From b1abf96cecc01884eb8542ad262b7735534fdb41 Mon Sep 17 00:00:00 2001
From: graham sanderson <graham.sanderson@raspberrypi.com>
Date: Mon, 8 Jul 2024 18:54:48 -0500
Subject: [PATCH] Revert "Add C11 standard atomic support (#1645)"
This reverts commit 01dec6fb6f1fb735faede453f32aeef5364d6230.
---
src/rp2_common/CMakeLists.txt | 1 -
src/rp2_common/pico_atomic/CMakeLists.txt | 11 -
.../pico_atomic/include/stdatomic.h | 27 --
src/rp2_common/pico_atomic/pico_atomic.c | 345 ------------------
src/rp2_common/pico_runtime/CMakeLists.txt | 3 -
5 files changed, 387 deletions(-)
delete mode 100644 src/rp2_common/pico_atomic/CMakeLists.txt
delete mode 100644 src/rp2_common/pico_atomic/include/stdatomic.h
delete mode 100644 src/rp2_common/pico_atomic/pico_atomic.c
diff --git a/src/rp2_common/CMakeLists.txt b/src/rp2_common/CMakeLists.txt
index 19c52c1..82f56f8 100644
--- a/src/rp2_common/CMakeLists.txt
+++ b/src/rp2_common/CMakeLists.txt
@@ -51,7 +51,6 @@ if (NOT PICO_BARE_METAL)
pico_add_subdirectory(pico_malloc)
pico_add_subdirectory(pico_printf)
pico_add_subdirectory(pico_rand)
- pico_add_subdirectory(pico_atomic)
pico_add_subdirectory(pico_stdio)
pico_add_subdirectory(pico_stdio_semihosting)
diff --git a/src/rp2_common/pico_atomic/CMakeLists.txt b/src/rp2_common/pico_atomic/CMakeLists.txt
deleted file mode 100644
index 5670430..0000000
--- a/src/rp2_common/pico_atomic/CMakeLists.txt
+++ /dev/null
@@ -1,11 +0,0 @@
-if (NOT TARGET pico_atomic)
- pico_add_library(pico_atomic)
-
- target_sources(pico_atomic INTERFACE
- ${CMAKE_CURRENT_LIST_DIR}/pico_atomic.c
- )
-
- target_include_directories(pico_atomic_headers INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
-
- target_link_libraries(pico_atomic INTERFACE pico_sync)
-endif()
diff --git a/src/rp2_common/pico_atomic/include/stdatomic.h b/src/rp2_common/pico_atomic/include/stdatomic.h
deleted file mode 100644
index 071286f..0000000
--- a/src/rp2_common/pico_atomic/include/stdatomic.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * Copyright (c) 2024 Raspberry Pi (Trading) Ltd.
- * Copyright (c) 2024 Stephen Street (stephen@redrocketcomputing.com).
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#ifndef __STDATOMIC_H
-#define __STDATOMIC_H
-
-#include_next <stdatomic.h>
-
-#undef atomic_flag_test_and_set
-#undef atomic_flag_test_and_set_explicit
-#undef atomic_flag_clear
-#undef atomic_flag_clear_explicit
-
-extern _Bool __atomic_test_and_set_m0(volatile void *mem, int model);
-extern void __atomic_clear_m0 (volatile void *mem, int model);
-
-#define atomic_flag_test_and_set(PTR) __atomic_test_and_set_m0((PTR), __ATOMIC_SEQ_CST)
-#define atomic_flag_test_and_set_explicit(PTR, MO) __atomic_test_and_set_m0((PTR), (MO))
-
-#define atomic_flag_clear(PTR) __atomic_clear_m0((PTR), __ATOMIC_SEQ_CST)
-#define atomic_flag_clear_explicit(PTR, MO) __atomic_clear_m0((PTR), (MO))
-
-#endif
diff --git a/src/rp2_common/pico_atomic/pico_atomic.c b/src/rp2_common/pico_atomic/pico_atomic.c
deleted file mode 100644
index 8dd6b96..0000000
--- a/src/rp2_common/pico_atomic/pico_atomic.c
+++ /dev/null
@@ -1,345 +0,0 @@
-/*
- * Copyright (c) 2024 Raspberry Pi (Trading) Ltd.
