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regulator: qcom_spmi: Constify struct spmi_voltage_range

Message ID ef2a4b6df61e19470ddf6cbd1f3ca1ce88a3c1a0.1747570556.git.christophe.jaillet@wanadoo.fr
State Accepted
Commit e9be77134469df4a11da898bec2bfc137700a9f3
Headers show
Series regulator: qcom_spmi: Constify struct spmi_voltage_range | expand

Commit Message

Christophe JAILLET May 18, 2025, 12:16 p.m. UTC 
'struct spmi_voltage_range' are only modified at runtime to compile a
field, n_voltages, that could be computed at compile time.

So, simplify spmi_calculate_num_voltages() and compute n_voltages at
compile time within the SPMI_VOLTAGE_RANGE macro.

Constifying these structures moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  85437	  26776	    512	 112725	  1b855	drivers/regulator/qcom_spmi-regulator.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  86857	  24760	    512	 112129	  1b601	drivers/regulator/qcom_spmi-regulator.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested-only.

I've also checked in the .s file that n_voltages was set initialized with
the correct value.
---
 drivers/regulator/qcom_spmi-regulator.c | 69 ++++++++++++-------------
 1 file changed, 32 insertions(+), 37 deletions(-)

Comments

Mark Brown May 20, 2025, 9:20 a.m. UTC | #1 
On Sun, 18 May 2025 14:16:21 +0200, Christophe JAILLET wrote:
> 'struct spmi_voltage_range' are only modified at runtime to compile a
> field, n_voltages, that could be computed at compile time.
> 
> So, simplify spmi_calculate_num_voltages() and compute n_voltages at
> compile time within the SPMI_VOLTAGE_RANGE macro.
> 
> Constifying these structures moves some data to a read-only section, so
> increase overall security.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next

Thanks!

[1/1] regulator: qcom_spmi: Constify struct spmi_voltage_range
      commit: e9be77134469df4a11da898bec2bfc137700a9f3

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark
diff mbox series

Patch

diff --git a/drivers/regulator/qcom_spmi-regulator.c b/drivers/regulator/qcom_spmi-regulator.c
index d66a0f61637e..c1a41ce70b36 100644
--- a/drivers/regulator/qcom_spmi-regulator.c
+++ b/drivers/regulator/qcom_spmi-regulator.c
@@ -400,7 +400,7 @@  struct spmi_voltage_range {
  * so that range[i].set_point_max_uV < range[i+1].set_point_min_uV.
  */
 struct spmi_voltage_set_points {
-	struct spmi_voltage_range		*range;
+	const struct spmi_voltage_range		*range;
 	int					count;
 	unsigned				n_voltages;
 };
@@ -474,6 +474,9 @@  struct spmi_regulator_data {
 		.set_point_max_uV	= _set_point_max_uV, \
 		.step_uV		= _step_uV, \
 		.range_sel		= _range_sel, \
+		.n_voltages		= (_set_point_max_uV != 0) ? \
+						((_set_point_max_uV - _set_point_min_uV) / _step_uV) + 1 : \
+						0, \
 	}
 
 #define DEFINE_SPMI_SET_POINTS(name) \
@@ -489,110 +492,110 @@  struct spmi_voltage_set_points name##_set_points = { \
  * increasing and unique.  The set_voltage callback functions expect these
  * properties to hold.
  */
-static struct spmi_voltage_range pldo_ranges[] = {
+static const struct spmi_voltage_range pldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(2,  750000,  750000, 1537500, 1537500, 12500),
 	SPMI_VOLTAGE_RANGE(3, 1500000, 1550000, 3075000, 3075000, 25000),
 	SPMI_VOLTAGE_RANGE(4, 1750000, 3100000, 4900000, 4900000, 50000),
 };
 
-static struct spmi_voltage_range nldo1_ranges[] = {
+static const struct spmi_voltage_range nldo1_ranges[] = {
 	SPMI_VOLTAGE_RANGE(2,  750000,  750000, 1537500, 1537500, 12500),
 };
 
-static struct spmi_voltage_range nldo2_ranges[] = {
+static const struct spmi_voltage_range nldo2_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,       0,       0, 1537500, 12500),
 	SPMI_VOLTAGE_RANGE(1,  375000,  375000,  768750,  768750,  6250),
 	SPMI_VOLTAGE_RANGE(2,  750000,  775000, 1537500, 1537500, 12500),
 };
 
-static struct spmi_voltage_range nldo3_ranges[] = {
+static const struct spmi_voltage_range nldo3_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,  375000, 1537500, 1537500, 12500),
 	SPMI_VOLTAGE_RANGE(1,  375000,       0,       0, 1537500, 12500),
 	SPMI_VOLTAGE_RANGE(2,  750000,       0,       0, 1537500, 12500),
 };
 
-static struct spmi_voltage_range ln_ldo_ranges[] = {
+static const struct spmi_voltage_range ln_ldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(1,  690000,  690000, 1110000, 1110000, 60000),
 	SPMI_VOLTAGE_RANGE(0, 1380000, 1380000, 2220000, 2220000, 120000),
 };
 
