[PATCH] ppc: seq_file conversion for ppc_htab

This converts the 32-bit ppc htab code to use the seq_file interfaces.

Less code means fewer bugs..

diff --git a/arch/ppc/kernel/ppc_htab.c b/arch/ppc/kernel/ppc_htab.c
index ac30ec217c9e61fdfd2dc7f38c2c24183a362903..74051e0d4402758f85751862415efe36ea5f6109 100644 (file)
--- a/arch/ppc/kernel/ppc_htab.c
+++ b/arch/ppc/kernel/ppc_htab.c
@@ -30,11 +30,9 @@
 #include <asm/system.h>
 #include <asm/reg.h>
 
-static ssize_t ppc_htab_read(struct file * file, char __user * buf,
-                            size_t count, loff_t *ppos);
+static int ppc_htab_show(struct seq_file *m, void *v);
 static ssize_t ppc_htab_write(struct file * file, const char __user * buffer,
                              size_t count, loff_t *ppos);
-static long long ppc_htab_lseek(struct file * file, loff_t offset, int orig);
 int proc_dol2crvec(ctl_table *table, int write, struct file *filp,
                  void __user *buffer, size_t *lenp);
 
@@ -49,10 +47,17 @@ extern unsigned long pte_errors;
 extern unsigned int primary_pteg_full;
 extern unsigned int htab_hash_searches;
 
+static int ppc_htab_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, ppc_htab_show, NULL);
+}
+
 struct file_operations ppc_htab_operations = {
-        .llseek =       ppc_htab_lseek,
-        .read =         ppc_htab_read,
-        .write =        ppc_htab_write,
+       .open           = ppc_htab_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .write          = ppc_htab_write,
+       .release        = single_release,
 };
 
 static char *pmc1_lookup(unsigned long mmcr0)
@@ -96,8 +101,7 @@ static char *pmc2_lookup(unsigned long mmcr0)
  * is _REALLY_ slow (see the nested for loops below) but nothing
  * in here should be really timing critical. -- Cort
  */
-static ssize_t ppc_htab_read(struct file * file, char __user * buf,
-                            size_t count, loff_t *ppos)
+static int ppc_htab_show(struct seq_file *m, void *v)
 {
        unsigned long mmcr0 = 0, pmc1 = 0, pmc2 = 0;
        int n = 0;
@@ -105,22 +109,18 @@ static ssize_t ppc_htab_read(struct file * file, char __user * buf,
        unsigned int kptes = 0, uptes = 0;
        PTE *ptr;
 #endif /* CONFIG_PPC_STD_MMU */
-       char buffer[512];
-
-       if (count < 0)
-               return -EINVAL;
 
        if (cur_cpu_spec[0]->cpu_features & CPU_FTR_604_PERF_MON) {
                mmcr0 = mfspr(SPRN_MMCR0);
                pmc1 = mfspr(SPRN_PMC1);
                pmc2 = mfspr(SPRN_PMC2);
-               n += sprintf( buffer + n,
+               seq_printf(m,
                              "604 Performance Monitoring\n"
                              "MMCR0\t\t: %08lx %s%s ",
                              mmcr0,
                              ( mmcr0>>28 & 0x2 ) ? "(user mode counted)" : "",
                              ( mmcr0>>28 & 0x4 ) ? "(kernel mode counted)" : "");
-               n += sprintf( buffer + n,
+               seq_printf(m,
                              "\nPMC1\t\t: %08lx (%s)\n"
                              "PMC2\t\t: %08lx (%s)\n",
                              pmc1, pmc1_lookup(mmcr0),
@@ -129,10 +129,9 @@ static ssize_t ppc_htab_read(struct file * file, char __user * buf,
 
 #ifdef CONFIG_PPC_STD_MMU
        /* if we don't have a htab */
-       if ( Hash_size == 0 )
-       {
-               n += sprintf( buffer + n, "No Hash Table used\n");
-               goto return_string;
+       if ( Hash_size == 0 ) {
+               seq_printf(m, "No Hash Table used\n");
+               return 0;
        }
 
 #ifndef CONFIG_PPC64BRIDGE
@@ -151,7 +150,7 @@ static ssize_t ppc_htab_read(struct file * file, char __user * buf,
        }
 #endif
 
-       n += sprintf( buffer + n,
+       seq_printf(m,
                      "PTE Hash Table Information\n"
                      "Size\t\t: %luKb\n"
                      "Buckets\t\t: %lu\n"
@@ -173,7 +172,7 @@ static ssize_t ppc_htab_read(struct file * file, char __user * buf,
 #endif
                );
 
-       n += sprintf( buffer + n,
+       seq_printf(m,
                      "Reloads\t\t: %lu\n"
                      "Preloads\t: %lu\n"
                      "Searches\t: %u\n"
@@ -181,23 +180,13 @@ static ssize_t ppc_htab_read(struct file * file, char __user * buf,
                      "Evicts\t\t: %lu\n",
                      htab_reloads, htab_preloads, htab_hash_searches,
                      primary_pteg_full, htab_evicts);
-return_string:
 #endif /* CONFIG_PPC_STD_MMU */
 
-       n += sprintf( buffer + n,
+       seq_printf(m,
                      "Non-error misses: %lu\n"
                      "Error misses\t: %lu\n",
                      pte_misses, pte_errors);
-       if (*ppos >= strlen(buffer))
-               return 0;
-       if (n > strlen(buffer) - *ppos)
-               n = strlen(buffer) - *ppos;
-       if (n > count)
-               n = count;
-       if (copy_to_user(buf, buffer + *ppos, n))
-               return -EFAULT;
-       *ppos += n;
-       return n;
+       return 0;
 }
 
 /*
@@ -210,7 +199,7 @@ static ssize_t ppc_htab_write(struct file * file, const char __user * ubuffer,
        unsigned long tmp;
        char buffer[16];
 
-       if ( current->uid != 0 )
+       if (!capable(CAPS_SYS_ADMIN))
                return -EACCES;
        if (strncpy_from_user(buffer, ubuffer, 15))
                return -EFAULT;
@@ -330,26 +319,6 @@ static ssize_t ppc_htab_write(struct file * file, const char __user * ubuffer,
 #endif /* CONFIG_PPC_STD_MMU */
 }
 
-
-static long long
-ppc_htab_lseek(struct file * file, loff_t offset, int orig)
-{
-    long long ret = -EINVAL;
-
-    lock_kernel();
-    switch (orig) {
-    case 0:
-       file->f_pos = offset;
-       ret = file->f_pos;
-       break;
-    case 1:
-       file->f_pos += offset;
-       ret = file->f_pos;
-    }
-    unlock_kernel();
-    return ret;
-}
-
 int proc_dol2crvec(ctl_table *table, int write, struct file *filp,
                  void __user *buffer_arg, size_t *lenp)
 {