Commit Graph

184 Commits

Author SHA1 Message Date
Mark Johnston
f3e982e764 Define a unified pmap structure for i386.
The overloading of struct pmap for PAE and non-PAE pmaps results in
three distinct layouts for the structure, which is embedded in
struct vmspace.  This causes a large number of duplicate structure
definitions in the i386 kernel's CTF type graph.

Since most pmap fields are the same in the two pmaps, simply provide
side-by-side variants of the fields that are distinct, using fixed-size
types.

PR:		242689
Reviewed by:	kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D22896
2020-01-07 15:59:31 +00:00
Mark Johnston
5cff1f4dc3 Introduce vm_page_astate.
This is a 32-bit structure embedded in each vm_page, consisting mostly
of page queue state.  The use of a structure makes it easy to store a
snapshot of a page's queue state in a stack variable and use cmpset
loops to update that state without requiring the page lock.

This change merely adds the structure and updates references to atomic
state fields.  No functional change intended.

Reviewed by:	alc, jeff, kib
Sponsored by:	Netflix, Intel
Differential Revision:	https://reviews.freebsd.org/D22650
2019-12-10 18:14:50 +00:00
Jeff Roberson
2194393787 Move phys_avail definition into MI code. It is consumed in the MI layer and
doing so adds more flexibility with less redundant code.

Reviewed by:	jhb, markj, kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D21250
2019-08-16 00:45:14 +00:00
Konstantin Belousov
e7a9df16e6 Add kernel support for Intel userspace protection keys feature on
Skylake Xeons.

See SDM rev. 68 Vol 3 4.6.2 Protection Keys and the description of the
RDPKRU and WRPKRU instructions.

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D18893
2019-02-20 09:51:13 +00:00
Konstantin Belousov
9a52756044 i386: Merge PAE and non-PAE pmaps into same kernel.
Effectively all i386 kernels now have two pmaps compiled in: one
managing PAE pagetables, and another non-PAE. The implementation is
selected at cold time depending on the CPU features. The vm_paddr_t is
always 64bit now. As result, nx bit can be used on all capable CPUs.

Option PAE only affects the bus_addr_t: it is still 32bit for non-PAE
configs, for drivers compatibility. Kernel layout, esp. max kernel
address, low memory PDEs and max user address (same as trampoline
start) are now same for PAE and for non-PAE regardless of the type of
page tables used.

Non-PAE kernel (when using PAE pagetables) can handle physical memory
up to 24G now, larger memory requires re-tuning the KVA consumers and
instead the code caps the maximum at 24G. Unfortunately, a lot of
drivers do not use busdma(9) properly so by default even 4G barrier is
not easy. There are two tunables added: hw.above4g_allow and
hw.above24g_allow, the first one is kept enabled for now to evaluate
the status on HEAD, second is only for dev use.

i386 now creates three freelists if there is any memory above 4G, to
allow proper bounce pages allocation. Also, VM_KMEM_SIZE_SCALE changed
from 3 to 1.

The PAE_TABLES kernel config option is retired.

In collaboarion with: pho
Discussed with:	emaste
Reviewed by:	markj
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D18894
2019-01-30 02:07:13 +00:00
Konstantin Belousov
f2c79297eb Fix i386 LINT build after r342769.
It seems that libkern/mcount.c is the only consumer of vm/pmap.h that
does not include machine/atomic.h.  Make it work by bringing
machine/atomic.h when pmap.h is used for kernel non-asm .c file.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-01-04 19:10:46 +00:00
Konstantin Belousov
0598e55ea3 i386: Use atomic 64bit load to read PDE value from PAE pagetables in
pmap_kextract().

pmap_kextract() can race with promotion/demotion on the kernel page
table, in which case current non-atomic 64bit read would see torn
value, breaking pmap_kextract().  pmap_kextract() would correctly
handle either promoted or demoted PDE, but not a mix where one word
is from a different state.

It requires PAE and > 4G memory to reproduce.  We observed this in
real loads, both for intensive use of malloc(9)/free(9) where
vtoslab() returned invalid pointer to the slab, and with the use of
busdma_bounce, where incorrect page was bounced.

In collaboration with:	pho
Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D18714
2019-01-04 17:33:07 +00:00
Konstantin Belousov
3c72855616 More references to pmap_cold().
MFC after:	3 days
Sponsored by:	The FreeBSD Foundation
2018-12-31 18:11:04 +00:00
Konstantin Belousov
d12c446550 Convert x86 cache invalidation functions to ifuncs.
This simplifies the runtime logic and reduces the number of
runtime-constant branches.

