On Sun, 30 Dec 2018, I wrote:
On Sat, 29 Dec 2018, LEROY Christophe wrote:
Finn Thain fthain@telegraphics.com.au a ?crit?:
Make use of arch_nvram_ops in device drivers so that the nvram_* function exports can be removed.
Since they are no longer global symbols, rename the PPC32 nvram_* functions appropriately.
Signed-off-by: Finn Thain fthain@telegraphics.com.au
arch/powerpc/kernel/setup_32.c | 8 ++++---- drivers/char/generic_nvram.c | 4 ++-- drivers/video/fbdev/controlfb.c | 4 ++-- drivers/video/fbdev/imsttfb.c | 4 ++-- drivers/video/fbdev/matrox/matroxfb_base.c | 2 +- drivers/video/fbdev/platinumfb.c | 4 ++-- drivers/video/fbdev/valkyriefb.c | 4 ++-- 7 files changed, 15 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index e0d045677472..bdbe6acbef11 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -152,20 +152,18 @@ __setup("l3cr=", ppc_setup_l3cr);
#ifdef CONFIG_GENERIC_NVRAM
-unsigned char nvram_read_byte(int addr) +static unsigned char ppc_nvram_read_byte(int addr) { if (ppc_md.nvram_read_val) return ppc_md.nvram_read_val(addr); return 0xff; } -EXPORT_SYMBOL(nvram_read_byte);
-void nvram_write_byte(unsigned char val, int addr) +static void ppc_nvram_write_byte(unsigned char val, int addr) { if (ppc_md.nvram_write_val) ppc_md.nvram_write_val(addr, val); } -EXPORT_SYMBOL(nvram_write_byte);
static ssize_t ppc_nvram_get_size(void) { @@ -182,6 +180,8 @@ static long ppc_nvram_sync(void) }
const struct nvram_ops arch_nvram_ops = {
- .read_byte = ppc_nvram_read_byte,
- .write_byte = ppc_nvram_write_byte, .get_size = ppc_nvram_get_size, .sync = ppc_nvram_sync,
}; diff --git a/drivers/char/generic_nvram.c b/drivers/char/generic_nvram.c index f32d5663de95..41b76bf9614e 100644 --- a/drivers/char/generic_nvram.c +++ b/drivers/char/generic_nvram.c @@ -48,7 +48,7 @@ static ssize_t read_nvram(struct file *file, char __user *buf, if (*ppos >= nvram_len) return 0; for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
if (__put_user(nvram_read_byte(i), p))
if (__put_user(arch_nvram_ops.read_byte(i), p))Instead of modifying all drivers (in this patch and previous ones related to other arches), wouldn't it be better to add helpers like the following in nvram.h:
Static inline unsigned char nvram_read_byte(int addr) { return arch_nvram_ops.read_byte(addr); }
Is there some benefit, or is that just personal taste?
Avoiding changes to call sites avoids code review, but I think 1) the thinkpad_acpi changes have already been reviewed and 2) the fbdev changes need review anyway.
Your suggesion would add several new entities and one extra layer of indirection.
Contrary to what I said above, this kind of double indirection could be useful if it allows us to avoid the kind of double indirection which Arnd objected to (which arises when an arch_nvram_ops method invokes a ppc_md method). For example,
static inline unsigned char nvram_read_byte(int addr) { #ifdef CONFIG_PPC return ppc_md.nvram_read_byte(addr); #else return arch_nvram_ops.read_byte(addr); #endif }
I'll try this approach for v9 if there are no objections. It may be the least invasive approach. Also, arch_nvram_ops can remain const.
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