stm32: Improvements to CAN bus ID generation. And added a small fast hash library (#3165)

Improved CAM bus ID generation, there were issues with ID collisions.
Added a small fast hash library.

Signed-off-by: Pontus Borg <liquidpontus@yahoo.se>
This commit is contained in:
bondus 2020-08-10 03:07:59 +02:00 committed by GitHub
parent 04bd48ca9d
commit 35d28e880d
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GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 142 additions and 6 deletions

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@ -74,3 +74,7 @@ revision 425a42d82006cf0aa24be27b483d2f6a41607489. The code is taken
from the repo's hc-sr04-range-sensor directory. It has been modified
so that the IEP definitions compile correctly. See pru_rpmsg.patch for
the modifications.
The fast-hash directory contains code from:
https://github.com/ztanml/fast-hash
revision ae3bb53c199fe75619e940b5b6a3584ede99c5fc

75
lib/fast-hash/fasthash.c Normal file
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@ -0,0 +1,75 @@
/* The MIT License
Copyright (C) 2012 Zilong Tan (eric.zltan@gmail.com)
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
#include "fasthash.h"
// Compression function for Merkle-Damgard construction.
// This function is generated using the framework provided.
#define mix(h) ({ \
(h) ^= (h) >> 23; \
(h) *= 0x2127599bf4325c37ULL; \
(h) ^= (h) >> 47; })
uint64_t fasthash64(const void *buf, size_t len, uint64_t seed)
{
const uint64_t m = 0x880355f21e6d1965ULL;
const uint64_t *pos = (const uint64_t *)buf;
const uint64_t *end = pos + (len / 8);
const unsigned char *pos2;
uint64_t h = seed ^ (len * m);
uint64_t v;
while (pos != end) {
v = *pos++;
h ^= mix(v);
h *= m;
}
pos2 = (const unsigned char*)pos;
v = 0;
switch (len & 7) {
case 7: v ^= (uint64_t)pos2[6] << 48;
case 6: v ^= (uint64_t)pos2[5] << 40;
case 5: v ^= (uint64_t)pos2[4] << 32;
case 4: v ^= (uint64_t)pos2[3] << 24;
case 3: v ^= (uint64_t)pos2[2] << 16;
case 2: v ^= (uint64_t)pos2[1] << 8;
case 1: v ^= (uint64_t)pos2[0];
h ^= mix(v);
h *= m;
}
return mix(h);
}
uint32_t fasthash32(const void *buf, size_t len, uint32_t seed)
{
// the following trick converts the 64-bit hashcode to Fermat
// residue, which shall retain information from both the higher
// and lower parts of hashcode.
uint64_t h = fasthash64(buf, len, seed);
return h - (h >> 32);
}

56
lib/fast-hash/fasthash.h Normal file
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@ -0,0 +1,56 @@
/* The MIT License
Copyright (C) 2012 Zilong Tan (eric.zltan@gmail.com)
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
#ifndef _FASTHASH_H
#define _FASTHASH_H
#include <stdint.h>
#include <stdio.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* fasthash32 - 32-bit implementation of fasthash
* @buf: data buffer
* @len: data size
* @seed: the seed
*/
uint32_t fasthash32(const void *buf, size_t len, uint32_t seed);
/**
* fasthash64 - 64-bit implementation of fasthash
* @buf: data buffer
* @len: data size
* @seed: the seed
*/
uint64_t fasthash64(const void *buf, size_t len, uint64_t seed);
#ifdef __cplusplus
}
#endif
#endif

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@ -17,7 +17,7 @@ CFLAGS-$(CONFIG_MACH_STM32F1) += -mcpu=cortex-m3 -Ilib/stm32f1/include
CFLAGS-$(CONFIG_MACH_STM32F2) += -mcpu=cortex-m3 -Ilib/stm32f2/include
CFLAGS-$(CONFIG_MACH_STM32F4) += -mcpu=cortex-m4 -Ilib/stm32f4/include
CFLAGS-$(CONFIG_MACH_STM32F4) += -mfpu=fpv4-sp-d16 -mfloat-abi=hard
CFLAGS += $(CFLAGS-y) -D$(MCU_UPPER) -mthumb -Ilib/cmsis-core
CFLAGS += $(CFLAGS-y) -D$(MCU_UPPER) -mthumb -Ilib/cmsis-core -Ilib/fast-hash
CFLAGS_klipper.elf += --specs=nano.specs --specs=nosys.specs
CFLAGS_klipper.elf += -T $(OUT)src/generic/armcm_link.ld
@ -46,9 +46,11 @@ src-$(CONFIG_USBSERIAL) += $(usb-src-y) stm32/chipid.c generic/usb_cdc.c
serial-src-y := stm32/serial.c
serial-src-$(CONFIG_MACH_STM32F0) := stm32/stm32f0_serial.c
src-$(CONFIG_SERIAL) += $(serial-src-y) generic/serial_irq.c
can-src-$(CONFIG_CANSERIAL) += stm32/can.c
can-src-$(CONFIG_CANSERIAL) += stm32/can.c ../lib/fast-hash/fasthash.c
src-$(CONFIG_CANSERIAL) += $(can-src-y) generic/serial_irq.c
dirs-$(CONFIG_CANSERIAL) += lib/fast-hash
# Binary output file rules
target-y += $(OUT)klipper.bin

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@ -15,6 +15,7 @@
#include "sched.h" // DECL_INIT
#include <string.h>
#include "can.h"
#include <fasthash.h>
#if (CONFIG_CAN_PINS_PA11_PA12)
DECL_CONSTANT_STR("RESERVE_PINS_CAN", "PA11,PA12");
@ -151,10 +152,8 @@ static void can_transmit(uint32_t id, uint32_t dlc, uint8_t *pkt)
// Convert Unique 96-bit value into 48 bit representation
static void pack_uuid(uint8_t* u)
{
for(int i=0; i<SHORT_UUID_LEN; i++) {
u[i] = *((uint8_t*)(UID_BASE+i)) ^
*((uint8_t*)(UID_BASE+i+SHORT_UUID_LEN));
}
uint64_t hash = fasthash64((uint8_t*)UID_BASE, 12, 0xA16231A7);
memcpy(u, &hash, SHORT_UUID_LEN);
}
static void can_uuid_resp(void)