Commit d52b761e authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
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kfifo: add kfifo_dma_out_prepare_mapped() 



When the kfifo buffer is already dma-mapped, one cannot use the kfifo
API to fill in an SG list.

Add kfifo_dma_in_prepare_mapped() which allows exactly this. A mapped
dma_addr_t is passed and it is filled into provided sgl too. Including
the dma_len.

Signed-off-by: default avatarJiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20240405060826.2521-8-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fea0dde0

include/linux/kfifo.h

+25 −12
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 
 * to lock the reader.

 */



#include <linux/dma-mapping.h>

#include <linux/kernel.h>

#include <linux/spinlock.h>

#include <linux/stddef.h>
@@ -709,11 +710,12 @@ __kfifo_int_must_check_helper( \ 
)



/**

 * kfifo_dma_in_prepare - setup a scatterlist for DMA input

 * kfifo_dma_in_prepare_mapped - setup a scatterlist for DMA input

 * @fifo: address of the fifo to be used

 * @sgl: pointer to the scatterlist array

 * @nents: number of entries in the scatterlist array

 * @len: number of elements to transfer

 * @dma: mapped dma address to fill into @sgl

 *

 * This macro fills a scatterlist for DMA input.

 * It returns the number entries in the scatterlist array.
@@ -721,7 +723,7 @@ __kfifo_int_must_check_helper( \ 
 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these macros.

 */

#define	kfifo_dma_in_prepare(fifo, sgl, nents, len) \

#define	kfifo_dma_in_prepare_mapped(fifo, sgl, nents, len, dma) \

({ \

	typeof((fifo) + 1) __tmp = (fifo); \

	struct scatterlist *__sgl = (sgl); \
@@ -730,10 +732,14 @@ __kfifo_int_must_check_helper( \ 
	const size_t __recsize = sizeof(*__tmp->rectype); \

	struct __kfifo *__kfifo = &__tmp->kfifo; \

	(__recsize) ? \

	__kfifo_dma_in_prepare_r(__kfifo, __sgl, __nents, __len, __recsize) : \

	__kfifo_dma_in_prepare(__kfifo, __sgl, __nents, __len); \

	__kfifo_dma_in_prepare_r(__kfifo, __sgl, __nents, __len, __recsize, \

				 dma) : \

	__kfifo_dma_in_prepare(__kfifo, __sgl, __nents, __len, dma); \

})



#define kfifo_dma_in_prepare(fifo, sgl, nents, len) \

	kfifo_dma_in_prepare_mapped(fifo, sgl, nents, len, DMA_MAPPING_ERROR)



/**

 * kfifo_dma_in_finish - finish a DMA IN operation

 * @fifo: address of the fifo to be used
@@ -758,11 +764,12 @@ __kfifo_int_must_check_helper( \ 
})



/**

 * kfifo_dma_out_prepare - setup a scatterlist for DMA output

 * kfifo_dma_out_prepare_mapped - setup a scatterlist for DMA output

 * @fifo: address of the fifo to be used

 * @sgl: pointer to the scatterlist array

 * @nents: number of entries in the scatterlist array

 * @len: number of elements to transfer

 * @dma: mapped dma address to fill into @sgl

 *

 * This macro fills a scatterlist for DMA output which at most @len bytes

 * to transfer.
@@ -772,7 +779,7 @@ __kfifo_int_must_check_helper( \ 
 * Note that with only one concurrent reader and one concurrent

 * writer, you don't need extra locking to use these macros.

 */

#define	kfifo_dma_out_prepare(fifo, sgl, nents, len) \

#define	kfifo_dma_out_prepare_mapped(fifo, sgl, nents, len, dma) \

({ \

	typeof((fifo) + 1) __tmp = (fifo);  \

	struct scatterlist *__sgl = (sgl); \
@@ -781,10 +788,14 @@ __kfifo_int_must_check_helper( \ 
	const size_t __recsize = sizeof(*__tmp->rectype); \

	struct __kfifo *__kfifo = &__tmp->kfifo; \

	(__recsize) ? \

	__kfifo_dma_out_prepare_r(__kfifo, __sgl, __nents, __len, __recsize) : \

	__kfifo_dma_out_prepare(__kfifo, __sgl, __nents, __len); \

	__kfifo_dma_out_prepare_r(__kfifo, __sgl, __nents, __len, __recsize, \

				  dma) : \

	__kfifo_dma_out_prepare(__kfifo, __sgl, __nents, __len, dma); \

})



#define	kfifo_dma_out_prepare(fifo, sgl, nents, len) \

	kfifo_dma_out_prepare_mapped(fifo, sgl, nents, len, DMA_MAPPING_ERROR)



