Re: [PATCH 25/26] arm: Don't use create_proc_read_entry() [RFC]

[Tony Lindgren <tony@atomide.com>]

* David Howells <dhowells@redhat.com> [130411 06:35]:
> Don't use create_proc_read_entry() as that is deprecated, but rather use
> proc_create_data() and seq_file instead.
> 
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Russell King <linux@arm.linux.org.uk>
> cc: Kevin Hilman <khilman@deeprootsystems.com>

Looks like the mach-omap1/pm.c part we can make into
a debugfs entry as it only contains PM debug data. But
that we can do after this patch.

Acked-by: Tony Lindgren <tony@atomide.com>

> cc: linux-arm-kernel@lists.infradead.org
> cc: linux-omap@vger.kernel.org
> ---
> 
>  arch/arm/kernel/swp_emulate.c |   42 +++++++++++++-----------------
>  arch/arm/mach-omap1/pm.c      |   58 +++++++++++++++++------------------------
>  2 files changed, 43 insertions(+), 57 deletions(-)
> 
> diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
> index 0bba47a..087fc32 100644
> --- a/arch/arm/kernel/swp_emulate.c
> +++ b/arch/arm/kernel/swp_emulate.c
> @@ -21,6 +21,7 @@
>  #include <linux/init.h>
>  #include <linux/kernel.h>
>  #include <linux/proc_fs.h>
> +#include <linux/seq_file.h>
>  #include <linux/sched.h>
>  #include <linux/syscalls.h>
>  #include <linux/perf_event.h>
> @@ -79,27 +80,27 @@ static unsigned long abtcounter;
>  static pid_t         previous_pid;
>  
>  #ifdef CONFIG_PROC_FS
> -static int proc_read_status(char *page, char **start, off_t off, int count,
> -			    int *eof, void *data)
> +static int proc_status_show(struct seq_file *m, void *v)
>  {
> -	char *p = page;
> -	int len;
> -
> -	p += sprintf(p, "Emulated SWP:\t\t%lu\n", swpcounter);
> -	p += sprintf(p, "Emulated SWPB:\t\t%lu\n", swpbcounter);
> -	p += sprintf(p, "Aborted SWP{B}:\t\t%lu\n", abtcounter);
> +	seq_printf(m, "Emulated SWP:\t\t%lu\n", swpcounter);
> +	seq_printf(m, "Emulated SWPB:\t\t%lu\n", swpbcounter);
> +	seq_printf(m, "Aborted SWP{B}:\t\t%lu\n", abtcounter);
>  	if (previous_pid != 0)
> -		p += sprintf(p, "Last process:\t\t%d\n", previous_pid);
> -
> -	len = (p - page) - off;
> -	if (len < 0)
> -		len = 0;
> -
> -	*eof = (len <= count) ? 1 : 0;
> -	*start = page + off;
> +		seq_printf(m, "Last process:\t\t%d\n", previous_pid);
> +	return 0;
> +}
>  
> -	return len;
> +static int proc_status_open(struct inode *inode, struct file *file)
> +{
> +	return single_open(file, proc_status_show, PDE_DATA(inode));
>  }
> +
> +static const struct file_operations proc_status_fops = {
> +	.open		= proc_status_open,
> +	.read		= seq_read,
> +	.llseek		= seq_lseek,
> +	.release	= seq_release,
> +};
>  #endif
>  
>  /*
> @@ -266,12 +267,7 @@ static struct undef_hook swp_hook = {
>  static int __init swp_emulation_init(void)
>  {
>  #ifdef CONFIG_PROC_FS
> -	struct proc_dir_entry *res;
> -
> -	res = create_proc_read_entry("cpu/swp_emulation", S_IRUGO, NULL,
> -					proc_read_status, NULL);
> -
> -	if (!res)
> +	if (!proc_create("cpu/swp_emulation", S_IRUGO, NULL, &proc_status_fops))
>  		return -ENOMEM;
>  #endif /* CONFIG_PROC_FS */
>  
> diff --git a/arch/arm/mach-omap1/pm.c b/arch/arm/mach-omap1/pm.c
> index 7a7690a..2645e37 100644
> --- a/arch/arm/mach-omap1/pm.c
> +++ b/arch/arm/mach-omap1/pm.c
> @@ -38,6 +38,7 @@
>  #include <linux/suspend.h>
>  #include <linux/sched.h>
>  #include <linux/proc_fs.h>
> +#include <linux/seq_file.h>
>  #include <linux/interrupt.h>
>  #include <linux/sysfs.h>
>  #include <linux/module.h>
