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Sonny Rao 04a85d1234 powerpc/BSR: Fix BSR to allow mmap of small BSR on 64k kernel 
On Mon, Nov 17, 2008 at 01:26:13AM -0600, Sonny Rao wrote:
> On Fri, Nov 07, 2008 at 04:28:29PM +1100, Paul Mackerras wrote:
> > Sonny Rao writes:
> >
> > > Fix the BSR driver to allow small BSR devices, which are limited to a
> > > single 4k space, on a 64k page kernel.  Previously the driver would
> > > reject the mmap since the size was smaller than PAGESIZE (or because
> > > the size was greater than the size of the device).  Now, we check for
> > > this case use remap_4k_pfn(). Also, take out code to set vm_flags,
> > > as the remap_pfn functions will do this for us.
> >
> > Thanks.
> >
> > Do we know that the BSR size will always be 4k if it's not a multiple
> > of 64k?  Is it possible that we could get 8k, 16k or 32k or BSRs?
> > If it is possible, what does the user need to be able to do?  Do they
> > just want to map 4k, or might then want to map the whole thing?
>
>
> Hi Paul, I took a look at changing the driver to reject a request for
> mapping more than a single 4k page, however the only indication we get
> of the requested size in the mmap function is the vma size, and this
> is always one page at minimum.  So, it's not possible to determine if
> the user wants one 4k page or more.  As I noted in my first response,
> there is only one case where this is even possible and I don't think
> it is a significant concern.
>
> I did notice that I left out the check to see if the user is trying to
> map more than the device length, so I fixed that.  Here's the revised
> patch.

Alright, I've reworked this now so that if we get one of these cases
where there's a bsr that's > 4k and < 64k on a 64k kernel we'll only
advertise that it is a 4k BSR to userspace.  I think this is the best
solution since user programs are only supposed to look at sysfs to
determine how much can be mapped, and libbsr does this as well.

Please consider for 2.6.31 as a fix, thanks.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-06-26 14:37:26 +10:00
..
agp Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2009-06-20 10:15:30 -07:00
hw_random MIPS: hwrng: Add TX4939 RNG driver 2009-06-17 11:06:27 +01:00
ip2 tty: rewrite the ldisc locking 2009-06-11 08:51:01 -07:00
ipmi ipmi: remove driver_data direct access of struct device 2009-06-15 21:30:27 -07:00
mwave mwave: struct device - replace bus_id with dev_name(), dev_set_name() 2009-01-06 10:44:38 -08:00
pcmcia pcmcia/cm4000: fix lock imbalance 2009-06-22 11:32:24 -07:00
rio rio: addition has higher precedence than ?: 2009-04-06 14:36:43 -07:00
tpm TPM: get_event_name stack corruption 2009-05-20 08:30:05 +10:00
xilinx_hwicap xilinx_hwicap: remove improper wording in license statement 2008-12-17 11:23:07 -08:00
.gitignore
amiserial.c trivial: typo (en|dis|avail|remove)bale -> (en|dis|avail|remove)able 2009-06-12 18:01:45 +02:00
apm-emulation.c APM emulation: Notify about all suspend events, not just APM invoked ones (v2) 2008-07-16 23:27:02 +02:00
applicom.c applicom: Auto-load applicom module when device opened. 2009-04-06 14:36:30 -07:00
applicom.h
bfin_jtag_comm.c bfin_jtag_comm: clean up printk usage 2009-06-22 11:32:23 -07:00
bfin-otp.c
briq_panel.c briq_panel: BKL pushdown 2008-06-20 14:05:55 -06:00
bsr.c powerpc/BSR: Fix BSR to allow mmap of small BSR on 64k kernel 2009-06-26 14:37:26 +10:00
cd1865.h
ChangeLog
consolemap.c consolemap: indentation & braces disagree - reindent 2009-01-06 15:59:30 -08:00
cp437.uni unicode table for cp437 2008-12-13 11:25:49 -08:00
cs5535_gpio.c Add a bunch of cycle_kernel_lock() calls 2008-06-20 14:05:53 -06:00
