for (i = 0; i < cnt; i++)
>  		freq_tbl[i].frequency = be32_to_cpup(val++);
> -	}
>  
> -	freq_tbl[i].driver_data = i;
>  	freq_tbl[i].frequency = CPUFREQ_TABLE_END;

Is this some bug fix?

Re: [PATCH] cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table

[Viresh Kumar]

On 28 March 2014 18:59, Joe Perches <joe@perches.com> wrote:
> There seems to be some sort of bug fix in the
> patch at the very end too?

I have mentioned that in the log:

Along with that we also remove use of .driver_data from SPEAr driver as it
doesn't use it at all. Also, writing zero to .driver_data is not required for
powernow-k8 as it is already zero.

> Perhaps a better fix would be to use kcalloc for
> all the allocs with a multiply.

That would make the change very big now as there are lots of drivers
which are already using kzalloc() and so wouldn't like to do that in this
patch atleast..

Re: [PATCH] cpufreq: create another field .flags in cpufreq_frequency_table

[Lukasz Majewski]

Hi Viresh,

> diff --git a/drivers/cpufreq/exynos4x12-cpufreq.c
> b/drivers/cpufreq/exynos4x12-cpufreq.c index 7c11ace..8c4c6a5 100644
> --- a/drivers/cpufreq/exynos4x12-cpufreq.c
> +++ b/drivers/cpufreq/exynos4x12-cpufreq.c
> @@ -30,21 +30,21 @@ static unsigned int exynos4x12_volt_table[] = {
>  };
> 
>  static struct cpufreq_frequency_table exynos4x12_freq_table[] = {
> -       {CPUFREQ_BOOST_FREQ, 1500 * 1000},
> -       {L1, 1400 * 1000},
> -       {L2, 1300 * 1000},
> -       {L3, 1200 * 1000},
> -       {L4, 1100 * 1000},
> -       {L5, 1000 * 1000},
> -       {L6,  900 * 1000},
> -       {L7,  800 * 1000},
> -       {L8,  700 * 1000},
> -       {L9,  600 * 1000},
> -       {L10, 500 * 1000},
> -       {L11, 400 * 1000},
> -       {L12, 300 * 1000},
> -       {L13, 200 * 1000},
> -       {0, CPUFREQ_TABLE_END},
> +       {CPUFREQ_BOOST_FREQ, 0, 1500 * 1000},
> +       {0, L1, 1400 * 1000},
> +       {0, L2, 1300 * 1000},
> +       {0, L3, 1200 * 1000},
> +       {0, L4, 1100 * 1000},
> +       {0, L5, 1000 * 1000},
> +       {0, L6,  900 * 1000},
> +       {0, L7,  800 * 1000},
> +       {0, L8,  700 * 1000},
> +       {0, L9,  600 * 1000},
> +       {0, L10, 500 * 1000},
> +       {0, L11, 400 * 1000},
> +       {0, L12, 300 * 1000},
> +       {0, L13, 200 * 1000},
> +       {0, 0, CPUFREQ_TABLE_END},
>  };

Looks correct for me.

One little remark - since cpufreq_frequency_tables are defined as
static it seems like we don't need to explicitly specify the 0, for
flags field.

Something like {, L13, 200 * 1000}, shall be enough.

> +/* Special Values of .flags field */
> +#define CPUFREQ_BOOST_FREQ     0x1

Maybe (1 << 0) to explicitly show that those are flags.

> 
>  struct cpufreq_frequency_table {
> +       unsigned int    flags;
>         unsigned int    driver_data; /* driver specific data, not

The driver_data shall be changed to int. However I suppose that it will
be done at separate patch.

> used by core */ unsigned int    frequency; /* kHz - doesn't need to
> be in ascending
>                                     * order */

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group

Re: [PATCH] cpufreq: create another field .flags in cpufreq_frequency_table

[Viresh Kumar]

On 28 March 2014 15:49, Lukasz Majewski <l.majewski@samsung.com> wrote:
> One little remark - since cpufreq_frequency_tables are defined as
> static it seems like we don't need to explicitly specify the 0, for
> flags field.
>
> Something like {, L13, 200 * 1000}, shall be enough.

This looks awkward, writing zero is better. The other option was to do
it like this:

{.driver_data = L13, .frequency = 200 * 1000}

But I didn't wanted to make such changes in this patch.

>> +/* Special Values of .flags field */
>> +#define CPUFREQ_BOOST_FREQ     0x1
>
> Maybe (1 << 0) to explicitly show that those are flags.

Will do that in case I resend this patch, otherwise it wouldn't
harm for now.

