[PATCH v2 1/2] regmap: Add hardware spinlock support

[PATCH v2 1/2] regmap: Add hardware spinlock support

[Baolin Wang]

On some platforms, when reading or writing some special registers through
regmap, we should acquire one hardware spinlock to synchronize between
the multiple subsystems. Thus this patch adds the hardware spinlock
support for regmap.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
Changes since v1:
 - Move hwspinlock.h including to regmap.c file.
 - Remove hwspin_trylock_xxx() functions.
 - We always set the timeout as maximum values to avoid getting lock failed.
 - Coding style fixes.
---
 drivers/base/regmap/internal.h |    2 +
 drivers/base/regmap/regmap.c   |  101 +++++++++++++++++++++++++++++++++-------
 include/linux/regmap.h         |    6 +++
 3 files changed, 93 insertions(+), 16 deletions(-)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 2a4435d..8641183 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -157,6 +157,8 @@ struct regmap {
 
 	struct rb_root range_tree;
 	void *selector_work_buf;	/* Scratch buffer used for selector */
+
+	struct hwspinlock *hwlock;
 };
 
 struct regcache_ops {
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index b9a779a..999e981 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -20,6 +20,7 @@
 #include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/log2.h>
+#include <linux/hwspinlock.h>
 
 #define CREATE_TRACE_POINTS
 #include "trace.h"
@@ -413,6 +414,49 @@ static unsigned int regmap_parse_64_native(const void *buf)
 }
 #endif
 
+static void regmap_lock_hwlock(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_lock_timeout(map->hwlock, UINT_MAX);
+}
+
+static void regmap_lock_hwlock_irq(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_lock_timeout_irq(map->hwlock, UINT_MAX);
+}
+
+static void regmap_lock_hwlock_irqsave(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_lock_timeout_irqsave(map->hwlock, UINT_MAX,
+				    &map->spinlock_flags);
+}
+
+static void regmap_unlock_hwlock(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_unlock(map->hwlock);
+}
+
+static void regmap_unlock_hwlock_irq(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_unlock_irq(map->hwlock);
+}
+
+static void regmap_unlock_hwlock_irqrestore(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_unlock_irqrestore(map->hwlock, &map->spinlock_flags);
+}
+
 static void regmap_lock_mutex(void *__map)
 {
 	struct regmap *map = __map;
@@ -627,6 +671,29 @@ struct regmap *__regmap_init(struct device *dev,
 		map->lock = config->lock;
 		map->unlock = config->unlock;
 		map->lock_arg = config->lock_arg;
+	} else if (config->hwlock_id) {
+		map->hwlock = hwspin_lock_request_specific(config->hwlock_id);
+		if (!map->hwlock) {
+			ret = -ENXIO;
+			goto err_map;
+		}
+
+		switch (config->hwlock_mode) {
+		case HWLOCK_IRQSTATE:
+			map->lock = regmap_lock_hwlock_irqsave;
+			map->unlock = regmap_unlock_hwlock_irqrestore;
+			break;
+		case HWLOCK_IRQ:
+			map->lock = regmap_lock_hwlock_irq;
+			map->unlock = regmap_unlock_hwlock_irq;
+			break;
+		default:
+			map->lock = regmap_lock_hwlock;
+			map->unlock = regmap_unlock_hwlock;
+			break;
+		}
+
+		map->lock_arg = map;
 	} else {
 		if ((bus && bus->fast_io) ||
 		    config->fast_io) {
@@ -729,7 +796,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_2_6_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -739,7 +806,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_4_12_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -749,7 +816,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_7_9_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -759,7 +826,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_10_14_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -779,13 +846,13 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_reg = regmap_format_16_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
 	case 24:
 		if (reg_endian != REGMAP_ENDIAN_BIG)
-			goto err_map;
+			goto err_hwlock;
 		map->format.format_reg = regmap_format_24;
 		break;
 
