| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Thu, 3 Jan 2013 14:27:55 +0000
From: Mark Brown <broonie@...nsource.wolfsonmicro.com>
To: linux-kernel@...r.kernel.org
Cc: Mark Brown <broonie@...nsource.wolfsonmicro.com>
Subject: [PATCH 2/2] regmap: irq: Use a bulk read for interrupt status where possible
If the interrupt status registers are a single block of registers and the
chip supports bulk reads then do a single bulk read rather than pay the
extra I/O cost. This restores the original behaviour which was lost when
support for register striding was added.
Signed-off-by: Mark Brown <broonie@...nsource.wolfsonmicro.com>
---
drivers/base/regmap/regmap-irq.c | 67 +++++++++++++++++++++++++++++++++-----
1 file changed, 59 insertions(+), 8 deletions(-)
diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index 329be98..4eab586 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -34,6 +34,7 @@ struct regmap_irq_chip_data {
int irq;
int wake_count;
+ void *status_reg_buf;
unsigned int *status_buf;
unsigned int *mask_buf;
unsigned int *mask_buf_def;
@@ -170,18 +171,58 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
}
}
- for (i = 0; i < data->chip->num_regs; i++) {
- ret = regmap_read(map, chip->status_base + (i * map->reg_stride
- * data->irq_reg_stride),
- &data->status_buf[i]);
-
+ /*
+ * Read in the statuses, using a single bulk read if possible
+ * in order to reduce the I/O overheads.
+ */
+ if (!map->use_single_rw && map->reg_stride == 1 &&
+ data->irq_reg_stride == 1) {
+ u8 *buf8 = data->status_reg_buf;
+ u16 *buf16 = data->status_reg_buf;
+ u32 *buf32 = data->status_reg_buf;
+
+ ret = regmap_bulk_read(map, chip->status_base,
+ data->status_reg_buf,
+ chip->num_regs);
if (ret != 0) {
dev_err(map->dev, "Failed to read IRQ status: %d\n",
- ret);
- if (chip->runtime_pm)
- pm_runtime_put(map->dev);
+ ret);
return IRQ_NONE;
}
+
+ for (i = 0; i < data->chip->num_regs; i++) {
+ switch (map->format.val_bytes) {
+ case 1:
+ data->status_buf[i] = buf8[i];
+ break;
+ case 2:
+ data->status_buf[i] = buf16[i];
+ break;
+ case 4:
+ data->status_buf[i] = buf32[i];
+ break;
+ default:
+ BUG();
+ return IRQ_NONE;
+ }
+ }
+
+ } else {
+ for (i = 0; i < data->chip->num_regs; i++) {
+ ret = regmap_read(map, chip->status_base +
+ (i * map->reg_stride
+ * data->irq_reg_stride),
+ &data->status_buf[i]);
+
+ if (ret != 0) {
+ dev_err(map->dev,
+ "Failed to read IRQ status: %d\n",
+ ret);
+ if (chip->runtime_pm)
+ pm_runtime_put(map->dev);
+ return IRQ_NONE;
+ }
+ }
}
/*
@@ -327,6 +368,14 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
else
d->irq_reg_stride = 1;
+ if (map->reg_stride == 1 && chip->irq_reg_stride == 1) {
+ d->status_reg_buf = kzalloc(sizeof(unsigned int) *
+ chip->num_regs,
+ GFP_KERNEL);
+ if (!d->status_reg_buf)
+ goto err_alloc;
+ }
+
mutex_init(&d->lock);
for (i = 0; i < chip->num_irqs; i++)
@@ -397,6 +446,7 @@ err_alloc:
kfree(d->mask_buf_def);
kfree(d->mask_buf);
kfree(d->status_buf);
+ kfree(d->status_reg_buf);
kfree(d);
return ret;
}
@@ -418,6 +468,7 @@ void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *d)
kfree(d->wake_buf);
kfree(d->mask_buf_def);
kfree(d->mask_buf);
+ kfree(d->status_reg_buf);
kfree(d->status_buf);
kfree(d);
}
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists