Le 15/04/2020 à 17:24, Wang Wenhu a écrit :
A driver for freescale 85xx platforms to access the Cache-Sram form
user level. This is extremely helpful for some user-space applications
that require high performance memory accesses.
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: Christophe Leroy <christophe.le...@c-s.fr>
Cc: Scott Wood <o...@buserror.net>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Wang Wenhu <wenhu.w...@vivo.com>
---
Changes since v1:
* Addressed comments of Greg K-H
* Moved kfree(info->name) into uio_info_free_internal()
---
drivers/uio/Kconfig | 8 ++
drivers/uio/Makefile | 1 +
drivers/uio/uio_fsl_85xx_cache_sram.c | 182 ++++++++++++++++++++++++++
3 files changed, 191 insertions(+)
create mode 100644 drivers/uio/uio_fsl_85xx_cache_sram.c
diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index 202ee81cfc2b..afd38ec13de0 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -105,6 +105,14 @@ config UIO_NETX
To compile this driver as a module, choose M here; the module
will be called uio_netx.
+config UIO_FSL_85XX_CACHE_SRAM
+ tristate "Freescale 85xx Cache-Sram driver"
+ depends on FSL_85XX_CACHE_SRAM
Is there any point having FSL_85XX_CACHE_SRAM without this ?
Should it be the other way round, leave FSL_85XX_CACHE_SRAM unselectable
by user, and this driver select FSL_85XX_CACHE_SRAM instead of depending
on it ?
+ help
+ Generic driver for accessing the Cache-Sram form user level. This
+ is extremely helpful for some user-space applications that require
+ high performance memory accesses.
+
config UIO_FSL_ELBC_GPCM
tristate "eLBC/GPCM driver"
depends on FSL_LBC
diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
index c285dd2a4539..be2056cffc21 100644
--- a/drivers/uio/Makefile
+++ b/drivers/uio/Makefile
@@ -10,4 +10,5 @@ obj-$(CONFIG_UIO_NETX) += uio_netx.o
obj-$(CONFIG_UIO_PRUSS) += uio_pruss.o
obj-$(CONFIG_UIO_MF624) += uio_mf624.o
obj-$(CONFIG_UIO_FSL_ELBC_GPCM) += uio_fsl_elbc_gpcm.o
+obj-$(CONFIG_UIO_FSL_85XX_CACHE_SRAM) += uio_fsl_85xx_cache_sram.o
obj-$(CONFIG_UIO_HV_GENERIC) += uio_hv_generic.o
diff --git a/drivers/uio/uio_fsl_85xx_cache_sram.c
b/drivers/uio/uio_fsl_85xx_cache_sram.c
new file mode 100644
index 000000000000..fb6903fdaddb
--- /dev/null
+++ b/drivers/uio/uio_fsl_85xx_cache_sram.c
@@ -0,0 +1,182 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Vivo Communication Technology Co. Ltd.
+ * Copyright (C) 2020 Wang Wenhu <wenhu.w...@vivo.com>
+ * All rights reserved.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/uio_driver.h>
+#include <linux/stringify.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <asm/fsl_85xx_cache_sram.h>
+
+#define DRIVER_NAME "uio_fsl_85xx_cache_sram"
+#define UIO_NAME "uio_cache_sram"
+
+static const struct of_device_id uio_mpc85xx_l2ctlr_of_match[] = {
+ { .compatible = "uio,fsl,p2020-l2-cache-controller", },
+ { .compatible = "uio,fsl,p2010-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1020-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1011-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1013-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1022-l2-cache-controller", },
+ { .compatible = "uio,fsl,mpc8548-l2-cache-controller", },
+ { .compatible = "uio,fsl,mpc8544-l2-cache-controller", },
+ { .compatible = "uio,fsl,mpc8572-l2-cache-controller", },
+ { .compatible = "uio,fsl,mpc8536-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1021-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1012-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1025-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1016-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1024-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1015-l2-cache-controller", },
+ { .compatible = "uio,fsl,p1010-l2-cache-controller", },
+ { .compatible = "uio,fsl,bsc9131-l2-cache-controller", },
+ {},
+};
+
+static void uio_info_free_internal(struct uio_info *info)
+{
+ struct uio_mem *uiomem = &info->mem[0];
+
+ while (uiomem < &info->mem[MAX_UIO_MAPS]) {
+ if (uiomem->size) {
+ mpc85xx_cache_sram_free(uiomem->internal_addr);
+ kfree(uiomem->name);
+ }
+ uiomem++;
+ }
+
+ kfree(info->name);
+}
+
+static int uio_fsl_85xx_cache_sram_probe(struct platform_device *pdev)
+{
+ struct device_node *parent = pdev->dev.of_node;
+ struct device_node *node = NULL;
+ struct uio_info *info;
+ struct uio_mem *uiomem;
+ const char *dt_name;
+ u32 mem_size;
+ u32 align;
Align is not used outside of the for loop, it should be declared in the
loop block.
