From 4db8699bcfa8faddb5727b1cb010a4d9b8a42e8c Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 29 Jul 2005 16:15:00 -0700 Subject: [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 Signed-off-by: Tony Luck --- include/asm-ia64/pal.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'include/asm-ia64/pal.h') diff --git a/include/asm-ia64/pal.h b/include/asm-ia64/pal.h index 2303a10ee59..e828377ad29 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. */ -- cgit v1.2.3