Commit Graph

105 Commits

Author SHA1 Message Date
Konstantin Belousov
43f48b65c0 Move the declaration of vm_phys_paddr_to_vm_page() from vm/vm_page.h
to vm/vm_phys.h, where it belongs.

Requested and reviewed by:	alc
MFC after:	2 weeks
2012-11-16 05:55:56 +00:00
Konstantin Belousov
1c771f9222 After the PHYS_TO_VM_PAGE() function was de-inlined, the main reason
to pull vm_param.h was removed.  Other big dependency of vm_page.h on
vm_param.h are PA_LOCK* definitions, which are only needed for
in-kernel code, because modules use KBI-safe functions to lock the
pages.

Stop including vm_param.h into vm_page.h. Include vm_param.h
explicitely for the kernel code which needs it.

Suggested and reviewed by:	alc
MFC after:    2 weeks
2012-08-05 14:11:42 +00:00
Konstantin Belousov
df2f557df6 Do not double-reference the found vm object in cdev_pager_lookup().
vm_pager_object_lookup() already referenced the object.

Note that there is no in-tree consumers of cdev_pager_lookup(). The
only known user of the function is i915 gem driver, which is not yet
imported. This should make the KPI change minor.

Submitted by:	avg
MFC after:	1 week
2012-05-18 10:23:47 +00:00
Konstantin Belousov
b7ac5a8571 Add new pager type, OBJT_MGTDEVICE. It provides the device pager
which carries fictitous managed pages. In particular, the consumers of
the new object type can remove all mappings of the device page with
pmap_remove_all().

The range of physical addresses used for fake page allocation shall be
registered with vm_phys_fictitious_reg_range() interface to allow the
PHYS_TO_VM_PAGE() to work in pmap.

Most likely, only i386 and amd64 pmaps can handle fictitious managed
pages right now.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
2012-05-12 20:49:58 +00:00
Konstantin Belousov
286790a7dd Update the device pager interface, while keeping the compatibility
layer for old KPI and KBI.  New interface should be used together with
d_mmap_single cdevsw method.

Device pager can be allocated with the cdev_pager_allocate(9)
function, which takes struct cdev_pager_ops, containing
constructor/destructor and page fault handler methods supplied by
driver.

Constructor and destructor, called at the pager allocation and
deallocation time, allow the driver to handle per-object private data.

The pager handler is called to handle page fault on the vm map entry
backed by the driver pager. Driver shall return either the vm_page_t
which should be mapped, or error code (which does not cause kernel
panic anymore). The page handler interface has a placeholder to
specify the access mode causing the fault, but currently PROT_READ is
always passed there.

Sponsored by:	The FreeBSD Foundation
Reviewed by:	alc
MFC after:	1 month
2011-11-15 14:40:00 +00:00
Konstantin Belousov
339772b003 Fix a race in the device pager allocation. If another thread won and
allocated the device pager for the given handle, then the object
fictitious pages list and the object membership in the global object
list still need to be initialized. Otherwise, dev_pager_dealloc() will
traverse uninitialized pointers.

Reported and tested by: pho
Reviewed by:    jhb
Approved by:	re (kensmith)
MFC after:      1 week
2011-07-30 14:13:57 +00:00
Attilio Rao
91a1929f07 Handle a race between device_pager and devsw in a more graceful manner:
return an error code rather than panic the kernel.

Sponsored by:	Sandvine Incorporated
Reviewed by:	kib
Tested by:	pho
MFC after:	2 weeks
2011-07-06 15:09:52 +00:00
Alan Cox
10cf256074 Eliminate duplication of the fake page code and zone by the device and sg
pagers.

Reviewed by:	jhb
2011-03-11 07:07:48 +00:00
Alan Cox
44e46b9e53 Explicitly initialize the page's queue field to PQ_NONE instead of relying
on PQ_NONE being zero.

Redefine PQ_NONE and PQ_COUNT so that a page queue isn't allocated for
PQ_NONE.

Reviewed by:	kib@
2011-01-17 19:17:26 +00:00
Konstantin Belousov
3979450b4c Add new make_dev_p(9) flag MAKEDEV_ETERNAL to inform devfs that created
cdev will never be destroyed. Propagate the flag to devfs vnodes as
VV_ETERNVALDEV. Use the flags to avoid acquiring devmtx and taking a
thread reference on such nodes.

