Minor optimizations for Intel pinctrl

PATCH Superseded Raag Jadav 3 participants 11 messages Jun 8, 2023

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GPIO Pin control Pin controller - Intel

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Raag Jadav

author

2023-06-08 07:01 UTC #0 lore raw

cover Minor optimizations for Intel pinctrl

This series implements minor optimizations for Intel pinctrl driver.

The numbers are as tested with gcc 7.5.0 and may vary with newer versions.

Raag Jadav (4):
pinctrl: intel: optimize set_mux hook
pinctrl: intel: optimize irq_set_type hook
pinctrl: intel: simplify exit path of set_mux hook
pinctrl: intel: simplify exit path of gpio_request_enable hook

 drivers/pinctrl/intel/pinctrl-intel.c | 63 +++++++++++++++------------
 1 file changed, 35 insertions(+), 28 deletions(-)

Signature · 1 line

2.17.1

Raag Jadav

author

2023-06-08 07:02 UTC #1 lore raw

PATCH 1/4 pinctrl: intel: optimize set_mux hook

Utilize a temporary variable for common shift operation inside ->set_mux() hook and save a few bytes.

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-3 (-3)

Function                                     old     new   delta
intel_pinmux_set_mux                         245     242      -3

Total: Before=10472, After=10469, chg -0.03%

Signed-off-by Raag Jadav <[email protected]>

---
 drivers/pinctrl/intel/pinctrl-intel.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

drivers/pinctrl/intel/pinctrl-intel.c +5 -4

index c7a71c49df0a..e8adf2580321 100644
@@ -411,18 +411,19 @@ static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev,
 	/* Now enable the mux setting for each pin in the group */
 	for (i = 0; i < grp->grp.npins; i++) {
 		void __iomem *padcfg0;
-		u32 value;
+		u32 value, pmode;
 
 		padcfg0 = intel_get_padcfg(pctrl, grp->grp.pins[i], PADCFG0);
-		value = readl(padcfg0);
 
+		value = readl(padcfg0);
 		value &= ~PADCFG0_PMODE_MASK;
 
 		if (grp->modes)
-			value |= grp->modes[i] << PADCFG0_PMODE_SHIFT;
+			pmode = grp->modes[i];
 		else
-			value |= grp->mode << PADCFG0_PMODE_SHIFT;
+			pmode = grp->mode;
 
+		value |= pmode << PADCFG0_PMODE_SHIFT;
 		writel(value, padcfg0);
 	}

Signature · 1 line

2.17.1

Mika Westerberg

maintainer

2023-06-08 08:08 UTC #2 lore raw

Re: [PATCH v1 1/4] pinctrl: intel: optimize set_mux hook

Quoted 7 lines · Raag Jadav

Utilize a temporary variable for common shift operation inside ->set_mux() hook and save a few bytes.
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-3 (-3)
Function                                     old     new   delta
intel_pinmux_set_mux                         245     242      -3
Total: Before=10472, After=10469, chg -0.03%

Shouldn't the compiler be able to optimize this if you ask with the -Ox options?

I don't really see much benefit for "optimizations" like this. That said using temporary variable here improves readability so this one is acceptable by me. As long as you change the commit message accordingly.

Quoted 35 lines

Signed-off-by Raag Jadav <[email protected]>

---
 drivers/pinctrl/intel/pinctrl-intel.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

drivers/pinctrl/intel/pinctrl-intel.c +5 -4

index c7a71c49df0a..e8adf2580321 100644
@@ -411,18 +411,19 @@ static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev,
 	/* Now enable the mux setting for each pin in the group */
 	for (i = 0; i < grp->grp.npins; i++) {
 		void __iomem *padcfg0;
-		u32 value;
+		u32 value, pmode;
 
 		padcfg0 = intel_get_padcfg(pctrl, grp->grp.pins[i], PADCFG0);
-		value = readl(padcfg0);
 
+		value = readl(padcfg0);
 		value &= ~PADCFG0_PMODE_MASK;
 
 		if (grp->modes)
-			value |= grp->modes[i] << PADCFG0_PMODE_SHIFT;
+			pmode = grp->modes[i];
 		else
-			value |= grp->mode << PADCFG0_PMODE_SHIFT;
+			pmode = grp->mode;
 
+		value |= pmode << PADCFG0_PMODE_SHIFT;
 		writel(value, padcfg0);
 	}

Signature · 1 line

2.17.1

Jadav, Raag

author

2023-06-08 10:21 UTC #3 lore raw

RE: [PATCH v1 1/4] pinctrl: intel: optimize set_mux hook

Quoted 11 lines · Raag Jadav

Quoted 7 lines
Utilize a temporary variable for common shift operation inside ->set_mux() hook and save a few bytes.
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-3 (-3)
Function                                     old     new   delta
intel_pinmux_set_mux                         245     242      -3
Total: Before=10472, After=10469, chg -0.03%
Shouldn't the compiler be able to optimize this if you ask with the -Ox options?

