2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 13:13:57 +08:00
linux-next/drivers/char
Stefani Seibold 4457d98459 kfifo: fix kfifo miss use of nozami.c
There are different types of a fifo which can not handled in C without a
lot of overhead.  So i decided to write the API as a set of macros, which
is the only way to do a kind of template meta programming without C++.
This macros handles the different types of fifos in a transparent way.

There are a lot of benefits:

- Compile time handling of the different fifo types
- Better performance (a save put or get of an integer does only generate
  9 assembly instructions on a x86)
- Type save
- Cleaner interface, the additional kfifo_..._rec() functions are gone
- Easier to use
- Less error prone
- Different types of fifos: it is now possible to define a int fifo or
  any other type. See below for an example.
- Smaller footprint for none byte type fifos
- No need of creating a second hidden variable, like in the old DEFINE_KFIFO

The API was not changed.

There are now real in place fifos where the data space is a part of the
structure.  The fifo needs now 20 byte plus the fifo space.  Dynamic
assigned or allocated create a little bit more code.

Most of the macros code will be optimized away and simple generate a
function call.  Only the really small one generates inline code.

Additionally you can now create fifos for any data type, not only the
"unsigned char" byte streamed fifos.

There is also a new kfifo_put and kfifo_get function, to handle a single
element in a fifo.  This macros generates inline code, which is lit bit
larger but faster.

I know that this kind of macros are very sophisticated and not easy to
maintain.  But i have all tested and it works as expected.  I analyzed the
output of the compiler and for the x86 the code is as good as hand written
assembler code.  For the byte stream fifo the generate code is exact the
same as with the current kfifo implementation.  For all other types of
fifos the code is smaller before, because the interface is easier to use.

The main goal was to provide an API which is very intuitive, save and easy
to use.  So linux will get now a powerful fifo API which provides all what
a developer needs.  This will save in the future a lot of kernel space,
since there is no need to write an own implementation.  Most of the device
driver developers need a fifo, and also deep kernel development will gain
benefit from this API.

Here are the results of the text section usage:

Example 1:
                        kfifo_put/_get  kfifo_in/out    current kfifo
dynamic allocated       0x000002a8      0x00000291      0x00000299
in place                0x00000291      0x0000026e      0x00000273

kfifo.c                 new             old
text section size       0x00000be5      0x000008b2

As you can see, kfifo_put/kfifo_get creates a little bit more code than
kfifo_in/kfifo_out, but it is much faster (the code is inline).

The code is complete hand crafted and optimized.  The text section size is
as small as possible.  You get all the fifo handling in only 3 kb.  This
includes type safe fix size records, dynamic records and DMA handling.

This should be the final version. All requested features are implemented.

Note: Most features of this API doesn't have any users.  All functions
which are not used in the next 9 months will be removed.  So, please adapt
your drivers and other sources as soon as possible to the new API and post
it.

This are the features which are currently not used in the kernel:

kfifo_to_user()
kfifo_from_user()
kfifo_dma_....() macros
kfifo_esize()
kfifo_recsize()
kfifo_put()
kfifo_get()

The fixed size record elements, exclude "unsigned char" fifo's and the
variable size records fifo's

This patch:

