| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <201103111628.57549.arnd@arndb.de>
Date: Fri, 11 Mar 2011 16:28:57 +0100
From: Arnd Bergmann <arnd@...db.de>
To: linux-arm-kernel@...ts.infradead.org
Cc: Subhasish Ghosh <subhasish@...tralsolutions.com>,
davinci-linux-open-source@...ux.davincidsp.com,
sachi@...tralsolutions.com, Samuel Ortiz <sameo@...ux.intel.com>,
nsekhar@...com, open list <linux-kernel@...r.kernel.org>,
m-watkins@...com, "Marc Kleine-Budde" <mkl@...gutronix.de>
Subject: Re: [PATCH v3 1/7] mfd: add pruss mfd driver.
On Tuesday 08 March 2011, Subhasish Ghosh wrote:
> +struct da8xx_pruss {
> + struct device *dev;
> + spinlock_t lock;
> + struct resource *res;
> + struct clk *clk;
> + u32 clk_freq;
> + void __iomem *ioaddr;
> +};
> +s32 pruss_disable(struct device *dev, u8 pruss_num)
> +{
> + struct da8xx_pruss *pruss = dev_get_drvdata(dev->parent);
> + struct da8xx_prusscore_regs *h_pruss;
> + struct pruss_map *pruss_mmap = (struct pruss_map *)pruss->ioaddr;
> + u32 temp_reg;
> + u32 delay_cnt;
Can you explain the significance of pruss_num? As far as I
can tell, you always pass constants in here, so it should
be possible to determine the number from the device.
> + if ((pruss_num != DA8XX_PRUCORE_0) && (pruss_num != DA8XX_PRUCORE_1))
> + return -EINVAL;
> +
> + spin_lock(&pruss->lock);
> + if (pruss_num == DA8XX_PRUCORE_0) {
> + /* pruss deinit */
> + __raw_writel(0xFFFFFFFF, (PRUSS_INTC_STATCLRINT0 & 0xFFFF));
> + /* Disable PRU0 */
> + h_pruss = (struct da8xx_prusscore_regs *)
> + &pruss_mmap->core[DA8XX_PRUCORE_0];
> +
> + temp_reg = __raw_readl(&h_pruss->CONTROL);
> + temp_reg = (temp_reg &
> + ~DA8XX_PRUCORE_CONTROL_COUNTENABLE_MASK) |
> + ((DA8XX_PRUCORE_CONTROL_COUNTENABLE_DISABLE <<
> + DA8XX_PRUCORE_CONTROL_COUNTENABLE_SHIFT) &
> + DA8XX_PRUCORE_CONTROL_COUNTENABLE_MASK);
> + __raw_writel(temp_reg, &h_pruss->CONTROL);
Better use readl/writel, the __raw_ variants are not reliable in general.
> + for (delay_cnt = 0x10000; delay_cnt > 0; delay_cnt--) {
> +
> + temp_reg = __raw_readl(&h_pruss->CONTROL);
> + temp_reg = (temp_reg &
> + ~DA8XX_PRUCORE_CONTROL_ENABLE_MASK) |
> + ((DA8XX_PRUCORE_CONTROL_ENABLE_DISABLE <<
> + DA8XX_PRUCORE_CONTROL_ENABLE_SHIFT) &
> + DA8XX_PRUCORE_CONTROL_ENABLE_MASK);
> + __raw_writel(temp_reg, &h_pruss->CONTROL);
> + }
> +
> + /* Reset PRU0 */
> + for (delay_cnt = 0x10000; delay_cnt > 0; delay_cnt--)
> + __raw_writel(DA8XX_PRUCORE_CONTROL_RESETVAL,
> + &h_pruss->CONTROL);
Why do you need to reset it 65536 times? Is once not enough?