Reviewed by:	alc, markj
Sponsored by:	The FreeBSD Foundation
Approved by:	re (gjb)
Differential revision:	https://reviews.freebsd.org/D16736
2018-09-19 19:35:02 +00:00
Konstantin Belousov
60b7423434 Unify amd64 and i386 vmspace0 pmap activation.
Add pmap_activate_boot() for i386, move the invocation on APs from MD
init_secondary() to x86 init_secondary_tail().

Suggested by:	alc
Reviewed by:	alc, markj
Sponsored by:	The FreeBSD Foundation
Approved by:	re (marius)
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D16893
2018-08-25 15:21:28 +00:00
Konstantin Belousov
e45b89d23d Add pmap_is_valid_memattr(9).
Discussed with:	alc
Sponsored by:	The FreeBSD Foundation, Mellanox Technologies
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D15583
2018-08-01 18:45:51 +00:00
Mark Johnston
697be9a3bd Restore the check for the page size extension after r332489.
Without this, the support for transparent superpage promotion on i386
was left disabled.

Reviewed by:	alc, kib
Differential Revision:	https://reviews.freebsd.org/D16279
2018-07-15 22:18:31 +00:00
Alan Cox
8c0873714c Add support for pmap_enter(..., psind=1) to the i386 pmap. In other words,
add support for explicitly requesting that pmap_enter() create a 2 or 4 MB
page mapping.  (Essentially, this feature allows the machine-independent
layer to create superpage mappings preemptively, and not wait for automatic
promotion to occur.)

Export pmap_ps_enabled() to the machine-independent layer.

Add a flag to pmap_pv_insert_pde() that specifies whether it should fail or
reclaim a PV entry when one is not available.

Refactor pmap_enter_pde() into two functions, one by the same name, that is
a general-purpose function for creating PDE PG_PS mappings, and another,
pmap_enter_4mpage(), that is used to prefault 2 or 4 MB read- and/or
execute-only mappings for execve(2), mmap(2), and shmat(2).

Reviewed by:	kib
Tested by:	pho
Differential Revision:	https://reviews.freebsd.org/D16246
2018-07-14 17:20:27 +00:00
Konstantin Belousov
d86c1f0dc1 i386 4/4G split.
The change makes the user and kernel address spaces on i386
independent, giving each almost the full 4G of usable virtual addresses
except for one PDE at top used for trampoline and per-CPU trampoline
stacks, and system structures that must be always mapped, namely IDT,
GDT, common TSS and LDT, and process-private TSS and LDT if allocated.

By using 1:1 mapping for the kernel text and data, it appeared
possible to eliminate assembler part of the locore.S which bootstraps
initial page table and KPTmap.  The code is rewritten in C and moved
into the pmap_cold(). The comment in vmparam.h explains the KVA
layout.

There is no PCID mechanism available in protected mode, so each
kernel/user switch forth and back completely flushes the TLB, except
for the trampoline PTD region. The TLB invalidations for userspace
becomes trivial, because IPI handlers switch page tables. On the other
hand, context switches no longer need to reload %cr3.

copyout(9) was rewritten to use vm_fault_quick_hold().  An issue for
new copyout(9) is compatibility with wiring user buffers around sysctl
handlers. This explains two kind of locks for copyout ptes and
accounting of the vslock() calls.  The vm_fault_quick_hold() AKA slow
path, is only tried after the 'fast path' failed, which temporary
changes mapping to the userspace and copies the data to/from small
per-cpu buffer in the trampoline.  If a page fault occurs during the
copy, it is short-circuit by exception.s to not even reach C code.

The change was motivated by the need to implement the Meltdown
mitigation, but instead of KPTI the full split is done.  The i386
architecture already shows the sizing problems, in particular, it is
impossible to link clang and lld with debugging.  I expect that the
issues due to the virtual address space limits would only exaggerate
and the split gives more liveness to the platform.

Tested by: pho
Discussed with:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Differential revision:	https://reviews.freebsd.org/D14633
2018-04-13 20:30:49 +00:00
Pedro F. Giffuni
51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00
Warner Losh
fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00
Alan Cox
0314966858 Refine the fix from r312954. Specifically, add a new PDE-only flag,
PG_PROMOTED, that indicates whether lingering 4KB page mappings might
need to be flushed on a PDE change that restricts or destroys a 2MB
page mapping.  This flag allows the pmap to avoid range invalidations
that are both unnecessary and costly.

