Hi, Christophe, dev_kzalloc really looks better. I will update the patch with the comments addressed.
Thanks, Wenhu From: Christophe Leroy <christophe.le...@c-s.fr> Date: 2020-04-16 19:49:01 To:Wang Wenhu <wenhu.w...@vivo.com>,gre...@linuxfoundation.org, linux-ker...@vger.kernel.org,o...@buserror.net,linuxppc-dev@lists.ozlabs.org cc: ker...@vivo.com,Michael Ellerman <m...@ellerman.id.au> Subject: Re: [PATCH RESEND,v3,4/4] drivers: uio: new driver for fsl_85xx_cache_sram> > >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 <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 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.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_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.w...@vivo.com>"); >> +MODULE_DESCRIPTION("Freescale MPC85xx Cache-Sram UIO Platform Driver"); >> +MODULE_ALIAS("platform:" DRIVER_NAME); >> +MODULE_LICENSE("GPL v2"); >> > >Christophe