-static struct spmi_voltage_range smps_ranges[] = {
+static const struct spmi_voltage_range smps_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,  375000, 1562500, 1562500, 12500),
 	SPMI_VOLTAGE_RANGE(1, 1550000, 1575000, 3125000, 3125000, 25000),
 };
 
-static struct spmi_voltage_range ftsmps_ranges[] = {
+static const struct spmi_voltage_range ftsmps_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,       0,  350000, 1275000, 1275000,  5000),
 	SPMI_VOLTAGE_RANGE(1,       0, 1280000, 2040000, 2040000, 10000),
 };
 
-static struct spmi_voltage_range ftsmps2p5_ranges[] = {
+static const struct spmi_voltage_range ftsmps2p5_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,   80000,  350000, 1355000, 1355000,  5000),
 	SPMI_VOLTAGE_RANGE(1,  160000, 1360000, 2200000, 2200000, 10000),
 };
 
-static struct spmi_voltage_range ftsmps426_ranges[] = {
+static const struct spmi_voltage_range ftsmps426_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,       0,  320000, 1352000, 1352000,  4000),
 };
 
-static struct spmi_voltage_range boost_ranges[] = {
+static const struct spmi_voltage_range boost_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 4000000, 4000000, 5550000, 5550000, 50000),
 };
 
-static struct spmi_voltage_range boost_byp_ranges[] = {
+static const struct spmi_voltage_range boost_byp_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 2500000, 2500000, 5200000, 5650000, 50000),
 };
 
-static struct spmi_voltage_range ult_lo_smps_ranges[] = {
+static const struct spmi_voltage_range ult_lo_smps_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,  375000, 1562500, 1562500, 12500),
 	SPMI_VOLTAGE_RANGE(1,  750000,       0,       0, 1525000, 25000),
 };
 
-static struct spmi_voltage_range ult_ho_smps_ranges[] = {
+static const struct spmi_voltage_range ult_ho_smps_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1550000, 1550000, 2325000, 2325000, 25000),
 };
 
-static struct spmi_voltage_range ult_nldo_ranges[] = {
+static const struct spmi_voltage_range ult_nldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  375000,  375000, 1537500, 1537500, 12500),
 };
 
-static struct spmi_voltage_range ult_pldo_ranges[] = {
+static const struct spmi_voltage_range ult_pldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1750000, 1750000, 3337500, 3337500, 12500),
 };
 
-static struct spmi_voltage_range pldo660_ranges[] = {
+static const struct spmi_voltage_range pldo660_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1504000, 1504000, 3544000, 3544000, 8000),
 };
 
-static struct spmi_voltage_range nldo660_ranges[] = {
+static const struct spmi_voltage_range nldo660_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  320000,  320000, 1304000, 1304000, 8000),
 };
 
-static struct spmi_voltage_range ht_lvpldo_ranges[] = {
+static const struct spmi_voltage_range ht_lvpldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1504000, 1504000, 2000000, 2000000, 8000),
 };
 
-static struct spmi_voltage_range ht_nldo_ranges[] = {
+static const struct spmi_voltage_range ht_nldo_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0,  312000,  312000, 1304000, 1304000, 8000),
 };
 
-static struct spmi_voltage_range hfs430_ranges[] = {
+static const struct spmi_voltage_range hfs430_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 320000, 320000, 2040000, 2040000, 8000),
 };
 
-static struct spmi_voltage_range ht_p150_ranges[] = {
+static const struct spmi_voltage_range ht_p150_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1616000, 1616000, 3304000, 3304000, 8000),
 };
 
-static struct spmi_voltage_range ht_p600_ranges[] = {
+static const struct spmi_voltage_range ht_p600_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 1704000, 1704000, 1896000, 1896000, 8000),
 };
 
-static struct spmi_voltage_range nldo_510_ranges[] = {
+static const struct spmi_voltage_range nldo_510_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 320000, 320000, 1304000, 1304000, 8000),
 };
 
-static struct spmi_voltage_range ftsmps510_ranges[] = {
+static const struct spmi_voltage_range ftsmps510_ranges[] = {
 	SPMI_VOLTAGE_RANGE(0, 300000, 300000, 1372000, 1372000, 4000),
 };
 
@@ -1676,18 +1679,10 @@  static const struct spmi_regulator_mapping supported_regulators[] = {
 
 static void spmi_calculate_num_voltages(struct spmi_voltage_set_points *points)
 {
-	unsigned int n;
-	struct spmi_voltage_range *range = points->range;
-
-	for (; range < points->range + points->count; range++) {
-		n = 0;
-		if (range->set_point_max_uV) {
-			n = range->set_point_max_uV - range->set_point_min_uV;
-			n = (n / range->step_uV) + 1;
-		}
-		range->n_voltages = n;
-		points->n_voltages += n;
-	}
+	const struct spmi_voltage_range *range = points->range;
+
+	for (; range < points->range + points->count; range++)
+		points->n_voltages += range->n_voltages;
 }
 
 static int spmi_regulator_match(struct spmi_regulator *vreg, u16 force_type)