Re: [PATCH 5/5] drivers: uio: new driver for fsl_85xx_cache_sram

On Wed, Apr 15, 2020 at 05:33:46AM -0700, Wang Wenhu wrote:

Nit, you don't need this sentance anymore now that you have the SPDX
line above

+ */
+
+#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_VERSION	"0.1.0"

Don't do DRIVER_VERSIONs, they never work once the code is in the kernel
tree.

+#define DRIVER_NAME	"uio_fsl_85xx_cache_sram"

KBUILD_MODNAME?

+#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++;
+	}
+}
+
+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;
+	void *virt;
+	phys_addr_t phys;
+	int ret = -ENODEV;
+
+	/* alloc uio_info for one device */
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info) {
+		dev_err(&pdev->dev, "kzalloc uio_info failed\n");

kzalloc already says this.

+		ret = -ENOMEM;
+		goto err_out;
+	}
+
+	/* 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) {
+		dev_err(&pdev->dev, "error kstrdup uio_name\n");

kstrdup should have given you an error string already, right?

+		ret = -ENOMEM;
+		goto err_info_free;
+	}
+
+	uiomem = &info->mem[0];
+	for_each_child_of_node(parent, node) {
+		if (!node) {
+			dev_err(&pdev->dev, "device's OF-node is NULL\n");

How can this happen?

+			continue;

Why not error out?

+		}
+
+		ret = of_property_read_u32(node, "cache-mem-size", &mem_size);
+		if (ret) {
+			dev_err(&pdev->dev, "missing cache-mem-size value\n");

You don't exit?

+			continue;
+		}
+
+		if (mem_size == 0) {
+			dev_err(&pdev->dev, "cache-mem-size should not be 0\n");

Again, you don't exit?

+			continue;
+		}
+
+		align = 2;
+		while (align < mem_size)
+			align *= 2;
+		virt = mpc85xx_cache_sram_alloc(mem_size, &phys, align);
+		if (!virt) {
+			dev_err(&pdev->dev, "allocate 0x%x cache-mem failed\n", mem_size);

You don't exit?

+			continue;
+		}
+
+		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, "device has more than "
+				 __stringify(MAX_UIO_MAPS)
+				 " I/O memory resources.\n");

What can someone do with that?

thanks,

greg k-h