@@ -801,7 +868,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_reg = regmap_format_32_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -818,13 +885,13 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_reg = regmap_format_64_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 #endif
 
 	default:
-		goto err_map;
+		goto err_hwlock;
 	}
 
 	if (val_endian == REGMAP_ENDIAN_NATIVE)
@@ -853,12 +920,12 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.parse_val = regmap_parse_16_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 	case 24:
 		if (val_endian != REGMAP_ENDIAN_BIG)
-			goto err_map;
+			goto err_hwlock;
 		map->format.format_val = regmap_format_24;
 		map->format.parse_val = regmap_parse_24;
 		break;
@@ -879,7 +946,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.parse_val = regmap_parse_32_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 #ifdef CONFIG_64BIT
@@ -900,7 +967,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.parse_val = regmap_parse_64_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 #endif
@@ -909,18 +976,18 @@ struct regmap *__regmap_init(struct device *dev,
 	if (map->format.format_write) {
 		if ((reg_endian != REGMAP_ENDIAN_BIG) ||
 		    (val_endian != REGMAP_ENDIAN_BIG))
-			goto err_map;
+			goto err_hwlock;
 		map->use_single_write = true;
 	}
 
 	if (!map->format.format_write &&
 	    !(map->format.format_reg && map->format.format_val))
-		goto err_map;
+		goto err_hwlock;
 
 	map->work_buf = kzalloc(map->format.buf_size, GFP_KERNEL);
 	if (map->work_buf == NULL) {
 		ret = -ENOMEM;
-		goto err_map;
+		goto err_hwlock;
 	}
 
 	if (map->format.format_write) {
@@ -1041,6 +1108,8 @@ struct regmap *__regmap_init(struct device *dev,
 err_range:
 	regmap_range_exit(map);
 	kfree(map->work_buf);
+err_hwlock:
+	hwspin_lock_free(map->hwlock);
 err_map:
 	kfree(map);
 err:
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 978abfb..edc32aa 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -273,6 +273,9 @@ struct regmap_access_table {
  *
  * @ranges: Array of configuration entries for virtual address ranges.
  * @num_ranges: Number of range configuration entries.
+ * @hwlock_id: Specify the hardware spinlock id.
+ * @hwlock_mode: The hardware spinlock mode, should be HWLOCK_IRQSTATE,
+ *		 HWLOCK_IRQ or 0.
  */
 struct regmap_config {
 	const char *name;
@@ -317,6 +320,9 @@ struct regmap_config {
 
 	const struct regmap_range_cfg *ranges;
 	unsigned int num_ranges;
+
+	unsigned int hwlock_id;
+	unsigned int hwlock_mode;
 };
 
 /**
-- 
1.7.9.5

[PATCH v2 2/2] mfd: syscon: Add hardware spinlock support

[Baolin Wang]

Some system control registers need hardware spinlock to synchronize
between the multiple subsystems, so we should add hardware spinlock
support for syscon.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
Changes since v1:
 - Remove timeout configuration.
 - Modify the binding file to add hwlocks.
---
 Documentation/devicetree/bindings/mfd/syscon.txt |    1 +
 drivers/mfd/syscon.c                             |    7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt
index 408f768..3120fdf 100644
--- a/Documentation/devicetree/bindings/mfd/syscon.txt
+++ b/Documentation/devicetree/bindings/mfd/syscon.txt
@@ -16,6 +16,7 @@ Required properties:
 Optional property:
 - reg-io-width: the size (in bytes) of the IO accesses that should be
   performed on the device.
+- hwlocks: reference to a phandle of a hardware spinlock provider node.
 
 Examples:
 gpr: iomuxc-gpr@020e0000 {
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index b93fe4c..f1dccce 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -13,6 +13,7 @@
  */
 
 #include <linux/err.h>
+#include <linux/hwspinlock.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/list.h>
@@ -87,6 +88,12 @@ static struct syscon *of_syscon_register(struct device_node *np)
 	if (ret)
 		reg_io_width = 4;
 
+	ret = of_hwspin_lock_get_id(np, 0);
+	if (ret > 0) {
+		syscon_config.hwlock_id = ret;
+		syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
+	}
+
 	syscon_config.reg_stride = reg_io_width;
 	syscon_config.val_bits = reg_io_width * 8;
 	syscon_config.max_register = resource_size(&res) - reg_io_width;
-- 
1.7.9.5

Applied "regmap: Add hardware spinlock support" to the regmap tree

[Mark Brown]

The patch

   regmap: Add hardware spinlock support

has been applied to the regmap tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git 

