Messages in this thread | | | Subject | Re: [PATCH v2,5/5] drivers: uio: new driver for fsl_85xx_cache_sram | From | Christophe Leroy <> | Date | Wed, 15 Apr 2020 18:52:24 +0200 |
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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 <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 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.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_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.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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