freebsd-skq/sys/sparc64/include/tsb.h
Marius Strobl 4d05e7b184 On UltraSPARC-III+ and greater take advantage of ASI_ATOMIC_QUAD_LDD_PHYS,
which takes an physical address instead of an virtual one, for loading TTEs
of the kernel TSB so we no longer need to lock the kernel TSB into the dTLB,
which only has a very limited number of lockable dTLB slots. The net result
is that we now basically can handle a kernel TSB of any size and no longer
need to limit the kernel address space based on the number of dTLB slots
available for locked entries. Consequently, other parts of the trap handlers
now also only access the the kernel TSB via its physical address in order
to avoid nested traps, as does the PMAP bootstrap code as we haven't taken
over the trap table at that point, yet. Apart from that the kernel TSB now
is accessed via a direct mapping when we are otherwise taking advantage of
ASI_ATOMIC_QUAD_LDD_PHYS so no further code changes are needed. Most of this
is implemented by extending the patching of the TSB addresses and mask as
well as the ASIs used to load it into the trap table so the runtime overhead
of this change is rather low. Currently the use of ASI_ATOMIC_QUAD_LDD_PHYS
is not yet enabled on SPARC64 CPUs due to lack of testing and due to the
fact it might require minor adjustments there.
Theoretically it should be possible to use the same approach also for the
user TSB, which already is not locked into the dTLB, avoiding nested traps.
However, for reasons I don't understand yet OpenSolaris only does that with
SPARC64 CPUs. On the other hand I think that also addressing the user TSB
physically and thus avoiding nested traps would get us closer to sharing
this code with sun4v, which only supports trap level 0 and 1, so eventually
we could have a single kernel which runs on both sun4u and sun4v (as does
Linux and OpenBSD).

Developed at and committed from:	27C3
2010-12-29 16:59:33 +00:00

97 lines
3.2 KiB
C

/*-
* Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Berkeley Software Design Inc's name may not be used to endorse or
* promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: BSDI: pmap.v9.h,v 1.10.2.6 1999/08/23 22:18:44 cp Exp
* $FreeBSD$
*/
#ifndef _MACHINE_TSB_H_
#define _MACHINE_TSB_H_
#define TSB_PAGES_SHIFT (4)
#define TSB_PAGES (1 << TSB_PAGES_SHIFT)
#define TSB_BSHIFT (TSB_PAGES_SHIFT + PAGE_SHIFT)
#define TSB_BSIZE (1 << TSB_BSHIFT)
#define TSB_BUCKET_SHIFT (2)
#define TSB_BUCKET_SIZE (1 << TSB_BUCKET_SHIFT)
#define TSB_BUCKET_ADDRESS_BITS \
(TSB_BSHIFT - TSB_BUCKET_SHIFT - TTE_SHIFT)
#define TSB_BUCKET_MASK ((1 << TSB_BUCKET_ADDRESS_BITS) - 1)
#ifndef LOCORE
#define TSB_SIZE (TSB_BSIZE / sizeof(struct tte))
extern struct tte *tsb_kernel;
extern vm_size_t tsb_kernel_mask;
extern vm_size_t tsb_kernel_size;
extern vm_paddr_t tsb_kernel_phys;
extern u_int tsb_kernel_ldd_phys;
static __inline struct tte *
tsb_vpntobucket(pmap_t pm, vm_offset_t vpn)
{
return (&pm->pm_tsb[(vpn & TSB_BUCKET_MASK) << TSB_BUCKET_SHIFT]);
}
static __inline struct tte *
tsb_vtobucket(pmap_t pm, u_long sz, vm_offset_t va)
{
return (tsb_vpntobucket(pm, va >> TTE_PAGE_SHIFT(sz)));
}
static __inline struct tte *
tsb_kvpntotte(vm_offset_t vpn)
{
return (&tsb_kernel[vpn & tsb_kernel_mask]);
}
static __inline struct tte *
tsb_kvtotte(vm_offset_t va)
{
return (tsb_kvpntotte(va >> PAGE_SHIFT));
}
typedef int (tsb_callback_t)(struct pmap *, struct pmap *, struct tte *,
vm_offset_t);
struct tte *tsb_tte_lookup(pmap_t pm, vm_offset_t va);
void tsb_tte_remove(struct tte *stp);
struct tte *tsb_tte_enter(pmap_t pm, vm_page_t m, vm_offset_t va, u_long sz,
u_long data);
void tsb_tte_local_remove(struct tte *tp);
void tsb_foreach(pmap_t pm1, pmap_t pm2, vm_offset_t start, vm_offset_t end,
tsb_callback_t *callback);
#endif /* !LOCORE */
#endif /* !_MACHINE_TSB_H_ */