On Sun, 30 Dec 2018, I wrote:
On Sat, 29 Dec 2018, LEROY Christophe wrote:
Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxx>
---
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.
--
