2b94c69d1d
3 Commits
| Author | SHA1 | Message | Date | |
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Bill Paul
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2b94c69d1d |
Continue my efforts to imitate Windows as closely as possible by
attempting to duplicate Windows spinlocks. Windows spinlocks differ from FreeBSD spinlocks in the way they block preemption. FreeBSD spinlocks use critical_enter(), which masks off _all_ interrupts. This prevents any other threads from being scheduled, but it also prevents ISRs from running. In Windows, preemption is achieved by raising the processor IRQL to DISPATCH_LEVEL, which prevents other threads from preempting you, but does _not_ prevent device ISRs from running. (This is essentially what Solaris calls dispatcher locks.) The Windows spinlock itself (kspin_lock) is just an integer value which is atomically set when you acquire the lock and atomically cleared when you release it. FreeBSD doesn't have IRQ levels, so we have to cheat a little by using thread priorities: normal thread priority is PASSIVE_LEVEL, lowest interrupt thread priority is DISPATCH_LEVEL, highest thread priority is DEVICE_LEVEL (PI_REALTIME) and critical_enter() is HIGH_LEVEL. In practice, only PASSIVE_LEVEL and DISPATCH_LEVEL matter to us. The immediate benefit of all this is that I no longer have to rely on a mutex pool. Now, I'm sure many people will be seized by the urge to criticize me for doing an end run around our own spinlock implementation, but it makes more sense to do it this way. Well, it does to me anyway. Overview of the changes: - Properly implement hal_lock(), hal_unlock(), hal_irql(), hal_raise_irql() and hal_lower_irql() so that they more closely resemble their Windows counterparts. The IRQL is determined by thread priority. - Make ntoskrnl_lock_dpc() and ntoskrnl_unlock_dpc() do what they do in Windows, which is to atomically set/clear the lock value. These routines are designed to be called from DISPATCH_LEVEL, and are actually half of the work involved in acquiring/releasing spinlocks. - Add FASTCALL1(), FASTCALL2() and FASTCALL3() macros/wrappers that allow us to call a _fastcall function in spite of the fact that our version of gcc doesn't support __attribute__((__fastcall__)) yet. The macros take 1, 2 or 3 arguments, respectively. We need to call hal_lock(), hal_unlock() etc... ourselves, but can't really invoke the function directly. I could have just made the underlying functions native routines and put _fastcall wrappers around them for the benefit of Windows binaries, but that would create needless bloat. - Remove ndis_mtxpool and all references to it. We don't need it anymore. - Re-implement the NdisSpinLock routines so that they use hal_lock() and friends like they do in Windows. - Use the new spinlock methods for handling lookaside lists and linked list updates in place of the mutex locks that were there before. - Remove mutex locking from ndis_isr() and ndis_intrhand() since they're already called with ndis_intrmtx held in if_ndis.c. - Put ndis_destroy_lock() code under explicit #ifdef notdef/#endif. It turns out there are some drivers which stupidly free the memory in which their spinlocks reside before calling ndis_destroy_lock() on them (touch-after-free bug). The ADMtek wireless driver is guilty of this faux pas. (Why this doesn't clobber Windows I have no idea.) - Make NdisDprAcquireSpinLock() and NdisDprReleaseSpinLock() into real functions instead of aliasing them to NdisAcaquireSpinLock() and NdisReleaseSpinLock(). The Dpr routines use KeAcquireSpinLockAtDpcLevel() level and KeReleaseSpinLockFromDpcLevel(), which acquires the lock without twiddling the IRQL. - In ndis_linksts_done(), do _not_ call ndis_80211_getstate(). Some drivers may call the status/status done callbacks as the result of setting an OID: ndis_80211_getstate() gets OIDs, which means we might cause the driver to recursively access some of its internal structures unexpectedly. The ndis_ticktask() routine will call ndis_80211_getstate() for us eventually anyway. - Fix the channel setting code a little in ndis_80211_setstate(), and initialize the channel to IEEE80211_CHAN_ANYC. (The Microsoft spec says you're not supposed to twiddle the channel in BSS mode; I may need to enforce this later.) This fixes the problems I was having with the ADMtek adm8211 driver: we were setting the channel to a non-standard default, which would cause it to fail to associate in BSS mode. - Use hal_raise_irql() to raise our IRQL to DISPATCH_LEVEL when calling certain miniport routines, per the Microsoft documentation. I think that's everything. Hopefully, other than fixing the ADMtek driver, there should be no apparent change in behavior. |
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Bill Paul
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ece759a4da |
The definition for __stdcall logically belongs in pe_var.h, but
the definitions for NDIS_BUS_SPACE_IO and NDIS_BUS_SPACE_MEM logically belong in hal_var.h. At least, that's my story, and I'm sticking to it. Also, remove definition of __stdcall from if_ndis.c now that it's pulled in from pe_var.h. |
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Bill Paul
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c854fc1092 |
Commit the first cut of Project Evil, also known as the NDISulator.
