From 2752654043fd14cb8f2b759ee9409c6c5942c157 Mon Sep 17 00:00:00 2001 From: Mahavir Jain Date: Fri, 8 Mar 2019 11:00:49 +0530 Subject: [PATCH 1/2] spi_flash: fix stale read issue for memory mapped partition On flash program operation (either erase or write), if corresponding address has cache mapping present then cache is explicitly flushed (for both pro and app cpu) Closes https://github.com/espressif/esp-idf/issues/2146 --- components/spi_flash/cache_utils.h | 10 +- components/spi_flash/flash_mmap.c | 140 ++++++++------------- components/spi_flash/flash_ops.c | 17 ++- components/spi_flash/sim/flash_mock_util.c | 6 +- 4 files changed, 72 insertions(+), 101 deletions(-) diff --git a/components/spi_flash/cache_utils.h b/components/spi_flash/cache_utils.h index 9cd9ad6b49..d482c4da79 100644 --- a/components/spi_flash/cache_utils.h +++ b/components/spi_flash/cache_utils.h @@ -48,12 +48,10 @@ void spi_flash_disable_interrupts_caches_and_other_cpu_no_os(); // This function is implied to be called when other CPU is not running or running code from IRAM. void spi_flash_enable_interrupts_caches_no_os(); -// Mark the pages containing a flash region as having been -// erased or written to. This means the flash cache needs -// to be evicted before these pages can be flash_mmap()ed again, -// as they may contain stale data -// +// Flushes cache if address range has corresponding valid cache mappings +// Recommended to use post flash program operation (erase or write) // Only call this while holding spi_flash_op_lock() -void spi_flash_mark_modified_region(uint32_t start_addr, uint32_t length); +// Returns true if cache was flushed, false otherwise +bool spi_flash_check_and_flush_cache(uint32_t start_addr, uint32_t length); #endif //ESP_SPI_FLASH_CACHE_UTILS_H diff --git a/components/spi_flash/flash_mmap.c b/components/spi_flash/flash_mmap.c index d649a74603..534a7e3d35 100644 --- a/components/spi_flash/flash_mmap.c +++ b/components/spi_flash/flash_mmap.c @@ -47,19 +47,6 @@ #define VADDR1_FIRST_USABLE_ADDR 0x400D0000 #define PRO_IRAM0_FIRST_USABLE_PAGE ((VADDR1_FIRST_USABLE_ADDR - VADDR1_START_ADDR) / SPI_FLASH_MMU_PAGE_SIZE + 64) -/* Ensure pages in a region haven't been marked as written via - spi_flash_mark_modified_region(). If the page has - been written, flush the entire flash cache before returning. - - This ensures stale cache entries are never read after fresh calls - to spi_flash_mmap(), while keeping the number of cache flushes to a - minimum. - - Returns true if cache was flushed. -*/ - -static bool spi_flash_ensure_unmodified_region(size_t start_addr, size_t length); - typedef struct mmap_entry_{ uint32_t handle; int page; @@ -144,7 +131,7 @@ esp_err_t IRAM_ATTR spi_flash_mmap_pages(const int *pages, size_t page_count, sp const void** out_ptr, spi_flash_mmap_handle_t* out_handle) { esp_err_t ret; - bool did_flush, need_flush = false; + bool need_flush = false; if (!page_count) { return ESP_ERR_INVALID_ARG; } @@ -163,12 +150,6 @@ esp_err_t IRAM_ATTR spi_flash_mmap_pages(const int *pages, size_t page_count, sp spi_flash_disable_interrupts_caches_and_other_cpu(); - did_flush = 0; - for (int i = 0; i < page_count; i++) { - if (spi_flash_ensure_unmodified_region(pages[i]*SPI_FLASH_MMU_PAGE_SIZE, SPI_FLASH_MMU_PAGE_SIZE)) { - did_flush = 1; - } - } spi_flash_mmap_init(); // figure out the memory region where we should look for pages int region_begin; // first page to check @@ -243,7 +224,7 @@ esp_err_t IRAM_ATTR spi_flash_mmap_pages(const int *pages, size_t page_count, sp Working on a long term fix that doesn't require invalidating entire cache. */ - if (!did_flush && need_flush) { + if (need_flush) { #if CONFIG_SPIRAM_SUPPORT esp_spiram_writeback_cache(); #endif @@ -338,71 +319,6 @@ uint32_t IRAM_ATTR spi_flash_mmap_get_free_pages(spi_flash_mmap_memory_t memory) return count; } -/* 256-bit (up to 16MB of 