From 5245c924c2191ee0f39d8586a57178baba13dbf2 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Fri, 27 Jun 2014 16:56:18 +0200 Subject: [PATCH] s390/qdio: add helpers to manage qdio buffers Users of qdio buffers employ different strategies to manage these buffers. The qeth driver uses huge contiguous buffers which leads to high order allocations with all their downsides. This patch provides helpers to allocate, free, and reset arrays of qdio buffers using non contiguous pages. Reviewed-by: Martin Peschke Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/qdio.h | 4 +++ drivers/s390/cio/qdio_setup.c | 53 +++++++++++++++++++++++++++++++++++ 2 files changed, 57 insertions(+) diff --git a/arch/s390/include/asm/qdio.h b/arch/s390/include/asm/qdio.h index d786c634e052..06f3034605a1 100644 --- a/arch/s390/include/asm/qdio.h +++ b/arch/s390/include/asm/qdio.h @@ -415,6 +415,10 @@ struct qdio_brinfo_entry_l2 { #define QDIO_FLAG_SYNC_OUTPUT 0x02 #define QDIO_FLAG_PCI_OUT 0x10 +int qdio_alloc_buffers(struct qdio_buffer **buf, unsigned int count); +void qdio_free_buffers(struct qdio_buffer **buf, unsigned int count); +void qdio_reset_buffers(struct qdio_buffer **buf, unsigned int count); + extern int qdio_allocate(struct qdio_initialize *); extern int qdio_establish(struct qdio_initialize *); extern int qdio_activate(struct ccw_device *); diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c index f5f4a91fab44..f76bff68d1de 100644 --- a/drivers/s390/cio/qdio_setup.c +++ b/drivers/s390/cio/qdio_setup.c @@ -17,6 +17,8 @@ #include "qdio.h" #include "qdio_debug.h" +#define QBUFF_PER_PAGE (PAGE_SIZE / sizeof(struct qdio_buffer)) + static struct kmem_cache *qdio_q_cache; static struct kmem_cache *qdio_aob_cache; @@ -32,6 +34,57 @@ void qdio_release_aob(struct qaob *aob) } EXPORT_SYMBOL_GPL(qdio_release_aob); +/** + * qdio_free_buffers() - free qdio buffers + * @buf: array of pointers to qdio buffers + * @count: number of qdio buffers to free + */ +void qdio_free_buffers(struct qdio_buffer **buf, unsigned int count) +{ + int pos; + + for (pos = 0; pos < count; pos += QBUFF_PER_PAGE) + free_page((unsigned long) buf[pos]); +} +EXPORT_SYMBOL_GPL(qdio_free_buffers); + +/** + * qdio_alloc_buffers() - allocate qdio buffers + * @buf: array of pointers to qdio buffers + * @count: number of qdio buffers to allocate + */ +int qdio_alloc_buffers(struct qdio_buffer **buf, unsigned int count) +{ + int pos; + + for (pos = 0; pos < count; pos += QBUFF_PER_PAGE) { + buf[pos] = (void *) get_zeroed_page(GFP_KERNEL); + if (!buf[pos]) { + qdio_free_buffers(buf, count); + return -ENOMEM; + } + } + for (pos = 0; pos < count; pos++) + if (pos % QBUFF_PER_PAGE) + buf[pos] = buf[pos - 1] + 1; + return 0; +} +EXPORT_SYMBOL_GPL(qdio_alloc_buffers); + +/** + * qdio_reset_buffers() - reset qdio buffers + * @buf: array of pointers to qdio buffers + * @count: number of qdio buffers that will be zeroed + */ +void qdio_reset_buffers(struct qdio_buffer **buf, unsigned int count) +{ + int pos; + + for (pos = 0; pos < count; pos++) + memset(buf[pos], 0, sizeof(struct qdio_buffer)); +} +EXPORT_SYMBOL_GPL(qdio_reset_buffers); + /* * qebsm is only available under 64bit but the adapter sets the feature * flag anyway, so we manually override it. -- GitLab