#ifndef _UAPI_ASM_GENERIC_IOCTL_H
#define _UAPI_ASM_GENERIC_IOCTL_H
/* ioctl command encoding: 32 bits total, command in lower 16 bits,
* size of the parameter structure in the lower 14 bits of the
* upper 16 bits.
* Encoding the size of the parameter structure in the ioctl request
* is useful for catching programs compiled with old versions
* and to avoid overwriting user space outside the user buffer area.
* The highest 2 bits are reserved for indicating the ``access mode''.
* NOTE: This limits the max parameter size to 16kB -1 !
*/
/*
* The following is for compatibility across the various Linux
* platforms. The generic ioctl numbering scheme doesn't really enforce
* a type field. De facto, however, the top 8 bits of the lower 16
* bits are indeed used as a type field, so we might just as well make
* this explicit here. Please be sure to use the decoding macros
* below from now on.
*/
#define _IOC_NRBITS 8
#define _IOC_TYPEBITS 8
/*
* Let any architecture override either of the following before
* including this file.
*/
#ifndef _IOC_SIZEBITS
# define _IOC_SIZEBITS 14
#endif
#ifndef _IOC_DIRBITS
# define _IOC_DIRBITS 2
#endif
#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1)
#define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1)
#define _IOC_NRSHIFT 0
#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
/*
* Direction bits, which any architecture can choose to override
* before including this file.
*/
#ifndef _IOC_NONE
# define _IOC_NONE 0U
#endif
#ifndef _IOC_WRITE
# define _IOC_WRITE 1U
#endif
#ifndef _IOC_READ
# define _IOC_READ 2U
#endif
#define _IOC(dir,type,nr,size) \
(((dir) << _IOC_DIRSHIFT) | \
((type) << _IOC_TYPESHIFT) | \
((nr) << _IOC_NRSHIFT) | \
((size) << _IOC_SIZESHIFT))
#ifndef __KERNEL__
#define _IOC_TYPECHECK(t) (sizeof(t))
#endif
/* used to create numbers */
#define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0)
#define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)))
#define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
#define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
#define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size))
#define _IOW_BAD(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
#define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
/* used to decode ioctl numbers.. */
#define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
#define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
#define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
#define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
/* ...and for the drivers/sound files... */
#define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT)
#define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT)
#define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
#define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT)
#define IOCSIZE_SHIFT (_IOC_SIZESHIFT)
#endif /* _UAPI_ASM_GENERIC_IOCTL_H */
reset?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>reset/oxsemi,ox820.h
cpufreq: intel_pstate: Disable energy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.
This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.
It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.
On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.
Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.
There are several ways to address this problem.
First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.
Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.
Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".
Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: 4.6+ <stable@vger.kernel.org> # 4.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>