1189be6508
This makes the kernel use 1TB segments for all kernel mappings and for user addresses of 1TB and above, on machines which support them (currently POWER5+, POWER6 and PA6T). We detect that the machine supports 1TB segments by looking at the ibm,processor-segment-sizes property in the device tree. We don't currently use 1TB segments for user addresses < 1T, since that would effectively prevent 32-bit processes from using huge pages unless we also had a way to revert to using 256MB segments. That would be possible but would involve extra complications (such as keeping track of which segment size was used when HPTEs were inserted) and is not addressed here. Parts of this patch were originally written by Ben Herrenschmidt. Signed-off-by: Paul Mackerras <paulus@samba.org>
254 lines
6.0 KiB
C
254 lines
6.0 KiB
C
/*
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* iSeries hashtable management.
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* Derived from pSeries_htab.c
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*
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* SMP scalability work:
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* Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <asm/machdep.h>
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#include <asm/pgtable.h>
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#include <asm/mmu.h>
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#include <asm/mmu_context.h>
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#include <asm/abs_addr.h>
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#include <linux/spinlock.h>
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#include "call_hpt.h"
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static spinlock_t iSeries_hlocks[64] __cacheline_aligned_in_smp =
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{ [0 ... 63] = SPIN_LOCK_UNLOCKED};
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/*
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* Very primitive algorithm for picking up a lock
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*/
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static inline void iSeries_hlock(unsigned long slot)
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{
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if (slot & 0x8)
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slot = ~slot;
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spin_lock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
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}
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static inline void iSeries_hunlock(unsigned long slot)
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{
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if (slot & 0x8)
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slot = ~slot;
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spin_unlock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
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}
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long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
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unsigned long pa, unsigned long rflags,
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unsigned long vflags, int psize)
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{
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long slot;
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struct hash_pte lhpte;
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int secondary = 0;
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BUG_ON(psize != MMU_PAGE_4K);
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/*
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* The hypervisor tries both primary and secondary.
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* If we are being called to insert in the secondary,
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* it means we have already tried both primary and secondary,
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* so we return failure immediately.
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*/
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if (vflags & HPTE_V_SECONDARY)
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return -1;
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iSeries_hlock(hpte_group);
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slot = HvCallHpt_findValid(&lhpte, va >> HW_PAGE_SHIFT);
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if (unlikely(lhpte.v & HPTE_V_VALID)) {
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if (vflags & HPTE_V_BOLTED) {
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HvCallHpt_setSwBits(slot, 0x10, 0);
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HvCallHpt_setPp(slot, PP_RWXX);
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iSeries_hunlock(hpte_group);
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if (slot < 0)
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return 0x8 | (slot & 7);
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else
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return slot & 7;
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}
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BUG();
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}
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if (slot == -1) { /* No available entry found in either group */
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iSeries_hunlock(hpte_group);
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return -1;
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}
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if (slot < 0) { /* MSB set means secondary group */
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vflags |= HPTE_V_SECONDARY;
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secondary = 1;
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slot &= 0x7fffffffffffffff;
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}
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lhpte.v = hpte_encode_v(va, MMU_PAGE_4K, MMU_SEGSIZE_256M) |
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vflags | HPTE_V_VALID;
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lhpte.r = hpte_encode_r(phys_to_abs(pa), MMU_PAGE_4K) | rflags;
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/* Now fill in the actual HPTE */
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HvCallHpt_addValidate(slot, secondary, &lhpte);
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iSeries_hunlock(hpte_group);
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return (secondary << 3) | (slot & 7);
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}
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static unsigned long iSeries_hpte_getword0(unsigned long slot)
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{
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struct hash_pte hpte;
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HvCallHpt_get(&hpte, slot);
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return hpte.v;
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}
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static long iSeries_hpte_remove(unsigned long hpte_group)
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{
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unsigned long slot_offset;
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int i;
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unsigned long hpte_v;
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/* Pick a random slot to start at */
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slot_offset = mftb() & 0x7;
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iSeries_hlock(hpte_group);
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for (i = 0; i < HPTES_PER_GROUP; i++) {
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hpte_v = iSeries_hpte_getword0(hpte_group + slot_offset);
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if (! (hpte_v & HPTE_V_BOLTED)) {
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HvCallHpt_invalidateSetSwBitsGet(hpte_group +
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slot_offset, 0, 0);
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iSeries_hunlock(hpte_group);
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return i;
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}
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slot_offset++;
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slot_offset &= 0x7;
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}
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iSeries_hunlock(hpte_group);
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return -1;
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}
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/*
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* The HyperVisor expects the "flags" argument in this form:
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* bits 0..59 : reserved
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* bit 60 : N
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* bits 61..63 : PP2,PP1,PP0
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*/
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static long iSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
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unsigned long va, int psize, int ssize, int local)
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{
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struct hash_pte hpte;
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unsigned long want_v;
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iSeries_hlock(slot);
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HvCallHpt_get(&hpte, slot);
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want_v = hpte_encode_v(va, MMU_PAGE_4K, MMU_SEGSIZE_256M);
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if (HPTE_V_COMPARE(hpte.v, want_v) && (hpte.v & HPTE_V_VALID)) {
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/*
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* Hypervisor expects bits as NPPP, which is
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* different from how they are mapped in our PP.
