Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH v2] hvc_dcc : add support to armv4 and armv5 core | Date | Mon, 3 Sep 2012 12:57:27 +0000 |
| |
On Friday 31 August 2012, Stephen Boyd wrote: > > +static int hvc_dcc_put_chars_v6(uint32_t vt, const char *buf, int count) > > +{ > > + int i; > > + > > + for (i = 0; i < count; i++) { > > + while (__dcc_getstatus_v6() & DCC_STATUS_TX_V6) > > + cpu_relax(); > > + > > + __dcc_putchar_v6(buf[i]); > > + } > > + > > + return count; > > +} > > It's unfortunate that the main logic is duplicated. I wonder if we could > push the runtime decision slightly lower into the accessor functions > instead and make some new functions dcc_tx_busy() and dcc_rx_busy() or > something. Then these loops stay the same.
Agreed. Ideally, you should be able to get the code to be compiled into the same binary as before for ARMv6+. If only the inline assembly differs, you can do something like
static inline char __dcc_getchar(void) { char __c;
if (__LINUX_ARM_ARCH >= 6) asm volatile("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg" : "=r" (__c)); else asm volatile ("mrc p14, 0, %0, c1, c0 @ read comms data reg" : "=r" (ret)); isb();
return __c; }
Arnd
| |