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fix(mmap): fixed some API read wrong data via mmap when flash being erased/written while XIP on PSRAM

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Before:

The cache won't be disabled when XIP on psram. But during flash
erasing/programming, read data will be courrupt.

When XIP in psram is enabled, the image is not mapped to the cache so
usually there will be no flash access. The only way to read from flash
is via the driver or use mmap. The driver has protection during erasing,
while th mmap region not.

Now:

Mmap APIs provide a flag to make mmap->unmap region mutually exclusive
to flash erase/programming when XIP from psram. SPI Flash write APIs
will benefit from this. When the flag is used, no concurrent access to
mapped region will happen while writing; otherwise the cache will be
disable to avoid data corruption.

Most ESP-IDF APIs calls mmap with this flag. As for users calling
mmap-like APIs directly, they can choose whether to enable this by a
flag.

Closes https://github.com/espressif/esp-idf/issues/14897
This commit is contained in:
Xiao Xufeng
2026-06-16 01:00:43 +08:00
committed by Michael (XIAO Xufeng)
parent ec956162ab
commit 789ce684c9
73 changed files with 1678 additions and 487 deletions
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docs/en/api-reference/peripherals/spi_flash/index.rst
+25
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@@ -172,6 +172,31 @@ Note that since memory mapping happens in pages, it may be possible to read data
mmap is supported by cache, so it can only be used on main flash.
.. only:: not esp32
.. _blocks_write_flag:
About the :cpp:enumerator:`SPI_FLASH_MMAP_FLAG_BLOCKS_WRITE` flag
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
When flash erasing/writing happen while cache mapping exists, it often causes some cache region to be invalidated and reloaded again. To improve the performance, it is suggested to specify this flag when you are sure:
1. This mapping will end in a short time, and
2. Before the mapping ends, you don't need to erase or write the flash.
This flag will prevent all writes until the corresponding munmap is called. Most ESP-IDF APIs that rely on the mapping to flash internally use this flag.
.. only:: SOC_SPI_MEM_SUPPORT_AUTO_SUSPEND or SOC_SPIRAM_XIP_SUPPORTED
This flag also helps to prevent the cache being disabled when you are using following modes. See their documentation for more details.
.. list::
:SOC_SPIRAM_XIP_SUPPORTED: - :ref:`xip_from_psram`
:SOC_SPI_MEM_SUPPORT_AUTO_SUSPEND: - :ref:`auto-suspend`
This flag is implemented by a lock in the SPI Flash driver. The lock is taken when :cpp:func:`spi_flash_mmap` (or mmap-like APIs) is called with the flag and released until corresponding unmap is called. There is a reference counter internally allowing concurrent mapping to the flash. Only after the last mapping to Flash with the flag is revoked (counter equals 0) can the flash erasing/writing APIs start execution.
SPI Flash Implementation
------------------------