64KB pages) bitset of all flash pages - that have been written to since last cache flush. - - Before mmaping a page, need to flush caches if that page has been - written to. - - Note: It's possible to do some additional performance tweaks to - this algorithm, as we actually only need to flush caches if a page - was first mmapped, then written to, then is about to be mmaped a - second time. This is a fair bit more complex though, so unless - there's an access pattern that this would significantly boost then - it's probably not worth it. -*/ -static uint32_t written_pages[256/32]; - -static bool update_written_pages(size_t start_addr, size_t length, bool mark); - -void IRAM_ATTR spi_flash_mark_modified_region(size_t start_addr, size_t length) -{ - update_written_pages(start_addr, length, true); -} - -static IRAM_ATTR bool spi_flash_ensure_unmodified_region(size_t start_addr, size_t length) -{ - return update_written_pages(start_addr, length, false); -} - -/* generic implementation for the previous two functions */ -static inline IRAM_ATTR bool update_written_pages(size_t start_addr, size_t length, bool mark) -{ - /* align start_addr & length to full MMU pages */ - uint32_t page_start_addr = start_addr & ~(SPI_FLASH_MMU_PAGE_SIZE-1); - length += (start_addr - page_start_addr); - length = (length + SPI_FLASH_MMU_PAGE_SIZE - 1) & ~(SPI_FLASH_MMU_PAGE_SIZE-1); - for (uint32_t addr = page_start_addr; addr < page_start_addr + length; addr += SPI_FLASH_MMU_PAGE_SIZE) { - int page = addr / SPI_FLASH_MMU_PAGE_SIZE; - if (page >= 256) { - return false; /* invalid address */ - } - - int idx = page / 32; - uint32_t bit = 1 << (page % 32); - - if (mark) { - written_pages[idx] |= bit; - } else if (written_pages[idx] & bit) { - /* it is tempting to write a version of this that only - flushes each CPU's cache as needed. However this is - tricky because mmaped memory can be used on un-pinned - cores, or the pointer passed between CPUs. - */ -#if CONFIG_SPIRAM_SUPPORT - esp_spiram_writeback_cache(); -#endif - Cache_Flush(0); -#ifndef CONFIG_FREERTOS_UNICORE - Cache_Flush(1); -#endif - bzero(written_pages, sizeof(written_pages)); - return true; - } - } - return false; -} - uint32_t spi_flash_cache2phys(const void *cached) { intptr_t c = (intptr_t)cached; @@ -464,3 +380,55 @@ const void *IRAM_ATTR spi_flash_phys2cache(uint32_t phys_offs, spi_flash_mmap_me spi_flash_enable_interrupts_caches_and_other_cpu(); return NULL; } + +static bool IRAM_ATTR is_page_mapped_in_cache(uint32_t phys_page) +{ + int start[2], end[2]; + + /* SPI_FLASH_MMAP_DATA */ + start[0] = 0; + end[0] = 64; + + /* SPI_FLASH_MMAP_INST */ + start[1] = PRO_IRAM0_FIRST_USABLE_PAGE; + end[1] = 256; + + DPORT_INTERRUPT_DISABLE(); + for (int j = 0; j < 2; j++) { + for (int i = start[j]; i < end[j]; i++) { + if (DPORT_SEQUENCE_REG_READ((uint32_t)&DPORT_PRO_FLASH_MMU_TABLE[i]) == phys_page) { + DPORT_INTERRUPT_RESTORE(); + return true; + } + } + } + DPORT_INTERRUPT_RESTORE(); + return false; +} + +/* Validates if given flash address has corresponding cache mapping, if yes, flushes cache memories */ +IRAM_ATTR bool spi_flash_check_and_flush_cache(size_t start_addr, size_t length) +{ + /* align start_addr & length to full MMU pages */ + uint32_t page_start_addr = start_addr & ~(SPI_FLASH_MMU_PAGE_SIZE-1); + length += (start_addr - page_start_addr); + length = (length + SPI_FLASH_MMU_PAGE_SIZE - 1) & ~(SPI_FLASH_MMU_PAGE_SIZE-1); + for (uint32_t addr = page_start_addr; addr < page_start_addr + length; addr += SPI_FLASH_MMU_PAGE_SIZE) { + uint32_t page = addr / SPI_FLASH_MMU_PAGE_SIZE; + if (page >= 256) { + return false; /* invalid address */ + } + + if (is_page_mapped_in_cache(page)) { +#if CONFIG_SPIRAM_SUPPORT + esp_spiram_writeback_cache(); +#endif + Cache_Flush(0); +#ifndef CONFIG_FREERTOS_UNICORE + Cache_Flush(1); +#endif + return true; + } + } + return