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*/
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HvCallHpt_setPp(slot, (newpp & 0x3) | ((newpp & 0x4) << 1));
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iSeries_hunlock(slot);
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return 0;
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}
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iSeries_hunlock(slot);
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return -1;
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}
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/*
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* Functions used to find the PTE for a particular virtual address.
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* Only used during boot when bolting pages.
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*
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* Input : vpn : virtual page number
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* Output: PTE index within the page table of the entry
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* -1 on failure
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*/
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static long iSeries_hpte_find(unsigned long vpn)
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{
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struct hash_pte hpte;
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long slot;
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/*
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* The HvCallHpt_findValid interface is as follows:
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* 0xffffffffffffffff : No entry found.
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* 0x00000000xxxxxxxx : Entry found in primary group, slot x
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* 0x80000000xxxxxxxx : Entry found in secondary group, slot x
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*/
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slot = HvCallHpt_findValid(&hpte, vpn);
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if (hpte.v & HPTE_V_VALID) {
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if (slot < 0) {
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slot &= 0x7fffffffffffffff;
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slot = -slot;
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}
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} else
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slot = -1;
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return slot;
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}
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/*
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* Update the page protection bits. Intended to be used to create
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* guard pages for kernel data structures on pages which are bolted
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* in the HPT. Assumes pages being operated on will not be stolen.
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* Does not work on large pages.
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*
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* No need to lock here because we should be the only user.
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*/
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static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
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int psize, int ssize)
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{
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unsigned long vsid,va,vpn;
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long slot;
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BUG_ON(psize != MMU_PAGE_4K);
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vsid = get_kernel_vsid(ea, MMU_SEGSIZE_256M);
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va = (vsid << 28) | (ea & 0x0fffffff);
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vpn = va >> HW_PAGE_SHIFT;
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slot = iSeries_hpte_find(vpn);
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if (slot == -1)
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panic("updateboltedpp: Could not find page to bolt\n");
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HvCallHpt_setPp(slot, newpp);
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}
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static void iSeries_hpte_invalidate(unsigned long slot, unsigned long va,
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int psize, int ssize, int local)
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{
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unsigned long hpte_v;
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unsigned long avpn = va >> 23;
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unsigned long flags;
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local_irq_save(flags);
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iSeries_hlock(slot);
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hpte_v = iSeries_hpte_getword0(slot);
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if ((HPTE_V_AVPN_VAL(hpte_v) == avpn) && (hpte_v & HPTE_V_VALID))
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HvCallHpt_invalidateSetSwBitsGet(slot, 0, 0);
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iSeries_hunlock(slot);
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local_irq_restore(flags);
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}
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void __init hpte_init_iSeries(void)
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{
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ppc_md.hpte_invalidate = iSeries_hpte_invalidate;
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ppc_md.hpte_updatepp = iSeries_hpte_updatepp;
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ppc_md.hpte_updateboltedpp = iSeries_hpte_updateboltedpp;
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ppc_md.hpte_insert = iSeries_hpte_insert;
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ppc_md.hpte_remove = iSeries_hpte_remove;
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}
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