Messages in this thread | | | Subject | Re: [PATCH RESEND,v3,4/4] drivers: uio: new driver for fsl_85xx_cache_sram | From | Christophe Leroy <> | Date | Thu, 16 Apr 2020 13:49:01 +0200 |
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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@linuxfoundation.org> > Cc: Christophe Leroy <christophe.leroy@c-s.fr> > Cc: Scott Wood <oss@buserror.net> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: linuxppc-dev@lists.ozlabs.org > Signed-off-by: Wang Wenhu <wenhu.wang@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@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@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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