| Message ID | 20150823104130.287718296@telegraphics.com.au (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
James, would you please review and ack this patch, and patch 01/25 also? On Sun, 23 Aug 2015, Finn Thain wrote: > By implementing an arch_nvram_ops struct, any platform can re-use the > drivers/char/nvram module without needing any arch-specific code > in that module. Atari does so here. > > Atari has one user of nvram_check_checksum() whereas the other platforms > (i.e. x86 and ARM platforms) have none at all. Replace this > validate-checksum-and-read-byte sequence with the equivalent > rtc_nvram_ops.read() call and remove the now unused functions. > > Signed-off-by: Finn Thain <fthain@telegraphics.com.au> > Tested-by: Christian T. Steigies <cts@debian.org> > Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> > > --- > > The advantage of the new ops struct over the old global nvram_* functions > is that the misc device module can be shared by different platforms > without requiring every platform to implement every nvram_* function. > E.g. only RTC "CMOS" NVRAMs have a checksum for the entire NVRAM > and only PowerPC platforms have a "sync" ioctl. > > --- > arch/m68k/atari/nvram.c | 89 ++++++++++++++++++++++++++++------------------ > drivers/scsi/atari_scsi.c | 8 ++-- > include/linux/nvram.h | 9 ++++ > 3 files changed, 70 insertions(+), 36 deletions(-) > > Index: linux/arch/m68k/atari/nvram.c > =================================================================== > --- linux.orig/arch/m68k/atari/nvram.c 2015-08-23 20:40:55.000000000 +1000 > +++ linux/arch/m68k/atari/nvram.c 2015-08-23 20:40:57.000000000 +1000 > @@ -38,33 +38,12 @@ unsigned char __nvram_read_byte(int i) > return CMOS_READ(NVRAM_FIRST_BYTE + i); > } > > -unsigned char nvram_read_byte(int i) > -{ > - unsigned long flags; > - unsigned char c; > - > - spin_lock_irqsave(&rtc_lock, flags); > - c = __nvram_read_byte(i); > - spin_unlock_irqrestore(&rtc_lock, flags); > - return c; > -} > -EXPORT_SYMBOL(nvram_read_byte); > - > /* This races nicely with trying to read with checksum checking */ > void __nvram_write_byte(unsigned char c, int i) > { > CMOS_WRITE(c, NVRAM_FIRST_BYTE + i); > } > > -void nvram_write_byte(unsigned char c, int i) > -{ > - unsigned long flags; > - > - spin_lock_irqsave(&rtc_lock, flags); > - __nvram_write_byte(c, i); > - spin_unlock_irqrestore(&rtc_lock, flags); > -} > - > /* On Ataris, the checksum is over all bytes except the checksum bytes > * themselves; these are at the very end. > */ > @@ -83,18 +62,6 @@ int __nvram_check_checksum(void) > (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff)); > } > > -int nvram_check_checksum(void) > -{ > - unsigned long flags; > - int rv; > - > - spin_lock_irqsave(&rtc_lock, flags); > - rv = __nvram_check_checksum(); > - spin_unlock_irqrestore(&rtc_lock, flags); > - return rv; > -} > -EXPORT_SYMBOL(nvram_check_checksum); > - > static void __nvram_set_checksum(void) > { > int i; > @@ -106,6 +73,62 @@ static void __nvram_set_checksum(void) > __nvram_write_byte(sum, ATARI_CKS_LOC + 1); > } > > +static ssize_t nvram_read(char *buf, size_t count, loff_t *ppos) > +{ > + char *p = buf; > + loff_t i; > + > + spin_lock_irq(&rtc_lock); > + > + if (!__nvram_check_checksum()) { > + spin_unlock_irq(&rtc_lock); > + return -EIO; > + } > + > + for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) > + *p = __nvram_read_byte(i); > + > + spin_unlock_irq(&rtc_lock); > + > + *ppos = i; > + return p - buf; > +} > + > +static ssize_t nvram_write(char *buf, size_t count, loff_t *ppos) > +{ > + char *p = buf; > + loff_t i; > + > + spin_lock_irq(&rtc_lock); > + > + if (!__nvram_check_checksum()) { > + spin_unlock_irq(&rtc_lock); > + return -EIO; > + } > + > + for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) > + __nvram_write_byte(*p, i); > + > + __nvram_set_checksum(); > + > + spin_unlock_irq(&rtc_lock); > + > + *ppos = i; > + return p - buf; > +} > + > +static ssize_t nvram_get_size(void) > +{ > + return NVRAM_BYTES; > +} > + > +const struct nvram_ops arch_nvram_ops = { > + .read = nvram_read, > + .write = nvram_write, > + .get_size = nvram_get_size, > +}; > +EXPORT_SYMBOL(arch_nvram_ops); > + > #ifdef CONFIG_PROC_FS > static struct { > unsigned char val; > Index: linux/drivers/scsi/atari_scsi.c > =================================================================== > --- linux.orig/drivers/scsi/atari_scsi.c 2015-08-23 20:40:53.000000000 +1000 > +++ linux/drivers/scsi/atari_scsi.c 2015-08-23 20:40:57.000000000 +1000 > @@ -880,13 +880,15 @@ static int __init atari_scsi_probe(struc > #ifdef CONFIG_NVRAM > else > /* Test if a host id is set in the NVRam */ > - if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) { > - unsigned char b = nvram_read_byte(14); > + if (ATARIHW_PRESENT(TT_CLK)) { > + unsigned char b; > + loff_t offset = 14; > + ssize_t count = arch_nvram_ops.read(&b, 1, &offset); > > /* Arbitration enabled? (for TOS) > * If yes, use configured host ID > */ > - if (b & 0x80) > + if ((count == 1) && (b & 0x80)) > atari_scsi_template.this_id = b & 7; > } > #endif > Index: linux/include/linux/nvram.h > =================================================================== > --- linux.orig/include/linux/nvram.h 2015-08-23 20:40:53.000000000 +1000 > +++ linux/include/linux/nvram.h 2015-08-23 20:40:57.000000000 +1000 > @@ -10,4 +10,13 @@ extern void __nvram_write_byte(unsigned > extern void nvram_write_byte(unsigned char c, int i); > extern int __nvram_check_checksum(void); > extern int nvram_check_checksum(void); > + > +struct nvram_ops { > + ssize_t (*read)(char *, size_t, loff_t *); > + ssize_t (*write)(char *, size_t, loff_t *); > + ssize_t (*get_size)(void); > +}; > + > +extern const struct nvram_ops arch_nvram_ops; > + > #endif /* _LINUX_NVRAM_H */ > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-m68k" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
Index: linux/arch/m68k/atari/nvram.c =================================================================== --- linux.orig/arch/m68k/atari/nvram.c 2015-08-23 20:40:55.000000000 +1000 +++ linux/arch/m68k/atari/nvram.c 2015-08-23 20:40:57.000000000 +1000 @@ -38,33 +38,12 @@ unsigned char __nvram_read_byte(int i) return CMOS_READ(NVRAM_FIRST_BYTE + i); } -unsigned char nvram_read_byte(int i) -{ - unsigned long flags; - unsigned char c; - - spin_lock_irqsave(&rtc_lock, flags); - c = __nvram_read_byte(i); - spin_unlock_irqrestore(&rtc_lock, flags); - return c; -} -EXPORT_SYMBOL(nvram_read_byte); - /* This races nicely with trying to read with checksum checking */ void __nvram_write_byte(unsigned char c, int i) { CMOS_WRITE(c, NVRAM_FIRST_BYTE + i); } -void nvram_write_byte(unsigned char c, int i) -{ - unsigned long flags; - - spin_lock_irqsave(&rtc_lock, flags); - __nvram_write_byte(c, i); - spin_unlock_irqrestore(&rtc_lock, flags); -} - /* On Ataris, the checksum is over all bytes except the checksum bytes * themselves; these are at the very end. */ @@ -83,18 +62,6 @@ int __nvram_check_checksum(void) (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff)); } -int nvram_check_checksum(void) -{ - unsigned long flags; - int rv; - - spin_lock_irqsave(&rtc_lock, flags); - rv = __nvram_check_checksum(); - spin_unlock_irqrestore(&rtc_lock, flags); - return rv; -} -EXPORT_SYMBOL(nvram_check_checksum); - static void __nvram_set_checksum(void) { int i; @@ -106,6 +73,62 @@ static void __nvram_set_checksum(void) __nvram_write_byte(sum, ATARI_CKS_LOC + 1); } +static ssize_t nvram_read(char *buf, size_t count, loff_t *ppos) +{ + char *p = buf; + loff_t i; + + spin_lock_irq(&rtc_lock); + + if (!__nvram_check_checksum()) { + spin_unlock_irq(&rtc_lock); + return -EIO; + } + + for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) + *p = __nvram_read_byte(i); + + spin_unlock_irq(&rtc_lock); + + *ppos = i; + return p - buf; +} + +static ssize_t nvram_write(char *buf, size_t count, loff_t *ppos) +{ + char *p = buf; + loff_t i; + + spin_lock_irq(&rtc_lock); + + if (!__nvram_check_checksum()) { + spin_unlock_irq(&rtc_lock); + return -EIO; + } + + for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) + __nvram_write_byte(*p, i); + + __nvram_set_checksum(); + + spin_unlock_irq(&rtc_lock); + + *ppos = i; + return p - buf; +} + +static ssize_t nvram_get_size(void) +{ + return NVRAM_BYTES; +} + +const struct nvram_ops arch_nvram_ops = { + .read = nvram_read, + .write = nvram_write, + .get_size = nvram_get_size, +}; +EXPORT_SYMBOL(arch_nvram_ops); + #ifdef CONFIG_PROC_FS static struct { unsigned char val; Index: linux/drivers/scsi/atari_scsi.c =================================================================== --- linux.orig/drivers/scsi/atari_scsi.c 2015-08-23 20:40:53.000000000 +1000 +++ linux/drivers/scsi/atari_scsi.c 2015-08-23 20:40:57.000000000 +1000 @@ -880,13 +880,15 @@ static int __init atari_scsi_probe(struc #ifdef CONFIG_NVRAM else /* Test if a host id is set in the NVRam */ - if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) { - unsigned char b = nvram_read_byte(14); + if (ATARIHW_PRESENT(TT_CLK)) { + unsigned char b; + loff_t offset = 14; + ssize_t count = arch_nvram_ops.read(&b, 1, &offset); /* Arbitration enabled? (for TOS) * If yes, use configured host ID */ - if (b & 0x80) + if ((count == 1) && (b & 0x80)) atari_scsi_template.this_id = b & 7; } #endif Index: linux/include/linux/nvram.h =================================================================== --- linux.orig/include/linux/nvram.h 2015-08-23 20:40:53.000000000 +1000 +++ linux/include/linux/nvram.h 2015-08-23 20:40:57.000000000 +1000 @@ -10,4 +10,13 @@ extern void __nvram_write_byte(unsigned extern void nvram_write_byte(unsigned char c, int i); extern int __nvram_check_checksum(void); extern int nvram_check_checksum(void); + +struct nvram_ops { + ssize_t (*read)(char *, size_t, loff_t *); + ssize_t (*write)(char *, size_t, loff_t *); + ssize_t (*get_size)(void); +}; + +extern const struct nvram_ops arch_nvram_ops; + #endif /* _LINUX_NVRAM_H */