| Message ID | 20230803131918.53727-1-andriy.shevchenko@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v4,1/1] drm/i915: Move abs_diff() to math.h | expand |
On Thu, Aug 03, 2023 at 10:24:46AM -0700, Andrew Morton wrote: > On Thu, 3 Aug 2023 16:19:18 +0300 Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: ... > > +#define abs_diff(a, b) ({ \ > > + typeof(a) __a = (a); \ > > + typeof(b) __b = (b); \ > > + (void)(&__a == &__b); \ > > + __a > __b ? (__a - __b) : (__b - __a); \ > > +}) > > Can we document it please? > > Also, the open-coded type comparison could be replaced with __typecheck()? > > And why the heck isn't __typecheck() in typecheck.h, to be included by > minmax.h. > > etcetera. Sigh. I'll grab it, but please at least send along some > kerneldoc? Sure and thank you!
From: Andrew Morton > Sent: 03 August 2023 18:25 > > On Thu, 3 Aug 2023 16:19:18 +0300 Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > > abs_diff() belongs to math.h. Move it there. > > This will allow others to use it. > > > > ... > > > > --- a/include/linux/math.h > > +++ b/include/linux/math.h > > @@ -155,6 +155,13 @@ __STRUCT_FRACT(u32) > > __builtin_types_compatible_p(typeof(x), unsigned type), \ > > ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other) > > > > +#define abs_diff(a, b) ({ \ > > + typeof(a) __a = (a); \ > > + typeof(b) __b = (b); \ > > + (void)(&__a == &__b); \ > > + __a > __b ? (__a - __b) : (__b - __a); \ > > +}) > > Can we document it please? > > Also, the open-coded type comparison could be replaced with __typecheck()? > > And why the heck isn't __typecheck() in typecheck.h, to be included by > minmax.h. And why would you want to use __typecheck() anyway? It pretty much isn't the test you are looking for. If you are trying to explicitly avoid converting negative value to large positive unsigned ones then you want something like: is_signed_type(typeof(a)) == is_signed_type(typeof(b)) but it isn't even that simple :-) David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c index 6b2d8a1e2aa9..290e856fe9e9 100644 --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c @@ -21,6 +21,7 @@ * DEALINGS IN THE SOFTWARE. */ +#include <linux/math.h> #include <linux/string_helpers.h> #include "i915_reg.h" diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h index ba62eb5d7c51..04e6810954b2 100644 --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.h +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.h @@ -29,13 +29,6 @@ #include "intel_wakeref.h" -/*FIXME: Move this to a more appropriate place. */ -#define abs_diff(a, b) ({ \ - typeof(a) __a = (a); \ - typeof(b) __b = (b); \ - (void) (&__a == &__b); \ - __a > __b ? (__a - __b) : (__b - __a); }) - enum tc_port; struct drm_i915_private; struct intel_atomic_state; diff --git a/drivers/gpu/ipu-v3/ipu-image-convert.c b/drivers/gpu/ipu-v3/ipu-image-convert.c index af1612044eef..841316582ea9 100644 --- a/drivers/gpu/ipu-v3/ipu-image-convert.c +++ b/drivers/gpu/ipu-v3/ipu-image-convert.c @@ -7,7 +7,10 @@ #include <linux/interrupt.h> #include <linux/dma-mapping.h> +#include <linux/math.h> + #include <video/imx-ipu-image-convert.h> + #include "ipu-prv.h" /* @@ -543,7 +546,7 @@ static void find_best_seam(struct ipu_image_convert_ctx *ctx, unsigned int in_pos; unsigned int in_pos_aligned; unsigned int in_pos_rounded; - unsigned int abs_diff; + unsigned int diff; /* * Tiles in the right row / bottom column may not be allowed to @@ -575,15 +578,11 @@ static void find_best_seam(struct ipu_image_convert_ctx *ctx, (in_edge - in_pos_rounded) % in_burst) continue; - if (in_pos < in_pos_aligned) - abs_diff = in_pos_aligned - in_pos; - else - abs_diff = in_pos - in_pos_aligned; - - if (abs_diff < min_diff) { + diff = abs_diff(in_pos, in_pos_aligned); + if (diff < min_diff) { in_seam = in_pos_rounded; out_seam = out_pos; - min_diff = abs_diff; + min_diff = diff; } } diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 3dc14dcb01ca..0ead88c5a19a 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -222,16 +222,11 @@ static inline int calculate_baud_abs_diff(struct uart_port *port, unsigned int baud, unsigned int mode) { unsigned int n = port->uartclk / (mode * baud); - int abs_diff; if (n == 0) n = 1; - abs_diff = baud - (port->uartclk / (mode * n)); - if (abs_diff < 0) - abs_diff = -abs_diff; - - return abs_diff; + return abs_diff(baud, port->uartclk / (mode * n)); } /* diff --git a/drivers/video/fbdev/core/svgalib.c b/drivers/video/fbdev/core/svgalib.c index 9e01322fabe3..2cba158888ea 100644 --- a/drivers/video/fbdev/core/svgalib.c +++ b/drivers/video/fbdev/core/svgalib.c @@ -14,6 +14,7 @@ #include <linux/kernel.h> #include <linux/string.h> #include <linux/fb.h> +#include <linux/math.h> #include <linux/svga.h> #include <asm/types.h> #include <asm/io.h> @@ -372,12 +373,6 @@ EXPORT_SYMBOL(svga_get_caps); * F_VCO = (F_BASE * M) / N * F_OUT = F_VCO / (2^R) */ - -static inline u32 abs_diff(u32 a, u32 b) -{ - return (a > b) ? (a - b) : (b - a); -} - int svga_compute_pll(const struct svga_pll *pll, u32 f_wanted, u16 *m, u16 *n, u16 *r, int node) { u16 am, an, ar; diff --git a/include/linux/math.h b/include/linux/math.h index 2d388650c556..336e3e3678e7 100644 --- a/include/linux/math.h +++ b/include/linux/math.h @@ -155,6 +155,13 @@ __STRUCT_FRACT(u32) __builtin_types_compatible_p(typeof(x), unsigned type), \ ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other) +#define abs_diff(a, b) ({ \ + typeof(a) __a = (a); \ + typeof(b) __b = (b); \ + (void)(&__a == &__b); \ + __a > __b ? (__a - __b) : (__b - __a); \ +}) + /** * reciprocal_scale - "scale" a value into range [0, ep_ro) * @val: value