[PATCH RESEND,v3,4/4] drivers: uio: new driver for fsl_85xx_cache_sram
Christophe Leroy
christophe.leroy at c-s.fr
Thu Apr 16 21:49:01 AEST 2020
Le 16/04/2020 à 13:16, 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 <gregkh at linuxfoundation.org>
> Cc: Christophe Leroy <christophe.leroy at c-s.fr>
> Cc: Scott Wood <oss at buserror.net>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: linuxppc-dev at lists.ozlabs.org
> Signed-off-by: Wang Wenhu <wenhu.wang at vivo.com>
> ---
> Changes since v1:
> * Addressed comments from Greg K-H
> * Moved kfree(info->name) into uio_info_free_internal()
> Changes since v2:
> * Addressed comments from Greg, Scott and Christophe
> * Use "uiomem->internal_addr" as if condition for sram memory free,
> and memset the uiomem entry
> * Modified of_match_table make the driver apart from Cache-Sram HW info
> which belong to the HW level driver fsl_85xx_cache_sram to match
> * Use roundup_pow_of_two for align calculation
> * Remove useless clear block of uiomem entries.
> * Use UIO_INFO_VER micro for info->version, and define it as
> "devicetree,pseudo", meaning this is pseudo device and probed from
> device tree configuration
> * Select FSL_85XX_CACHE_SRAM rather than depends on it
> ---
> drivers/uio/Kconfig | 9 ++
> drivers/uio/Makefile | 1 +
> drivers/uio/uio_fsl_85xx_cache_sram.c | 158 ++++++++++++++++++++++++++
> 3 files changed, 168 insertions(+)
> create mode 100644 drivers/uio/uio_fsl_85xx_cache_sram.c
>
> diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
> index 202ee81cfc2b..9c3b47461b71 100644
> --- a/drivers/uio/Kconfig
> +++ b/drivers/uio/Kconfig
> @@ -105,6 +105,15 @@ 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_SOC_BOOKE && PPC32
> + select FSL_85XX_CACHE_SRAM
> + 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..8701df695307
> --- /dev/null
> +++ b/drivers/uio/uio_fsl_85xx_cache_sram.c
> @@ -0,0 +1,158 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020 Vivo Communication Technology Co. Ltd.
> + * Copyright (C) 2020 Wang Wenhu <wenhu.wang at 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_INFO_VER "devicetree,pseudo"
> +#define UIO_NAME "uio_cache_sram"
> +
> +static void uio_info_free_internal(struct uio_info *info)
> +{
> + struct uio_mem *uiomem = info->mem;
> +
> + while (uiomem < &info->mem[MAX_UIO_MAPS]) {
As suggested by Scott, maybe it would be better to use a loop with an
index, something like
for (i = 0; i < MAX_UIO_MAPS; i++, uiomem++) {
struct uio_mem *uiomem = info->mem[i];
> + if (uiomem->internal_addr) {
> + mpc85xx_cache_sram_free(uiomem->internal_addr);
> + kfree(uiomem->name);
Unneeded when using devm_kstrdup(), see in the probe function.
> + memset(uiomem, 0, sizeof(*uiomem));
> + }
> + uiomem++;
> + }
> +
> + kfree(info->name);
That's a bit unbalanced. This function is handy for the things allocated
inside the loop, but for the info->name allocated outside the loop, it
should be released outside this function.
At the end if you use devm_kstrdup(), it will void anyway.
> +}
> +
> +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;
> + int ret;
> +
> + /* alloc uio_info for one device */
> + info = kzalloc(sizeof(*info), GFP_KERNEL);
Maybe use devm_kzalloc(). That way, it will be automatically freed when
the driver is released, both a normal release and on probe failure.
> + 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);
Can use devm_kstrdup()
> + if (!info->name) {
> + ret = -ENOMEM;
If using devm_kzalloc(), you can then directly do return -ENOMEM, and
the release will be automatic.
> + goto err_info_free;
> + }
> +
> + uiomem = info->mem;
> + for_each_child_of_node(parent, node) {
> + void *virt;
> + phys_addr_t phys;
> +
> + ret = of_property_read_u32(node, "cache-mem-size", &mem_size);
> + if (ret) {
> + ret = -EINVAL;
> + goto err_info_free_internal;
> + }
> +
> + if (mem_size == 0) {
> + dev_err(&pdev->dev, "cache-mem-size should not be 0\n");
> + ret = -EINVAL;
> + goto err_info_free_internal;
> + }
> +
> + virt = mpc85xx_cache_sram_alloc(mem_size,
> + &phys,
I think &phys can fit on first line.
> + roundup_pow_of_two(mem_size));
> + if (!virt) {
> + /* mpc85xx_cache_sram_alloc to define the real cause */
> + ret = -ENOMEM;
> + goto err_info_free_internal;
> + }
> +
> + uiomem->memtype = UIO_MEM_PHYS;
> + uiomem->addr = phys;
> + uiomem->size = mem_size;
> + uiomem->name = kstrdup(node->name, GFP_KERNEL);;
Use devm_kstrdup()
> + uiomem->internal_addr = virt;
> + uiomem++;
> +
> + if (uiomem >= &info->mem[MAX_UIO_MAPS]) {
> + dev_warn(&pdev->dev, "more than %d uio-maps for device.\n",
> + MAX_UIO_MAPS);
> + break;
> + }
> + }
> +
> + if (uiomem == info->mem) {
> + dev_err(&pdev->dev, "error no valid uio-map configured\n");
> + ret = -EINVAL;
> + goto err_info_free_internal;
Is there anything to free up if nothing has been allocated ?
> + }
> +
> + info->version = UIO_INFO_VER;
> +
> + /* register uio device */
> + if (uio_register_device(&pdev->dev, info)) {
> + dev_err(&pdev->dev, "uio registration failed\n");
> + ret = -ENODEV;
> + goto err_info_free_internal;
> + }
> +
> + platform_set_drvdata(pdev, info);
> +
> + return 0;
> +err_info_free_internal:
> + uio_info_free_internal(info);
> +err_info_free:
> + kfree(info);
Shouldn't be needed when using devm_kzalloc().
> + 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);
Not needed when using dev_kzalloc()
> +
> + return 0;
> +}
> +
> +static const struct of_device_id uio_mpc85xx_l2ctlr_of_match[] = {
> + { .compatible = "uio,mpc85xx-cache-sram", },
> + {},
> +};
> +
> +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.wang at vivo.com>");
> +MODULE_DESCRIPTION("Freescale MPC85xx Cache-Sram UIO Platform Driver");
> +MODULE_ALIAS("platform:" DRIVER_NAME);
> +MODULE_LICENSE("GPL v2");
>
Christophe
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