In collaboration with:	pho
MFC after:	1 month
2010-08-06 09:42:15 +00:00
Alan Cox
eb00b276ab Eliminate page queues locking around most calls to vm_page_free(). 2010-05-06 18:58:32 +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
Robert Noland
cfd7bacef2 Update d_mmap() to accept vm_ooffset_t and vm_memattr_t.
This replaces d_mmap() with the d_mmap2() implementation and also
changes the type of offset to vm_ooffset_t.

Purge d_mmap2().

All driver modules will need to be rebuilt since D_VERSION is also
bumped.

Reviewed by:	jhb@
MFC after:	Not in this lifetime...
2009-12-29 21:51:28 +00:00
John Baldwin
2fa8c8d21e Extend the device pager to support different memory attributes on different
pages in an object.
- Add a new variant of d_mmap() currently called d_mmap2() which accepts
  an additional in/out parameter that is the memory attribute to use for
  the requested page.
- A driver either uses d_mmap() or d_mmap2() for all requests but not both.
  The current implementation uses a flag in the cdevsw (D_MMAP2) to indicate
  that the driver provides a d_mmap2() handler instead of d_mmap().  This
  is done to make the change ABI compatible with existing drivers and
  MFC'able to 7 and 8.

Submitted by:	alc
MFC after:	1 month
2009-08-28 14:06:55 +00:00
Alan Cox
9861cbc6ca Change the handling of fictitious pages by pmap_page_set_memattr() on
amd64 and i386.  Essentially, fictitious pages provide a mechanism for
creating aliases for either normal or device-backed pages.  Therefore,
pmap_page_set_memattr() on a fictitious page needn't update the direct
map or flush the cache.  Such actions are the responsibility of the
"primary" instance of the page or the device driver that "owns" the
physical address.  For example, these actions are already performed by
pmap_mapdev().

The device pager needn't restore the memory attributes on a fictitious
page before releasing it.  It's now pointless.

Add pmap_page_set_memattr() to the Xen pmap.

Approved by:	re (kib)
2009-07-19 21:40:19 +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
Konstantin Belousov
3364c323e6 Implement global and per-uid accounting of the anonymous memory. Add
rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved
for the uid.

The accounting information (charge) is associated with either map entry,
or vm object backing the entry, assuming the object is the first one
in the shadow chain and entry does not require COW. Charge is moved
from entry to object on allocation of the object, e.g. during the mmap,
assuming the object is allocated, or on the first page fault on the
entry. It moves back to the entry on forks due to COW setup.

The per-entry granularity of accounting makes the charge process fair
for processes that change uid during lifetime, and decrements charge
for proper uid when region is unmapped.

The interface of vm_pager_allocate(9) is extended by adding struct ucred *,
that is used to charge appropriate uid when allocation if performed by
kernel, e.g. md(4).

Several syscalls, among them is fork(2), may now return ENOMEM when
global or per-uid limits are enforced.

In collaboration with:	pho
Reviewed by:	alc
Approved by:	re (kensmith)
2009-06-23 20:45:22 +00:00
Alan Cox
ce1b857f33 Validate the page in one place, dev_pager_getpages(), rather than doing it
in two places, dev_pager_getfake() and dev_pager_updatefake().

Compare a pointer to "NULL" rather than "0".
2009-06-22 19:09:48 +00:00
Alan Cox
6f0489c670 Strive for greater consistency among the places that implement real,
fictious, and contiguous page allocation.  Eliminate unnecessary
reinitialization of a page's fields.
2009-06-21 00:21:33 +00:00
Konstantin Belousov
7818e0a545 Save previous content of the td_fpop before storing the current
filedescriptor into it. Make sure that td_fpop is NULL when calling
d_mmap from dev_pager_getpages().

Change guards against td_fpop field being non-NULL with private state
for another device, and against sudden clearing the td_fpop. This
could occur when either a driver method calls another driver through
the filedescriptor operation, or a page fault happen while driver is
writing to a memory backed by another driver.

Noted by:	rwatson
Tested by:	rnoland
MFC after:	3 days
2008-09-26 14:50:49 +00:00
Alan Cox
e46cd4132c Preset a device object's alignment ("pg_color") based upon the
physical address of the device's memory.  This enables
pmap_align_superpage() to propose a virtual address for mapping the
device memory that permits the use of superpage mappings.
2008-05-17 16:26:34 +00:00
Konstantin Belousov
daab56673e Remove comment that is no longer quite true.
Noted by:	alc
Approved by:	re (kensmith)
2007-08-18 16:41:31 +00:00
Konstantin Belousov
deea654ebf Protect the creation of the device pager with the dev_pager_mtx. Lookup
of device pager in the pagers list by handle is now synchronized with
its removal from the list, and dev_pager_mtx is put before vm object
lock in lock order. Dispose the dev_pager_sx lock, since dev_pager_mtx
now covers the same block.

