From: Martyn Welch <martyn.welch@gefanuc•com>
To: Benjamin Herrenschmidt <benh@kernel•crashing.org>
Cc: linuxppc-dev@ozlabs•org
Subject: Re: [PATCH 2/5] Mechanism to enable use Generic NVRAM driver for different size chips
Date: Thu, 23 Jul 2009 12:31:15 +0100 [thread overview]
Message-ID: <4A684A03.5010803@gefanuc.com> (raw)
In-Reply-To: <1248334988.3367.77.camel@pasglop>
Benjamin Herrenschmidt wrote:
> On Thu, 2009-07-02 at 17:12 +0100, Martyn Welch wrote:
>
>> Remove the reliance on a staticly defined NVRAM size, allowing platforms to support NVRAMs with sizes differing from the standard. A fall back value is provided for platforms not supporting this extension.
>>
>> Signed-off-by: Martyn Welch <martyn.welch@gefanuc•com>
>>
>
> What about other archs that use this driver ? They would also need
> that new nvram_size() ...
>
I'm fairly confident that this driver is solely used by the PowerPC
architecture. The config option being set in arch/powerpc/Kconfig[1].
Other than the obvious matches in drivers/char/Makefile[2] and powerpc
defconfigs, the only other places I can find the option being used are:
* As a requirement for CONFIG_NVRAM on the PowerPC platform in
drivers/char/Kconfig[3]
* In "include/config/auto.conf" and "include/linux/autoconf.h". Are
these for generation of generic configs?
Martyn
[1]
http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/benh/powerpc.git;a=blob;f=arch/powerpc/Kconfig#l145
[2]
http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/benh/powerpc.git;a=blob;f=drivers/char/Makefile#l83
[3]
http://git.kernel.org/gitweb.cgi?p=linux/kernel/git/benh/powerpc.git;a=blob;f=drivers/char/Kconfig#l777
> BTW. This patch touches non-arch code so should at least be CCed to lkml
>
> Cheers,
> Ben.
>
>
>> ---
>>
>> arch/powerpc/include/asm/nvram.h | 3 +++
>> arch/powerpc/kernel/setup_32.c | 8 ++++++++
>> drivers/char/generic_nvram.c | 27 ++++++++++++++++++++-------
>> 3 files changed, 31 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/nvram.h b/arch/powerpc/include/asm/nvram.h
>> index efde5ac..71df8b2 100644
>> --- a/arch/powerpc/include/asm/nvram.h
>> +++ b/arch/powerpc/include/asm/nvram.h
>> @@ -107,6 +107,9 @@ extern void pmac_xpram_write(int xpaddr, u8 data);
>> /* Synchronize NVRAM */
>> extern void nvram_sync(void);
>>
>> +/* Determine NVRAM size */
>> +extern ssize_t nvram_size(void);
>> +
>> /* Normal access to NVRAM */
>> extern unsigned char nvram_read_byte(int i);
>> extern void nvram_write_byte(unsigned char c, int i);
>> diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
>> index 1d15424..28f7570 100644
>> --- a/arch/powerpc/kernel/setup_32.c
>> +++ b/arch/powerpc/kernel/setup_32.c
>> @@ -208,6 +208,14 @@ void nvram_write_byte(unsigned char val, int addr)
>> }
>> EXPORT_SYMBOL(nvram_write_byte);
>>
>> +ssize_t nvram_size(void)
>> +{
>> + if (ppc_md.nvram_size)
>> + return ppc_md.nvram_size();
>> + return -1;
>> +}
>> +EXPORT_SYMBOL(nvram_size);
>> +
>> void nvram_sync(void)
>> {
>> if (ppc_md.nvram_sync)
>> diff --git a/drivers/char/generic_nvram.c b/drivers/char/generic_nvram.c
>> index a00869c..e5f71f3 100644
>> --- a/drivers/char/generic_nvram.c
>> +++ b/drivers/char/generic_nvram.c
>> @@ -2,7 +2,7 @@
>> * Generic /dev/nvram driver for architectures providing some
>> * "generic" hooks, that is :
>> *
>> - * nvram_read_byte, nvram_write_byte, nvram_sync
>> + * nvram_read_byte, nvram_write_byte, nvram_sync, nvram_size
>> *
