From: Sebastian Ott <sebott@linux.ibm.com>
Date: Wed, 27 Feb 2019 13:56:08 +0100
Subject: s390/airq: provide cacheline aligned ivs
Git-commit: 414cbd1e3d14ec0e60666a0fb9d8ae2d77eb7c63
Patch-mainline: v5.2-rc1
References: jsc#SLE-5789 FATE#327042 bsc#1134730 LTC#173388
Provide the ability to create cachesize aligned interrupt vectors.
These will be used for per-CPU interrupt vectors.
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
arch/s390/include/asm/airq.h | 10 ++++++----
drivers/s390/cio/airq.c | 39 ++++++++++++++++++++++++++++++++++-----
2 files changed, 40 insertions(+), 9 deletions(-)
--- a/arch/s390/include/asm/airq.h
+++ b/arch/s390/include/asm/airq.h
@@ -34,13 +34,15 @@ struct airq_iv {
unsigned int *data; /* 32 bit value associated with each bit */
unsigned long bits; /* Number of bits in the vector */
unsigned long end; /* Number of highest allocated bit + 1 */
+ unsigned long flags; /* Allocation flags */
spinlock_t lock; /* Lock to protect alloc & free */
};
-#define AIRQ_IV_ALLOC 1 /* Use an allocation bit mask */
-#define AIRQ_IV_BITLOCK 2 /* Allocate the lock bit mask */
-#define AIRQ_IV_PTR 4 /* Allocate the ptr array */
-#define AIRQ_IV_DATA 8 /* Allocate the data array */
+#define AIRQ_IV_ALLOC 1 /* Use an allocation bit mask */
+#define AIRQ_IV_BITLOCK 2 /* Allocate the lock bit mask */
+#define AIRQ_IV_PTR 4 /* Allocate the ptr array */
+#define AIRQ_IV_DATA 8 /* Allocate the data array */
+#define AIRQ_IV_CACHELINE 16 /* Cacheline alignment for the vector */
struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags);
void airq_iv_release(struct airq_iv *iv);
--- a/drivers/s390/cio/airq.c
+++ b/drivers/s390/cio/airq.c
@@ -26,6 +26,8 @@
static DEFINE_SPINLOCK(airq_lists_lock);
static struct hlist_head airq_lists[MAX_ISC+1];
+static struct kmem_cache *airq_iv_cache;
+
/**
* register_adapter_interrupt() - register adapter interrupt handler
* @airq: pointer to adapter interrupt descriptor
@@ -128,10 +130,21 @@ struct airq_iv *airq_iv_create(unsigned
if (!iv)
goto out;
iv->bits = bits;
+ iv->flags = flags;
size = BITS_TO_LONGS(bits) * sizeof(unsigned long);
- iv->vector = kzalloc(size, GFP_KERNEL);
- if (!iv->vector)
- goto out_free;
+
+ if (flags & AIRQ_IV_CACHELINE) {
+ if ((cache_line_size() * BITS_PER_BYTE) < bits)
+ goto out_free;
+
+ iv->vector = kmem_cache_zalloc(airq_iv_cache, GFP_KERNEL);
+ if (!iv->vector)
+ goto out_free;
+ } else {
+ iv->vector = kzalloc(size, GFP_KERNEL);
+ if (!iv->vector)
+ goto out_free;
+ }
if (flags & AIRQ_IV_ALLOC) {
iv->avail = kmalloc(size, GFP_KERNEL);
if (!iv->avail)
@@ -164,7 +177,10 @@ out_free:
kfree(iv->ptr);
kfree(iv->bitlock);
kfree(iv->avail);
- kfree(iv->vector);
+ if (iv->flags & AIRQ_IV_CACHELINE)
+ kmem_cache_free(airq_iv_cache, iv->vector);
+ else
+ kfree(iv->vector);
kfree(iv);
out:
return NULL;
@@ -180,7 +196,10 @@ void airq_iv_release(struct airq_iv *iv)
kfree(iv->data);
kfree(iv->ptr);
kfree(iv->bitlock);
- kfree(iv->vector);
+ if (iv->flags & AIRQ_IV_CACHELINE)
+ kmem_cache_free(airq_iv_cache, iv->vector);
+ else
+ kfree(iv->vector);
kfree(iv->avail);
kfree(iv);
}
@@ -274,3 +293,13 @@ unsigned long airq_iv_scan(struct airq_i
return bit;
}
EXPORT_SYMBOL(airq_iv_scan);
+
+static int __init airq_init(void)
+{
+ airq_iv_cache = kmem_cache_create("airq_iv_cache", cache_line_size(),
+ cache_line_size(), 0, NULL);
+ if (!airq_iv_cache)
+ return -ENOMEM;
+ return 0;
+}
+subsys_initcall(airq_init);