Reviewed by:	kib, markj
MFC after:	6 weeks
Differential Revision:	https://reviews.freebsd.org/D9665
2017-02-26 19:54:02 +00:00
Mark Johnston
dbbaf04f1e Remove support for idle page zeroing.
Idle page zeroing has been disabled by default on all architectures since
r170816 and has some bugs that make it seemingly unusable. Specifically,
the idle-priority pagezero thread exacerbates contention for the free page
lock, and yields the CPU without releasing it in non-preemptive kernels. The
pagezero thread also does not behave correctly when superpage reservations
are enabled: its target is a function of v_free_count, which includes
reserved-but-free pages, but it is only able to zero pages belonging to the
physical memory allocator.

Reviewed by:	alc, imp, kib
Differential Revision:	https://reviews.freebsd.org/D7714
2016-09-03 20:38:13 +00:00
Konstantin Belousov
27691a24ab For amd64 non-PCID machines, and for i386 machines with support for
the PG_G global pte flag, pmap_invalidate_all() fails to flush global
TLB entries [*].  This is because TLB shootdown handler for such
configs reloads CR3, and on i386 pmap_invalidate_all() does the same
for the initiating CPU.  Note that current code does not issue total
invalidation requests for the kernel_pmap.

Rename amd64 function invltlb_globpcid() to invltlb_glob(), it is not
specific for PCID for quite some time, and implement the same
functionality for i386.  Use the function instead of invltlb() in
shootdown handlers and in i386 pmap_invalidate_all(), but only for the
kernel pmap (which maps pages with the PG_G attribute set), which
takes care of PG_G TLB entries on flush.

To detect the affected pmap in i386 TLB shootdown handler, pmap should
be passed to the smp_masked_invltlb() function, which makes amd64 and
i386 TLB shootdown code almost identical.  Merge the code under x86/.

Noted by:	jhb [*]
Reviewed by:	cem, jhb, pho
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D4346
2015-12-03 11:14:14 +00:00
John Baldwin
ed95805e90 Remove support for Xen PV domU kernels. Support for HVM domU kernels
remains.  Xen is planning to phase out support for PV upstream since it
is harder to maintain and has more overhead.  Modern x86 CPUs include
virtualization extensions that support HVM guests instead of PV guests.
In addition, the PV code was i386 only and not as well maintained recently
as the HVM code.
- Remove the i386-only NATIVE option that was used to disable certain
  components for PV kernels.  These components are now standard as they
  are on amd64.
- Remove !XENHVM bits from PV drivers.
- Remove various shims required for XEN (e.g. PT_UPDATES_FLUSH, LOAD_CR3,
  etc.)
- Remove duplicate copy of <xen/features.h>.
- Remove unused, i386-only xenstored.h.

Differential Revision:	https://reviews.freebsd.org/D2362
Reviewed by:	royger
Tested by:	royger (i386/amd64 HVM domU and amd64 PVH dom0)
Relnotes:	yes
2015-04-30 15:48:48 +00:00
Konstantin Belousov
34c15db9cd Add config option PAE_TABLES for the i386 kernel. It switches pmap to
use PAE format for the page tables, but does not incur other
consequences of the full PAE config.  In particular, vm_paddr_t and
bus_addr_t are left 32bit, and max supported memory is still limited
by 4GB.

The option allows to have nx permissions for memory mappings on i386
kernel, while keeping the usual i386 KBI and avoiding the kernel data
sizing problems typical for the PAE config.

Intel documented that the PAE format for page tables is available
starting with the Pentium Pro, but it is possible that the plain
Pentium CPUs have the required support (Appendix H).  The goal is to
enable the option and non-exec mappings on i386 for the GENERIC
kernel.  Anybody wanting a useful system on 486, have to reconfigure
the modern i386 kernel anyway.

Discussed with:	alc, jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-04-13 15:22:45 +00:00
Konstantin Belousov
a7496c776d Explain that vm_page_array is mapped to describe the memory, not the
memory itself.  Provide the formula to calculate the number of
required page tables.  Correct the size of the struct vm_page for
non-PAE case.

Reviewed by:	alc, jhb (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-04-08 19:46:13 +00:00
Konstantin Belousov
07a92f34d6 Add an argument to the x86 pmap_invalidate_cache_range() to request
forced invalidation of the cache range regardless of the presence of
self-snoop feature.  Some recent Intel GPUs in some modes are not
coherent, and dirty lines in CPU cache must be flushed before the
pages are transferred to GPU domain.

Reviewed by:	alc (previous version)
Tested by:	pho (amd64)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-10-08 16:48:03 +00:00
John Baldwin
4f67a8c5e9 Don't waste a page of KVA for the boot-time memory test on x86. For amd64,
reuse the first page of the crashdumpmap as CMAP1/CADDR1.  For i386,
remove CMAP1/CADDR1 entirely and reuse CMAP3/CADDR3 for the memory test.

