[PATCH 03/10] hwspinlock/omap: simplify allocation scheme

From: Ohad Ben-Cohen
Date: Mon Sep 12 2011 - 12:49:40 EST


Instead of allocating every hwspinlock separately, allocate
them all in one shot.

This both simplifies the driver and helps achieving better
slab utilization.

Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Ohad Ben-Cohen <ohad@xxxxxxxxxx>
---
drivers/hwspinlock/omap_hwspinlock.c | 51 +++++++++++----------------------
1 files changed, 17 insertions(+), 34 deletions(-)

diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c
index 1d19fe9..d058348 100644
--- a/drivers/hwspinlock/omap_hwspinlock.c
+++ b/drivers/hwspinlock/omap_hwspinlock.c
@@ -52,6 +52,7 @@ struct omap_hwspinlock {
struct omap_hwspinlock_state {
int num_locks; /* Total number of locks in system */
void __iomem *io_base; /* Mapped base address */
+ struct omap_hwspinlock lock[0]; /* Array of 'num_locks' locks */
};

static int omap_hwspinlock_trylock(struct hwspinlock *lock)
@@ -95,7 +96,6 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev)
{
struct omap_hwspinlock *omap_lock;
struct omap_hwspinlock_state *state;
- struct hwspinlock *lock;
struct resource *res;
void __iomem *io_base;
int i, ret;
@@ -104,15 +104,9 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev)
if (!res)
return -ENODEV;

- state = kzalloc(sizeof(*state), GFP_KERNEL);
- if (!state)
- return -ENOMEM;
-
io_base = ioremap(res->start, resource_size(res));
- if (!io_base) {
- ret = -ENOMEM;
- goto free_state;
- }
+ if (!io_base)
+ return -ENOMEM;

/* Determine number of locks */
i = readl(io_base + SYSSTATUS_OFFSET);
@@ -124,7 +118,15 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev)
goto iounmap_base;
}

- state->num_locks = i * 32;
+ i *= 32; /* actual number of locks in this device */
+
+ state = kzalloc(sizeof(*state) + i * sizeof(*omap_lock), GFP_KERNEL);
+ if (!state) {
+ ret = -ENOMEM;
+ goto iounmap_base;
+ }
+
+ state->num_locks = i;
state->io_base = io_base;

platform_set_drvdata(pdev, state);
@@ -136,11 +138,7 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev)
pm_runtime_enable(&pdev->dev);

for (i = 0; i < state->num_locks; i++) {
- omap_lock = kzalloc(sizeof(*omap_lock), GFP_KERNEL);
- if (!omap_lock) {
- ret = -ENOMEM;
- goto free_locks;
- }
+ omap_lock = &state->lock[i];

omap_lock->lock.dev = &pdev->dev;
omap_lock->lock.id = i;
@@ -148,30 +146,19 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev)
omap_lock->addr = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i;

ret = hwspin_lock_register(&omap_lock->lock);
- if (ret) {
- kfree(omap_lock);
+ if (ret)
goto free_locks;
- }
}

return 0;

free_locks:
- while (--i >= 0) {
- lock = hwspin_lock_unregister(i);
- /* this should't happen, but let's give our best effort */
- if (!lock) {
- dev_err(&pdev->dev, "%s: cleanups failed\n", __func__);
- continue;
- }
- omap_lock = to_omap_hwspinlock(lock);
- kfree(omap_lock);
- }
+ while (--i >= 0)
+ hwspin_lock_unregister(i);
pm_runtime_disable(&pdev->dev);
+ kfree(state);
iounmap_base:
iounmap(io_base);
-free_state:
- kfree(state);
return ret;
}

@@ -179,7 +166,6 @@ static int omap_hwspinlock_remove(struct platform_device *pdev)
{
struct omap_hwspinlock_state *state = platform_get_drvdata(pdev);
struct hwspinlock *lock;
- struct omap_hwspinlock *omap_lock;
int i;

for (i = 0; i < state->num_locks; i++) {
@@ -190,9 +176,6 @@ static int omap_hwspinlock_remove(struct platform_device *pdev)
dev_err(&pdev->dev, "%s: failed on %d\n", __func__, i);
return -EBUSY;
}
-
- omap_lock = to_omap_hwspinlock(lock);
- kfree(omap_lock);
}

pm_runtime_disable(&pdev->dev);
--
1.7.4.1

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