void read_decode_mmu_bcr()

in mm/tlb.c [563:610]

• 44 lines of code
• 3 McCabe index (conditional complexity)

void read_decode_mmu_bcr(void)
{
	struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
	unsigned int tmp;
	struct bcr_mmu_3 {
#ifdef CONFIG_CPU_BIG_ENDIAN
	unsigned int ver:8, ways:4, sets:4, res:3, sasid:1, pg_sz:4,
		     u_itlb:4, u_dtlb:4;
#else
	unsigned int u_dtlb:4, u_itlb:4, pg_sz:4, sasid:1, res:3, sets:4,
		     ways:4, ver:8;
#endif
	} *mmu3;

	struct bcr_mmu_4 {
#ifdef CONFIG_CPU_BIG_ENDIAN
	unsigned int ver:8, sasid:1, sz1:4, sz0:4, res:2, pae:1,
		     n_ways:2, n_entry:2, n_super:2, u_itlb:3, u_dtlb:3;
#else
	/*           DTLB      ITLB      JES        JE         JA      */
	unsigned int u_dtlb:3, u_itlb:3, n_super:2, n_entry:2, n_ways:2,
		     pae:1, res:2, sz0:4, sz1:4, sasid:1, ver:8;
#endif
	} *mmu4;

	tmp = read_aux_reg(ARC_REG_MMU_BCR);
	mmu->ver = (tmp >> 24);

	if (is_isa_arcompact() && mmu->ver == 3) {
		mmu3 = (struct bcr_mmu_3 *)&tmp;
		mmu->pg_sz_k = 1 << (mmu3->pg_sz - 1);
		mmu->sets = 1 << mmu3->sets;
		mmu->ways = 1 << mmu3->ways;
		mmu->u_dtlb = mmu3->u_dtlb;
		mmu->u_itlb = mmu3->u_itlb;
		mmu->sasid = mmu3->sasid;
	} else {
		mmu4 = (struct bcr_mmu_4 *)&tmp;
		mmu->pg_sz_k = 1 << (mmu4->sz0 - 1);
		mmu->s_pg_sz_m = 1 << (mmu4->sz1 - 11);
		mmu->sets = 64 << mmu4->n_entry;
		mmu->ways = mmu4->n_ways * 2;
		mmu->u_dtlb = mmu4->u_dtlb * 4;
		mmu->u_itlb = mmu4->u_itlb * 4;
		mmu->sasid = mmu4->sasid;
		pae_exists = mmu->pae = mmu4->pae;
	}
}