Noted by:	kensmith
Reviewed by:	alc
Approved by:	re (kensmith)
2007-08-07 15:36:25 +00:00
Alan Cox
b5e8f167b9 Consider a scenario in which one processor, call it Pt, is performing
vm_object_terminate() on a device-backed object at the same time that
another processor, call it Pa, is performing dev_pager_alloc() on the
same device.  The problem is that vm_pager_object_lookup() should not be
allowed to return a doomed object, i.e., an object with OBJ_DEAD set,
but it does.  In detail, the unfortunate sequence of events is: Pt in
vm_object_terminate() holds the doomed object's lock and sets OBJ_DEAD
on the object.  Pa in dev_pager_alloc() holds dev_pager_sx and calls
vm_pager_object_lookup(), which returns the doomed object.  Next, Pa
calls vm_object_reference(), which requires the doomed object's lock, so
Pa waits for Pt to release the doomed object's lock.  Pt proceeds to the
point in vm_object_terminate() where it releases the doomed object's
lock.  Pa is now able to complete vm_object_reference() because it can
now complete the acquisition of the doomed object's lock.  So, now the
doomed object has a reference count of one!  Pa releases dev_pager_sx
and returns the doomed object from dev_pager_alloc().  Pt now acquires
dev_pager_mtx, removes the doomed object from dev_pager_object_list,
releases dev_pager_mtx, and finally calls uma_zfree with the doomed
object.  However, the doomed object is still in use by Pa.

Repeating my key point, vm_pager_object_lookup() must not return a
doomed object.  Moreover, the test for the object's state, i.e.,
doomed or not, and the increment of the object's reference count
should be carried out atomically.

Reviewed by:	kib
Approved by:	re (kensmith)
MFC after:	3 weeks
2007-08-05 21:04:32 +00:00
Konstantin Belousov
c6199d59e3 Do not acquire Giant unconditionally around the calls to the cdevsw
d_mmap methods. prep_cdevsw() already installs the shims that
acquire/drop Giant for the methods of a driver that specified the
D_NEEDGIANT flag.

Reviewed by:	alc
Approved by:	re (kensmith)
2007-08-05 05:40:52 +00:00
Alan Cox
9af80719db Replace PG_BUSY with VPO_BUSY. In other words, changes to the page's
busy flag, i.e., VPO_BUSY, are now synchronized by the per-vm object
lock instead of the global page queues lock.
2006-10-22 04:28:14 +00:00
Alan Cox
25017df472 Ensure that the page's new field for object-synchronized flags is always
initialized to zero.

Call vm_page_sleep_if_busy() instead of duplicating its implementation in
vm_page_grab().
2006-08-11 17:18:58 +00:00
Alan Cox
25f2e1c8cc Add a comment to the effect that fictitious pages do not require the
initialization of their machine-dependent fields.
2005-06-10 17:27:54 +00:00
Warner Losh
60727d8b86 /* -> /*- for license, minor formatting changes 2005-01-07 02:29:27 +00:00
Poul-Henning Kamp
751fdd08fe Use dev_re[fl]thread() to maintain a ref on the device driver while
we call the ->d_mmap function.
2004-09-24 05:59:11 +00:00
Doug Rabson
c413d99c4e In dev_pager_updatefake, m->valid is typically 0 on entry. It
should be set to VM_PAGE_BITS_ALL before returning, to ensure that
neither vm_pager_get_pages nor vm_fault calls vm_page_zero_invalid
after dev_pager_getpages has returned.

Submitted by: tegge
2004-08-04 08:58:58 +00:00
Doug Rabson
92bab635d3 Fix a memory leak in the device pager which is exposed by the NVIDIA
OpenGL driver.

Submitted by: nvidia (possibly also tegge)
2004-07-30 11:09:18 +00:00
Poul-Henning Kamp
89c9c53da0 Do the dreaded s/dev_t/struct cdev */
Bump __FreeBSD_version accordingly.
2004-06-16 09:47:26 +00:00
Alan Cox
87aefa499a Push down Giant into vm_pager_get_pages(). The only get pages methods that
require Giant are in the device and vnode pagers.
2004-04-23 06:10:58 +00:00
Warner Losh
05eb3785e7 Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core
2004-04-06 20:15:37 +00:00
Alan Cox
2f7af3db57 Simplify the various pager allocation routines by computing the desired
object size once and assigning that value to a local variable.
2004-01-04 20:55:15 +00:00
Alan Cox
9aa3d17d37 The addition of a locking assertion to vm_page_zero_invalid() has revealed
a long-time bug: vm_pager_get_pages() assumes that m[reqpage] contains a
valid page upon return from pgo_getpages().  In the case of the device
pager this page has been freed and replaced by a fake page.  The fake page
is properly inserted into the vm object but m[reqpage] is left pointing
to a freed page.  For now, update m[reqpage] to point to the fake page.