Forgot to add. This is with default -O2.
Is it a good idea to mention it?

Quoted 3 lines

I don't really see much benefit for "optimizations" like this. That said using temporary variable here improves readability so this one is acceptable by me. As long as you change the commit message accordingly.

Mika Westerberg

maintainer

2023-06-08 10:56 UTC #4 lore raw

Re: [PATCH v1 1/4] pinctrl: intel: optimize set_mux hook

Quoted 9 lines · Raag

Quoted 9 lines · Raag Jadav
Quoted 7 lines
Utilize a temporary variable for common shift operation inside ->set_mux() hook and save a few bytes.
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-3 (-3)
Function                                     old     new   delta
intel_pinmux_set_mux                         245     242      -3
Total: Before=10472, After=10469, chg -0.03%

Quoted 5 lines

Quoted 2 lines
Shouldn't the compiler be able to optimize this if you ask with the -Ox options?
Forgot to add. This is with default -O2.
Is it a good idea to mention it?

Yes, I think it is.

Raag Jadav

author

2023-06-08 07:01 UTC #5 lore raw

PATCH 2/4 pinctrl: intel: optimize irq_set_type hook

In reply to Raag Jadav

Utilize a temporary variable for common shift operation inside ->irq_set_type() hook and save a few bytes. While at it, simplify if-else-if chain.

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-16 (-16)

Function                                     old     new   delta
intel_gpio_irq_type                          317     301     -16

Total: Before=10469, After=10453, chg -0.15%

Signed-off-by Raag Jadav <[email protected]>

---
 drivers/pinctrl/intel/pinctrl-intel.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

drivers/pinctrl/intel/pinctrl-intel.c +10 -9

index e8adf2580321..3f78066b1837 100644
@@ -1128,8 +1128,8 @@ static int intel_gpio_irq_type(struct irq_data *d, unsigned int type)
 	struct intel_pinctrl *pctrl = gpiochip_get_data(gc);
 	unsigned int pin = intel_gpio_to_pin(pctrl, irqd_to_hwirq(d), NULL, NULL);
 	unsigned long flags;
+	u32 value, rxevcfg;
 	void __iomem *reg;
-	u32 value;
 
 	reg = intel_get_padcfg(pctrl, pin, PADCFG0);
 	if (!reg)

@@ -1150,23 +1150,24 @@ static int intel_gpio_irq_type(struct irq_data *d, unsigned int type)
 	intel_gpio_set_gpio_mode(reg);
 
 	value = readl(reg);
-
 	value &= ~(PADCFG0_RXEVCFG_MASK | PADCFG0_RXINV);
 
 	if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
-		value |= PADCFG0_RXEVCFG_EDGE_BOTH << PADCFG0_RXEVCFG_SHIFT;
+		rxevcfg = PADCFG0_RXEVCFG_EDGE_BOTH;
 	} else if (type & IRQ_TYPE_EDGE_FALLING) {
-		value |= PADCFG0_RXEVCFG_EDGE << PADCFG0_RXEVCFG_SHIFT;
-		value |= PADCFG0_RXINV;
+		rxevcfg = PADCFG0_RXEVCFG_EDGE;
 	} else if (type & IRQ_TYPE_EDGE_RISING) {
-		value |= PADCFG0_RXEVCFG_EDGE << PADCFG0_RXEVCFG_SHIFT;
+		rxevcfg = PADCFG0_RXEVCFG_EDGE;
 	} else if (type & IRQ_TYPE_LEVEL_MASK) {
-		if (type & IRQ_TYPE_LEVEL_LOW)
-			value |= PADCFG0_RXINV;
+		rxevcfg = PADCFG0_RXEVCFG_LEVEL;
 	} else {
-		value |= PADCFG0_RXEVCFG_DISABLED << PADCFG0_RXEVCFG_SHIFT;
+		rxevcfg = PADCFG0_RXEVCFG_DISABLED;
 	}
 
+	if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW)
+		value |= PADCFG0_RXINV;
+
+	value |= rxevcfg << PADCFG0_RXEVCFG_SHIFT;
 	writel(value, reg);
 
 	if (type & IRQ_TYPE_EDGE_BOTH)

Signature · 1 line

2.17.1

Raag Jadav

author

2023-06-08 07:02 UTC #6 lore raw

PATCH 3/4 pinctrl: intel: simplify exit path of set_mux hook

In reply to Raag Jadav

Simplify exit path of ->set_mux() hook and save a few bytes.