false; +} diff --git a/components/spi_flash/flash_ops.c b/components/spi_flash/flash_ops.c index fa23e2a901..29dbb2fd60 100644 --- a/components/spi_flash/flash_ops.c +++ b/components/spi_flash/flash_ops.c @@ -238,6 +238,11 @@ esp_err_t IRAM_ATTR spi_flash_erase_range(uint32_t start_addr, uint32_t size) } } COUNTER_STOP(erase); + + spi_flash_guard_start(); + spi_flash_check_and_flush_cache(start_addr, size); + spi_flash_guard_end(); + return spi_flash_translate_rc(rc); } @@ -404,9 +409,9 @@ esp_err_t IRAM_ATTR spi_flash_write(size_t dst, const void *srcv, size_t size) out: COUNTER_STOP(write); - spi_flash_guard_op_lock(); - spi_flash_mark_modified_region(dst, size); - spi_flash_guard_op_unlock(); + spi_flash_guard_start(); + spi_flash_check_and_flush_cache(dst, size); + spi_flash_guard_end(); return spi_flash_translate_rc(rc); } @@ -470,9 +475,9 @@ esp_err_t IRAM_ATTR spi_flash_write_encrypted(size_t dest_addr, const void *src, COUNTER_ADD_BYTES(write, size); COUNTER_STOP(write); - spi_flash_guard_op_lock(); - spi_flash_mark_modified_region(dest_addr, size); - spi_flash_guard_op_unlock(); + spi_flash_guard_start(); + spi_flash_check_and_flush_cache(dest_addr, size); + spi_flash_guard_end(); return spi_flash_translate_rc(rc); } diff --git a/components/spi_flash/sim/flash_mock_util.c b/components/spi_flash/sim/flash_mock_util.c index 3d9d4186b5..dd3190c39c 100644 --- a/components/spi_flash/sim/flash_mock_util.c +++ b/components/spi_flash/sim/flash_mock_util.c @@ -11,9 +11,9 @@ void spi_flash_init(const char* chip_size, size_t block_size, size_t sector_size _spi_flash_init(chip_size, block_size, sector_size, page_size, partition_bin); } -void spi_flash_mark_modified_region(size_t start_addr, size_t length) +bool spi_flash_check_and_flush_cache(size_t start_addr, size_t length) { - return; + return true; } esp_rom_spiflash_result_t esp_rom_spiflash_unlock() @@ -54,4 +54,4 @@ void spi_flash_disable_interrupts_caches_and_other_cpu_no_os() void spi_flash_enable_interrupts_caches_no_os() { return; -} \ No newline at end of file +} From 16adb9d62aa9cca917105e4f539868ca0346fc4b Mon Sep 17 00:00:00 2001 From: Mahavir Jain Date: Fri, 8 Mar 2019 11:07:10 +0530 Subject: [PATCH 2/2] spi_flash: add test case for stale read issue on memory mapped partition --- components/spi_flash/test/test_mmap.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/components/spi_flash/test/test_mmap.c b/components/spi_flash/test/test_mmap.c index 135aa3cdad..4cdb775943 100644 --- a/components/spi_flash/test/test_mmap.c +++ b/components/spi_flash/test/test_mmap.c @@ -68,7 +68,6 @@ static void setup_mmap_tests() } /* Only rewrite the sector if it has changed */ if (sector_needs_write) { - printf("setup_mmap_tests(): Prepping sector %d\n", abs_sector); ESP_ERROR_CHECK( spi_flash_erase_sector((uint16_t) abs_sector) ); ESP_ERROR_CHECK( spi_flash_write(sector_offs, (const uint8_t *) buffer, sizeof(buffer)) ); } @@ -402,3 +401,24 @@ TEST_CASE("munmap followed by mmap flushes cache", "[spi_flash]") TEST_ASSERT_NOT_EQUAL(0, memcmp(buf, data, sizeof(buf))); } +TEST_CASE("no stale data read post mmap and write partition", "[spi_flash]") +{ + const char buf[] = "Test buffer data for partition"; + char read_data[sizeof(buf)]; + setup_mmap_tests(); + + const esp_partition_t *p = get_test_data_partition(); + + const uint32_t* data; + spi_flash_mmap_handle_t handle; + TEST_ESP_OK(esp_partition_mmap(p, 0, SPI_FLASH_MMU_PAGE_SIZE, + SPI_FLASH_MMAP_DATA, (const void **) &data, &handle) ); + memcpy(read_data, data, sizeof(read_data)); + TEST_ESP_OK(esp_partition_erase_range(p, 0, SPI_FLASH_MMU_PAGE_SIZE)); + TEST_ESP_OK(esp_partition_write(p, 0, buf, sizeof(buf))); + /* This should retrigger actual flash content read */ + memcpy(read_data, data, sizeof(read_data)); + + spi_flash_munmap(handle); + TEST_ASSERT_EQUAL(0, memcmp(buf, read_data, sizeof(buf))); +}