> @@ -423,22 +424,11 @@ void omap1_pm_suspend(void)
>  }
>  
>  #if defined(DEBUG) && defined(CONFIG_PROC_FS)
> -static int g_read_completed;
> -
>  /*
>   * Read system PM registers for debugging
>   */
> -static int omap_pm_read_proc(
> -	char *page_buffer,
> -	char **my_first_byte,
> -	off_t virtual_start,
> -	int length,
> -	int *eof,
> -	void *data)
> +static int omap_pm_proc_show(struct seq_file *m, void *v)
>  {
> -	int my_buffer_offset = 0;
> -	char * const my_base = page_buffer;
> -
>  	ARM_SAVE(ARM_CKCTL);
>  	ARM_SAVE(ARM_IDLECT1);
>  	ARM_SAVE(ARM_IDLECT2);
> @@ -479,10 +469,7 @@ static int omap_pm_read_proc(
>  		MPUI1610_SAVE(EMIFS_CONFIG);
>  	}
>  
> -	if (virtual_start == 0) {
> -		g_read_completed = 0;
> -
> -		my_buffer_offset += sprintf(my_base + my_buffer_offset,
> +	seq_printf(m,
>  		   "ARM_CKCTL_REG:            0x%-8x     \n"
>  		   "ARM_IDLECT1_REG:          0x%-8x     \n"
>  		   "ARM_IDLECT2_REG:          0x%-8x     \n"
> @@ -512,8 +499,8 @@ static int omap_pm_read_proc(
>  		   ULPD_SHOW(ULPD_STATUS_REQ),
>  		   ULPD_SHOW(ULPD_POWER_CTRL));
>  
> -		if (cpu_is_omap7xx()) {
> -			my_buffer_offset += sprintf(my_base + my_buffer_offset,
> +	if (cpu_is_omap7xx()) {
> +		seq_printf(m,
>  			   "MPUI7XX_CTRL_REG	     0x%-8x \n"
>  			   "MPUI7XX_DSP_STATUS_REG:      0x%-8x \n"
>  			   "MPUI7XX_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
> @@ -526,8 +513,8 @@ static int omap_pm_read_proc(
>  			   MPUI7XX_SHOW(MPUI_DSP_API_CONFIG),
>  			   MPUI7XX_SHOW(EMIFF_SDRAM_CONFIG),
>  			   MPUI7XX_SHOW(EMIFS_CONFIG));
> -		} else if (cpu_is_omap15xx()) {
> -			my_buffer_offset += sprintf(my_base + my_buffer_offset,
> +	} else if (cpu_is_omap15xx()) {
> +		seq_printf(m,
>  			   "MPUI1510_CTRL_REG             0x%-8x \n"
>  			   "MPUI1510_DSP_STATUS_REG:      0x%-8x \n"
>  			   "MPUI1510_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
> @@ -540,8 +527,8 @@ static int omap_pm_read_proc(
>  			   MPUI1510_SHOW(MPUI_DSP_API_CONFIG),
>  			   MPUI1510_SHOW(EMIFF_SDRAM_CONFIG),
>  			   MPUI1510_SHOW(EMIFS_CONFIG));
> -		} else if (cpu_is_omap16xx()) {
> -			my_buffer_offset += sprintf(my_base + my_buffer_offset,
> +	} else if (cpu_is_omap16xx()) {
> +		seq_printf(m,
>  			   "MPUI1610_CTRL_REG             0x%-8x \n"
>  			   "MPUI1610_DSP_STATUS_REG:      0x%-8x \n"
>  			   "MPUI1610_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
> @@ -554,25 +541,28 @@ static int omap_pm_read_proc(
>  			   MPUI1610_SHOW(MPUI_DSP_API_CONFIG),
>  			   MPUI1610_SHOW(EMIFF_SDRAM_CONFIG),
>  			   MPUI1610_SHOW(EMIFS_CONFIG));
> -		}
> -
> -		g_read_completed++;
> -	} else if (g_read_completed >= 1) {
> -		 *eof = 1;
> -		 return 0;
>  	}
> -	g_read_completed++;
>  
> -	*my_first_byte = page_buffer;
> -	return  my_buffer_offset;
> +	return 0;
> +}
> +
> +static int omap_pm_proc_open(struct inode *inode, struct file *file)
> +{
> +	return single_open(file, omap_pm_proc_show, PDE_DATA(inode));
>  }
>  
> +static const struct file_operations omap_pm_proc_fops = {
> +	.open		= omap_pm_proc_open,
> +	.read		= seq_read,
> +	.llseek		= seq_lseek,
> +	.release	= seq_release,
> +};
> +
>  static void omap_pm_init_proc(void)
>  {
>  	/* XXX Appears to leak memory */
> -	create_proc_read_entry("driver/omap_pm",
> -			       S_IWUSR | S_IRUGO, NULL,
> -			       omap_pm_read_proc, NULL);
> +	create_proc("driver/omap_pm", S_IWUSR | S_IRUGO, NULL,
> +		    &omap_pm_proc_fops);
>  }
>  
>  #endif /* DEBUG && CONFIG_PROC_FS */
>