/**

 * kfifo_dma_out_finish - finish a DMA OUT operation

 * @fifo: address of the fifo to be used
@@ -905,10 +916,10 @@ extern int __kfifo_to_user(struct __kfifo *fifo, 
	void __user *to, unsigned long len, unsigned int *copied);



extern unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,

	struct scatterlist *sgl, int nents, unsigned int len);

	struct scatterlist *sgl, int nents, unsigned int len, dma_addr_t dma);



extern unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,

	struct scatterlist *sgl, int nents, unsigned int len);

	struct scatterlist *sgl, int nents, unsigned int len, dma_addr_t dma);



extern unsigned int __kfifo_out_peek(struct __kfifo *fifo,

	void *buf, unsigned int len);
@@ -930,13 +941,15 @@ extern int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to, 
	unsigned long len, unsigned int *copied, size_t recsize);



extern unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,

	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize);

	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize,

	dma_addr_t dma);



extern void __kfifo_dma_in_finish_r(struct __kfifo *fifo,

	unsigned int len, size_t recsize);



extern unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,

	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize);

	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize,

	dma_addr_t dma);



extern unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize);

lib/kfifo.c

+22 −12
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
 */



#include <linux/kernel.h>

#include <linux/dma-mapping.h>

#include <linux/export.h>

#include <linux/slab.h>

#include <linux/err.h>
@@ -307,7 +308,7 @@ EXPORT_SYMBOL(__kfifo_to_user); 


static unsigned int setup_sgl_buf(struct __kfifo *fifo, struct scatterlist *sgl,

				  unsigned int data_offset, int nents,

				  unsigned int len)

				  unsigned int len, dma_addr_t dma)

{

	const void *buf = fifo->data + data_offset;
@@ -316,11 +317,16 @@ static unsigned int setup_sgl_buf(struct __kfifo *fifo, struct scatterlist *sgl, 


	sg_set_buf(sgl, buf, len);



	if (dma != DMA_MAPPING_ERROR) {

		sg_dma_address(sgl) = dma + data_offset;

		sg_dma_len(sgl) = len;

	}



	return 1;

}



static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,

		int nents, unsigned int len, unsigned int off)

		int nents, unsigned int len, unsigned int off, dma_addr_t dma)

{

	unsigned int size = fifo->mask + 1;

	unsigned int esize = fifo->esize;
@@ -335,14 +341,15 @@ static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl, 
	}

	len_to_end = min(len, size - off);



	n = setup_sgl_buf(fifo, sgl, off, nents, len_to_end);

	n += setup_sgl_buf(fifo, sgl + n, 0, nents - n, len - len_to_end);

	n = setup_sgl_buf(fifo, sgl, off, nents, len_to_end, dma);

	n += setup_sgl_buf(fifo, sgl + n, 0, nents - n, len - len_to_end, dma);



	return n;

}



unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,

		struct scatterlist *sgl, int nents, unsigned int len)

		struct scatterlist *sgl, int nents, unsigned int len,

		dma_addr_t dma)

{

	unsigned int l;
@@ -350,12 +357,13 @@ unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo, 
	if (len > l)

		len = l;



	return setup_sgl(fifo, sgl, nents, len, fifo->in);

	return setup_sgl(fifo, sgl, nents, len, fifo->in, dma);

}

EXPORT_SYMBOL(__kfifo_dma_in_prepare);



unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,

		struct scatterlist *sgl, int nents, unsigned int len)

		struct scatterlist *sgl, int nents, unsigned int len,

		dma_addr_t dma)

{

	unsigned int l;
@@ -363,7 +371,7 @@ unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo, 
	if (len > l)

		len = l;



	return setup_sgl(fifo, sgl, nents, len, fifo->out);

	return setup_sgl(fifo, sgl, nents, len, fifo->out, dma);

}

EXPORT_SYMBOL(__kfifo_dma_out_prepare);
@@ -547,7 +555,8 @@ int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to, 
EXPORT_SYMBOL(__kfifo_to_user_r);



unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,

	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)

	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize,

	dma_addr_t dma)

{

	BUG_ON(!nents);
@@ -556,7 +565,7 @@ unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo, 
	if (len + recsize > kfifo_unused(fifo))

		return 0;



	return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize);

	return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize, dma);

}

EXPORT_SYMBOL(__kfifo_dma_in_prepare_r);
@@ -570,7 +579,8 @@ void __kfifo_dma_in_finish_r(struct __kfifo *fifo, 
EXPORT_SYMBOL(__kfifo_dma_in_finish_r);



unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,

	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)

	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize,

	dma_addr_t dma)

{

	BUG_ON(!nents);
@@ -579,7 +589,7 @@ unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo, 
	if (len + recsize > fifo->in - fifo->out)

		return 0;



	return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize);

	return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize, dma);

}

EXPORT_SYMBOL(__kfifo_dma_out_prepare_r);