提交 · b13de4b7adeb7a5e37a5aa78d5a4926c3cd4e131 · openeuler / Kernel

12 4月, 2017 2 次提交

s390/spinlock: remove compare and delay instruction · b13de4b7

由 Martin Schwidefsky 提交于 3月 24, 2017

The CAD instruction never worked quite as expected for the spinlock
code. It has been disabled by default with git commit 61b0b016,
if the "cad" kernel parameter is specified it is enabled for both user
space and the spinlock code. Leave the option to enable the instruction
for user space but remove it from the spinlock code.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

b13de4b7

s390/spinlock: use atomic primitives for spinlocks · 02c503ff

由 Martin Schwidefsky 提交于 11月 28, 2016

Add a couple more __atomic_xxx function to atomic_ops.h and use them
to replace the compare-and-swap inlines in the spinlock code. This
changes the type of the lock value from unsigned int to int.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

02c503ff

05 4月, 2017 7 次提交

s390/cpumf: simplify detection of guest samples · df26c2e8

由 Martin Schwidefsky 提交于 4月 04, 2017

There are three different code levels in regard to the identification
of guest samples. They differ in the way the LPP instruction is used.

1) Old kernels without the LPP instruction. The guest program parameter
   is always zero.
2) Newer kernels load the process pid into the program parameter with LPP.
   The guest program parameter is non-zero if the guest executes in a
   process != idle.
3) The latest kernels load ((1UL << 31) | pid) with LPP to make the value
   non-zero even for the idle task. The guest program parameter is non-zero
   if the guest is running.

All kernels load the process pid to CR4 on context switch. The CPU sampling
code uses the value in CR4 to decide between guest and host samples in case
the guest program parameter is zero. The three cases:

1) CR4==pid, gpp==0
2) CR4==pid, gpp==pid
3) CR4==pid, gpp==((1UL << 31) | pid)

The load-control instruction to load the pid into CR4 is expensive and the
goal is to remove it. To distinguish the host CR4 from the guest pid for
the idle process the maximum value 0xffff for the PASN is used.
This adds a fourth case for a guest OS with an updated kernel:

4) CR4==0xffff, gpp=((1UL << 31) | pid)

The host kernel will have CR4==0xffff and will use (gpp!=0 || CR4!==0xffff)
to identify guest samples. This works nicely with all 4 cases, the only
possible issue would be a guest with an old kernel (gpp==0) and a process
pid of 0xffff. Well, don't do that..
Suggested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

df26c2e8

s390/pci: remove forward declaration · 561ecb0c

由 Sebastian Ott 提交于 3月 27, 2017

Move a struct definition to get rid of a forward declaration.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

561ecb0c

s390/pci: increase the PCI_NR_FUNCTIONS default · b18601b0

由 Sebastian Ott 提交于 3月 27, 2017

Users complained that they are hitting the limit of 64 functions (some
physical functions can spawn lots of virtual functions). Double the
default limit. With the latest savings in static data usage this
increases the image size by only 520 bytes.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

b18601b0

s390/pci: reduce iomap size (even more) · b0c8ce89

由 Sebastian Ott 提交于 3月 27, 2017

Commit c506fff3 ("s390/pci: resize iomap") reduced the iomap
to NR_FUNCTIONS * PCI_BAR_COUNT elements. Since we only support
functions with 64bit BARs we can cut that number in half.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

b0c8ce89

s390/pci: remove duplicated define · 4e0cca7d

由 Sebastian Ott 提交于 3月 27, 2017

Address space identifiers are already defined in <asm/pci_insn.h>.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

4e0cca7d

s390/pci: remove unused function · 02f5cb9f

由 Sebastian Ott 提交于 3月 27, 2017

barsize was never used. Get rid of it.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

02f5cb9f

s390: use 64-bit lctlg to load task pid to cr4 on context switch · cab36c26

由 Martin Schwidefsky 提交于 4月 03, 2017

The 32-bit lctl instruction is quite a bit slower than the 64-bit
counter part lctlg. Use the faster instruction.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

cab36c26

31 3月, 2017 24 次提交

Merge branch 'vfio-ccw-for-martin' of... · 6fb81d69

由 Martin Schwidefsky 提交于 3月 31, 2017

Merge branch 'vfio-ccw-for-martin' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features

Pull vfio-ccw branch to add the basic channel I/O passthrough
intrastructure based on vfio.

The focus is on supporting dasd-eckd(cu_type/dev_type = 0x3990/0x3390)
as the target device.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

6fb81d69

MAINTAINERS: Add vfio-ccw maintainers · 1877888d