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

>From 8698b9364710e7bac84b3af07dd410e39c8c2e08 Mon Sep 17 00:00:00 2001
From: Baolin Wang <baolin.wang@linaro.org>
Date: Wed, 1 Nov 2017 10:11:55 +0800
Subject: [PATCH] regmap: Add hardware spinlock support

On some platforms, when reading or writing some special registers through
regmap, we should acquire one hardware spinlock to synchronize between
the multiple subsystems. Thus this patch adds the hardware spinlock
support for regmap.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/base/regmap/internal.h |   2 +
 drivers/base/regmap/regmap.c   | 101 ++++++++++++++++++++++++++++++++++-------
 include/linux/regmap.h         |   6 +++
 3 files changed, 93 insertions(+), 16 deletions(-)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 2a4435d76028..8641183cac2f 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -157,6 +157,8 @@ struct regmap {
 
 	struct rb_root range_tree;
 	void *selector_work_buf;	/* Scratch buffer used for selector */
+
+	struct hwspinlock *hwlock;
 };
 
 struct regcache_ops {
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index b9a779a4a739..999e981a174a 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -20,6 +20,7 @@
 #include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/log2.h>
+#include <linux/hwspinlock.h>
 
 #define CREATE_TRACE_POINTS
 #include "trace.h"
@@ -413,6 +414,49 @@ static unsigned int regmap_parse_64_native(const void *buf)
 }
 #endif
 
+static void regmap_lock_hwlock(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_lock_timeout(map->hwlock, UINT_MAX);
+}
+
+static void regmap_lock_hwlock_irq(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_lock_timeout_irq(map->hwlock, UINT_MAX);
+}
+
+static void regmap_lock_hwlock_irqsave(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_lock_timeout_irqsave(map->hwlock, UINT_MAX,
+				    &map->spinlock_flags);
+}
+
+static void regmap_unlock_hwlock(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_unlock(map->hwlock);
+}
+
+static void regmap_unlock_hwlock_irq(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_unlock_irq(map->hwlock);
+}
+
+static void regmap_unlock_hwlock_irqrestore(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_unlock_irqrestore(map->hwlock, &map->spinlock_flags);
+}
+
 static void regmap_lock_mutex(void *__map)
 {
 	struct regmap *map = __map;
@@ -627,6 +671,29 @@ struct regmap *__regmap_init(struct device *dev,
 		map->lock = config->lock;
 		map->unlock = config->unlock;
 		map->lock_arg = config->lock_arg;
+	} else if (config->hwlock_id) {
+		map->hwlock = hwspin_lock_request_specific(config->hwlock_id);
+		if (!map->hwlock) {
+			ret = -ENXIO;
+			goto err_map;
+		}
+
+		switch (config->hwlock_mode) {
+		case HWLOCK_IRQSTATE:
+			map->lock = regmap_lock_hwlock_irqsave;
+			map->unlock = regmap_unlock_hwlock_irqrestore;
+			break;
+		case HWLOCK_IRQ:
+			map->lock = regmap_lock_hwlock_irq;
+			map->unlock = regmap_unlock_hwlock_irq;
+			break;
+		default:
+			map->lock = regmap_lock_hwlock;
+			map->unlock = regmap_unlock_hwlock;
+			break;
+		}
+
+		map->lock_arg = map;
 	} else {
 		if ((bus && bus->fast_io) ||
 		    config->fast_io) {
@@ -729,7 +796,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_2_6_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -739,7 +806,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_4_12_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -749,7 +816,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_7_9_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -759,7 +826,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_10_14_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -779,13 +846,13 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_reg = regmap_format_16_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
 	case 24:
 		if (reg_endian != REGMAP_ENDIAN_BIG)
-			goto err_map;
+			goto err_hwlock;
 		map->format.format_reg = regmap_format_24;
 		break;
 
