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From: laurentiu.tudor@nxp.com
To: hch@lst.de, stern@rowland.harvard.edu,
	gregkh@linuxfoundation.org, linux-usb@vger.kernel.org,
	marex@denx.de
Cc: leoyang.li@nxp.com, linux-kernel@vger.kernel.org,
	robin.murphy@arm.com, noring@nocrew.org, JuergenUrban@gmx.de
Subject: [PATCH v6 1/5] lib/genalloc.c: Add gen_pool_dma_zalloc() for zeroed DMA allocations
Date: Wed, 22 May 2019 17:27:44 +0300	[thread overview]
Message-ID: <20190522142748.10078-2-laurentiu.tudor@nxp.com> (raw)
In-Reply-To: <20190522142748.10078-1-laurentiu.tudor@nxp.com>

From: Fredrik Noring <noring@nocrew.org>

gen_pool_dma_zalloc() is a zeroed memory variant of gen_pool_dma_alloc().
Document return values of both, and indicate NULL as a "%NULL" constant.

Signed-off-by: Fredrik Noring <noring@nocrew.org>
Tested-by: Fredrik Noring <noring@nocrew.org>
---
 include/linux/genalloc.h |  1 +
 lib/genalloc.c           | 29 ++++++++++++++++++++++++++++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index dd0a452373e7..6c62eeca754f 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -121,6 +121,7 @@ extern unsigned long gen_pool_alloc_algo(struct gen_pool *, size_t,
 		genpool_algo_t algo, void *data);
 extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size,
 		dma_addr_t *dma);
+void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma);
 extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
 extern void gen_pool_for_each_chunk(struct gen_pool *,
 	void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *);
diff --git a/lib/genalloc.c b/lib/genalloc.c
index 7e85d1e37a6e..5db43476a19b 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -337,12 +337,14 @@ EXPORT_SYMBOL(gen_pool_alloc_algo);
  * gen_pool_dma_alloc - allocate special memory from the pool for DMA usage
  * @pool: pool to allocate from
  * @size: number of bytes to allocate from the pool
- * @dma: dma-view physical address return value.  Use NULL if unneeded.
+ * @dma: dma-view physical address return value.  Use %NULL if unneeded.
  *
  * Allocate the requested number of bytes from the specified pool.
  * Uses the pool allocation function (with first-fit algorithm by default).
  * Can not be used in NMI handler on architectures without
  * NMI-safe cmpxchg implementation.
+ *
+ * Return: virtual address of the allocated memory, or %NULL on failure
  */
 void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
 {
@@ -362,6 +364,31 @@ void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
 }
 EXPORT_SYMBOL(gen_pool_dma_alloc);
 
+/**
+ * gen_pool_dma_zalloc - allocate special zeroed memory from the pool for
+ * DMA usage
+ * @pool: pool to allocate from
+ * @size: number of bytes to allocate from the pool
+ * @dma: dma-view physical address return value.  Use %NULL if unneeded.
+ *
+ * Allocate the requested number of zeroed bytes from the specified pool.
+ * Uses the pool allocation function (with first-fit algorithm by default).
+ * Can not be used in NMI handler on architectures without
+ * NMI-safe cmpxchg implementation.
+ *
+ * Return: virtual address of the allocated zeroed memory, or %NULL on failure
+ */
+void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)
+{
+	void *vaddr = gen_pool_dma_alloc(pool, size, dma);
+
+	if (vaddr)
+		memset(vaddr, 0, size);
+
+	return vaddr;
+}
+EXPORT_SYMBOL(gen_pool_dma_zalloc);
+
 /**
  * gen_pool_free - free allocated special memory back to the pool
  * @pool: pool to free to
-- 
2.17.1


  reply	other threads:[~2019-05-22 14:27 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-22 14:27 [PATCH v6 0/5] prerequisites for device reserved local mem rework laurentiu.tudor
2019-05-22 14:27 ` laurentiu.tudor [this message]
2019-05-22 14:27 ` [PATCH v6 2/5] USB: use genalloc for USB HCs with local memory laurentiu.tudor
2019-05-22 14:27 ` [PATCH v6 3/5] usb: host: ohci-sm501: init genalloc for " laurentiu.tudor
2019-05-22 14:27 ` [PATCH v6 4/5] usb: host: ohci-tmio: " laurentiu.tudor
2019-05-22 14:27 ` [PATCH v6 5/5] USB: drop HCD_LOCAL_MEM flag laurentiu.tudor
2019-05-23  6:56 ` [PATCH v6 0/5] prerequisites for device reserved local mem rework Christoph Hellwig
2019-05-23  7:07   ` Greg KH
2019-05-23  7:12     ` Christoph Hellwig
2019-05-28  5:58     ` Christoph Hellwig
2019-05-28  6:47       ` Greg KH
2019-05-28  6:52         ` Christoph Hellwig

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