User of the kernel fifo should never bypass the API and directly access
the fifo structure.  Otherwise it will be very hard to maintain the API.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-11 08:59:23 -07:00
..
agp agp: intel-agp: do not use PCI resources before pci_enable_device() 2010-08-05 12:28:25 +10:00
hw_random Merge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6 2010-08-05 15:57:35 -07:00
ip2 tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
ipmi ipmi: print info for spmi and smbios paths like acpi and pci 2010-08-11 08:59:20 -07:00
mwave mwave: fix read buffer overflow 2009-09-24 07:21:03 -07:00
pcmcia Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2010-08-09 21:05:52 -07:00
rio include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
tpm tpm_tis: fix subsequent suspend failures 2010-07-26 10:25:45 +10:00
xilinx_hwicap of: Remove duplicate fields from of_platform_driver 2010-05-22 00:10:40 -06:00
.gitignore
amiserial.c tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
apm-emulation.c drivers: Push down BKL into various drivers 2010-05-17 05:27:41 +02:00
applicom.c drivers/char/applicom.c: use memdup_user 2010-05-27 09:12:50 -07:00
applicom.h
bfin_jtag_comm.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
bfin-otp.c const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
briq_panel.c tty: replace BKL with a new tty_lock 2010-08-10 13:47:43 -07:00
bsr.c of/address: Clean up function declarations 2010-08-01 01:42:42 -06:00
cd1865.h
consolemap.c consolemap: indentation & braces disagree - reindent 2009-01-06 15:59:30 -08:00
cp437.uni
cs5535_gpio.c drivers: Remove BKL from cs5535_gpio 2009-10-14 17:36:48 +02:00
cyclades.c tty: introduce wait_event_interruptible_tty 2010-08-10 13:47:43 -07:00
defkeymap.c_shipped
defkeymap.map
digi1.h
digiFep1.h
digiPCI.h
ds1302.c
ds1620.c drivers: Push down BKL into various drivers 2010-05-17 05:27:41 +02:00
dsp56k.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
dtlk.c drivers: Push down BKL into various drivers 2010-05-17 05:27:41 +02:00
efirtc.c efirtc: explicitly set llseek to no_llseek 2009-12-16 07:19:59 -08:00
epca.c epca: Kill the big kernel lock 2010-08-10 13:47:40 -07:00
epca.h
epcaconfig.h
generic_nvram.c drivers: Push down BKL into various drivers 2010-05-17 05:27:41 +02:00
generic_serial.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
genrtc.c drivers: Push down BKL into various drivers 2010-05-17 05:27:41 +02:00
hangcheck-timer.c hangcheck-timer: fix x86_32 bugs 2010-05-25 08:07:02 -07:00
hpet.c drivers: Push down BKL into various drivers 2010-05-17 05:27:41 +02:00
hvc_beat.c Merge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6 2010-02-25 15:38:37 -08:00
hvc_console.c hvc_console: use "*_console" nomenclature to avoid modpost warning. 2010-07-09 11:28:24 +10:00
hvc_console.h hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_irq.c hvc_console: Call free_irq() only if request_irq() was successful 2009-01-13 14:48:01 +11:00
hvc_iseries.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
hvc_iucv.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hvc_rtas.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_tile.c arch/tile: catch up on various minor cleanups. 2010-07-06 13:42:15 -04:00
hvc_udbg.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_vio.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvc_xen.c hvc_console: make the ops pointer const. 2010-02-24 14:22:32 +10:30
hvcs.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hvsi.c hvc_console: use "*_console" nomenclature to avoid modpost warning. 2010-07-09 11:28:24 +10:00
i8k.c procfs: Push down the bkl from ioctl 2010-05-17 03:06:12 +02:00
isicom.c isicom: kill off the BKL 2010-08-10 13:47:40 -07:00
istallion.c tty: introduce wait_event_interruptible_tty 2010-08-10 13:47:43 -07:00
Kconfig ramoops: add HAS_IOMEM dependency 2010-06-04 15:21:44 -07:00
keyboard.c tty: Move the vt_tty field from the vc_data into the standard tty_port 2010-08-10 13:47:42 -07:00
lp.c lp: move compat_ioctl handling into lp.c 2009-12-10 22:55:36 +01:00
Makefile tty: implement BTM as mutex instead of BKL 2010-08-10 13:47:44 -07:00
mbcs.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mbcs.h
mem.c Fix init ordering of /dev/console vs callers of modprobe 2010-08-06 09:17:02 -07:00
