CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: d...@cvs.openbsd.org2020/07/17 00:33:07 Modified files: sys/dev/pci: if_ix.c files.pci Log message: use the system stoeplitz key instead of a random one. while here, stash the rss hash value from rx descriptors in the mbuf as a flow id.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: d...@cvs.openbsd.org2020/07/17 00:27:36 Modified files: sys/dev/pci: files.pci if_ix.c if_ix.h ixgbe.h Log message: enable multiq support for ix. this is an updated version of a diff from christiano haesbaert by way of mpi@ to enable the use of multiple tx and rx rings with msi-x. now that patrick@ got interrupts on multiple cpus working on arm64, i can commit this. the main changes are to use an intrmap pointer as the flag for whether msix has been enabled or not, and to use the intrmap to establish vectors on multiple cpus. tested by hrvoje popovski
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 23:59:05 Modified files: usr.bin/ssh: ssh_config.5 Log message: fix macro slip in previous;
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: dera...@cvs.openbsd.org 2020/07/16 21:59:39 Modified files: distrib/sets/lists/comp: md.powerpc64 Log message: sync
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: d...@cvs.openbsd.org2020/07/16 21:51:32 Modified files: usr.bin/ssh: sftp-server.c Log message: log error message for process_write() write failures
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: dtuc...@cvs.openbsd.org 2020/07/16 21:43:42 Modified files: usr.bin/ssh: ssh.c ssh_config ssh_config.5 sshconnect.c Log message: Add a '%k' TOKEN that expands to the effective HostKey of the destination. This allows, eg, keeping host keys in individual files using "UserKnownHostsFile ~/.ssh/known_hosts.d/%k". bz#1654, ok djm@, jmc@ (man page bits)
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: jmatt...@cvs.openbsd.org2020/07/16 21:37:37 Modified files: sys/dev/pci: if_mcx.c Log message: Virtual functions are effectively identical to full physical functions, so we can attach to them too. ok dlg@
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: d...@cvs.openbsd.org2020/07/16 21:37:36 Modified files: sys/dev/pci: if_myx.c Log message: name the rx rings so systat mb shows them.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: dtuc...@cvs.openbsd.org 2020/07/16 21:26:58 Modified files: regress/usr.bin/ssh: percent.sh Log message: Add tests for expansions on UserKnownHostsFile.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: jmatt...@cvs.openbsd.org2020/07/16 21:23:18 Modified files: sys/dev/pci: if_mcx.c Log message: Consistently use the port type and speed register (PTYS) to determine if the link is up, rather than the operational status (PAOS). ok dlg@
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: dtuc...@cvs.openbsd.org 2020/07/16 21:23:10 Modified files: usr.bin/ssh: ssh.c ssh_config.5 Log message: Add %-TOKEN, environment variable and tilde expansion to UserKnownHostsFile, allowing the file to be automagically split up in the configuration (eg bz#1654). ok djm@, man page parts jmc@
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: d...@cvs.openbsd.org2020/07/16 20:58:14 Modified files: sys/dev/pci: if_myx.c Log message: add kstats to myx. myx is unusually minimal, so there's not a lot of information that the chip provides. the most interesting is the number of packets the chip drops cos of a lack of space on the rx rings.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: gkoeh...@cvs.openbsd.org2020/07/16 19:36:41 Modified files: sys/kern : kern_tc.c Log message: Read ogen from the other timehands; fixes tk_generation If th0.th_generation == th1.th_generation when we update the user timekeep page, then tk_generation doesn't change, so libc may calculate the wrong time. Now th0 and th1 share the sequence so th0.th_generation != th1.th_generation. ok kettenis@ cheloha@
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: k...@cvs.openbsd.org2020/07/16 18:36:42 Modified files: sys/dev/ata: atascsi.c Log message: Always a joker hiding somewhere. Access adapter_buswidth via link->bus->sb_adapter_buswidth.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs
Module name:src
Changes by: chel...@cvs.openbsd.org 2020/07/16 17:06:43
Modified files:
sys/kern : kern_tc.c
Log message:
adjtime(2): distribute skew along arbitrary period on runtime clock
The adjtime(2) adjustment is applied at up to 5000ppm/sec from
tc_windup(). At the start of each UTC second, ntp_update_second() is
called from tc_windup() and up to 5000ppm worth of skew is deducted
from the timehands' th_adjtimedelta member and moved to the
th_adjustment member. The resulting th_adjustment value is then mixed
into the th_scale member and thus the system UTC time is slowly nudged
in a particular direction.
