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| author | Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | 2005-07-30 01:15:00 +0200 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2005-08-27 00:09:24 +0200 |
| commit | 4db8699bcfa8faddb5727b1cb010a4d9b8a42e8c (patch) | |
| tree | eb4cb14927ed9cf4507f875cd69fe35f87b3b3bc /include/asm-ia64/pal.h | |
| parent | [PATCH] hppfs: fix symlink error path (diff) | |
| download | linux-4db8699bcfa8faddb5727b1cb010a4d9b8a42e8c.tar.xz linux-4db8699bcfa8faddb5727b1cb010a4d9b8a42e8c.zip | |
[IA64] Add ACPI based P-state support
Patch to support P-state transitions on ia64. This driver is based on ACPI,
and uses the ACPI processor driver interface to find out the P-state support
information for the processor. This driver plugs into generic cpufreq
infrastructure.
Once this driver is loaded successfully, ondemand/userspace governor can be
used to change the CPU frequency dynamically based on load or on request from
userspace process.
Refer :
ACPI specification -
http://www.acpi.info
P-state related PAL calls -
http://developer.intel.com/design/itanium/downloads/24869909.pdf
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'include/asm-ia64/pal.h')
| -rw-r--r-- | include/asm-ia64/pal.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/include/asm-ia64/pal.h b/include/asm-ia64/pal.h index 2303a10ee595..e828377ad295 100644 --- a/include/asm-ia64/pal.h +++ b/include/asm-ia64/pal.h @@ -75,6 +75,8 @@ #define PAL_CACHE_READ 259 /* read tag & data of cacheline for diagnostic testing */ #define PAL_CACHE_WRITE 260 /* write tag & data of cacheline for diagnostic testing */ #define PAL_VM_TR_READ 261 /* read contents of translation register */ +#define PAL_GET_PSTATE 262 /* get the current P-state */ +#define PAL_SET_PSTATE 263 /* set the P-state */ #ifndef __ASSEMBLY__ @@ -1111,6 +1113,25 @@ ia64_pal_halt_info (pal_power_mgmt_info_u_t *power_buf) return iprv.status; } +/* Get the current P-state information */ +static inline s64 +ia64_pal_get_pstate (u64 *pstate_index) +{ + struct ia64_pal_retval iprv; + PAL_CALL_STK(iprv, PAL_GET_PSTATE, 0, 0, 0); + *pstate_index = iprv.v0; + return iprv.status; +} + +/* Set the P-state */ +static inline s64 +ia64_pal_set_pstate (u64 pstate_index) +{ + struct ia64_pal_retval iprv; + PAL_CALL_STK(iprv, PAL_SET_PSTATE, pstate_index, 0, 0); + return iprv.status; +} + /* Cause the processor to enter LIGHT HALT state, where prefetching and execution are * suspended, but cache and TLB coherency is maintained. */ |