Reviewed by:	alc, peter
MFC after:	2 weeks
2014-02-11 22:02:40 +00:00
Justin T. Gibbs
76acc41fb7 Implement vector callback for PVHVM and unify event channel implementations
Re-structure Xen HVM support so that:
	- Xen is detected and hypercalls can be performed very
	  early in system startup.
	- Xen interrupt services are implemented using FreeBSD's native
	  interrupt delivery infrastructure.
	- the Xen interrupt service implementation is shared between PV
	  and HVM guests.
	- Xen interrupt handlers can optionally use a filter handler
	  in order to avoid the overhead of dispatch to an interrupt
	  thread.
	- interrupt load can be distributed among all available CPUs.
	- the overhead of accessing the emulated local and I/O apics
	  on HVM is removed for event channel port events.
	- a similar optimization can eventually, and fairly easily,
	  be used to optimize MSI.

Early Xen detection, HVM refactoring, PVHVM interrupt infrastructure,
and misc Xen cleanups:

Sponsored by: Spectra Logic Corporation

Unification of PV & HVM interrupt infrastructure, bug fixes,
and misc Xen cleanups:

Submitted by: Roger Pau Monné
Sponsored by: Citrix Systems R&D

sys/x86/x86/local_apic.c:
sys/amd64/include/apicvar.h:
sys/i386/include/apicvar.h:
sys/amd64/amd64/apic_vector.S:
sys/i386/i386/apic_vector.s:
sys/amd64/amd64/machdep.c:
sys/i386/i386/machdep.c:
sys/i386/xen/exception.s:
sys/x86/include/segments.h:
	Reserve IDT vector 0x93 for the Xen event channel upcall
	interrupt handler.  On Hypervisors that support the direct
	vector callback feature, we can request that this vector be
	called directly by an injected HVM interrupt event, instead
	of a simulated PCI interrupt on the Xen platform PCI device.
	This avoids all of the overhead of dealing with the emulated
	I/O APIC and local APIC.  It also means that the Hypervisor
	can inject these events on any CPU, allowing upcalls for
	different ports to be handled in parallel.

sys/amd64/amd64/mp_machdep.c:
sys/i386/i386/mp_machdep.c:
	Map Xen per-vcpu area during AP startup.

sys/amd64/include/intr_machdep.h:
sys/i386/include/intr_machdep.h:
	Increase the FreeBSD IRQ vector table to include space
	for event channel interrupt sources.

sys/amd64/include/pcpu.h:
sys/i386/include/pcpu.h:
	Remove Xen HVM per-cpu variable data.  These fields are now
	allocated via the dynamic per-cpu scheme.  See xen_intr.c
	for details.

sys/amd64/include/xen/hypercall.h:
sys/dev/xen/blkback/blkback.c:
sys/i386/include/xen/xenvar.h:
sys/i386/xen/clock.c:
sys/i386/xen/xen_machdep.c:
sys/xen/gnttab.c:
	Prefer FreeBSD primatives to Linux ones in Xen support code.

sys/amd64/include/xen/xen-os.h:
sys/i386/include/xen/xen-os.h:
sys/xen/xen-os.h:
sys/dev/xen/balloon/balloon.c:
sys/dev/xen/blkback/blkback.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/console/xencons_ring.c:
sys/dev/xen/control/control.c:
sys/dev/xen/netback/netback.c:
sys/dev/xen/netfront/netfront.c:
sys/dev/xen/xenpci/xenpci.c:
sys/i386/i386/machdep.c:
sys/i386/include/pmap.h:
sys/i386/include/xen/xenfunc.h:
sys/i386/isa/npx.c:
sys/i386/xen/clock.c:
sys/i386/xen/mp_machdep.c:
sys/i386/xen/mptable.c:
sys/i386/xen/xen_clock_util.c:
sys/i386/xen/xen_machdep.c:
sys/i386/xen/xen_rtc.c:
sys/xen/evtchn/evtchn_dev.c:
sys/xen/features.c:
sys/xen/gnttab.c:
sys/xen/gnttab.h:
sys/xen/hvm.h:
sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbus_if.m:
sys/xen/xenbus/xenbusb_front.c:
sys/xen/xenbus/xenbusvar.h:
sys/xen/xenstore/xenstore.c:
sys/xen/xenstore/xenstore_dev.c:
sys/xen/xenstore/xenstorevar.h:
	Pull common Xen OS support functions/settings into xen/xen-os.h.

sys/amd64/include/xen/xen-os.h:
sys/i386/include/xen/xen-os.h:
sys/xen/xen-os.h:
	Remove constants, macros, and functions unused in FreeBSD's Xen
	support.

