64-by-32-bit divisions are prominent in the NuttX, even on 32-bit
machines. Luckily, many of them use a constant divisor that allows
for a much faster multiplication by the divisor's reciprocal.
The compiler already performs this optimization when compiling a 32-by-32
division with a constant divisor. Unfortunately, on 32-bit machines, gcc
does not optimize 64-by-32 divisions in that case, except for constant
divisors that happen to be a power of 2.
Let's avoid the slow path whenever the divisor is constant by manually
computing the reciprocal ourselves and performing the multiplication
inline. In most cases, this improves performance of 64-by-32 divisions
by about two orders of magnitude compared to the __div64_32() fallback,
especially on architectures lacking a native div instruction.
Signed-off-by: ligd <liguiding1@xiaomi.com>
CID 1266677: (#2 of 2): Use 32-bit time_t (Y2K38_SAFETY)
1. declaration_with_small_time_t: Declare use of time_t, which is defined as 32 bits wide on this platform, while the minimum safe width is 64.
Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
Signed-off-by: ligd <liguiding1@xiaomi.com>
Using the ts/tick conversion functions provided in clock.h
Do this caused we want speed up the time calculation, so change:
clock_time2ticks, clock_ticks2time, clock_timespec_add,
clock_timespec_compare, clock_timespec_subtract... to MACRO
Signed-off-by: ligd <liguiding1@xiaomi.com>
This commit refactors the wdog module to use absolute time representation internally. The main improvements include:
1. Fixed recursive watchdog handling caused by calling wd_start within watchdog timeout callback function.
2. Simplified timer processing to improve performance and enhance code readability.
3. Improved accuracy of timers.
4. Reduced critical section and interrupt disable time, improving real-time performance.
Signed-off-by: ouyangxiangzhen <ouyangxiangzhen@xiaomi.com>
Signed-off-by: ligd <liguiding1@xiaomi.com>
reason:
In SMP, when a context switch occurs, restore_critical_section is executed.
To reduce the time taken for context switching, we directly pass the required
parameters to restore_critical_section instead of acquiring them repeatedly.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
reason:
In the SMP, when a context switch occurs, restore_critical_section is executed.
In order to reduce the time taken for context switching,
we inline the restore_critical_section function.
Given that restore_critical_section is small in size
and is called from only one location, inlining it does not increase the size of the image.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
Add new driver frameworks: force feedback for vibrator, like linux,
unify vendor vibrator driver using.
Incorporating a force feedback-based driving framework to replace the
conventional driver/motor setup for controlling vibrators not only
enhances the precision and responsiveness of the haptic feedback but
also aligns better with the advancements in Linux-based driver systems.
refs docs link: https://www.kernel.org/doc/html/v4.19/input/ff.html
Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
Add common ivshmem driver, provide the ivshmem bus mechisam, so
many ivshmem based driver can change to pci_ivshmem based
Signed-off-by: Bowen Wang <wangbowen6@xiaomi.com>
Rptun is a rptun fremework driver base on the Inter-Virtual Machine
Share Memory Device.
With this driver, two NuttX runs in different QEMU can communicate
with each other by the rpmsg api.
Signed-off-by: Bowen Wang <wangbowen6@xiaomi.com>
We can see them in ifconfig:
ap> ifconfig
wlan0 Link encap:Ethernet HWaddr 42:64:7f:b3:12:03 at UP mtu 1500
inet addr:10.0.1.2 DRaddr:10.0.1.1 Mask:255.255.255.0
inet6 DRaddr: ::
RX: Received Fragment Errors Bytes
00000b9b 00000000 00000000 21daf5
IPv4 IPv6 ARP Dropped
00000a33 00000137 00000031 00000000
TX: Queued Sent Errors Timeouts Bytes
00000ac4 00000ac4 00000000 00000000 1a2103
Total Errors: 00000000
Signed-off-by: meijian <meijian@xiaomi.com>
Basic amg88xx sensor handling (open, close, read, ioctl).
No interrupts supported. I intend to add support for this feature when I
gain more know-how on nuttx/posix.