>> * Note that an additional hook is supported for PowerMac only
>> * for getting the nvram "partition" informations
>> @@ -28,6 +28,8 @@
>>
>> #define NVRAM_SIZE 8192
>>
>> +static ssize_t nvram_len;
>> +
>> static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
>> {
>> lock_kernel();
>> @@ -36,7 +38,7 @@ static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
>> offset += file->f_pos;
>> break;
>> case 2:
>> - offset += NVRAM_SIZE;
>> + offset += nvram_len;
>> break;
>> }
>> if (offset < 0) {
>> @@ -56,9 +58,9 @@ static ssize_t read_nvram(struct file *file, char __user *buf,
>>
>> if (!access_ok(VERIFY_WRITE, buf, count))
>> return -EFAULT;
>> - if (*ppos >= NVRAM_SIZE)
>> + if (*ppos >= nvram_len)
>> return 0;
>> - for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count)
>> + for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
>> if (__put_user(nvram_read_byte(i), p))
>> return -EFAULT;
>> *ppos = i;
>> @@ -74,9 +76,9 @@ static ssize_t write_nvram(struct file *file, const char __user *buf,
>>
>> if (!access_ok(VERIFY_READ, buf, count))
>> return -EFAULT;
>> - if (*ppos >= NVRAM_SIZE)
>> + if (*ppos >= nvram_len)
>> return 0;
>> - for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) {
>> + for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
>> if (__get_user(c, p))
>> return -EFAULT;
>> nvram_write_byte(c, i);
>> @@ -133,9 +135,20 @@ static struct miscdevice nvram_dev = {
>>
>> int __init nvram_init(void)
>> {
>> + int ret = 0;
>> +
>> printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
>> NVRAM_VERSION);
>> - return misc_register(&nvram_dev);
>> + ret = misc_register(&nvram_dev);
>> + if (ret != 0)
>> + goto out;
>> +
>> + nvram_len = nvram_size();
>> + if (nvram_len < 0)
>> + nvram_len = NVRAM_SIZE;
>> +
>> +out:
>> + return ret;
>> }
>>
>> void __exit nvram_cleanup(void)
>>
>
>
--
Martyn Welch MEng MPhil MIET (Principal Software Engineer) T:+44(0)1327322748
GE Fanuc Intelligent Platforms Ltd, |Registered in England and Wales
Tove Valley Business Park, Towcester, |(3828642) at 100 Barbirolli Square,
Northants, NN12 6PF, UK T:+44(0)1327359444 |Manchester,M2 3AB VAT:GB 927559189
next prev parent reply other threads:[~2009-07-23 11:30 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-02 16:12 [PATCH 0/5] Generic NVRAM support for large MMIO devices Martyn Welch
2009-07-02 16:12 ` [PATCH 1/5] Allow byte length reads from mmio NVRAM driver Martyn Welch
2009-07-02 16:12 ` [PATCH 2/5] Mechanism to enable use Generic NVRAM driver for different size chips Martyn Welch
2009-07-23 7:43 ` Benjamin Herrenschmidt
2009-07-23 11:31 ` Martyn Welch [this message]
2009-08-13 7:15 ` Benjamin Herrenschmidt
2009-08-13 8:03 ` [PATCH v2] " Martyn Welch
2009-08-13 8:05 ` Benjamin Herrenschmidt
2009-07-02 16:12 ` [PATCH 3/5] powerpc/86xx: Enable NVRAM on GE Fanuc's SBC610 Martyn Welch
2009-11-05 14:10 ` Kumar Gala
2009-11-05 14:23 ` Martyn Welch
2009-11-05 14:41 ` Kumar Gala
2009-11-05 14:53 ` Martyn Welch
2009-11-12 14:03 ` Kumar Gala
2009-07-02 16:12 ` [PATCH 4/5] powerpc/86xx: Support for NVRAM on GE Fanuc's SBC310 Martyn Welch
2009-11-12 14:04 ` Kumar Gala
2009-07-02 16:12 ` [PATCH 5/5] powerpc/86xx: Support for NVRAM on GE Fanuc's PPC9A Martyn Welch
2009-11-12 14:04 ` Kumar Gala
2009-07-23 7:44 ` [PATCH 0/5] Generic NVRAM support for large MMIO devices Benjamin Herrenschmidt
2009-07-24 9:25 ` Martyn Welch
2009-07-24 10:35 ` Benjamin Herrenschmidt
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