Re: [RFC PATCH net-next 09/12] net: lan966x: add the basic lan966x driver

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Horatiu Vultur <horatiu.vultur@microchip.com>
Cc: davem@davemloft.net, kuba@kernel.org, robh+dt@kernel.org,
	andrew@lunn.ch, f.fainelli@gmail.com,
	alexandre.belloni@bootlin.com, vladimir.oltean@nxp.com,
	UNGLinuxDriver@microchip.com, netdev@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-phy@lists.infradead.org, linux-pm@vger.kernel.org
Subject: Re: [RFC PATCH net-next 09/12] net: lan966x: add the basic lan966x driver
Date: Mon, 20 Sep 2021 14:46:30 +0100	[thread overview]
Message-ID: <YUiQtrIodmyAZ476@shell.armlinux.org.uk> (raw)
In-Reply-To: <20210920095218.1108151-10-horatiu.vultur@microchip.com>

On Mon, Sep 20, 2021 at 11:52:15AM +0200, Horatiu Vultur wrote:
> diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
> new file mode 100644
> index 000000000000..2984f510ae27
> --- /dev/null
> +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
> @@ -0,0 +1,350 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +#include <asm/memory.h>
> +#include <linux/module.h>
> +#include <linux/if_bridge.h>
> +#include <linux/iopoll.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_net.h>
> +#include <linux/reset.h>
> +
> +#include "lan966x_main.h"
> +
> +#define READL_SLEEP_US			10
> +#define READL_TIMEOUT_US		100000000
> +
> +#define IO_RANGES 2
> +
> +static const struct of_device_id lan966x_match[] = {
> +	{ .compatible = "microchip,lan966x-switch" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, mchp_lan966x_match);
> +
> +struct lan966x_main_io_resource {
> +	enum lan966x_target id;
> +	phys_addr_t offset;
> +	int range;
> +};
> +
> +static const struct lan966x_main_io_resource lan966x_main_iomap[] =  {
> +	{ TARGET_CPU,                   0xc0000, 0 }, /* 0xe00c0000 */
> +	{ TARGET_ORG,                         0, 1 }, /* 0xe2000000 */
> +	{ TARGET_GCB,                    0x4000, 1 }, /* 0xe2004000 */
> +	{ TARGET_QS,                     0x8000, 1 }, /* 0xe2008000 */
> +	{ TARGET_CHIP_TOP,              0x10000, 1 }, /* 0xe2010000 */
> +	{ TARGET_REW,                   0x14000, 1 }, /* 0xe2014000 */
> +	{ TARGET_SYS,                   0x28000, 1 }, /* 0xe2028000 */
> +	{ TARGET_HSIO,                  0x2c000, 1 }, /* 0xe202c000 */
> +	{ TARGET_DEV,                   0x34000, 1 }, /* 0xe2034000 */
> +	{ TARGET_DEV +  1,              0x38000, 1 }, /* 0xe2038000 */
> +	{ TARGET_DEV +  2,              0x3c000, 1 }, /* 0xe203c000 */
> +	{ TARGET_DEV +  3,              0x40000, 1 }, /* 0xe2040000 */
> +	{ TARGET_DEV +  4,              0x44000, 1 }, /* 0xe2044000 */
> +	{ TARGET_DEV +  5,              0x48000, 1 }, /* 0xe2048000 */
> +	{ TARGET_DEV +  6,              0x4c000, 1 }, /* 0xe204c000 */
> +	{ TARGET_DEV +  7,              0x50000, 1 }, /* 0xe2050000 */
> +	{ TARGET_QSYS,                 0x100000, 1 }, /* 0xe2100000 */
> +	{ TARGET_AFI,                  0x120000, 1 }, /* 0xe2120000 */
> +	{ TARGET_ANA,                  0x140000, 1 }, /* 0xe2140000 */
> +};
> +
> +static int lan966x_create_targets(struct platform_device *pdev,
> +				  struct lan966x *lan966x)
> +{
> +	struct resource *iores[IO_RANGES];
> +	void __iomem *iomem[IO_RANGES];
> +	void __iomem *begin[IO_RANGES];
> +	int idx;
> +
> +	for (idx = 0; idx < IO_RANGES; idx++) {
> +		iores[idx] = platform_get_resource(pdev, IORESOURCE_MEM,
> +						   idx);
> +		iomem[idx] = devm_ioremap(&pdev->dev,
> +					  iores[idx]->start,
> +					  resource_size(iores[idx]));

This is buggy. If platform_get_resource() returns NULL, you will oops
the kernel.

In any case, this code will be ripe for janitor patching. Please
consider using devm_platform_ioremap_resource() now, before someone
converts your code to use this function.

-- 
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