Submitted by:	tegge
2003-10-05 22:23:44 +00:00
Jeff Roberson
f3c625e47a - Use the UMA_ZONE_VM flag on the fakepg and object zones to prevent
vm recursion and LORs.  This may be necessary for other zones created in
   the vm but this needs to be verified.
2003-10-04 14:21:53 +00:00
Poul-Henning Kamp
4e6586002d Use sparse struct initializations for struct pagerops.
This makes grepping for which pagers implement which methods easier.
2003-08-05 06:51:26 +00:00
Alan Cox
a8ab48702b Assert that the vm object is locked on entry to dev_pager_getpages(). 2003-06-24 19:48:34 +00:00
Alan Cox
8630c1173e Add vm object locking to various pagers' "get pages" methods, i386 stack
management functions, and a u area management function.
2003-06-13 03:02:28 +00:00
David E. O'Brien
874651b13c Use __FBSDID(). 2003-06-11 23:50:51 +00:00
Jake Burkholder
227f9a1c58 - Add vm_paddr_t, a physical address type. This is required for systems
where physical addresses larger than virtual addresses, such as i386s
  with PAE.
- Use this to represent physical addresses in the MI vm system and in the
  i386 pmap code.  This also changes the paddr parameter to d_mmap_t.
- Fix printf formats to handle physical addresses >4G in the i386 memory
  detection code, and due to kvtop returning vm_paddr_t instead of u_long.

Note that this is a name change only; vm_paddr_t is still the same as
vm_offset_t on all currently supported platforms.

Sponsored by:	DARPA, Network Associates Laboratories
Discussed with:	re, phk (cdevsw change)
2003-03-25 00:07:06 +00:00
Maxime Henrion
07159f9c56 Cleanup of the d_mmap_t interface.
- Get rid of the useless atop() / pmap_phys_address() detour.  The
  device mmap handlers must now give back the physical address
  without atop()'ing it.
- Don't borrow the physical address of the mapping in the returned
  int.  Now we properly pass a vm_offset_t * and expect it to be
  filled by the mmap handler when the mapping was successful.  The
  mmap handler must now return 0 when successful, any other value
  is considered as an error.  Previously, returning -1 was the only
  way to fail.  This change thus accidentally fixes some devices
  which were bogusly returning errno constants which would have been
  considered as addresses by the device pager.
- Garbage collect the poorly named pmap_phys_address() now that it's
  no longer used.
- Convert all the d_mmap_t consumers to the new API.

I'm still not sure wheter we need a __FreeBSD_version bump for this,
since and we didn't guarantee API/ABI stability until 5.1-RELEASE.

Discussed with:		alc, phk, jake
Reviewed by:		peter
Compile-tested on:	LINT (i386), GENERIC (alpha and sparc64)
Runtime-tested on:	i386
2003-02-25 03:21:22 +00:00
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
Alfred Perlstein
44956c9863 Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.
2003-01-21 08:56:16 +00:00
Alan Cox
60e15726af o Lock accesses to the page queues. 2002-07-12 02:55:55 +00:00
Ian Dowse
6395da5437 Complete the initial set of VM changes required to support full
64-bit file sizes. This step simply addresses the remaining overflows,
and does attempt to optimise performance. The details are:

 o Use a 64-bit type for the vm_object `size' and the size argument
   to vm_object_allocate().
 o Use the correct type for index variables in dev_pager_getpages(),
   vm_object_page_clean() and vm_object_page_remove().
 o Avoid an overflow in the i386 pmap_object_init_pt().
2002-06-25 22:14:06 +00:00
Alan Cox
c8664f82a5 o Replace mtx_assert(&Giant, MA_OWNED) in dev_pager_alloc()
with the acquisition and release of Giant.  (Annotate as MPSAFE.)
 o Reorder the sanity checks in dev_pager_alloc() to reduce
   the time that Giant is held.
2002-06-22 18:36:51 +00:00
John Baldwin
6008862bc2 Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on:	i386, alpha, sparc64
2002-04-04 21:03:38 +00:00