return;
#ifdef CONFIG_ALTIVEC
- if (cur_cpu_spec->cpu_features & CPU_FTR_ALTIVEC)
+ if (cpu_has_feature(CPU_FTR_ALTIVEC))
asm volatile ("dssall");
#endif /* CONFIG_ALTIVEC */
- if (cur_cpu_spec->cpu_features & CPU_FTR_SLB)
+ if (cpu_has_feature(CPU_FTR_SLB))
switch_slb(tsk, next);
else
switch_stab(tsk, next);
local_irq_restore(flags);
}
-/* VSID allocation
- * ===============
- *
- * We first generate a 36-bit "proto-VSID". For kernel addresses this
- * is equal to the ESID, for user addresses it is:
- * (context << 15) | (esid & 0x7fff)
- *
- * The two forms are distinguishable because the top bit is 0 for user
- * addresses, whereas the top two bits are 1 for kernel addresses.
- * Proto-VSIDs with the top two bits equal to 0b10 are reserved for
- * now.
- *
- * The proto-VSIDs are then scrambled into real VSIDs with the
- * multiplicative hash:
- *
- * VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
- * where VSID_MULTIPLIER = 268435399 = 0xFFFFFC7
- * VSID_MODULUS = 2^36-1 = 0xFFFFFFFFF
- *
- * This scramble is only well defined for proto-VSIDs below
- * 0xFFFFFFFFF, so both proto-VSID and actual VSID 0xFFFFFFFFF are
- * reserved. VSID_MULTIPLIER is prime, so in particular it is
- * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
- * Because the modulus is 2^n-1 we can compute it efficiently without
- * a divide or extra multiply (see below).
- *
- * This scheme has several advantages over older methods:
- *
- * - We have VSIDs allocated for every kernel address
- * (i.e. everything above 0xC000000000000000), except the very top
- * segment, which simplifies several things.
- *
- * - We allow for 15 significant bits of ESID and 20 bits of
- * context for user addresses. i.e. 8T (43 bits) of address space for
- * up to 1M contexts (although the page table structure and context
- * allocation will need changes to take advantage of this).
- *
- * - The scramble function gives robust scattering in the hash
- * table (at least based on some initial results). The previous
- * method was more susceptible to pathological cases giving excessive
- * hash collisions.
- */
-
-/*
- * WARNING - If you change these you must make sure the asm
- * implementations in slb_allocate(), do_stab_bolted and mmu.h
- * (ASM_VSID_SCRAMBLE macro) are changed accordingly.
- *
- * You'll also need to change the precomputed VSID values in head.S
- * which are used by the iSeries firmware.
- */
-
-static inline unsigned long vsid_scramble(unsigned long protovsid)
-{
-#if 0
- /* The code below is equivalent to this function for arguments
- * < 2^VSID_BITS, which is all this should ever be called
- * with. However gcc is not clever enough to compute the
- * modulus (2^n-1) without a second multiply. */
- return ((protovsid * VSID_MULTIPLIER) % VSID_MODULUS);
-#else /* 1 */
- unsigned long x;
-
- x = protovsid * VSID_MULTIPLIER;
- x = (x >> VSID_BITS) + (x & VSID_MODULUS);
- return (x + ((x+1) >> VSID_BITS)) & VSID_MODULUS;
-#endif /* 1 */
-}
-
-/* This is only valid for addresses >= KERNELBASE */
-static inline unsigned long get_kernel_vsid(unsigned long ea)
-{
- return vsid_scramble(ea >> SID_SHIFT);
-}
-
-/* This is only valid for user addresses (which are below 2^41) */
-static inline unsigned long get_vsid(unsigned long context, unsigned long ea)
-{
- return vsid_scramble((context << USER_ESID_BITS)
- | (ea >> SID_SHIFT));
-}
-
#endif /* __PPC64_MMU_CONTEXT_H */
git://git.onelab.eu / linux-2.6.git / blobdiff