Re: [PATCH v12 1/2] drivers/coresight: Add UltraSoc System Memory Buffer driver

From: Suzuki K Poulose
Date: Mon Nov 14 2022 - 08:59:46 EST

On 14/11/2022 13:06, hejunhao wrote:


On 2022/11/14 18:49, Suzuki K Poulose wrote:
On 11/11/2022 22:06, kernel test robot wrote:
Hi Junhao,

I love your patch! Perhaps something to improve:

[auto build test WARNING on soc/for-next]
[also build test WARNING on linus/master v6.1-rc4 next-20221111]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Junhao-He/Add-support-for-UltraSoc-System-Memory-Buffer/20221109-215158
base: https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git for-next
patch link: https://lore.kernel.org/r/20221109135008.9485-2-hejunhao3%40huawei.com
patch subject: [PATCH v12 1/2] drivers/coresight: Add UltraSoc System Memory Buffer driver
config: arm64-randconfig-s033-20221111
compiler: aarch64-linux-gcc (GCC) 12.1.0
reproduce:
         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
         chmod +x ~/bin/make.cross
         # apt-get install sparse
         # sparse version: v0.6.4-39-gce1a6720-dirty
         # https://github.com/intel-lab-lkp/linux/commit/49ede03fd874b65deca5382ea84c3377188136da
         git remote add linux-review https://github.com/intel-lab-lkp/linux
         git fetch --no-tags linux-review Junhao-He/Add-support-for-UltraSoc-System-Memory-Buffer/20221109-215158
         git checkout 49ede03fd874b65deca5382ea84c3377188136da
         # save the config file
         mkdir build_dir && cp config build_dir/.config
         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/hwtracing/coresight/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>

sparse warnings: (new ones prefixed by >>)
drivers/hwtracing/coresight/ultrasoc-smb.c:113:33: sparse: sparse: cast removes address space '__iomem' of expression
drivers/hwtracing/coresight/ultrasoc-smb.c:354:17: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected void const * @@     got void [noderef] __iomem * @@
    drivers/hwtracing/coresight/ultrasoc-smb.c:354:17: sparse: expected void const *
    drivers/hwtracing/coresight/ultrasoc-smb.c:354:17: sparse: got void [noderef] __iomem *
drivers/hwtracing/coresight/ultrasoc-smb.c:354:17: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected void const * @@     got void [noderef] __iomem * @@
    drivers/hwtracing/coresight/ultrasoc-smb.c:354:17: sparse: expected void const *
    drivers/hwtracing/coresight/ultrasoc-smb.c:354:17: sparse: got void [noderef] __iomem *
    drivers/hwtracing/coresight/ultrasoc-smb.c:354:17: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected void const * @@     got void [noderef] __iomem * @@
    drivers/hwtracing/coresight/ultrasoc-smb.c:354:17: sparse: expected void const *
    drivers/hwtracing/coresight/ultrasoc-smb.c:354:17: sparse: got void [noderef] __iomem *
drivers/hwtracing/coresight/ultrasoc-smb.c:463:14: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected void [noderef] __iomem *base @@     got void * @@
    drivers/hwtracing/coresight/ultrasoc-smb.c:463:14: sparse: expected void [noderef] __iomem *base
    drivers/hwtracing/coresight/ultrasoc-smb.c:463:14: sparse: got void *

vim +/__iomem +113 drivers/hwtracing/coresight/ultrasoc-smb.c

     89
     90    static ssize_t smb_read(struct file *file, char __user *data, size_t len,
     91                loff_t *ppos)
     92    {
     93        struct smb_drv_data *drvdata = container_of(file->private_data,
     94                        struct smb_drv_data, miscdev);
     95        struct smb_data_buffer *sdb = &drvdata->sdb;
     96        struct device *dev = &drvdata->csdev->dev;
     97        ssize_t to_copy = 0;
     98
     99        mutex_lock(&drvdata->mutex);
    100
    101        if (!sdb->data_size) {
    102            smb_update_data_size(drvdata);
    103            if (!sdb->data_size)
    104                goto out;
    105        }
    106
    107        to_copy = min(sdb->data_size, len);
    108
    109        /* Copy parts of trace data when read pointer wrap around SMB buffer */
    110        if (sdb->rd_offset + to_copy > sdb->buf_size)
    111            to_copy = sdb->buf_size - sdb->rd_offset;
    112
  > 113        if (copy_to_user(data, (void *)sdb->buf_base + sdb->rd_offset,
    114                 to_copy)) {
    115            dev_dbg(dev, "Failed to copy data to user\n");
    116            to_copy = -EFAULT;
    117            goto out;
    118        }
    119

Please could we replace this with copy_to_user_fromio() ?

Suzuki

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Hi Suzuki,

This is a cache memory,  due to improper use of "__iomem" , the sparse generates warnings.
I has fix it in v13.
https://lore.kernel.org/lkml/20221114090316.63157-2-hejunhao3@xxxxxxxxxx/

I don't see a ChangeLog mentioning that this change. Please make sure
you accurately describe the changes (especially fixes like these).

Thanks
Suzuki


Best regards,
Junhao.