69 lines
1.3 KiB
C
69 lines
1.3 KiB
C
/*
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* arch/sh/boards/saturn/smp.c
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*
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* SMP support for the Sega Saturn.
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*
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* Copyright (c) 2002 Paul Mundt
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*
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* Released under the terms of the GNU GPL v2.0.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <asm/saturn/smpc.h>
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extern void start_secondary(void);
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void __smp_send_ipi(unsigned int cpu, unsigned int action)
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{
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/* Nothing here yet .. */
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}
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unsigned int __smp_probe_cpus(void)
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{
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/*
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* This is just a straightforward master/slave configuration,
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* and probing isn't really supported..
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*/
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return 2;
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}
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/*
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* We're only allowed to do byte-access to SMPC registers. In
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* addition to which, we treat them as write-only, since
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* reading from them will return undefined data.
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*/
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static inline void smpc_slave_stop(unsigned int cpu)
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{
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smpc_barrier();
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ctrl_outb(1, SMPC_STATUS);
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ctrl_outb(SMPC_CMD_SSHOFF, SMPC_COMMAND);
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smpc_barrier();
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}
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static inline void smpc_slave_start(unsigned int cpu)
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{
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ctrl_outb(1, SMPC_STATUS);
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ctrl_outb(SMPC_CMD_SSHON, SMPC_COMMAND);
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smpc_barrier();
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}
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void __smp_slave_init(unsigned int cpu)
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{
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register unsigned long vbr;
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void **entry;
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__asm__ __volatile__ ("stc vbr, %0\n\t" : "=r" (vbr));
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entry = (void **)(vbr + 0x310 + 0x94);
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smpc_slave_stop(cpu);
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*(void **)entry = (void *)start_secondary;
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smpc_slave_start(cpu);
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}
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