misc.c char: add WARN_ON() in misc_deregister() 2010-08-09 20:45:06 -07:00
mmtimer.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
moxa.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
moxa.h
mspec.c tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
mxser.c mxser: remove unnesesary NULL check 2010-08-10 13:47:45 -07:00
mxser.h
n_gsm.c drivers/char/n_gsm.c: add missing spin_unlock_irqrestore 2010-08-11 08:59:20 -07:00
n_hdlc.c tty: replace BKL with a new tty_lock 2010-08-10 13:47:43 -07:00
n_r3964.c tty: introduce wait_event_interruptible_tty 2010-08-10 13:47:43 -07:00
n_tty.c tty: Add EXTPROC support for LINEMODE 2010-08-10 13:47:39 -07:00
nozomi.c kfifo: fix kfifo miss use of nozami.c 2010-08-11 08:59:23 -07:00
nsc_gpio.c
nvram.c drivers: Push down BKL into various drivers 2010-05-17 05:27:41 +02:00
nwbutton.c
nwbutton.h
nwflash.c drivers: Push down BKL into various drivers 2010-05-17 05:27:41 +02:00
pc8736x_gpio.c drivers: Remove BKL from pc8736x_gpio 2009-10-14 17:36:52 +02:00
ppdev.c drivers/char/ppdev.c: use kasprintf 2010-05-27 09:12:50 -07:00
ps3flash.c drop unused dentry argument to ->fsync 2010-05-27 22:05:02 -04:00
pty.c tty: avoid recursive BTM in pty_close 2010-08-10 13:47:44 -07:00
ramoops.c char drivers: RAM oops/panic logger 2010-05-27 09:12:50 -07:00
random.c random: Reorder struct entropy_store to remove padding on 64bits 2010-07-31 19:58:00 +08:00
raw.c drivers: Push down BKL into various drivers 2010-05-17 05:27:41 +02:00
riscom8_reg.h
riscom8.c riscom8: kill use of lock_kernel 2010-08-10 13:47:40 -07:00
riscom8.h
rocket_int.h tty: rocketport uses different port flags to everyone else 2009-01-02 10:19:39 -08:00
rocket.c rocket: kill BKL 2010-08-10 13:47:40 -07:00
rocket.h tty: rocketport uses different port flags to everyone else 2009-01-02 10:19:39 -08:00
rtc.c sysctl: Drop & in front of every proc_handler. 2009-11-18 08:37:40 -08:00
scc.h m68k: atari - Rename "mfp" to "st_mfp" 2009-02-22 09:23:02 -08:00
scx200_gpio.c drivers: Remove BKL from scx200_gpio 2009-10-14 17:36:53 +02:00
selection.c tty: remove tty_lock_nested 2010-08-10 13:47:44 -07:00
ser_a2232.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
ser_a2232.h
ser_a2232fw.ax
ser_a2232fw.h
serial167.c tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
snsc_event.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
snsc.c
snsc.h
sonypi.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
specialix_io8.h
specialix.c tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
stallion.c stallion: prune lock_kernel calls 2010-08-10 13:47:40 -07:00
sx.c tty: replace BKL with a new tty_lock 2010-08-10 13:47:43 -07:00
sx.h
sxboards.h
sxwindow.h
synclink_gt.c tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
synclink.c tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
synclinkmp.c tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
sysrq.c sysrq,kdb: Use __handle_sysrq() for kdb's sysrq function 2010-07-21 19:27:07 -05:00
tb0219.c mips: Remove BKL from tb0219 2009-10-14 17:36:53 +02:00
tlclk.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
toshiba.c tosh: Use non bkl ioctl 2010-01-04 12:31:21 -08:00
tty_audit.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
tty_buffer.c tty: fix obsolete comment on tty_insert_flip_string_fixed_flag 2010-05-21 09:34:30 -07:00
tty_io.c tty_io: remove casts from void* 2010-08-10 13:47:44 -07:00
tty_ioctl.c tty: Add EXTPROC support for LINEMODE 2010-08-10 13:47:39 -07:00
tty_ldisc.c tty: remove tty_lock_nested 2010-08-10 13:47:44 -07:00
tty_mutex.c tty: implement BTM as mutex instead of BKL 2010-08-10 13:47:44 -07:00
tty_port.c tty: release BTM while sleeping in block_til_ready 2010-08-10 13:47:44 -07:00
uv_mmtimer.c x86, UV: Fix RTC latency bug by reading replicated cachelines 2010-01-27 11:33:53 +01:00
vc_screen.c tty: replace BKL with a new tty_lock 2010-08-10 13:47:43 -07:00
viotape.c of: Always use 'struct device.of_node' to get device node pointer. 2010-05-18 16:10:44 -06:00
virtio_console.c virtio: console: Fix crash when port is unplugged and blocked for write 2010-06-03 22:39:19 +09:30
vme_scc.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
vt_ioctl.c tty: introduce wait_event_interruptible_tty 2010-08-10 13:47:43 -07:00
vt.c tty: Move the vt_tty field from the vc_data into the standard tty_port 2010-08-10 13:47:42 -07:00