This works pretty well. The only issues have to do with the use of
the the edge of the UTC second as the start of the ntp_update_second()
period:
1. If the UTC clock jumps forward we can get stuck in a loop calling
ntp_update_second() from tc_windup(). We work around this with
a magic number, LARGE_STEP. If the UTC clock jumps forward more
than LARGE_STEP seconds we truncate the number of iterations to 2.
Per the comment in tc_windup(), we do 2 iterations instead of 1
iteration to account for a leap second we may have missed. This is
an anachronism: the OpenBSD kernel does not handle leap seconds
anymore.
Such jumps happen during settimeofday(2), during boot when we jump
the clock from zero to the RTC time, and during resume when we jump
the clock to the RTC time (again). They are unavoidable.
2. Changes to adjtime(2) are applied asynchronously. For example, if
you try to cancel the ongoing adjustment...
struct timeval zero = { 0, 0 };
adjtime(&zero, NULL);
... it can take up to one second for the adjustment to be cancelled.
In the meantime, the skew continues. This delayed application is not
intuitive or documented.
3. Adjustment is deducted from th_adjtimedelta across suspends of fewer
than LARGE_STEP seconds, even though we do not skew the clock while
we are suspended. This is unintuitive, incorrect, and undocumented.
We can avoid all of these problems by applying the adjustment along
an arbitrary period on the runtime clock instead of the UTC clock.
1. The runtime clock doesn't jump arbitrary amounts, so we never get
stuck in a loop and we don't need a magic number to test for this
possibility. With the removal of the magic number LARGE_STEP we
can also remove the leap second handling from the tc_windup() code.
2. With a new timehands member, th_next_ntp_update, we can track when
the next ntp_update_second() call should happen on the runtime clock.
This value can be updated during the adjtime(2) system call, so
changes to the skew happen *immediately* instead of up to one second
after the adjtime(2) call.
3. The runtime clock does not jump across a suspend: no skew is
deducted from th_adjtimedelta for any time we are offline and
unable to adjust the clock.
otto@ says the use of the runtime clock should not be a problem for
ntpd(8) or the NTP algorithm in general.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: patr...@cvs.openbsd.org 2020/07/16 15:49:41 Modified files: sys/dev/pci: if_mcx.c Log message: Pass the interrupt handler cookie instead of the pointer to it to intr_barrier(9). Fixes mysterious panics seen while working on intr_barrier(9) for arm64. ok jmatthew@
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 15:26:18 Modified files: libexec/ld.so/powerpc64: rtld_machine.c Log message: Rewrite loop to match what is written down in the ABI document. ok drahn@
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 15:18:09 Modified files: libexec/ld.so/powerpc64: ldasm.S rtld_machine.c Log message: Make lazy binding work. Committing on behalf of drahn@ who is a bit busy.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: k...@cvs.openbsd.org2020/07/16 15:18:31 Modified files: sys/arch/luna88k/dev: mb89352.c sys/arch/sparc64/dev: vdsk.c sys/arch/sparc64/sparc64: autoconf.c sys/dev: softraid.c vscsi.c sys/dev/ata: atascsi.c sys/dev/atapiscsi: atapiscsi.c sys/dev/ic : aac.c adv.c adw.c ahci.c aic6250.c aic6360.c aic79xx_openbsd.c aic7xxx_openbsd.c ami.c cac.c ciss.c gdt_common.c iha.c mfi.c mpi.c ncr53c9x.c nvme.c oosiop.c osiop.c qla.c qlw.c siop.c trm.c twe.c uha.c wd33c93.c sys/dev/isa: wds.c sys/dev/pci: arc.c ips.c mfii.c mpii.c qle.c vmwpvs.c sys/dev/pv : hvs.c vioblk.c vioscsi.c xbf.c sys/dev/sdmmc : sdmmc_scsi.c sys/dev/usb: umass_scsi.c Log message: Access adapter softc via link->bus->sb_adapter_softc. In sparc64 autoconf access 'luns' via sb_luns and 'adapter_buswidth' via sb_adapter_buswidth. Removes last post-config uses of the copies of bus related information in scsi_link.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: mill...@cvs.openbsd.org 2020/07/16 14:08:12 Modified files: lib/libc/time : strftime.c Log message: Remove obsolete LOCALE_HOME code we have never used (and never will). Upstream removed it in 2004. From Jan Stary.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:48:58 Modified files: sys/arch/powerpc64/stand: Makefile Added files: sys/arch/powerpc64/stand: Makefile.inc sys/arch/powerpc64/stand/boot: Makefile sys/arch/powerpc64/stand/rdboot: Makefile cmd.c cmd.h disk.c disk.h rdboot.c vars.c Log message: First stab at a bootloader for OpenBSD/powerpc64. Based on the same principle (and mostly copied from) the bootloader written by visa@ for OpenBSD/octeon. Needed because the petitboot environment provided by the OpenPower firmware is unsuitable for loading OpenBSD kernels properly.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:44:19 Modified files: share/man/man8/man8.powerpc64: MAKEDEV.8 etc/etc.powerpc64: MAKEDEV Log message: regen
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:42:18 Modified files: etc/etc.powerpc64: disktab Log message: Add disk description for bootloader ramdisk.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:42:47 Modified files: etc/etc.powerpc64: MAKEDEV.md Log message: Bootloader magic.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:41:04 Added files: sys/arch/powerpc64/conf: BOOT sys/arch/powerpc64/compile/BOOT: Makefile Log message: Add BOOT kernel config.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:37:58 Modified files: sys/arch/powerpc64/conf: files.powerpc64 sys/arch/powerpc64/include: conf.h sys/arch/powerpc64/powerpc64: conf.c Added files: sys/arch/powerpc64/dev: kexec.c kexec_subr.S sys/arch/powerpc64/include: kexec.h Log message: Add a pseudo-driver to "kexec" an OpenBSD/powerpc64 kernel. Heavily based on the octboot driver that we use for octeon. To be used in the bootloader kernel.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:29:36 src/sys/arch/powerpc64/compile/BOOT Update of /cvs/src/sys/arch/powerpc64/compile/BOOT In directory cvs.openbsd.org:/tmp/cvs-serv14226/BOOT Log Message: Directory /cvs/src/sys/arch/powerpc64/compile/BOOT added to the repository
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:26:08 src/sys/arch/powerpc64/stand/boot Update of /cvs/src/sys/arch/powerpc64/stand/boot In directory cvs.openbsd.org:/tmp/cvs-serv21402/boot Log Message: Directory /cvs/src/sys/arch/powerpc64/stand/boot added to the repository
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:26:08 src/sys/arch/powerpc64/stand/rdboot Update of /cvs/src/sys/arch/powerpc64/stand/rdboot In directory cvs.openbsd.org:/tmp/cvs-serv21402/rdboot Log Message: Directory /cvs/src/sys/arch/powerpc64/stand/rdboot added to the repository
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 13:10:33 Modified files: sys/arch/powerpc64/dev: xive.c Log message: Reset firmware state upon reboot.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: t...@cvs.openbsd.org2020/07/16 11:47:41 Modified files: usr.bin/ktrace : ktrace.1 ktrace.c Log message: add -T option to make time related system calls more prominent. ok deraadt
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: t...@cvs.openbsd.org2020/07/16 11:47:10 Modified files: lib/libc/dlfcn : init.c Log message: allow setenv LIBC_NOUSERTC to disable userland timekeeping, for ktrace. ok deraadt pirofti
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: to...@cvs.openbsd.org 2020/07/16 11:38:24 Modified files: sbin/iked : ikev2.c Log message: Remove unused assignment.
CVS: cvs.openbsd.org: www
CVSROOT:/cvs Module name:www Changes by: na...@cvs.openbsd.org 2020/07/16 11:29:39 Modified files: . : 67.html Log message: 6503 mips64el packages
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: to...@cvs.openbsd.org 2020/07/16 11:16:17 Modified files: sbin/iked : ikev2.c policy.c Log message: Make sure to update policy dependant SA fields after policy_lookup(). ok kn@ patrick@
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: k...@cvs.openbsd.org2020/07/16 08:44:55 Modified files: sys/scsi : cd.c mpath.c scsi_base.c scsi_ioctl.c scsiconf.c sd.c st.c Log message: Access scsibus_softc info (luns, adapter, adapter_target, adapter_softc, adapter_buswidth) via link->bus rather than using copies currently residing in the link.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: dera...@cvs.openbsd.org 2020/07/16 07:41:36 Modified files: distrib/sets/lists/base: md.powerpc64 distrib/sets/lists/comp: md.powerpc64 Log message: sync
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: patr...@cvs.openbsd.org 2020/07/16 07:03:39 Modified files: sys/arch/arm64/arm64: acpi_machdep.c intr.c sys/arch/arm64/dev: acpipci.c sys/arch/arm64/include: intr.h Log message: Store struct cpu_info * in arm64's interrupt wrap. intr_barrier() can already assume every cookie is wrapped and simply retrieve the pointer from it. It's a bit of a layer violation though, since only the intc should actually store that kind of information. This is good enough for now, but I'm already cooking up a diff to resolve this. ok dlg@
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: patr...@cvs.openbsd.org 2020/07/16 06:57:30 Modified files: sys/arch/arm64/arm64: acpi_machdep.c intr.c sys/arch/arm64/dev: acpipci.c sys/arch/arm64/include: intr.h Log message: To be able to have intr_barrier() on arm64, we need to be able to somehow gain access to the struct cpu_info * used to establish the interrupt. One possibility is to store the pointer in the cookie returned by the establish methods. A better way would be to ask the interrupt controller directly to do barrier. This means that all external facing interrupt establish functions need to wrap the cookie in a common way. We already do this for FDT-based interrupts. Also most PCI controllers already return the cookie from the FDT API, which is already wrapped. So arm64's acpi_intr_establish() and acpipci(4) now need to explicitly wrap it, since they call ic->ic_establish directly, which does not wrap. ok dlg@
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: k...@cvs.openbsd.org2020/07/16 06:38:44 Modified files: sys/scsi : scsiconf.c scsiconf.h Log message: Beef up struct scsibus_softc to hold the information needed to initialize the scsi_link's on the bus. After sucking this information out of the "prototype" link provided by the scsibus_attach_arg, no need to keep a pointer to that prototype.
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 04:17:09 Modified files: sys/dev/pci/drm/i915: i915_vma.c Log message: drm/i915: Also drop vm.ref along error paths for vma construction >From Chris Wilson 5e53344673fcf1df8ff52675ab0539fff26a8e29 in linux 5.7.y/5.7.9 cf1976b11372cac3b57fbae1831f66a4486355d3 in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 04:14:13 Modified files: sys/dev/pci/drm/i915: i915_vma.c Log message: drm/i915: Drop vm.ref for duplicate vma on construction >From Chris Wilson 98762e5b00567622d57295d2d3389aea2c37be03 in linux 5.7.y/5.7.9 42723673a193d5f8e30dba6ea9826d42262a502b in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 04:11:34 Modified files: sys/dev/pci/drm/amd/amdgpu: amdgpu_psp.c Log message: drm/amdgpu: asd function needs to be unloaded in suspend phase >From Huang Rui 22ff658396b44606163ad0231e8215309a26d613 in linux 5.7.y/5.7.9 20303ec5d2165ee6344190274bc59118921f71d9 in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 04:09:22 Modified files: sys/dev/pci/drm/amd/amdgpu: amdgpu_psp.c Log message: drm/amdgpu: add TMR destory function for psp >From Huang Rui 2c41c968c6f6480860c67210815cadc6507f5014 in linux 5.7.y/5.7.9 c564b8601ae917086751d90f464d5f19d731ece7 in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 04:07:02 Modified files: sys/dev/pci/drm/amd/amdgpu: amdgpu_job.c Log message: drm/amdgpu: don't do soft recovery if gpu_recovery=0 >From Marek Olsak d7915047a1d59474d06789a9dd1925064969e080 in linux 5.7.y/5.7.9 f4892c327a8e5df7ce16cab40897daf90baf6bec in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 04:03:45 Modified files: sys/dev/pci/drm/i915: i915_debugfs.c Log message: drm/i915: Skip stale object handle for debugfs per-file-stats >From Chris Wilson d073ed965cd908d320d49824dee02c80168f96a8 in linux 5.7.y/5.7.9 7dfbf8a07cf8c936b0d6cc810df6ae7923954d5b in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 04:01:41 Modified files: sys/dev/pci/drm/i915/gt: intel_context.c Log message: drm/i915/gt: Pin the rings before marking active >From Chris Wilson 096b85c64987a0ef4fcc6ac0e3c3661573828df1 in linux 5.7.y/5.7.9 5a383d443b29a140094430f3ad1d02fa1acc2b80 in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 03:59:17 Modified files: sys/dev/pci/drm/radeon: ci_dpm.c Log message: drm/radeon: fix double free >From Tom Rix 67e9648f20524ff6824ebeb26afea45f7d9c300d in linux 5.7.y/5.7.9 41855a898650803e24b284173354cc3e44d07725 in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 03:56:50 Modified files: sys/dev/pci/drm: drm_panel_orientation_quirks.c Log message: drm: panel-orientation-quirks: Use generic orientation-data for Acer S1003 >From Hans de Goede 109b3b4e2a0f5bfda023a1b91b404fac31ba6808 in linux 5.7.y/5.7.9 a05caf9e62a85d12da27e814ac13195f4683f21c in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 03:53:49 Modified files: sys/dev/pci/drm: drm_panel_orientation_quirks.c Log message: drm: panel-orientation-quirks: Add quirk for Asus T101HA panel >From Hans de Goede e64e92fea2bf85d9f33304faf973c46859afd0f7 in linux 5.7.y/5.7.9 6c22bc18a3b93a38018844636557ad02e588e055 in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 03:50:39 Modified files: sys/dev/pci/drm/ttm: ttm_bo.c Log message: drm/ttm: Fix dma_fence refcnt leak when adding move fence >From Xiyu Yang bfd4297fd74ebb18d05044e49f1ff2fedd2ece8d in linux 5.7.y/5.7.9 11425c4519e2c974a100fc984867046d905b9380 in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: j...@cvs.openbsd.org2020/07/16 03:48:22 Modified files: sys/dev/pci/drm/ttm: ttm_bo_vm.c Log message: drm/ttm: Fix dma_fence refcnt leak in ttm_bo_vm_fault_reserved >From Xiyu Yang f5e6ec57e3cbe37cd3ef52d18de6be9953ee105a in linux 5.7.y/5.7.9 37cc4b95d13f311c04aa8e9daacca3905ad45ca7 in mainline linux
CVS: cvs.openbsd.org: src
CVSROOT:/cvs Module name:src Changes by: kette...@cvs.openbsd.org2020/07/16 03:47:16 Modified files: sys/arch/powerpc64/powerpc64: pmap.c Log message: Since the page tables could be larger than 256MB allow for multiple segments to map them.
