From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Wang Subject: [PATCH v3 02/11] x86/intel_pstate: add some calculation related support Date: Thu, 11 Jun 2015 16:26:29 +0800 Message-ID: <1434011189-16804-1-git-send-email-wei.w.wang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org, jbeulich@suse.com Cc: andrew.cooper3@citrix.com, Wei Wang List-Id: xen-devel@lists.xenproject.org The added calculation related functions will be used in the intel_pstate.c. They are copied from the kernel(commit 2418f4f2, f3002134, eb18cba7). Signed-off-by: Wei Wang --- xen/include/asm-x86/div64.h | 72 +++++++++++++++++++++++++++++++++++++++++++++ xen/include/xen/kernel.h | 12 ++++++++ 2 files changed, 84 insertions(+) diff --git a/xen/include/asm-x86/div64.h b/xen/include/asm-x86/div64.h index dd49f64..daeb065 100644 --- a/xen/include/asm-x86/div64.h +++ b/xen/include/asm-x86/div64.h @@ -11,4 +11,76 @@ __rem; \ }) +static inline uint64_t div_u64_rem(uint64_t dividend, uint32_t divisor, + uint32_t *remainder) +{ + *remainder = do_div(dividend, divisor); + return dividend; +} + +static inline uint64_t div_u64(uint64_t dividend, uint32_t divisor) +{ + uint32_t remainder; + return div_u64_rem(dividend, divisor, &remainder); +} + +/* + * div64_u64 - unsigned 64bit divide with 64bit divisor + * @dividend: 64bit dividend + * @divisor: 64bit divisor + * + * This implementation is a modified version of the algorithm proposed + * by the book 'Hacker's Delight'. The original source and full proof + * can be found here and is available for use without restriction. + * + * 'http://www.hackersdelight.org/HDcode/newCode/divDouble.c.txt' + */ +static inline uint64_t div64_u64(uint64_t dividend, uint64_t divisor) +{ + uint32_t high = divisor >> 32; + uint64_t quot; + + if (high == 0) { + quot = div_u64(dividend, divisor); + } else { + int n = 1 + fls(high); + quot = div_u64(dividend >> n, divisor >> n); + + if (quot != 0) + quot--; + if ((dividend - quot * divisor) >= divisor) + quot++; + } + return quot; +} + +static inline int64_t div_s64_rem(int64_t dividend, int32_t divisor, + int32_t *remainder) +{ + int64_t quotient; + + if (dividend < 0) { + quotient = div_u64_rem(-dividend, ABS(divisor), + (uint32_t *)remainder); + *remainder = -*remainder; + if (divisor > 0) + quotient = -quotient; + } else { + quotient = div_u64_rem(dividend, ABS(divisor), + (uint32_t *)remainder); + if (divisor < 0) + quotient = -quotient; + } + return quotient; +} + +/* + * div_s64 - signed 64bit divide with 32bit divisor + */ +static inline int64_t div_s64(int64_t dividend, int32_t divisor) +{ + int32_t remainder; + return div_s64_rem(dividend, divisor, &remainder); +} + #endif diff --git a/xen/include/xen/kernel.h b/xen/include/xen/kernel.h index 548b64d..bfdcdb6 100644 --- a/xen/include/xen/kernel.h +++ b/xen/include/xen/kernel.h @@ -42,6 +42,18 @@ #define MIN(x,y) ((x) < (y) ? (x) : (y)) #define MAX(x,y) ((x) > (y) ? (x) : (y)) +/* + * clamp_t - return a value clamped to a given range using a given type + * @type: the type of variable to use + * @val: current value + * @lo: minimum allowable value + * @hi: maximum allowable value + * + * This macro does no typechecking and uses temporary variables of type + * 'type' to make all the comparisons. + */ +#define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi) + /** * container_of - cast a member of a structure out to the containing structure * -- 1.9.1