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-22 (-22)

Function                                     old     new   delta
intel_pinmux_set_mux                         242     220     -22

Total: Before=10453, After=10431, chg -0.21%

Signed-off-by Raag Jadav <[email protected]>

---
 drivers/pinctrl/intel/pinctrl-intel.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

drivers/pinctrl/intel/pinctrl-intel.c +8 -4

index 3f78066b1837..1b5745202058 100644
@@ -393,7 +393,10 @@ static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev,
 	struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
 	const struct intel_pingroup *grp = &pctrl->soc->groups[group];
 	unsigned long flags;
-	int i;
+	int i, ret;
+
+	/* In case we never really enter any of the below loops */
+	ret = 0;
 
 	raw_spin_lock_irqsave(&pctrl->lock, flags);

@@ -403,8 +406,8 @@ static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev,
 	 */
 	for (i = 0; i < grp->grp.npins; i++) {
 		if (!intel_pad_usable(pctrl, grp->grp.pins[i])) {
-			raw_spin_unlock_irqrestore(&pctrl->lock, flags);
-			return -EBUSY;
+			ret = -EBUSY;
+			goto out_unlock;
 		}
 	}

@@ -427,9 +430,10 @@ static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev,
 		writel(value, padcfg0);
 	}
 
+out_unlock:
 	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 
-	return 0;
+	return ret;
 }
 
 static void __intel_gpio_set_direction(void __iomem *padcfg0, bool input)

Signature · 1 line

2.17.1

Mika Westerberg

maintainer

2023-06-08 08:10 UTC #7 lore raw

Re: [PATCH v1 3/4] pinctrl: intel: simplify exit path of set_mux hook

Quoted 17 lines · Raag Jadav

Simplify exit path of ->set_mux() hook and save a few bytes.
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-22 (-22)
Function                                     old     new   delta
intel_pinmux_set_mux                         242     220     -22
Total: Before=10453, After=10431, chg -0.21%
Signed-off-by Raag Jadav <[email protected]>
---
 drivers/pinctrl/intel/pinctrl-intel.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)
drivers/pinctrl/intel/pinctrl-intel.c +0 -0
index 3f78066b1837..1b5745202058 100644

drivers/pinctrl/intel/pinctrl-intel.c static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev, · line 399

Quoted 8 lines

drivers/pinctrl/intel/pinctrl-intel.c +4 -1

@@ -393,7 +393,10 @@ static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev,
 	struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
 	const struct intel_pingroup *grp = &pctrl->soc->groups[group];
 	unsigned long flags;
-	int i;
+	int i, ret;
+
+	/* In case we never really enter any of the below loops */
+	ret = 0;

How can that happen?

Raag Jadav

author

2023-06-08 07:02 UTC #8 lore raw

PATCH 4/4 pinctrl: intel: simplify exit path of gpio_request_enable hook

In reply to Raag Jadav

Simplify exit path of ->gpio_request_enable() hook and save a few bytes.

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-36 (-36)

Function                                     old     new   delta
intel_gpio_request_enable                    186     150     -36

Total: Before=10431, After=10395, chg -0.35%

Signed-off-by Raag Jadav <[email protected]>

---
 drivers/pinctrl/intel/pinctrl-intel.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

drivers/pinctrl/intel/pinctrl-intel.c +12 ~~-11~~

index 1b5745202058..947797d87c93 100644
@@ -489,20 +489,22 @@ static int intel_gpio_request_enable(struct pinctrl_dev *pctldev,
 	struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
 	void __iomem *padcfg0;
 	unsigned long flags;
+	int ret;
 
 	padcfg0 = intel_get_padcfg(pctrl, pin, PADCFG0);
 
+	/* For positive cases */
+	ret = 0;
+
 	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	if (!intel_pad_owned_by_host(pctrl, pin)) {
-		raw_spin_unlock_irqrestore(&pctrl->lock, flags);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto out_unlock;
 	}
 
-	if (!intel_pad_is_unlocked(pctrl, pin)) {
-		raw_spin_unlock_irqrestore(&pctrl->lock, flags);
-		return 0;
-	}
+	if (!intel_pad_is_unlocked(pctrl, pin))
+		goto out_unlock;
 
