diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2025-08-26 15:18:58 +0300 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2025-08-28 12:17:32 +0300 |
| commit | 563e5eca4ea3b6e1901cbc7cd6dc42731a8d2999 (patch) | |
| tree | ee81fca2431a964f845ef9fdf86b60ef88945e6c /include | |
| parent | 9df8043a546d2eb3adfaba920c027c0d701c73a1 (diff) | |
| download | linux-563e5eca4ea3b6e1901cbc7cd6dc42731a8d2999.tar.xz | |
iopoll: Avoid evaluating 'cond' twice in poll_timeout_us()
Currently poll_timeout_us() evaluates 'cond' twice at the end
of the success case. This not desirable in case 'cond' itself
is expensive.
Avoid the double evaluation by tracking the return value in
a variable. Need to use a triple undescore '___ret' name to
avoid a conflict with an existing double undescore '__ret'
variable in the regmap code.
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Dibin Moolakadan Subrahmanian <dibin.moolakadan.subrahmanian@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: David Laight <david.laight.linux@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Matt Wagantall <mattw@codeaurora.org>
Cc: Dejin Zheng <zhengdejin5@gmail.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: intel-xe@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://lore.kernel.org/r/20250826121859.15497-2-ville.syrjala@linux.intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/iopoll.h | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h index 440aca5b4b59..d8c801ad68fa 100644 --- a/include/linux/iopoll.h +++ b/include/linux/iopoll.h @@ -36,23 +36,30 @@ u64 __timeout_us = (timeout_us); \ unsigned long __sleep_us = (sleep_us); \ ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \ + int ___ret; \ might_sleep_if((__sleep_us) != 0); \ if ((sleep_before_op) && __sleep_us) \ usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ for (;;) { \ op; \ - if (cond) \ + if (cond) { \ + ___ret = 0; \ break; \ + } \ if (__timeout_us && \ ktime_compare(ktime_get(), __timeout) > 0) { \ op; \ + if (cond) \ + ___ret = 0; \ + else \ + ___ret = -ETIMEDOUT; \ break; \ } \ if (__sleep_us) \ usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ cpu_relax(); \ } \ - (cond) ? 0 : -ETIMEDOUT; \ + ___ret; \ }) /** @@ -83,6 +90,7 @@ s64 __left_ns = __timeout_us * NSEC_PER_USEC; \ unsigned long __delay_us = (delay_us); \ u64 __delay_ns = __delay_us * NSEC_PER_USEC; \ + int ___ret; \ if ((delay_before_op) && __delay_us) { \ udelay(__delay_us); \ if (__timeout_us) \ @@ -90,10 +98,16 @@ } \ for (;;) { \ op; \ - if (cond) \ + if (cond) { \ + ___ret = 0; \ break; \ + } \ if (__timeout_us && __left_ns < 0) { \ op; \ + if (cond) \ + ___ret = 0; \ + else \ + ___ret = -ETIMEDOUT; \ break; \ } \ if (__delay_us) { \ @@ -105,7 +119,7 @@ if (__timeout_us) \ __left_ns--; \ } \ - (cond) ? 0 : -ETIMEDOUT; \ + ___ret; \ }) /** |