cyclades.c tty: rewrite the ldisc locking 2009-06-11 08:51:01 -07:00
defkeymap.c_shipped
defkeymap.map
digi1.h
digiFep1.h
digiPCI.h
ds1302.c rtc: use bcd2bin/bin2bcd 2008-10-20 08:52:41 -07:00
ds1620.c [ARM] netwinder: clean up GPIO naming 2008-12-13 09:12:07 +00:00
dsp56k.c device create: char: convert device_create_drvdata to device_create 2008-10-16 09:24:42 -07:00
dtlk.c dtlk: off by one in {read,write}_tts() 2009-06-19 16:46:06 -07:00
efirtc.c drivers/char/efirtc.c: removed duplicated #include 2008-08-04 16:59:56 -07:00
epca.c tty: rewrite the ldisc locking 2009-06-11 08:51:01 -07:00
epca.h epca: use tty_port 2008-07-20 17:12:36 -07:00
epcaconfig.h
esp.c esp: fix section mismatch warning 2009-04-07 08:31:03 -07:00
generic_nvram.c driver/char/generic_nvram: fix banner 2008-06-12 18:05:41 -07:00
generic_serial.c tty: Remove some pointless casts 2009-01-02 10:19:40 -08:00
genrtc.c genrtc: BKL pushdown 2008-06-20 14:05:57 -06:00
hangcheck-timer.c
hpet.c irq: change ACPI GSI APIs to also take a device argument 2009-04-28 12:21:17 +02:00
hvc_beat.c powerpc/cell: Use correct types in beat files 2009-01-08 16:25:16 +11:00
hvc_console.c hvc_console: Remove tty->low_latency 2009-01-16 16:15:16 +11:00
hvc_console.h powerpc: Make open count variables signed in hvcs/hvsi/hvc_console 2008-12-03 21:04:13 +11:00
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 drivers/hvc: Add missing __devexit_p() 2009-06-16 14:15:44 +10:00
hvc_iucv.c [S390] pm: hvc_iucv power management callbacks 2009-06-16 10:31:19 +02:00
hvc_rtas.c
hvc_udbg.c powerpc: udbg-based backend for hvc_console 2008-11-19 16:04:25 +11:00
hvc_vio.c drivers/hvc: Add missing __devexit_p() 2009-06-16 14:15:44 +10:00
hvc_xen.c hvc_console: Add a hangup notifier for backends 2008-10-22 10:59:54 +11:00
hvcs.c Merge commit 'origin/master' into next 2009-06-18 11:16:55 +10:00
hvsi.c hvc_console: Remove tty->low_latency on pseries backends 2009-03-11 10:44:26 +11:00
i8k.c i8k: Add Dell Vostro systems 2009-01-02 10:28:32 -08:00
isicom.c Char: isicom: fix build warning 2009-06-18 13:03:54 -07:00
istallion.c istallion: add missing __devexit marking 2009-06-19 16:46:06 -07:00
Kconfig drivers/char/rtc: disable legacy RTC driver on Blackfin systems 2009-06-18 13:03:43 -07:00
keyboard.c Input: keyboard - remove warning about raw mode not supported 2009-04-20 21:21:24 -07:00
lp.c device create: char: convert device_create_drvdata to device_create 2008-10-16 09:24:42 -07:00
Makefile tty: bfin_jtag_comm: emulate a TTY over the Blackfin EMUDAT/JTAG interface 2009-06-11 08:51:06 -07:00
mbcs.c mbcs: cdev lock_kernel() pushdown 2008-06-20 14:05:48 -06:00
mbcs.h
mem.c drivers/char/mem.c: memory_open() cleanup: lookup minor device number from devlist 2009-06-18 13:03:54 -07:00
misc.c Driver Core: misc: add nodename support for misc devices. 2009-06-15 21:30:25 -07:00
mmtimer.c mmtimer: Push BKL down into the ioctl handler 2008-07-17 11:34:49 -07:00
moxa.c Revert "char: moxa, prevent opening unavailable ports" 2009-06-22 11:24:43 -07:00
moxa.h Char: moxa, cleanup rx/tx 2008-04-30 08:29:43 -07:00
mspec.c mspec: convert nopfn to fault 2008-07-24 10:47:14 -07:00
mxser.c Remove low_latency flag setting from nozomi and mxser drivers 2009-06-24 09:55:50 -07:00
mxser.h mxser: convert large macros to functions 2008-04-30 08:29:49 -07:00
n_hdlc.c tty: n_hdlc add buffer flushing 2009-06-22 11:32:24 -07:00
n_r3964.c n_r3964: fix lock imbalance 2009-06-22 11:32:23 -07:00
n_tty.c tty: simplify buffer allocator cleanups 2009-06-11 08:51:02 -07:00
nozomi.c Remove low_latency flag setting from nozomi and mxser drivers 2009-06-24 09:55:50 -07:00
nsc_gpio.c
nvram.c [PATCH] nvram - convert PRINT_PROC to seq_file 2008-11-11 09:56:00 +00:00