- * Copyright (c) 2024 Stephen Street (stephen@redrocketcomputing.com).
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#include <stdbool.h>
-#include <stdint.h>
-
-#include "hardware/address_mapped.h"
-#include "hardware/regs/watchdog.h"
-#include "hardware/sync.h"
-
-#include "pico/config.h"
-
-#ifndef __optimize
-#define __optimize __attribute__((optimize("-Os")))
-#endif
-
-/* Must be powers of 2 */
-#define ATOMIC_STRIPE 4UL
-#define ATOMIC_LOCKS 16UL
-#define ATOMIC_LOCK_WIDTH 2UL
-#define ATOMIC_LOCK_IDX_Pos ((sizeof(unsigned long) * 8) - (__builtin_clz(ATOMIC_STRIPE - 1)))
-#define ATOMIC_LOCK_IDX_Msk (ATOMIC_LOCKS - 1UL)
-#define ATOMIC_LOCK_REG ((io_rw_32 *)(WATCHDOG_BASE + WATCHDOG_SCRATCH3_OFFSET))
-
-static __used __attribute__((section(".preinit_array.00030"))) void __atomic_init(void) {
- *ATOMIC_LOCK_REG = 0;
-}
-
-/*
- To eliminate interference with existing hardware spinlock usage and reduce multicore contention on
- unique atomic variables, we use one of the watchdog scratch registers (WATCHDOG_SCRATCH3) to
- implement 16, 2 bit, multicore locks, via a varation of Dekker's algorithm
- (see https://en.wikipedia.org/wiki/Dekker%27s_algorithm). The lock is selected as a
- function of the variable address and the stripe width which hashes variables
- addresses to locks numbers.
-*/
-static __optimize uint32_t __atomic_lock(volatile void *mem) {
- const uint32_t core = get_core_num();
- const uint32_t lock_idx = (((uintptr_t)mem) >> ATOMIC_LOCK_IDX_Pos) & ATOMIC_LOCK_IDX_Msk;
- const uint32_t lock_pos = lock_idx * ATOMIC_LOCK_WIDTH;
- const uint32_t lock_mask = ((1UL << ATOMIC_LOCK_WIDTH) - 1) << lock_pos;
- const uint32_t locked_mask = 1UL << (lock_pos + core);
-
- uint32_t state = save_and_disable_interrupts();
- while (true) {
-
- /* First set the bit */
- hw_set_bits(ATOMIC_LOCK_REG, locked_mask);
- __dmb();
-
- /* Did we get the lock? */
- if ((*ATOMIC_LOCK_REG & lock_mask) == locked_mask)
- break;
-
- /* Nope, clear our side */
- __dmb();
- hw_clear_bits(ATOMIC_LOCK_REG, locked_mask);
-
- /* Need to break any ties if the cores are in lock step, is this really required? */
- for (uint32_t i = core * 2; i > 0; --i)
- asm volatile ("nop");
- }
-
- return state;
-}
-
-static __optimize void __atomic_unlock(volatile void *mem, uint32_t state) {
- const uint32_t lock_idx = (((uintptr_t)mem) >> ATOMIC_LOCK_IDX_Pos) & ATOMIC_LOCK_IDX_Msk;
- const uint32_t lock_pos = lock_idx * ATOMIC_LOCK_WIDTH;
- const uint32_t locked_mask = 1UL << (lock_pos + get_core_num());
-
- __dmb();
- hw_clear_bits(ATOMIC_LOCK_REG, locked_mask);
- restore_interrupts(state);
-}
-
-__optimize uint8_t __atomic_fetch_add_1(volatile void *mem, uint8_t val, __unused int model) {
- volatile uint8_t *ptr = mem;
- uint8_t state = __atomic_lock(mem);
- uint8_t result = *ptr;
- *ptr += val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint8_t __atomic_fetch_sub_1(volatile void *mem, uint8_t val, __unused int model) {
- volatile uint8_t *ptr = mem;
- uint8_t state = __atomic_lock(mem);
- uint8_t result = *ptr;
- *ptr -= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint8_t __atomic_fetch_and_1(volatile void *mem, uint8_t val, __unused int model) {
- volatile uint8_t *ptr = mem;
- uint8_t state = __atomic_lock(mem);
- uint8_t result = *ptr;
- *ptr &= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint8_t __atomic_fetch_or_1(volatile void *mem, uint8_t val, __unused int model) {
- volatile uint8_t *ptr = mem;
- uint8_t state = __atomic_lock(mem);
- uint8_t result = *ptr;
