spi: aspeed: Improve handling of shared SPI

Merge series from Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>:

This patch series improves handling of SPI controllers that are
shared by spi-mem devices and other SPI peripherals.

The primary goal of this series is to support non-spi-mem devices in
the ASPEED FMC/SPI controller driver. It also addresses an issue in
the spi-mem framework observed when different types of SPI devices
operate concurrently on the same controller, ensuring that spi-mem
operations are properly serialized.

1 files changed, 5 insertions, 1 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 6f959d8ca4b4..f0d5be9dc736 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -608,7 +608,11 @@ enum {
 /*
  * Flags which should result in page tables being copied on fork. These are
  * flags which indicate that the VMA maps page tables which cannot be
- * reconsistuted upon page fault, so necessitate page table copying upon
+ * reconsistuted upon page fault, so necessitate page table copying upon fork.
+ *
+ * Note that these flags should be compared with the DESTINATION VMA not the
+ * source, as VM_UFFD_WP may not be propagated to destination, while all other
+ * flags will be.
  *
  * VM_PFNMAP / VM_MIXEDMAP - These contain kernel-mapped data which cannot be
  *                           reasonably reconstructed on page fault.