sys/xen/xen-os.h:
sys/i386/xen/xen_machdep.c:
sys/x86/xen/hvm.c:
	Introduce new functions xen_domain(), xen_pv_domain(), and
	xen_hvm_domain().  These are used in favor of #ifdefs so that
	FreeBSD can dynamically detect and adapt to the presence of
	a hypervisor.  The goal is to have an HVM optimized GENERIC,
	but more is necessary before this is possible.

sys/amd64/amd64/machdep.c:
sys/dev/xen/xenpci/xenpcivar.h:
sys/dev/xen/xenpci/xenpci.c:
sys/x86/xen/hvm.c:
sys/sys/kernel.h:
	Refactor magic ioport, Hypercall table and Hypervisor shared
	information page setup, and move it to a dedicated HVM support
	module.

	HVM mode initialization is now triggered during the
	SI_SUB_HYPERVISOR phase of system startup.  This currently
	occurs just after the kernel VM is fully setup which is
	just enough infrastructure to allow the hypercall table
	and shared info page to be properly mapped.

sys/xen/hvm.h:
sys/x86/xen/hvm.c:
	Add definitions and a method for configuring Hypervisor event
	delievery via a direct vector callback.

sys/amd64/include/xen/xen-os.h:
sys/x86/xen/hvm.c:

sys/conf/files:
sys/conf/files.amd64:
sys/conf/files.i386:
	Adjust kernel build to reflect the refactoring of early
	Xen startup code and Xen interrupt services.

sys/dev/xen/blkback/blkback.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkfront/block.h:
sys/dev/xen/control/control.c:
sys/dev/xen/evtchn/evtchn_dev.c:
sys/dev/xen/netback/netback.c:
sys/dev/xen/netfront/netfront.c:
sys/xen/xenstore/xenstore.c:
sys/xen/evtchn/evtchn_dev.c:
sys/dev/xen/console/console.c:
sys/dev/xen/console/xencons_ring.c
	Adjust drivers to use new xen_intr_*() API.

sys/dev/xen/blkback/blkback.c:
	Since blkback defers all event handling to a taskqueue,
	convert this task queue to a "fast" taskqueue, and schedule
	it via an interrupt filter.  This avoids an unnecessary
	ithread context switch.

sys/xen/xenstore/xenstore.c:
	The xenstore driver is MPSAFE.  Indicate as much when
	registering its interrupt handler.

sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbusvar.h:
	Remove unused event channel APIs.

sys/xen/evtchn.h:
	Remove all kernel Xen interrupt service API definitions
	from this file.  It is now only used for structure and
	ioctl definitions related to the event channel userland
	device driver.

	Update the definitions in this file to match those from
	NetBSD.  Implementing this interface will be necessary for
	Dom0 support.

sys/xen/evtchn/evtchnvar.h:
	Add a header file for implemenation internal APIs related
	to managing event channels event delivery.  This is used
	to allow, for example, the event channel userland device
	driver to access low-level routines that typical kernel
	consumers of event channel services should never access.

sys/xen/interface/event_channel.h:
sys/xen/xen_intr.h:
	Standardize on the evtchn_port_t type for referring to
	an event channel port id.  In order to prevent low-level
	event channel APIs from leaking to kernel consumers who
	should not have access to this data, the type is defined
	twice: Once in the Xen provided event_channel.h, and again
	in xen/xen_intr.h.  The double declaration is protected by
	__XEN_EVTCHN_PORT_DEFINED__ to ensure it is never declared
	twice within a given compilation unit.

sys/xen/xen_intr.h:
sys/xen/evtchn/evtchn.c:
sys/x86/xen/xen_intr.c:
sys/dev/xen/xenpci/evtchn.c:
sys/dev/xen/xenpci/xenpcivar.h:
	New implementation of Xen interrupt services.  This is
	similar in many respects to the i386 PV implementation with
	the exception that events for bound to event channel ports
	(i.e. not IPI, virtual IRQ, or physical IRQ) are further
	optimized to avoid mask/unmask operations that aren't
	necessary for these edge triggered events.

	Stubs exist for supporting physical IRQ binding, but will
	need additional work before this implementation can be
	fully shared between PV and HVM.

sys/amd64/amd64/mp_machdep.c:
sys/i386/i386/mp_machdep.c:
sys/i386/xen/mp_machdep.c
sys/x86/xen/hvm.c:
	Add support for placing vcpu_info into an arbritary memory
	page instead of using HYPERVISOR_shared_info->vcpu_info.
	This allows the creation of domains with more than 32 vcpus.

sys/i386/i386/machdep.c:
sys/i386/xen/clock.c:
sys/i386/xen/xen_machdep.c:
sys/i386/xen/exception.s:
	Add support for new event channle implementation.
2013-08-29 19:52:18 +00:00
Jung-uk Kim
1533b9f714 Reimplement atomic operations on PDEs and PTEs in pmap.h. This change
significantly reduces duplicate code and make it easier to read.

