38 lines
870 B
C
38 lines
870 B
C
#include <vhex/drivers/cpu.h>
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#include <vhex/arch/sh7305/cpu.h>
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/* Value of IMASK when atomic mode is entered */
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static int saved_IMASK = 0;
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/* Number of atomic mode levels */
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static unsigned int atomic_level = 0;
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/* cpu_atomic_start(): Enter atomic mode */
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void cpu_atomic_start(void)
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{
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/* There is no access problem to IMASK here because interrupts must
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preserve and restore it */
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cpu_sr_t SR = cpu_get_sr();
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cpu_sr_t SR2 = SR;
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SR2.IMASK = 15;
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cpu_set_sr(SR2);
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/* Now that we're alone, atomically update the atomic level */
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if(atomic_level == 0) saved_IMASK = SR.IMASK;
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atomic_level++;
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}
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/* cpu_atomic_end(): Exit atomic mode */
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void cpu_atomic_end(void)
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{
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cpu_sr_t SR = cpu_get_sr();
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/* Update atomic_level before restoring interrupts */
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atomic_level--;
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if(atomic_level == 0) {
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SR.IMASK = saved_IMASK;
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saved_IMASK = 0;
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}
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cpu_set_sr(SR);
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}
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