arm64/imx9: Add DMA memory allocator

Add a simple allocator for DMA safe memory. It will provide contiguous
blocks of memory with D-Cache line size alignment.

NOTE: The optimal granule size is the D-Cache line size (64), but due
to restrictions in the granule allocator this would result in a maximum
block size of 2K only, thus use 256B granules instead givin 8K max block
size.

Once the granule allocator is fixed this limitation can be removed.
This commit is contained in:
Ville Juven 2024-04-18 14:30:07 +03:00 committed by Xiang Xiao
parent 8821a0396a
commit 3079caf2ce
6 changed files with 270 additions and 0 deletions

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@ -24,6 +24,24 @@ endchoice # i.MX9 Chip Selection
endmenu # "i.MX9 Chip Selection"
config IMX9_DMA_ALLOC
bool "Enable DMA capable memory allocator"
depends on GRAN
default y if CONFIG_FAT_DMAMEMORY
menu "DMA Allocator Configuration"
depends on IMX9_DMA_ALLOC
config IMX9_DMA_ALLOC_POOL_SIZE
int "DMA allocator memory pool size in bytes"
default 4096
config IMX9_DMA_ALLOC_SECT
string "Section for DMA allocator memory pool, default is .bss"
default ".bss"
endmenu # DMA Allocator Configuration
config IMX9_FLEXIO_PWM
bool
select PWM_MULTICHAN

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@ -55,3 +55,7 @@ endif
ifeq ($(CONFIG_IMX9_EDMA), y)
CHIP_CSRCS += imx9_edma.c
endif
ifeq ($(CONFIG_IMX9_DMA_ALLOC),y)
CHIP_CSRCS += imx9_dma_alloc.c
endif

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@ -0,0 +1,145 @@
/****************************************************************************
* arch/arm64/src/imx9/imx9_dma_alloc.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <syslog.h>
#include <stdint.h>
#include <errno.h>
#include <nuttx/mm/gran.h>
#include <chip.h>
#if defined(CONFIG_IMX9_DMA_ALLOC)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* DMA buffers must be aligned with the D-Cache line boundaries to facilitate
* cache operations on the DMA buffers when the D-Cache is enabled.
*/
#define DMA_ALIGN ARMV8A_DCACHE_LINESIZE
#define DMA_ALIGN_MASK (DMA_ALIGN - 1)
#define DMA_ALIGN_UP(n) (((n) + DMA_ALIGN_MASK) & ~DMA_ALIGN_MASK)
/****************************************************************************
* Private Data
****************************************************************************/
static GRAN_HANDLE dma_allocator;
/* The DMA heap size constrains the total number of things that can be
* ready to do DMA at a time.
*
* For example, FAT DMA depends on one sector-sized buffer per filesystem
* plus one sector-sized buffer per file.
*
* We use a fundamental alignment / granule size of 64B; it fulfills the
* requirement for any DMA engine.
*/
static uint8_t g_dma_heap[CONFIG_IMX9_DMA_ALLOC_POOL_SIZE]
aligned_data(DMA_ALIGN) locate_data(CONFIG_IMX9_DMA_ALLOC_SECT);
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: imx9_dma_alloc_init
*
* Description:
* Initialize the DMA memory allocator.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned
* on failure.
*
****************************************************************************/
int imx9_dma_alloc_init(void)
{
/* Allocate 64B granules with 64B alignment */
/* REVISIT: Use 256B granule size to get 8K maximum allocation. This is a
* limitation in the granule allocator itself.
*/
dma_allocator = gran_initialize(g_dma_heap, sizeof(g_dma_heap), 8, 6);
if (dma_allocator == NULL)
{
return -ENOMEM;
}
return OK;
}
/****************************************************************************
* Name: imx9_dma_alloc
*
* Description:
* Allocate a contiguous block of physical memory for DMA.
*
* Input Parameters:
* size - Size of the requested block in bytes.
*
* Returned Value:
* Physical address of the first page on success; NULL on failure.
*
****************************************************************************/
void *imx9_dma_alloc(size_t size)
{
return gran_alloc(dma_allocator, size);
}
/****************************************************************************
* Name: imx9_dma_free
*
* Description:
* Free a previously allocated DMA memory block.
*
* Input Parameters:
* memory - Physical address of the first page of DMA memory.
* size - Size of the allocated block in bytes.
*
* Returned Value:
* None.
*
****************************************************************************/
void imx9_dma_free(void *memory, size_t size)
{
gran_free(dma_allocator, memory, size);
}
#endif /* CONFIG_IMX9_DMA_ALLOC */

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@ -0,0 +1,88 @@
/****************************************************************************
* arch/arm64/src/imx9/imx9_dma_alloc.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __ARCH_ARM64_SRC_IMX9_IMX9_DMA_ALLOC_H
#define __ARCH_ARM64_SRC_IMX9_IMX9_DMA_ALLOC_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: imx9_dma_alloc_init
*
* Description:
* Initialize the DMA memory allocator.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned
* on failure.
*
****************************************************************************/
int imx9_dma_alloc_init(void);
/****************************************************************************
* Name: imx9_dma_alloc
*
* Description:
* Allocate a contiguous block of physical memory for DMA.
*
* Input Parameters:
* size - Size of the requested block in bytes.
*
* Returned Value:
* Physical address of the first page on success; NULL on failure.
*
****************************************************************************/
void *imx9_dma_alloc(size_t size);
/****************************************************************************
* Name: imx9_dma_free
*
* Description:
* Free a previously allocated DMA memory block.
*
* Input Parameters:
* memory - Physical address of the first page of DMA memory.
* size - Size of the allocated block in bytes.
*
* Returned Value:
* None.
*
****************************************************************************/
void imx9_dma_free(void *memory, size_t size);
#ifdef CONFIG_FAT_DMAMEMORY
# define fat_dma_alloc(s) imx9_dma_alloc(s)
# define fat_dma_free(m,s) imx9_dma_free(m,s)
#endif
#endif /* __ARCH_ARM64_SRC_IMX9_IMX9_DMA_ALLOC_H */

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@ -26,11 +26,14 @@ CONFIG_EXAMPLES_HELLO=y
CONFIG_EXPERIMENTAL=y
CONFIG_FS_PROCFS=y
CONFIG_FS_ROMFS=y
CONFIG_GRAN=y
CONFIG_HAVE_CXX=y
CONFIG_HAVE_CXXINITIALIZE=y
CONFIG_I2C=y
CONFIG_I2C_RESET=y
CONFIG_IDLETHREAD_STACKSIZE=8192
CONFIG_IMX9_DMA_ALLOC=y
CONFIG_IMX9_DMA_ALLOC_POOL_SIZE=81920
CONFIG_IMX9_EDMA=y
CONFIG_IMX9_FLEXIO1_PWM=y
CONFIG_IMX9_GPIO_IRQ=y

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@ -29,6 +29,8 @@
#include <nuttx/fs/fs.h>
#include "imx9_dma_alloc.h"
#include "imx93-evk.h"
/****************************************************************************
@ -57,6 +59,16 @@ int imx9_bringup(void)
}
#endif
#ifdef CONFIG_IMX9_DMA_ALLOC
/* Initialize the DMA memory allocator */
ret = imx9_dma_alloc_init();
if (ret < 0)
{
syslog(LOG_ERR, "ERROR: Failed initialize DMA allocator: %d\n", ret);
}
#endif
#ifdef CONFIG_PWM
/* Configure PWM outputs */