+ void *virt;
Same for virt
+ phys_addr_t phys;
Same for phys
+ int ret = -ENODEV;
It looks like this init value is unneeded, you should leave 'ret'
uninitialised (unless I missed some way out and you get a warning).
+
+ /* alloc uio_info for one device */
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info) {
+ ret = -ENOMEM;
+ goto err_out;
Nothing special is done at err_out, you should instead do:
if (!info)
return -ENOMEM;
+ }
+
+ /* get optional uio name */
+ if (of_property_read_string(parent, "uio_name", &dt_name))
+ dt_name = UIO_NAME;
+
+ info->name = kstrdup(dt_name, GFP_KERNEL);
+ if (!info->name) {
+ ret = -ENOMEM;
+ goto err_info_free;
+ }
+
+ uiomem = &info->mem[0];
I'd prefer
uiomem = info->mem;
+ for_each_child_of_node(parent, node) {
+ ret = of_property_read_u32(node, "cache-mem-size", &mem_size);
+ if (ret) {
+ ret = -EINVAL;
+ goto err_info_free_internel;
+ }
+
+ if (mem_size == 0) {
+ dev_err(&pdev->dev, "cache-mem-size should not be 0\n");
+ ret = -EINVAL;
+ goto err_info_free_internel;
+ }
+
+ align = 2;
+ while (align < mem_size)
+ align *= 2;
I think ilog2() or one of it friends should be used here, maybe
roundup_pow_of_two()
+ virt = mpc85xx_cache_sram_alloc(mem_size, &phys, align);
+ if (!virt) {
+ /* mpc85xx_cache_sram_alloc to define the cause */
+ ret = -EINVAL;
Should it be -ENOMEM like any allocation failure ?
+ goto err_info_free_internel;
+ }
+
+ uiomem->memtype = UIO_MEM_PHYS;
+ uiomem->addr = phys;
+ uiomem->size = mem_size;
+ uiomem->name = kstrdup(node->name, GFP_KERNEL);;
+ uiomem->internal_addr = virt;
+ ++uiomem;
Usually people use
uiomem++;
+
+ if (uiomem >= &info->mem[MAX_UIO_MAPS]) {
I'd prefer
if (uiomem - info->mem >= MAX_UIO_MAPS) {
+ dev_warn(&pdev->dev, "more than %d uio-maps for
device.\n",
+ MAX_UIO_MAPS);
+ break;
+ }
+ }
+
+ while (uiomem < &info->mem[MAX_UIO_MAPS]) {
I'd prefer
while (uiomem - info->mem < MAX_UIO_MAPS) {
+ uiomem->size = 0;
+ ++uiomem;
+ }
+
+ if (info->mem[0].size == 0) {
Is there any point in doing all the clearing loop above if it's to bail
out here ?
Wouldn't it be cleaner to do the test above the clearing loop, by just
checking whether uiomem is still equal to info->mem ?
+ dev_err(&pdev->dev, "error no valid uio-map configured\n");
+ ret = -EINVAL;
+ goto err_info_free_internel;
+ }
+
+ info->version = "0.1.0";
Could you define some DRIVER_VERSION in the top of the file next to
DRIVER_NAME instead of hard coding in the middle on a function ?
+
+ /* register uio device */
+ if (uio_register_device(&pdev->dev, info)) {
+ dev_err(&pdev->dev, "uio registration failed\n");
+ ret = -ENODEV;
+ goto err_info_free_internel;
+ }
+
+ platform_set_drvdata(pdev, info);
+
+ return 0;
+err_info_free_internel:
Do you mean 'internal' instead of 'internel' ?
+ uio_info_free_internal(info);
+err_info_free:
+ kfree(info);
+err_out:
+ return ret;
+}
+
+static int uio_fsl_85xx_cache_sram_remove(struct platform_device *pdev)
+{
+ struct uio_info *info = platform_get_drvdata(pdev);
+
+ uio_unregister_device(info);
+
+ uio_info_free_internal(info);
+
+ kfree(info);
+
+ return 0;
+}
+
+static struct platform_driver uio_fsl_85xx_cache_sram = {
+ .probe = uio_fsl_85xx_cache_sram_probe,
+ .remove = uio_fsl_85xx_cache_sram_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = uio_mpc85xx_l2ctlr_of_match,
+ },
+};
+
+module_platform_driver(uio_fsl_85xx_cache_sram);
+
+MODULE_AUTHOR("Wang Wenhu <wenhu.w...@vivo.com>");
+MODULE_DESCRIPTION("Freescale MPC85xx Cache-Sram UIO Platform Driver");
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_LICENSE("GPL v2");
Christophe