Yes, it's what you think it is. Yes, you should run away now. This is a special compatibility module for allowing Windows NDIS miniport network drivers to be used with FreeBSD/x86. This provides _binary_ NDIS compatibility (not source): you can run NDIS driver code, but you can't build it. There are three main parts: sys/compat/ndis: the NDIS compat API, which provides binary compatibility functions for many routines in NDIS.SYS, HAL.dll and ntoskrnl.exe in Windows (these are the three modules that most NDIS miniport drivers use). The compat module also contains a small PE relocator/dynalinker which relocates the Windows .SYS image and then patches in our native routines. sys/dev/if_ndis: the if_ndis driver wrapper. This module makes use of the ndis compat API and can be compiled with a specially prepared binary image file (ndis_driver_data.h) containing the Windows .SYS image and registry key information parsed out of the accompanying .INF file. Once if_ndis.ko is built, it can be loaded and unloaded just like a native FreeBSD kenrel module. usr.sbin/ndiscvt: a special utility that converts foo.sys and foo.inf into an ndis_driver_data.h file that can be compiled into if_ndis.o. Contains an .inf file parser graciously provided by Matt Dodd (and mercilessly hacked upon by me) that strips out device ID info and registry key info from a .INF file and packages it up with a binary image array. The ndiscvt(8) utility also does some manipulation of the segments within the .sys file to make life easier for the kernel loader. (Doing the manipulation here saves the kernel code from having to move things around later, which would waste memory.) ndiscvt is only built for the i386 arch. Only files.i386 has been updated, and none of this is turned on in GENERIC. It should probably work on pc98. I have no idea about amd64 or ia64 at this point. This is still a work in progress. I estimate it's about %85 done, but I want it under CVS control so I can track subsequent changes. It has been tested with exactly three drivers: the LinkSys LNE100TX v4 driver (Lne100v4.sys), the sample Intel 82559 driver from the Windows DDK (e100bex.sys) and the Broadcom BCM43xx wireless driver (bcmwl5.sys). It still needs to have a net80211 stuff added to it. To use it, you would do something like this: # cd /sys/modules/ndis # make; make load # cd /sys/modules/if_ndis # ndiscvt -i /path/to/foo.inf -s /path/to/foo.sys -o ndis_driver_data.h # make; make load # sysctl -a | grep ndis All registry keys are mapped to sysctl nodes. Sometimes drivers refer to registry keys that aren't mentioned in foo.inf. If this happens, the NDIS API module creates sysctl nodes for these keys on the fly so you can tweak them. An example usage of the Broadcom wireless driver would be: # sysctl hw.ndis0.EnableAutoConnect=1 # sysctl hw.ndis0.SSID="MY_SSID" # sysctl hw.ndis0.NetworkType=0 (0 for bss, 1 for adhoc) # ifconfig ndis0 <my ipaddr> netmask 0xffffff00 up Things to be done: - get rid of debug messages - add in ndis80211 support - defer transmissions until after a status update with NDIS_STATUS_CONNECTED occurs - Create smarter lookaside list support - Split off if_ndis_pci.c and if_ndis_pccard.c attachments - Make sure PCMCIA support works - Fix ndiscvt to properly parse PCMCIA device IDs from INF files - write ndisapi.9 man page |