From: Arnd Bergmann <arnd@arndb•de>
To: linuxppc-dev@ozlabs•org
Cc: paulus@samba•org
Subject: Re: [PATCH 1/3] 82xx: some 82xx platform hook functions can be shared by different boards
Date: Tue, 17 Jul 2007 02:59:46 +0200 [thread overview]
Message-ID: <200707170259.47098.arnd@arndb.de> (raw)
In-Reply-To: <469B33F2.9040306@windriver.com>
On Monday 16 July 2007, Mark Zhan wrote:
> @@ -96,7 +94,7 @@
> pvid = mfspr(SPRN_PVR);
> svid = mfspr(SPRN_SVR);
>
> - seq_printf(m, "Vendor\t\t: Freescale Semiconductor\n");
> + seq_printf(m, "Vendor\t\t: %s\n", CPUINFO_VENDOR);
> seq_printf(m, "Machine\t\t: %s\n", CPUINFO_MACHINE);
> seq_printf(m, "PVR\t\t: 0x%x\n", pvid);
> seq_printf(m, "SVR\t\t: 0x%x\n", svid);
This is a step in the wrong direction. CPUINFO_{VENDOR,MACHINE}
comes from a platform specific header file, so you can not
use these definitions in platform independent code without
breaking multiplatform kernels.
One possible solution would be a platform specific show_cpuinfo()
function that calls a generic 82xx version and passes in the
two values. Even better would be to just dump whatever string
you find in the /model property in the device tree.
> +
> +#define RMR_CSRE 0x00000001
> +
> +void mpc82xx_restart(char *cmd)
> +{
> + __volatile__ unsigned char dummy;
> +
> + local_irq_disable();
> + ((cpm2_map_t *) cpm2_immr)->im_clkrst.car_rmr |= RMR_CSRE;
> +
> + /* Clear the ME,EE,IR & DR bits in MSR to cause checkstop */
> + mtmsr(mfmsr() & ~(MSR_ME | MSR_EE | MSR_IR | MSR_DR));
> + dummy = ((cpm2_map_t *) cpm2_immr)->im_clkrst.res[0];
> + printk("Restart failed\n");
> + while (1) ;
> +}
I know you're just moving that code, but it looks horribly wrong
nonetheless. cpm2_immr is an __iomem variable, so you must not
dereference it but instead should use the in_8() macro to
access it.
Once you get that right, you don't need the volatile variable
any more.
> +void mpc82xx_halt(void)
> +{
> + local_irq_disable();
> + while (1) ;
> +}
Here, as in the function above, there should at least be a cpu_relax()
in the final loop. If the CPU has a nap functionality or something
similar, that would be even better.
Arnd <><
next prev parent reply other threads:[~2007-07-17 1:02 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-16 9:01 [PATCH 1/3] 82xx: some 82xx platform hook functions can be shared by different boards Mark Zhan
2007-07-17 0:59 ` Arnd Bergmann [this message]
2007-07-17 5:31 ` Mark Zhan
2007-07-17 16:15 ` Scott Wood
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