Reviewed by:	alc, bde
2013-08-21 22:40:29 +00:00
Attilio Rao
774d251d99 Sync back vmcontention branch into HEAD:
Replace the per-object resident and cached pages splay tree with a
path-compressed multi-digit radix trie.
Along with this, switch also the x86-specific handling of idle page
tables to using the radix trie.

This change is supposed to do the following:
- Allowing the acquisition of read locking for lookup operations of the
  resident/cached pages collections as the per-vm_page_t splay iterators
  are now removed.
- Increase the scalability of the operations on the page collections.

The radix trie does rely on the consumers locking to ensure atomicity of
its operations.  In order to avoid deadlocks the bisection nodes are
pre-allocated in the UMA zone.  This can be done safely because the
algorithm needs at maximum one new node per insert which means the
maximum number of the desired nodes is the number of available physical
frames themselves.  However, not all the times a new bisection node is
really needed.

The radix trie implements path-compression because UFS indirect blocks
can lead to several objects with a very sparse trie, increasing the number
of levels to usually scan.  It also helps in the nodes pre-fetching by
introducing the single node per-insert property.

This code is not generalized (yet) because of the possible loss of
performance by having much of the sizes in play configurable.
However, efforts to make this code more general and then reusable in
further different consumers might be really done.

The only KPI change is the removal of the function vm_page_splay() which
is now reaped.
The only KBI change, instead, is the removal of the left/right iterators
from struct vm_page, which are now reaped.

Further technical notes broken into mealpieces can be retrieved from the
svn branch:
http://svn.freebsd.org/base/user/attilio/vmcontention/

Sponsored by:	EMC / Isilon storage division
In collaboration with:	alc, jeff
Tested by:	flo, pho, jhb, davide
Tested by:	ian (arm)
Tested by:	andreast (powerpc)
2013-03-18 00:25:02 +00:00
Attilio Rao
b38d37f7b5 Merge from vmc-playground branch:
Rename the pv_entry_t iterator from pv_list to pv_next.
Besides being more correct technically (as the name seems to suggest
this is a list while it is an iterator), it will also be needed by
vm_radix work to avoid a nameclash on macro expansions.

Sponsored by:	EMC / Isilon storage division
Reviewed by:	alc, jeff
Tested by:	flo, pho, jhb, davide
2013-03-02 14:19:08 +00:00
Alan Cox
6031c68de4 The page flag PGA_WRITEABLE is set and cleared exclusively by the pmap
layer, but it is read directly by the MI VM layer.  This change introduces
pmap_page_is_write_mapped() in order to completely encapsulate all direct
access to PGA_WRITEABLE in the pmap layer.

Aesthetics aside, I am making this change because amd64 will likely begin
using an alternative method to track write mappings, and having
pmap_page_is_write_mapped() in place allows me to make such a change
without further modification to the MI VM layer.

As an added bonus, tidy up some nearby comments concerning page flags.

Reviewed by:	kib
MFC after:	6 weeks
2012-06-16 18:56:19 +00:00
Alan Cox
33853281b4 Rename pmap_collect() to pmap_pv_reclaim() and rewrite it such that it no
longer uses the active and inactive paging queues.  Instead, the pmap now
maintains an LRU-ordered list of pv entry pages, and pmap_pv_reclaim() uses
this list to select pv entries for reclamation.

Note: The old pmap_collect() tried to avoid reclaiming mappings for pages
that have either a hold_count or a busy field that is non-zero.  However,
this isn't necessary for correctness, and the locking in pmap_collect() was
insufficient to guarantee that such mappings weren't reclaimed.  The new
pmap_pv_reclaim() doesn't even try.

MFC after:	5 weeks
2012-05-26 06:10:25 +00:00
Attilio Rao
71a19bdc64 Commit the support for removing cpumask_t and replacing it directly with
cpuset_t objects.
That is going to offer the underlying support for a simple bump of
MAXCPU and then support for number of cpus > 32 (as it is today).

Right now, cpumask_t is an int, 32 bits on all our supported architecture.
cpumask_t on the other side is implemented as an array of longs, and
easilly extendible by definition.

The architectures touched by this commit are the following:
- amd64
- i386
- pc98
- arm
- ia64
- XEN

while the others are still missing.
Userland is believed to be fully converted with the changes contained
here.

