Re: [PATCH v4,4/4] drivers: uio: new driver for fsl_85xx_cache_sram
From: Christophe Leroy
Date: Thu Apr 16 2020 - 11:44:08 EST
Le 16/04/2020 Ã 17:35, Wang Wenhu a ÃcritÂ:
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@xxxxxxxxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxx>
Cc: Scott Wood <oss@xxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Signed-off-by: Wang Wenhu <wenhu.wang@xxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
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
* of_match_table modified to be apart from HW info which belong to
the HW level driver fsl_85xx_cache_sram to match
* Use roundup_pow_of_two for align calc(really learned a lot from Christophe)
* 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
Changes since v3:
* Addressed comments from Christophe(use devm_xxx memory alloc interfaces)
---
drivers/uio/Kconfig | 9 ++
drivers/uio/Makefile | 1 +
drivers/uio/uio_fsl_85xx_cache_sram.c | 148 ++++++++++++++++++++++++++
3 files changed, 158 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..cb339d1f9019
--- /dev/null
+++ b/drivers/uio/uio_fsl_85xx_cache_sram.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Vivo Communication Technology Co. Ltd.
+ * Copyright (C) 2020 Wang Wenhu <wenhu.wang@xxxxxxxx>
+ * 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)
+{
+ int i;
+
+ for (i = 0; i < MAX_UIO_MAPS; i++) {
+ struct uio_mem *uiomem = &info->mem[i];
+
+ if (uiomem->internal_addr) {
+ mpc85xx_cache_sram_free(uiomem->internal_addr);
+ memset(uiomem, 0, sizeof(*uiomem));
+ }
+ }
+}
+
+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 = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ /* get optional uio name */
+ if (of_property_read_string(parent, "uio_name", &dt_name))
+ dt_name = UIO_NAME;
+
+ info->name = devm_kstrdup(&pdev->dev, dt_name, GFP_KERNEL);
+ if (!info->name)
+ return -ENOMEM;
+
+ 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_out;
+ }
+
+ if (mem_size == 0) {
+ dev_err(&pdev->dev, "error cache-mem-size should not be 0\n");
+ ret = -EINVAL;
+ goto err_out;
+ }
+
+ virt = mpc85xx_cache_sram_alloc(mem_size, &phys,
+ roundup_pow_of_two(mem_size));
+ if (!virt) {
+ /* mpc85xx_cache_sram_alloc to define the real cause */
+ ret = -ENOMEM;
+ goto err_out;
+ }
+
+ uiomem->memtype = UIO_MEM_PHYS;
+ uiomem->addr = phys;
+ uiomem->size = mem_size;
+ uiomem->name = kstrdup(node->name, GFP_KERNEL);;
+ 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 configuration found\n");
+ return -EINVAL;
+ }
+
+ info->version = UIO_INFO_VER;
+
+ /* register uio device */
+ if (uio_register_device(&pdev->dev, info)) {
+ dev_err(&pdev->dev, "error uio,cache-sram registration failed\n");
+ ret = -ENODEV;
+ goto err_out;
+ }
+
+ platform_set_drvdata(pdev, info);
+
+ return 0;
+err_out:
+ uio_info_free_internal(info);
+ 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);
+
+ 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@xxxxxxxx>");
+MODULE_DESCRIPTION("Freescale MPC85xx Cache-Sram UIO Platform Driver");
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_LICENSE("GPL v2");