@@ -801,7 +868,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_reg = regmap_format_32_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -818,13 +885,13 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_reg = regmap_format_64_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 #endif
 
 	default:
-		goto err_map;
+		goto err_hwlock;
 	}
 
 	if (val_endian == REGMAP_ENDIAN_NATIVE)
@@ -853,12 +920,12 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.parse_val = regmap_parse_16_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 	case 24:
 		if (val_endian != REGMAP_ENDIAN_BIG)
-			goto err_map;
+			goto err_hwlock;
 		map->format.format_val = regmap_format_24;
 		map->format.parse_val = regmap_parse_24;
 		break;
@@ -879,7 +946,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.parse_val = regmap_parse_32_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 #ifdef CONFIG_64BIT
@@ -900,7 +967,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.parse_val = regmap_parse_64_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 #endif
@@ -909,18 +976,18 @@ struct regmap *__regmap_init(struct device *dev,
 	if (map->format.format_write) {
 		if ((reg_endian != REGMAP_ENDIAN_BIG) ||
 		    (val_endian != REGMAP_ENDIAN_BIG))
-			goto err_map;
+			goto err_hwlock;
 		map->use_single_write = true;
 	}
 
 	if (!map->format.format_write &&
 	    !(map->format.format_reg && map->format.format_val))
-		goto err_map;
+		goto err_hwlock;
 
 	map->work_buf = kzalloc(map->format.buf_size, GFP_KERNEL);
 	if (map->work_buf == NULL) {
 		ret = -ENOMEM;
-		goto err_map;
+		goto err_hwlock;
 	}
 
 	if (map->format.format_write) {
@@ -1041,6 +1108,8 @@ struct regmap *__regmap_init(struct device *dev,
 err_range:
 	regmap_range_exit(map);
 	kfree(map->work_buf);
+err_hwlock:
+	hwspin_lock_free(map->hwlock);
 err_map:
 	kfree(map);
 err:
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 978abfbac617..edc32aac84d7 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -273,6 +273,9 @@ typedef void (*regmap_unlock)(void *);
  *
  * @ranges: Array of configuration entries for virtual address ranges.
  * @num_ranges: Number of range configuration entries.
+ * @hwlock_id: Specify the hardware spinlock id.
+ * @hwlock_mode: The hardware spinlock mode, should be HWLOCK_IRQSTATE,
+ *		 HWLOCK_IRQ or 0.
  */
 struct regmap_config {
 	const char *name;
@@ -317,6 +320,9 @@ struct regmap_config {
 
 	const struct regmap_range_cfg *ranges;
 	unsigned int num_ranges;
+
+	unsigned int hwlock_id;
+	unsigned int hwlock_mode;
 };
 
 /**
-- 
2.15.0.rc2

Re: [PATCH v2 1/2] regmap: Add hardware spinlock support

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 1150 bytes --]

On Wed, Nov 01, 2017 at 10:11:55AM +0800, Baolin Wang wrote:
> On some platforms, when reading or writing some special registers through
> regmap, we should acquire one hardware spinlock to synchronize between
> the multiple subsystems. Thus this patch adds the hardware spinlock
> support for regmap.

The following changes since commit 2bd6bf03f4c1c59381d62c61d03f6cc3fe71f66e:

  Linux 4.14-rc1 (2017-09-16 15:47:51 -0700)

are available in the Git repository at:

  https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git tags/regmap-hwspinlock-support

for you to fetch changes up to 8698b9364710e7bac84b3af07dd410e39c8c2e08:

  regmap: Add hardware spinlock support (2017-11-01 10:06:29 +0000)

----------------------------------------------------------------
regmap: Add hwspinlock support

----------------------------------------------------------------
Baolin Wang (1):
      regmap: Add hardware spinlock support

 drivers/base/regmap/internal.h |   2 +
 drivers/base/regmap/regmap.c   | 101 ++++++++++++++++++++++++++++++++++-------
 include/linux/regmap.h         |   6 +++
 3 files changed, 93 insertions(+), 16 deletions(-)

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH v2 2/2] mfd: syscon: Add hardware spinlock support

[Rob Herring]

On Wed, Nov 01, 2017 at 10:11:56AM +0800, Baolin Wang wrote:
> Some system control registers need hardware spinlock to synchronize
> between the multiple subsystems, so we should add hardware spinlock
> support for syscon.
> 
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> ---
> Changes since v1:
>  - Remove timeout configuration.
>  - Modify the binding file to add hwlocks.
> ---
>  Documentation/devicetree/bindings/mfd/syscon.txt |    1 +
>  drivers/mfd/syscon.c                             |    7 +++++++
>  2 files changed, 8 insertions(+)

Acked-by: Rob Herring <robh@kernel.org>