Some technical notes:
- This commit may be considered an ABI nop for all the architectures
  different from amd64 and ia64 (and sparc64 in the future)
- per-cpu members, which are now converted to cpuset_t, needs to be
  accessed avoiding migration, because the size of cpuset_t should be
  considered unknown
- size of cpuset_t objects is different from kernel and userland (this is
  primirally done in order to leave some more space in userland to cope
  with KBI extensions). If you need to access kernel cpuset_t from the
  userland please refer to example in this patch on how to do that
  correctly (kgdb may be a good source, for example).
- Support for other architectures is going to be added soon
- Only MAXCPU for amd64 is bumped now

The patch has been tested by sbruno and Nicholas Esborn on opteron
4 x 12 pack CPUs. More testing on big SMP is expected to came soon.
pluknet tested the patch with his 8-ways on both amd64 and i386.

Tested by:	pluknet, sbruno, gianni, Nicholas Esborn
Reviewed by:	jeff, jhb, sbruno
2011-05-05 14:39:14 +00:00
Konstantin Belousov
3136faa59d Make pmap_invalidate_cache_range() available for consumption on amd64.
Add pmap_invalidate_cache_pages() method on x86. It flushes the CPU
cache for the set of pages, which are not neccessary mapped. Since its
supposed use is to prepare the move of the pages ownership to a device
that does not snoop all CPU accesses to the main memory (read GPU in
GMCH), do not rely on CPU self-snoop feature.

amd64 implementation takes advantage of the direct map. On i386,
extract the helper pmap_flush_page() from pmap_page_set_memattr(), and
use it to make a temporary mapping of the flushed page.

Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2011-04-18 21:24:42 +00:00
John Baldwin
4cef260f42 Fix whitespace nit. 2011-02-22 14:58:14 +00:00
Alan Cox
e6ffa21488 Remove pmap fields that are either unused or not fully implemented.
Discussed with:	kib
2011-02-17 15:36:29 +00:00
Robert Watson
2913e88c91 Make "options XENHVM" compile for i386, not just amd64 -- a largely
mechanical change.  This opens the door for using PV device drivers
under Xen HVM on i386, as well as more general harmonisation of i386
and amd64 Xen support in FreeBSD.

Reviewed by:    cperciva
MFC after:      3 weeks
2011-01-04 14:49:54 +00:00
Colin Percival
90b7d33458 Make i386_set_ldt work on i386/XEN, step 2/5.
Don't map physical to machine page numbers in pte_load_store, since it uses
PT_SET_VA (which takes a physical page number and converts it to a machine
page number).

MFC after:	3 days
2010-12-31 17:39:58 +00:00
Colin Percival
8cdabbaf32 Add VTOM(va) macro as xpmap_ptom(VTOP(va)) to convert to machine addresses.
Clean up the code by converting xpmap_ptom(VTOP(...)) to VTOM(...) and
converting xpmap_ptom(VM_PAGE_TO_PHYS(...)) to VM_PAGE_TO_MACH(...).  In
a few places we take advantage of the fact that xpmap_ptom can commute with
setting PG_* flags.

This commit should have no net effect save to improve the readability of
this code.
2010-11-20 20:04:29 +00:00
Alan Cox
fb4c8540b2 Initialize KPTmap in locore so that vm86.c can call vtophys() (or really
pmap_kextract()) before pmap_bootstrap() is called.

Document the set of pmap functions that may be called before
pmap_bootstrap() is called.

Tested by:	bde@
Reviewed by:	kib@
Discussed with:	jhb@
MFC after:	6 weeks
2010-10-05 17:06:51 +00:00
Konstantin Belousov
b543e91ba5 Fix spacing.
Noted by:	pgollucci
MFC after:	3 weeks
2010-07-09 21:27:42 +00:00
Konstantin Belousov
2680dac9e1 For both i386 and amd64 pmap,
- change the type of pm_active to cpumask_t, which it is;
- in pmap_remove_pages(), compare with PCPU(curpmap), instead of
  dereferencing the long chain of pointers [1].
For amd64 pmap, remove the unneeded checks for validity of curpmap
in pmap_activate(), since curpmap should be always valid after
r209789.

Submitted by:	alc [1]
Reviewed by:	alc
MFC after:	3 weeks
2010-07-09 20:05:56 +00:00
Kip Macy
2965a45315 On Alan's advice, rather than do a wholesale conversion on a single
architecture from page queue lock to a hashed array of page locks
(based on a patch by Jeff Roberson), I've implemented page lock
support in the MI code and have only moved vm_page's hold_count
out from under page queue mutex to page lock. This changes
pmap_extract_and_hold on all pmaps.