> + } else if (pruss_num == DA8XX_PRUCORE_1) {
> + /* pruss deinit */
> + __raw_writel(0xFFFFFFFF, (PRUSS_INTC_STATCLRINT1 & 0xFFFF));
> + /* Disable PRU1 */
> + h_pruss = (struct da8xx_prusscore_regs *)
> + &pruss_mmap->core[DA8XX_PRUCORE_1];
> + temp_reg = __raw_readl(&h_pruss->CONTROL);
> + temp_reg = (temp_reg &
> + ~DA8XX_PRUCORE_CONTROL_COUNTENABLE_MASK) |
> + ((DA8XX_PRUCORE_CONTROL_COUNTENABLE_DISABLE <<
> + DA8XX_PRUCORE_CONTROL_COUNTENABLE_SHIFT) &
> + DA8XX_PRUCORE_CONTROL_COUNTENABLE_MASK);
> + __raw_writel(temp_reg, &h_pruss->CONTROL);
> +
> + for (delay_cnt = 0x10000; delay_cnt > 0; delay_cnt--) {
> +
> + temp_reg = __raw_readl(&h_pruss->CONTROL);
> + temp_reg = (temp_reg &
> + ~DA8XX_PRUCORE_CONTROL_ENABLE_MASK) |
> + ((DA8XX_PRUCORE_CONTROL_ENABLE_DISABLE <<
> + DA8XX_PRUCORE_CONTROL_ENABLE_SHIFT) &
> + DA8XX_PRUCORE_CONTROL_ENABLE_MASK);
> + __raw_writel(temp_reg, &h_pruss->CONTROL);
> + }
> +
> + /* Reset PRU1 */
> + for (delay_cnt = 0x10000; delay_cnt > 0; delay_cnt--)
> + __raw_writel(DA8XX_PRUCORE_CONTROL_RESETVAL,
> + &h_pruss->CONTROL);
> + }
> + spin_unlock(&pruss->lock);
This is almost the exact same code as for the DA8XX_PRUCORE_0 case.
Please be a little more creative in order to avoid such code duplication.
> + return 0;
> +}
> +EXPORT_SYMBOL(pruss_disable);
EXPORT_SYMBOL_GPL, please. Also for the other symbols.
> +s32 pruss_writeb(struct device *dev, u32 offset,
> + u8 *pdatatowrite, u16 bytestowrite)
> +{
> + struct da8xx_pruss *pruss = dev_get_drvdata(dev->parent);
> + u8 *paddresstowrite;
> + u16 loop;
> + offset = (u32)pruss->ioaddr + offset;
> + paddresstowrite = (u8 *) (offset);
> +
> + for (loop = 0; loop < bytestowrite; loop++)
> + __raw_writeb(*pdatatowrite++, paddresstowrite++);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(pruss_writeb);
I would recommend providing a simpler variant of your all I/O accessors,
which write a single word. Most of the users of these simply
pass bytestowrite=1 anyway, so the caller can become more readable.
Also, my comments about __raw_* and Marc's comments about the
type cast apply to all of these.
> +static int pruss_mfd_add_devices(struct platform_device *pdev)
> +{
> + struct da8xx_pruss_devices *dev_data = pdev->dev.platform_data;
> + struct device *dev = &pdev->dev;
> + struct mfd_cell cell;
> + u32 err, count;
> +
> + for (count = 0; dev_data[count].dev_name != NULL; count++) {
> + memset(&cell, 0, sizeof(struct mfd_cell));
> + cell.id = count;
> + cell.name = dev_data[count].dev_name;
> + cell.platform_data = dev_data[count].pdata;
> + cell.data_size = dev_data[count].pdata_size;
> + cell.resources = dev_data[count].resources;
> + cell.num_resources = dev_data[count].num_resources;
> +
> + err = mfd_add_devices(dev, 0, &cell, 1, NULL, 0);
> + if (err) {
> + dev_err(dev, "cannot add mfd cells\n");
> + return err;
> + }
> + dev_info(dev, "mfd: added %s device\n",
> + dev_data[count].dev_name);
> + }
> +
> + return err;
> +}
This would get much simpler if you just replaced the da8xx_pruss_devices
array with an mfd_cell array.
Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists