aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mm/proc-arm926.S
AgeCommit message (Collapse)Author
2015-03-28ARM: 8314/1: replace PROCINFO embedded branch with relative offsetArd Biesheuvel
This patch replaces the 'branch to setup()' instructions embedded in the PROCINFO structs with the offset to that setup function relative to the base of the struct. This preserves the position independent nature of that field, but uses a data item rather than an instruction. This is mainly done to prevent linker failures on large kernels, where the setup function is out of reach for the branch. Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-18ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+Russell King
ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-07-14arm: delete __cpuinit/__CPUINIT usage from all ARM usersPaul Gortmaker
The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the ARM uses of the __cpuinit macros from C code, and all __CPUINIT from assembly code. It also had two ".previous" section statements that were paired off against __CPUINIT (aka .section ".cpuinit.text") that also get removed here. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-04-08ARM: Do 15e0d9e37c (ARM: pm: let platforms select cpu_suspend support) properlyRussell King
Let's do the changes properly and fix the same problem everywhere, not just for one case. Cc: <stable@vger.kernel.org> # kernels containing 15e0d9e37c or equivalent Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-09-25ARM: mm: implement LoUIS API for cache maintenance opsLorenzo Pieralisi
ARM v7 architecture introduced the concept of cache levels and related control registers. New processors like A7 and A15 embed an L2 unified cache controller that becomes part of the cache level hierarchy. Some operations in the kernel like cpu_suspend and __cpu_disable do not require a flush of the entire cache hierarchy to DRAM but just the cache levels belonging to the Level of Unification Inner Shareable (LoUIS), which in most of ARM v7 systems correspond to L1. The current cache flushing API used in cpu_suspend and __cpu_disable, flush_cache_all(), ends up flushing the whole cache hierarchy since for v7 it cleans and invalidates all cache levels up to Level of Coherency (LoC) which cripples system performance when used in hot paths like hotplug and cpuidle. Therefore a new kernel cache maintenance API must be added to cope with latest ARM system requirements. This patch adds flush_cache_louis() to the ARM kernel cache maintenance API. This function cleans and invalidates all data cache levels up to the Level of Unification Inner Shareable (LoUIS) and invalidates the instruction cache for processors that support it (> v7). This patch also creates an alias of the cache LoUIS function to flush_kern_all for all processor versions prior to v7, so that the current cache flushing behaviour is unchanged for those processors. v7 cache maintenance code implements a cache LoUIS function that cleans and invalidates the D-cache up to LoUIS and invalidates the I-cache, according to the new API. Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Shawn Guo <shawn.guo@linaro.org>
2012-05-02ARM: 7408/1: cacheflush: return error to userspace when flushing syscall failsWill Deacon
The cacheflush syscall can fail for two reasons: (1) The arguments are invalid (nonsensical address range or no VMA) (2) The region generates a translation fault on a VIPT or PIPT cache This patch allows do_cache_op to return an error code to userspace in the case of the above. The various coherent_user_range implementations are modified to return 0 in the case of VIVT caches or -EFAULT in the case of an abort on v6/v7 cores. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-06ARM: proc-*.S: place cpu_reset functions into .idmap.text sectionWill Deacon
The CPU reset functions disable the MMU and therefore must be executed with an identity mapping in place. This patch places the CPU reset functions into the .idmap.text section, causing the idmap code to include them as part of the identity mapping. Acked-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-09-20ARM: pm: only use preallocated page table during resumeRussell King
Only use the preallocated page table during the resume, not while suspending. This avoids the overhead of having to switch unnecessarily to the resume page table in the suspend path. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-20ARM: pm: preallocate a page table for suspend/resumeRussell King
Preallocate a page table and setup an identity mapping for the MMU enable code. This means we don't have to "borrow" a page table to do this, avoiding complexities with L2 cache coherency. Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-28ARM: pm: arm920/926: fix number of registers savedRussell King
ARM920 and ARM926 save four registers, not three. Fix the size of the suspend region required. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-21ARM: Fix build errors caused by adding generic macrosRussell King
Commit 66a625a (ARM: mm: proc-macros: Add generic proc/cache/tlb struct definition macros) introduced build errors when PM_SLEEP is not enabled. The per-CPU do_suspend/do_resume functions are defined via the preprocessor to constant 0. However, the macros which use these were converted to assembly, resulting in undefined references to these functions. Fix that by moving the ! ifdef section into proc-macros.S and deleting it from all effected proc-*.S files. Acked-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-07ARM: mm: proc-arm926: Use the new processor struct macrosDave Martin
Signed-off-by: Dave Martin <dave.martin@linaro.org>
2011-04-02ARM: Make consolidated PM sleep code depend on PM_SLEEPRussell King
CONFIG_PM is now set whenever we support either runtime PM in addition to suspend and hibernate. This causes build errors when runtime PM is enabled on a platform, but the CPU does not have the appropriate support for suspend. So, switch this code to use CONFIG_PM_SLEEP rather than CONFIG_PM to allow runtime PM to be enabled without causing build errors. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-22ARM: pm: add generic CPU suspend/resume supportRussell King
This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-28ARM: 6466/1: implement flush_icache_all for the rest of the CPUsMika Westerberg
Commit 81d11955bf0 ("ARM: 6405/1: Handle __flush_icache_all for CONFIG_SMP_ON_UP") added a new function to struct cpu_cache_fns: flush_icache_all(). It also implemented this for v6 and v7 but not for v5 and backwards. Without the function pointer in place, we will be calling wrong cache functions. For example with ep93xx we get following: Unable to handle kernel paging request at virtual address ee070f38 pgd = c0004000 [ee070f38] *pgd=00000000 Internal error: Oops: 80000005 [#1] PREEMPT last sysfs file: Modules linked in: CPU: 0 Not tainted (2.6.36+ #1) PC is at 0xee070f38 LR is at __dma_alloc+0x11c/0x2d0 pc : [<ee070f38>] lr : [<c0032c8c>] psr: 60000013 sp : c581bde0 ip : 00000000 fp : c0472000 r10: c0472000 r9 : 000000d0 r8 : 00020000 r7 : 0001ffff r6 : 00000000 r5 : c0472400 r4 : c5980000 r3 : c03ab7e0 r2 : 00000000 r1 : c59a0000 r0 : c5980000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: c000717f Table: c0004000 DAC: 00000017 Process swapper (pid: 1, stack limit = 0xc581a270) [<c0032c8c>] (__dma_alloc+0x11c/0x2d0) [<c0032e5c>] (dma_alloc_writecombine+0x1c/0x24) [<c0204148>] (ep93xx_pcm_preallocate_dma_buffer+0x44/0x60) [<c02041c0>] (ep93xx_pcm_new+0x5c/0x88) [<c01ff188>] (snd_soc_instantiate_cards+0x8a8/0xbc0) [<c01ff59c>] (soc_probe+0xfc/0x134) [<c01adafc>] (platform_drv_probe+0x18/0x1c) [<c01acca4>] (driver_probe_device+0xb0/0x16c) [<c01ac284>] (bus_for_each_drv+0x48/0x84) [<c01ace90>] (device_attach+0x50/0x68) [<c01ac0f8>] (bus_probe_device+0x24/0x44) [<c01aad7c>] (device_add+0x2fc/0x44c) [<c01adfa8>] (platform_device_add+0x104/0x15c) [<c0015eb8>] (simone_init+0x60/0x94) [<c0021410>] (do_one_initcall+0xd0/0x1a4) __dma_alloc() calls (inlined) __dma_alloc_buffer() which ends up calling dmac_flush_range(). Now since the entries in the arm920_cache_fns are shifted by one, we jump into address 0xee070f38 which is actually next instruction after the arm920_cache_fns structure. So implement flush_icache_all() for the rest of the supported CPUs using a generic 'invalidate I cache' instruction. Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-08ARM: hotplug cpu: Keep processor information, startup code & ↵Russell King
__lookup_processor_type When hotplug CPU is enabled, we need to keep the list of supported CPUs, their setup functions, and __lookup_processor_type in place so that we can find and initialize secondary CPUs. Move these into the __CPUINIT section. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-27ARM: Factor out common code from cpu_proc_fin()Russell King
All implementations of cpu_proc_fin() start by disabling interrupts and then flush caches. Rather than have every processors proc_fin() implementation do this, move it out into generic code - and move the cache flush past setup_mm_for_reboot() (so it can benefit from having caches still enabled.) This allows cpu_proc_fin() to become independent of the L1/L2 cache types, and eventually move the L2 cache flushing into the L2 support code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-15ARM: dma-mapping: remove dmac_clean_range and dmac_inv_rangeRussell King
These are now unused, and so can be removed. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
2010-02-15ARM: dma-mapping: provide per-cpu type map/unmap functionsRussell King
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
2009-12-14ARM: add size argument to __cpuc_flush_dcache_pageRussell King
... and rename the function since it no longer operates on just pages. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-10-02ARM: 5727/1: Pass IFSR register to do_PrefetchAbort()Kirill A. Shutemov
Instruction fault status register, IFSR, was introduced on ARMv6 to provide status information about the last insturction fault. It needed for proper prefetch abort handling. Now we have three prefetch abort model: * legacy - for CPUs before ARMv6. They doesn't provide neither IFSR nor IFAR. We simulate IFSR with section translation fault status for them to generalize code; * ARMv6 - provides IFSR, but not IFAR; * ARMv7 - provides both IFSR and IFAR. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-10-01[ARM] Don't include asm/elf.h in asm codeRussell King
asm code really wants asm/hwcap.h, so include that instead. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-10-01[ARM] Convert set_pte_ext implementions to macrosRussell King
There are actually only four separate implementations of set_pte_ext. Use assembler macros to insert code for these into the proc-*.S files. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-05-17[ARM] 5034/1: fix arm{925,926,940,946} dma_flush_range() in WT modeLennert Buytenhek
The CPU's dma_flush_range() operation needs to clean+invalidate the given memory area if the cache is in writeback mode, or do just the invalidate part if the cache is in writethrough mode, but the current proc-arm{925,926,940,946} (incorrectly) do a cache clean in the latter case. This patch fixes that. Signed-off-by: Lennert Buytenhek <buytenh@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-24[ARM] fix 48d7927bdf071d05cf5d15b816cf06b0937cb84fCatalin Marinas
The proc-*.S files have the _prefetch_abort pointer placed at the end of the processor structure but the cpu-multi32.h defines it in the second position. The patch also fixes the support for XSC3 and the MMU-less CPUs (740, 7tdmi, 940, 946 and 9tdmi). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-18Add a prefetch abort handlerPaul Brook
This patch adds a prefetch abort handler similar to the data abort one and renames the latter for consistency. Initial implementation by Paul Brook with some renaming by Catalin Marinas. Signed-off-by: Paul Brook <paul@codesourcery.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2007-10-31[ARM] Fix FIQ issue with ARM926Russell King
Jon Eibertzon writes: > We have noticed that the I-cache is disabled while waiting for > interrupt in cpu_arm926_do_idle in arch/arm/mm/proc-arm926.S > and we are curious to know why, because this causes us a great > performance hit when executing in FIQ-handlers. Is it assumed > here that every individual FIQ-handler re-enables the I-cache? The I-cache disable is an errata workaround, so the solution is to disable FIQs across the section with the I-cache disabled. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-12-13[ARM] Unuse another Linux PTE bitRussell King
L_PTE_ASID is not really required to be stored in every PTE, since we can identify it via the address passed to set_pte_at(). So, create set_pte_ext() which takes the address of the PTE to set, the Linux PTE value, and the additional CPU PTE bits which aren't encoded in the Linux PTE value. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-12-08[ARM] Handle HWCAP_VFP in VFP support codeRussell King
Don't set HWCAP_VFP in the processor support file; not only does it depend on the processor features, but it also depends on the support code being present. Therefore, only set it if the support code detects that we have a VFP coprocessor attached. Also, move the VFP handling of the coprocessor access register into the VFP support code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-11-30[ARM] Include asm/elf.h instead of asm/procinfo.hRussell King
These files want to provide/access ELF hwcap information, so should be including asm/elf.h rather than asm/procinfo.h Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-06[ARM] 3773/1: Add the HWCAP_VFP bit for the ARM926 CPUsCatalin Marinas
Patch from Catalin Marinas The ARM926EJ-S CPU has the VFP coprocessor and therefore it should be shown in the /proc/cpuinfo if CONFIG_VFP is enabled. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-07-02Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (44 commits) [ARM] 3541/2: workaround for PXA27x erratum E7 [ARM] nommu: provide a way for correct control register value selection [ARM] 3705/1: add supersection support to ioremap() [ARM] 3707/1: iwmmxt: use the generic thread notifier infrastructure [ARM] 3706/2: ep93xx: add cirrus logic edb9315a support [ARM] 3704/1: format IOP Kconfig with tabs, create more consistency [ARM] 3703/1: Add help description for ARCH_EP80219 [ARM] 3678/1: MMC: Make OMAP MMC work [ARM] 3677/1: OMAP: Update H2 defconfig [ARM] 3676/1: ARM: OMAP: Fix dmtimers and timer32k to compile on OMAP1 [ARM] Add section support to ioremap [ARM] Fix sa11x0 SDRAM selection [ARM] Set bit 4 on section mappings correctly depending on CPU [ARM] 3666/1: TRIZEPS4 [1/5] core ARM: OMAP: Multiplexing for 24xx GPMC wait pin monitoring ARM: OMAP: Fix SRAM to use MT_MEMORY instead of MT_DEVICE ARM: OMAP: Update dmtimers ARM: OMAP: Make clock variables static ARM: OMAP: Fix GPMC compilation when DEBUG is defined ARM: OMAP: Mux updates for external DMA and GPIO ...
2006-07-01Merge nommu branchRussell King
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-29[ARM] Set bit 4 on section mappings correctly depending on CPURussell King
On some CPUs, bit 4 of section mappings means "update the cache when written to". On others, this bit is required to be one, and others it's required to be zero. Finally, on ARMv6 and above, setting it turns on "no execute" and prevents speculative prefetches. With all these combinations, no one value fits all CPUs, so we have to pick a value depending on the CPU type, and the area we're mapping. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-29[ARM] nommu: provide a way for correct control register value selectionRussell King
Most MMU-based CPUs have a restriction on the setting of the data cache enable and mmu enable bits in the control register, whereby if the data cache is enabled, the MMU must also be enabled. Enabling the data cache without the MMU is an invalid combination. However, there are CPUs where the data cache can be enabled without the MMU. In order to allow these CPUs to take advantage of that, provide a method whereby each proc-*.S file defines the control regsiter value for use with nommu (with the MMU disabled.) Later on, when we add support for enabling the MMU on these devices, we can adjust the "crval" macro to also enable the data cache for nommu. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-29[ARM] Remove yucky ifdefs to print "id(wb)BRR" suffix on CPU nameRussell King
The "id(wb)BRR" suffix reports which CPU debugging options were (or were not) selected at kernel build time. Rather than have every proc-*.S file implement this, report the control register value, from which this information can be deduced. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-28[ARM] nommu: Initial uCLinux support for MMU-based CPUsHyok S. Choi
In noMMU mode, various of functions which are defined in mm/proc-*.S is not valid or needed to be avoided. i.g. switch_mm is not needed, just returns and this makes the I & D caches are valid which shows great improvement of performance including task switching and IPC. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-25Merge nommu treeRussell King
Fix merge conflict in arch/arm/mm/proc-xscale.S Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-21[ARM] Remove unnecessary asm/hardware.h includesRussell King
asm/hardware.h is not required for the majority of processor support files, ioremap support, mm initialisation, acorn IO support, nor the debug code (which picks up its machine specific includes via debug-macros.S) Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-21[ARM] nommu: Move hardware page table definitions to pgtable-hwdef.hRussell King
Move the hardware PMD and PTE page table definitions from pgtable.h into pgtable-hwdef.h, and include pgtable-hwdef.h as necessary. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-09-20[ARM] 2926/1: .proc.info - postfix section with .init for `make buildcheck`Ben Dooks
Patch from Ben Dooks The `make buildcheck` is erroneously reporting that the .proc.info list is referencing items in the .init section as it is not itself postfixed with .init Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!