linux/drivers/misc
Vaibhav Jain 1b5df59e50 cxl: Fix possible idr warning when contexts are released
An idr warning is reported when a context is release after the capi card
is unbound from the cxl driver via sysfs. Below are the steps to
reproduce:

1. Create multiple afu contexts in an user-space application using libcxl.
2. Unbind capi card from cxl using command of form
   echo <capi-card-pci-addr> > /sys/bus/pci/drivers/cxl-pci/unbind
3. Exit/kill the application owning afu contexts.

After above steps a warning message is usually seen in the kernel logs
of the form "idr_remove called for id=<context-id> which is not
allocated."

This is caused by the function cxl_release_afu which destroys the
contexts_idr table. So when a context is release no entry for context pe
is found in the contexts_idr table and idr code prints this warning.

This patch fixes this issue by increasing & decreasing the ref-count on
the afu device when a context is initialized or when its freed
respectively. This prevents the afu from being released until all the
afu contexts have been released. The patch introduces two new functions
namely cxl_afu_get/put that manage the ref-count on the afu device.

Also the patch removes code inside cxl_dev_context_init that increases ref
on the afu device as its guaranteed to be alive during this function.

Reported-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-11-24 14:21:27 +11:00
..
altera-stapl drivers/misc/altera-stapl/altera.c: remove extraneous KERN_INFO prefix 2015-06-25 17:00:38 -07:00
c2port drivers: misc: Drop unlikely before IS_ERR(_OR_NULL) 2015-09-29 15:11:40 +02:00
cb710
cxl cxl: Fix possible idr warning when contexts are released 2015-11-24 14:21:27 +11:00
echo
eeprom - New Device Support 2015-11-06 10:23:50 -08:00
genwqe misc: genwqe: fix a comment typo 2015-10-04 12:57:15 +01:00
ibmasm
lis3lv02d spi: Drop owner assignment from spi_drivers 2015-10-28 10:30:17 +09:00
mei char/misc drivers for 4.4-rc1 2015-11-04 22:15:15 -08:00
mic misc: mic/scif: fix error code in scif_create_remote_lookup() 2015-10-17 21:49:48 -07:00
sgi-gru misc: sgi-gru: fix return of error 2015-10-04 12:55:59 +01:00
sgi-xp mm: rename alloc_pages_exact_node() to __alloc_pages_node() 2015-09-08 15:35:28 -07:00
ti-st ti-st: use worker instead of calling st_int_write in wake up 2015-09-20 22:52:13 -07:00
vmw_vmci misc/vmw_vmci: use kmemdup rather than duplicating its implementation 2015-09-20 19:27:58 -07:00
ad525x_dpot-i2c.c misc: ad525x_dpot: Remove unnecessary MODULE_ALIAS() 2015-09-20 19:33:29 -07:00
ad525x_dpot-spi.c spi: Drop owner assignment from spi_drivers 2015-10-28 10:30:17 +09:00
ad525x_dpot.c ad525x_dpot:Remove break after return 2015-01-12 05:04:12 -08:00
ad525x_dpot.h
apds990x.c misc: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
apds9802als.c
arm-charlcd.c
atmel_tclib.c misc: atmel_tclib: get and use slow clock 2015-10-06 12:33:14 +02:00
atmel-ssc.c Char/Misc driver patches for 3.19-rc1 2014-12-14 16:43:47 -08:00
bh1770glc.c misc: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
bh1780gli.c misc: bh1780: Add module aliases 2015-03-16 21:10:28 +01:00
bmp085-i2c.c misc: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
bmp085-spi.c spi: Drop owner assignment from spi_drivers 2015-10-28 10:30:17 +09:00
bmp085.c
bmp085.h
cs5535-mfgpt.c
ds1682.c misc: ds1682: clean up ds1682_eeprom_read() and ds1682_eeprom_write() 2015-08-05 13:53:39 -07:00
dummy-irq.c
enclosure.c enclosure: fix WARN_ON removing an adapter in multi-path devices 2015-03-31 08:53:36 +03:00
fsa9480.c
hmc6352.c
hpilo.c misc: hpilo: Change e-mail address from hp.com to hpe.com 2015-10-04 12:42:33 +01:00
hpilo.h
ics932s401.c
ioc4.c misc: ioc4: simplify wave period measurement in clock_calibrate 2015-01-12 05:04:11 -08:00
isl29003.c misc: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
isl29020.c
Kconfig VMware balloon: Enable notification via VMCI 2015-10-04 12:59:11 +01:00
kgdbts.c drivers/misc: make kgdbts.c slightly more explicitly non-modular 2015-09-20 19:32:35 -07:00
lattice-ecp3-config.c spi: Drop owner assignment from spi_drivers 2015-10-28 10:30:17 +09:00
lkdtm.c lkdtm: fix ACCESS_USERSPACE test 2015-10-29 09:02:16 +09:00
Makefile ARM: qcom: Add coincell charger driver 2015-07-29 13:37:18 -07:00
pch_phub.c
phantom.c
pti.c
qcom-coincell.c ARM: qcom: Add coincell charger driver 2015-07-29 13:37:18 -07:00
spear13xx_pcie_gadget.c spear13xx_pcie_gadget: use per-attribute show and store methods 2015-10-13 22:17:40 -07:00
sram.c misc: sram: partition base address belongs to __iomem space 2015-10-18 19:00:36 -07:00
ti_dac7512.c spi: Drop owner assignment from spi_drivers 2015-10-28 10:30:17 +09:00
tifm_7xx1.c misc: tifm: match return type of wait_for_completion_timeout 2015-03-25 11:36:38 +01:00
tifm_core.c
tsl2550.c misc: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
vexpress-syscfg.c
vmw_balloon.c mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM 2015-11-06 17:50:42 -08:00