- *ptr |= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint8_t __atomic_exchange_1(volatile void *mem, uint8_t val, __unused int model) {
- volatile uint8_t *ptr = mem;
- uint8_t state = __atomic_lock(mem);
- uint8_t result = *ptr;
- *ptr = val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize bool __atomic_compare_exchange_1(volatile void *mem, void *expected, uint8_t desired, __unused bool weak, __unused int success, __unused int failure) {
- bool result = false;
- volatile uint8_t *ptr = mem;
- uint8_t *e_ptr = expected;
- uint8_t state = __atomic_lock(mem);
- if (*ptr == *e_ptr) {
- *ptr = desired;
- result = true;
- } else
- *e_ptr = *ptr;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint16_t __atomic_fetch_add_2(volatile void *mem, uint16_t val, __unused int model) {
- volatile uint16_t *ptr = mem;
- uint16_t state = __atomic_lock(mem);
- uint16_t result = *ptr;
- *ptr += val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint16_t __atomic_fetch_sub_2(volatile void *mem, uint16_t val, __unused int model) {
- volatile uint16_t *ptr = mem;
- uint16_t state = __atomic_lock(mem);
- uint16_t result = *ptr;
- *ptr -= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint16_t __atomic_fetch_and_2(volatile void *mem, uint16_t val, __unused int model) {
- volatile uint16_t *ptr = mem;
- uint16_t state = __atomic_lock(mem);
- uint16_t result = *ptr;
- *ptr &= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint16_t __atomic_fetch_or_2(volatile void *mem, uint16_t val, __unused int model) {
- volatile uint16_t *ptr = mem;
- uint16_t state = __atomic_lock(mem);
- uint16_t result = *ptr;
- *ptr |= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint16_t __atomic_exchange_2(volatile void *mem, uint16_t val, __unused int model) {
- volatile uint16_t *ptr = mem;
- uint16_t state = __atomic_lock(mem);
- uint16_t result = *ptr;
- *ptr = val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize bool __atomic_compare_exchange_2(volatile void *mem, void *expected, uint16_t desired, __unused bool weak, __unused int success, __unused int failure) {
- bool result = false;
- volatile uint16_t *ptr = mem;
- uint16_t *e_ptr = expected;
- uint16_t state = __atomic_lock(mem);
- if (*ptr == *e_ptr) {
- *ptr = desired;
- result = true;
- } else
- *e_ptr = *ptr;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint32_t __atomic_fetch_add_4(volatile void *mem, uint32_t val, __unused int model) {
- volatile uint32_t *ptr = mem;
- uint32_t state = __atomic_lock(mem);
- uint32_t result = *ptr;
- *ptr += val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint32_t __atomic_fetch_sub_4(volatile void *mem, uint32_t val, __unused int model) {
- volatile uint32_t *ptr = mem;
- uint32_t state = __atomic_lock(mem);
- uint32_t result = *ptr;
- *ptr -= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint32_t __atomic_fetch_and_4(volatile void *mem, uint32_t val, __unused int model) {
- volatile uint32_t *ptr = mem;
- uint32_t state = __atomic_lock(mem);
- uint32_t result = *ptr;
- *ptr &= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint32_t __atomic_fetch_or_4(volatile void *mem, uint32_t val, __unused int model) {
- volatile uint32_t *ptr = mem;
- uint32_t state = __atomic_lock(mem);
- uint32_t result = *ptr;
- *ptr |= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint32_t __atomic_exchange_4(volatile void *mem, uint32_t val, __unused int model) {
- volatile uint32_t *ptr = mem;
- uint32_t state = __atomic_lock(mem);
- uint32_t result = *ptr;