nwbutton.c
nwbutton.h
nwflash.c [ARM] netwinder: clean up GPIO naming 2008-12-13 09:12:07 +00:00
pc8736x_gpio.c pc8736x_gpio: add support for PC87365 chips 2008-10-20 08:52:40 -07:00
ppdev.c ppdev: reduce kernel log spam 2009-06-18 13:03:54 -07:00
ps3flash.c ps3flash: Always read chunks of 256 KiB, and cache them 2009-06-15 16:47:27 +10:00
pty.c pty: Narrow the race on ldisc locking 2009-06-16 12:01:16 -07:00
random.c Avoid ICE in get_random_int() with gcc-3.4.5 2009-05-19 11:25:35 -07:00
raw.c Driver Core: raw: add nodename for raw devices 2009-06-15 21:30:26 -07:00
riscom8_reg.h
riscom8.c riscom8: Auto-load riscom8 module when device opened. 2009-04-06 14:36:31 -07:00
riscom8.h tty: add more tty_port fields 2008-07-20 17:12:38 -07:00
rocket_int.h tty: rocketport uses different port flags to everyone else 2009-01-02 10:19:39 -08:00
rocket.c rocket: fix test_bit parameters 2009-06-11 08:50:58 -07:00
rocket.h tty: rocketport uses different port flags to everyone else 2009-01-02 10:19:39 -08:00
rtc.c RTC: Remove the BKL. 2009-01-08 16:44:03 -07:00
scc.h m68k: atari - Rename "mfp" to "st_mfp" 2009-02-22 09:23:02 -08:00
scx200_gpio.c Add a bunch of cycle_kernel_lock() calls 2008-06-20 14:05:53 -06:00
selection.c tty: rewrite the ldisc locking 2009-06-11 08:51:01 -07:00
ser_a2232.c m68k: ser_a2232 - Kill warn_unused_result warnings 2009-01-12 20:56:39 +01:00
ser_a2232.h
ser_a2232fw.ax
ser_a2232fw.h
serial167.c tty: Remove some pointless casts 2009-01-02 10:19:40 -08:00
snsc_event.c byteorder: don't directly include linux/byteorder/generic.h 2008-05-16 12:01:45 -07:00
snsc.c device create: char: convert device_create_drvdata to device_create 2008-10-16 09:24:42 -07:00
snsc.h
sonypi.c Rationalize fasync return values 2009-03-16 08:34:35 -06:00
specialix_io8.h tty: add more tty_port fields 2008-07-20 17:12:38 -07:00
specialix.c specialix: Auto-load specialix module when device opened. 2009-04-06 14:36:31 -07:00
stallion.c tty: Add carrier processing on close to the tty_port core 2009-06-11 08:50:56 -07:00
sx.c sx.c: avoid referencing freed memory if copy_from_user() fails 2009-02-20 17:57:49 -08:00
sx.h
sxboards.h
sxwindow.h
synclink_gt.c synclink_gt: fix transmit race and timeout 2009-06-24 09:55:50 -07:00
synclink.c tty: Add carrier processing on close to the tty_port core 2009-06-11 08:50:56 -07:00
synclinkmp.c tty: Add carrier processing on close to the tty_port core 2009-06-11 08:50:56 -07:00
sysrq.c kexec: sysrq: simplify sysrq-c handler 2009-06-18 13:03:59 -07:00
tb0219.c Add a bunch of cycle_kernel_lock() calls 2008-06-20 14:05:53 -06:00
tlclk.c tlckl: BKL pushdown 2008-06-20 14:05:51 -06:00
toshiba.c toshiba: use ioremap_cached 2008-04-30 23:15:34 +02:00
tty_audit.c tty: remove buffer special casing 2009-06-11 08:51:02 -07:00
tty_buffer.c tty: split the buffering from tty_io 2008-10-13 09:51:40 -07:00
tty_io.c tty: fix sanity check 2009-06-16 12:01:16 -07:00
tty_ioctl.c tty: fix unused warning when TCGETX is not defined 2009-06-16 12:01:16 -07:00
tty_ldisc.c ldisc: debug aids 2009-06-16 12:01:16 -07:00
tty_port.c tty: fix tty_port_block_til_ready waiting 2009-06-24 09:55:50 -07:00
vc_screen.c vcs: hook sysfs devices into object lifetime instead of "binding" 2009-03-24 16:38:26 -07:00
viotape.c tape: beyond ARRAY_SIZE of viocd_diskinfo 2009-06-02 10:32:34 +10:00
virtio_console.c virtio: find_vqs/del_vqs virtio operations 2009-06-12 22:16:36 +09:30
vme_scc.c m68k: vme_scc - Kill warn_unused_result warnings 2009-01-12 20:56:38 +01:00
vr41xx_giu.c drivers/char: use nr_irqs 2008-10-16 16:52:05 +02:00
vt_ioctl.c vt_ioctl: fix lock imbalance 2009-06-22 11:32:24 -07:00
vt.c console: make blank timeout value a boot option 2009-06-16 19:47:52 -07:00