>>  struct cpufreq_frequency_table {
>> +       unsigned int    flags;
>>         unsigned int    driver_data; /* driver specific data, not
>
> The driver_data shall be changed to int. However I suppose that it will
> be done at separate patch.

I am not planning to change it for now. People storing 'int' into this
field would read it back into 'int' and so things would work as normal
I suppose.

Re: [PATCH] cpufreq: create another field .flags in cpufreq_frequency_table

[Gautham R Shenoy]

On Fri, Mar 28, 2014 at 02:23:20PM +0530, Viresh Kumar wrote:
> Currently cpufreq frequency table has two fields: frequency and driver_data.
> driver_data is only for driver's internal use and cpufreq core shouldn't use it
> at all. But with the introduction of BOOST frequencies, this assumption was
> broken and we started using it as a flag instead.
> 
> There are two problems due to this:
> - It is against the description of this field, as driver's data is used by core
>   now.
> - if drivers fill it with -3 for any frequency, then those frequencies are never
>   considered by cpufreq core as it is exactly same as value of
>   CPUFREQ_BOOST_FREQ, i.e. ~2.
> 
> The best way to get this fixed is by creating another field flags which will be
> used for such flags. This patch does that. Along with that various drivers need
> modifications due to the change of struct cpufreq_frequency_table.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Thanks for this patch. A minor comment below:

> diff --git a/drivers/cpufreq/exynos4x12-cpufreq.c b/drivers/cpufreq/exynos4x12-cpufreq.c
> index 7c11ace..8c4c6a5 100644
> --- a/drivers/cpufreq/exynos4x12-cpufreq.c
> +++ b/drivers/cpufreq/exynos4x12-cpufreq.c
> @@ -30,21 +30,21 @@ static unsigned int exynos4x12_volt_table[] = {
>  };
> 
>  static struct cpufreq_frequency_table exynos4x12_freq_table[] = {
> -	{CPUFREQ_BOOST_FREQ, 1500 * 1000},
> -	{L1, 1400 * 1000},
> -	{L2, 1300 * 1000},
> -	{L3, 1200 * 1000},
> -	{L4, 1100 * 1000},
> -	{L5, 1000 * 1000},
> -	{L6,  900 * 1000},
> -	{L7,  800 * 1000},
> -	{L8,  700 * 1000},
> -	{L9,  600 * 1000},
> -	{L10, 500 * 1000},
> -	{L11, 400 * 1000},
> -	{L12, 300 * 1000},
> -	{L13, 200 * 1000},
> -	{0, CPUFREQ_TABLE_END},
> +	{CPUFREQ_BOOST_FREQ, 0, 1500 * 1000},
                            ^^^
Functionally it might make no difference, but may be this line can be
rewritten as:
	  {CPUFREQ_BOOST_FREQ, L0, 1500 * 1000}
in order to be consistent with the subsequent entries of the table
which use the .driver_data field to record the indices. And L0 has
been defined in exynos-cpufreq.h 

But I shall leave it to you and Lukasz to decide if it is worth the
while.

> +	{0, L1, 1400 * 1000},
> +	{0, L2, 1300 * 1000},
> +	{0, L3, 1200 * 1000},
> +	{0, L4, 1100 * 1000},
> +	{0, L5, 1000 * 1000},
> +	{0, L6,  900 * 1000},
> +	{0, L7,  800 * 1000},
> +	{0, L8,  700 * 1000},
> +	{0, L9,  600 * 1000},
> +	{0, L10, 500 * 1000},
> +	{0, L11, 400 * 1000},
> +	{0, L12, 300 * 1000},
> +	{0, L13, 200 * 1000},
> +	{0, 0, CPUFREQ_TABLE_END},
>  };
> 

Reviewed-by: Gautham R Shenoy <ego@linux.vnet.ibm.com>

--
Thanks and Regards
gautham.

Re: [PATCH] cpufreq: set value of CPUFREQ_BOOST_FREQ to 0xABABABAB

[Viresh Kumar]

On 24 March 2014 12:18, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> Ideally, .driver_data field of struct cpufreq_frequency_table must not be used
> by core at all. But during a recent change if its value is same as
> CPUFREQ_BOOST_FREQ macro, then it is treated specially by core.
>
> The value of this macro was set to ~2 earlier, i.e. 0xFFFFFFFD. In case some
> driver is using this field for its own data and sets this field to -3, then with
> two's complement that value will also become 0xFFFFFFFD.
>
> To fix this issue, lets change value of this flag to a very uncommon value which
> shouldn't be used by any driver unless they want to use BOOST feature.
>
> Along with this update comments to make this more clear.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---

Please discard this patch now as I have sent a replacement patch.