 	/*
 	 * If pin is already configured in GPIO mode, we assume that

@@ -510,16 +512,15 @@ static int intel_gpio_request_enable(struct pinctrl_dev *pctldev,
 	 * potential glitches on the pin. Otherwise, for the pin in
 	 * alternative mode, consumer has to supply respective flags.
 	 */
-	if (intel_gpio_get_gpio_mode(padcfg0) == PADCFG0_PMODE_GPIO) {
-		raw_spin_unlock_irqrestore(&pctrl->lock, flags);
-		return 0;
-	}
+	if (intel_gpio_get_gpio_mode(padcfg0) == PADCFG0_PMODE_GPIO)
+		goto out_unlock;
 
 	intel_gpio_set_gpio_mode(padcfg0);
 
+out_unlock:
 	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 
-	return 0;
+	return ret;
 }
 
 static int intel_gpio_set_direction(struct pinctrl_dev *pctldev,

Signature · 1 line

2.17.1

Mika Westerberg

maintainer

2023-06-08 08:10 UTC #9 lore raw

Re: [PATCH v1 4/4] pinctrl: intel: simplify exit path of gpio_request_enable hook

Quoted 18 lines · Raag Jadav

Simplify exit path of ->gpio_request_enable() hook and save a few bytes.
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-36 (-36)
Function                                     old     new   delta
intel_gpio_request_enable                    186     150     -36
Total: Before=10431, After=10395, chg -0.35%
Signed-off-by Raag Jadav <[email protected]>
---
 drivers/pinctrl/intel/pinctrl-intel.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)
drivers/pinctrl/intel/pinctrl-intel.c +0 -0
index 1b5745202058..947797d87c93 100644

drivers/pinctrl/intel/pinctrl-intel.c static int intel_gpio_request_enable(struct pinctrl_dev *pctldev, · line 497

Quoted 9 lines

drivers/pinctrl/intel/pinctrl-intel.c +3 -0

@@ -489,20 +489,22 @@ static int intel_gpio_request_enable(struct pinctrl_dev *pctldev,
 	struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
 	void __iomem *padcfg0;
 	unsigned long flags;
+	int ret;
 
 	padcfg0 = intel_get_padcfg(pctrl, pin, PADCFG0);
 
+	/* For positive cases */
+	ret = 0;

You can set it

	int ret = 0;

and drop the useless comment.

Quoted 42 lines

drivers/pinctrl/intel/pinctrl-intel.c +9 ~~-11~~

+
 	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
 	if (!intel_pad_owned_by_host(pctrl, pin)) {
-		raw_spin_unlock_irqrestore(&pctrl->lock, flags);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto out_unlock;
 	}
 
-	if (!intel_pad_is_unlocked(pctrl, pin)) {
-		raw_spin_unlock_irqrestore(&pctrl->lock, flags);
-		return 0;
-	}
+	if (!intel_pad_is_unlocked(pctrl, pin))
+		goto out_unlock;
 
 	/*
 	 * If pin is already configured in GPIO mode, we assume that

@@ -510,16 +512,15 @@ static int intel_gpio_request_enable(struct pinctrl_dev *pctldev,
 	 * potential glitches on the pin. Otherwise, for the pin in
 	 * alternative mode, consumer has to supply respective flags.
 	 */
-	if (intel_gpio_get_gpio_mode(padcfg0) == PADCFG0_PMODE_GPIO) {
-		raw_spin_unlock_irqrestore(&pctrl->lock, flags);
-		return 0;
-	}
+	if (intel_gpio_get_gpio_mode(padcfg0) == PADCFG0_PMODE_GPIO)
+		goto out_unlock;
 
 	intel_gpio_set_gpio_mode(padcfg0);
 
+out_unlock:
 	raw_spin_unlock_irqrestore(&pctrl->lock, flags);
 
-	return 0;
+	return ret;
 }
 
 static int intel_gpio_set_direction(struct pinctrl_dev *pctldev,

Signature · 1 line

2.17.1

Andy Shevchenko

2023-06-08 14:30 UTC #10 lore raw

In reply to Raag Jadav

Quoted 3 lines · Raag Jadav

This series implements minor optimizations for Intel pinctrl driver.
The numbers are as tested with gcc 7.5.0 and may vary with newer versions.

Please, follow what Mika commented on on both series and issue v2 of each of them.

Signature · 2 lines

With Best Regards,
Andy Shevchenko