- *ptr = val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize bool __atomic_compare_exchange_4(volatile void *mem, void *expected, uint32_t desired, __unused bool weak, __unused int success, __unused int failure) {
- bool result = false;
- volatile uint32_t *ptr = mem;
- uint32_t *e_ptr = expected;
- uint32_t state = __atomic_lock(mem);
- if (*ptr == *e_ptr) {
- *ptr = desired;
- result = true;
- } else
- *e_ptr = *ptr;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint64_t __atomic_fetch_add_8(volatile void *mem, uint64_t val, __unused int model) {
- volatile uint64_t *ptr = mem;
- uint64_t state = __atomic_lock(mem);
- uint64_t result = *ptr;
- *ptr += val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint64_t __atomic_fetch_sub_8(volatile void *mem, uint64_t val, __unused int model) {
- volatile uint64_t *ptr = mem;
- uint64_t state = __atomic_lock(mem);
- uint64_t result = *ptr;
- *ptr -= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint64_t __atomic_fetch_and_8(volatile void *mem, uint64_t val, __unused int model) {
- volatile uint64_t *ptr = mem;
- uint64_t state = __atomic_lock(mem);
- uint64_t result = *ptr;
- *ptr &= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint64_t __atomic_fetch_or_8(volatile void *mem, uint64_t val, __unused int model) {
- volatile uint64_t *ptr = mem;
- uint64_t state = __atomic_lock(mem);
- uint64_t result = *ptr;
- *ptr |= val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint64_t __atomic_exchange_8(volatile void *mem, uint64_t val, __unused int model) {
- volatile uint64_t *ptr = mem;
- uint64_t state = __atomic_lock(mem);
- uint64_t result = *ptr;
- *ptr = val;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize bool __atomic_compare_exchange_8(volatile void *mem, void *expected, uint64_t desired, __unused bool weak, __unused int success, __unused int failure) {
- bool result = false;
- volatile uint64_t *ptr = mem;
- uint64_t *e_ptr = expected;
- uint64_t state = __atomic_lock(mem);
- if (*ptr == *e_ptr) {
- *ptr = desired;
- result = true;
- } else
- *e_ptr = *ptr;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize uint64_t __atomic_load_8(volatile void *mem, __unused int model) {
- volatile uint64_t *ptr = mem;
- uint32_t state = __atomic_lock(mem);
- uint32_t result = *ptr;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize void __atomic_store_8(volatile void *mem, uint64_t val, __unused int model) {
- volatile uint64_t *ptr = mem;
- uint32_t state = __atomic_lock(mem);
- *ptr = val;
- __atomic_unlock(mem, state);
-}
-
-__optimize bool __atomic_test_and_set_m0(volatile void *mem, __unused int model) {
- volatile bool *ptr = mem;
- uint32_t state = __atomic_lock(mem);
- volatile bool result = *ptr;
- *ptr = true;
- __atomic_unlock(mem, state);
- return result;
-}
-
-__optimize void __atomic_clear_m0(volatile void *mem, __unused int model) {
- volatile bool *ptr = mem;
- *ptr = false;
- __dmb();
-}
diff --git a/src/rp2_common/pico_runtime/CMakeLists.txt b/src/rp2_common/pico_runtime/CMakeLists.txt
index 791bf8f..9879ba1 100644
--- a/src/rp2_common/pico_runtime/CMakeLists.txt
+++ b/src/rp2_common/pico_runtime/CMakeLists.txt
@@ -35,9 +35,6 @@ endif()
if (TARGET pico_mem_ops)
pico_mirrored_target_link_libraries(pico_runtime INTERFACE pico_mem_ops)
endif()
-if (TARGET pico_atomic)
- pico_mirrored_target_link_libraries(pico_runtime INTERFACE pico_atomic)
-endif()
if (TARGET pico_standard_link)
pico_mirrored_target_link_libraries(pico_runtime INTERFACE pico_standard_link)
endif()
--
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