Supported by: Bitgravity Inc.

Discussed with: alc, jeffr, and kib
2010-04-30 00:46:43 +00:00
Alan Cox
cf3508519c Handle a race between pmap_kextract() and pmap_promote_pde(). This race is
known to cause a kernel crash in ZFS on i386 when superpage promotion is
enabled.

Tested by:	netchild
MFC after:	1 week
2010-01-23 18:42:28 +00:00
Alan Cox
28a5e2a5d7 Make pmap_set_pg() static. 2010-01-07 17:34:45 +00:00
John Baldwin
75e66e421a Improve pmap_change_attr() so that it is able to demote a large (2/4MB)
page into 4KB pages as needed.  This should be fairly rare in practice
on i386.  This includes merging the following changes from the amd64 pmap:
180430, 180485, 180845, 181043, 181077, and 196318.
- Add basic support for changing attributes on PDEs to pmap_change_attr()
  similar to the support in the initial version of pmap_change_attr() on
  amd64 including inlines for pmap_pde_attr() and pmap_pte_attr().
- Extend pmap_demote_pde() to include the ability to instantiate a new page
  table page where none existed before.
- Enhance pmap_change_attr().  Use pmap_demote_pde() to demote a 2/4MB page
  mapping to 4KB page mappings when the specified attribute change only
  applies to a portion of the 2/4MB page.  Previously, in such cases,
  pmap_change_attr() gave up and returned an error.
- Correct a critical accounting error in pmap_demote_pde().

Reviewed by:	alc
MFC after:	3 days
2009-08-31 17:42:52 +00:00
Konstantin Belousov
8a5ac5d56f As was done in r195820 for amd64, use clflush for flushing cache lines
when memory page caching attributes changed, and CPU does not support
self-snoop, but implemented clflush, for i386.

Take care of possible mappings of the page by sf buffer by utilizing
the mapping for clflush, otherwise map the page transiently. Amd64
used direct map.

Proposed and reviewed by:  alc
Approved by:   re (kensmith)
2009-07-29 08:49:58 +00:00
Alan Cox
3153e878dd Add support to the virtual memory system for configuring machine-
dependent memory attributes:

Rename vm_cache_mode_t to vm_memattr_t.  The new name reflects the
fact that there are machine-dependent memory attributes that have
nothing to do with controlling the cache's behavior.

Introduce vm_object_set_memattr() for setting the default memory
attributes that will be given to an object's pages.

Introduce and use pmap_page_{get,set}_memattr() for getting and
setting a page's machine-dependent memory attributes.  Add full
support for these functions on amd64 and i386 and stubs for them on
the other architectures.  The function pmap_page_set_memattr() is also
responsible for any other machine-dependent aspects of changing a
page's memory attributes, such as flushing the cache or updating the
direct map.  The uses include kmem_alloc_contig(), vm_page_alloc(),
and the device pager:

  kmem_alloc_contig() can now be used to allocate kernel memory with
  non-default memory attributes on amd64 and i386.

  vm_page_alloc() and the device pager will set the memory attributes
  for the real or fictitious page according to the object's default
  memory attributes.

Update the various pmap functions on amd64 and i386 that map pages to
incorporate each page's memory attributes in the mapping.

Notes: (1) Inherent to this design are safety features that prevent
the specification of inconsistent memory attributes by different
mappings on amd64 and i386.  In addition, the device pager provides a
warning when a device driver creates a fictitious page with memory
attributes that are inconsistent with the real page that the
fictitious page is an alias for. (2) Storing the machine-dependent
memory attributes for amd64 and i386 as a dedicated "int" in "struct
md_page" represents a compromise between space efficiency and the ease
of MFCing these changes to RELENG_7.

In collaboration with: jhb

Approved by:	re (kib)
2009-07-12 23:31:20 +00:00
Alan Cox
0f6766f3da Eliminate dead code. These definitions should have been deleted with the
introduction of i686_mem.c in r45405.

Merge adjacent #ifdef _KERNEL/#endif blocks.
2009-06-22 04:21:02 +00:00
Ed Schouten
3c7553cc20 Simplify the inline assembler (and correct potential error) of pte_load_store().
Submitted by:	Christoph Mallon
2009-06-13 13:56:06 +00:00
Alan Cox
b4862e19af Update stale comments. The alternate address space mapping was eliminated
when PAE support was added to i386.  The direct mapping exists on amd64.
2009-03-22 18:56:26 +00:00
Kip Macy
7e9608c858 PT_UPDATES_FLUSH() is used in common code so it needs to be defined
even in the !defined(XEN) case

MFC after:	1 month
2008-08-18 21:35:09 +00:00