Hi Graeme,
在 2011年10月26日下午1:55，Graeme Russ graeme.russ@gmail.com 寫道：
Hi Macpaul
[snip]
I'm going to change writeb/readb series functions from macro into inline functions.
For all arches? Have you seen /arch/x86/include/asm/io.h?
Currently, I have take a looked into arm, mips, and blackfin. Because the most probably common problem lead with the function replacement might be NS16550, so I check NS16550 at first.
According to your reminding, it seem there is no necessary for x86 to replace the macro. Is that correct? However I have no idea is there any other architecture like x86.
Is this a necessary for this machine to access 8-bytes data?
outb/inb access 8-bit data in a 16-bit address space and the ns16650 has (for the x86 architecture at least) byte aligned registers
Okay, so it's not actually an "ulong" casting.
Since inline functions are type sensitive, I've suggest to replace the macro for other machines like writeb(x, (uint)y) but Marek think this is not good enough. Could you give some comments?
Hmm, but eNET (well, all x86 really) would not use writeb/readb - outb/inb would be used instead so if you are only touching the writeb/readb, eNET would never see this. So I don't understand where your type conflicts are occuring
Because the the address passed into writeb and readb in ns16550.c will be "unsigned char" if they defined CONFIG_SYS_NS16550_REG_SIZE as "1" or "-4" and then will lead compile warnings when the address of inline function of writeb/readb is "unsigned int". (Please refer to include/ns16550.c)
Looking at the ulong cast, I was wondering why it was there, and the commit diff says I wrote it which is a bit of a worry :) x86 only has 65535 ports accessible via outb and inb, so I would have thought the case should have been a ushort, not a ulong.
Okay, so we can double confirmed it is an ushort not an ulong.
I'm sorry, but without a patch to see what you are actually doing, I'm having a bit of difficulty picturing what is happening and what could be going wrong...
Sorry not to add you at the beginning when the discussion begin. Because when I sent this patch, I thought it is only related to NDS32 arch at first.
For examples, the origin implementation in macro is this. #define __arch_getb(a) (*(unsigned char *)(a)) #define __arch_putb(v, a) (*(unsigned char *)(a) = (v))
#define dmb() __asm__ __volatile__ ("" : : : "memory") #define __iormb() dmb() #define __iowmb() dmb()
#define writeb(v, c) ({ u8 __v = v; __iowmb(); __arch_putb(__v, c); __v; }) #define readb(a) __arch_getb(a)
The new implementation in inline function will be like this.
static inline void writeb(unsigned char val, unsigned char *addr) { __iowmb(); __arch_putb(val, addr); } static inline unsigned char readb(unsigned char *addr) { u8 val;
val = __arch_getb(addr); __iormb(); return val; }