Using two distinct DMA zones turned out to be problematic. Here's an
attempt go back to a saner default.

I tested this on both a RPi4 and QEMU.

---

Changes since v2:
 - Introduce Ard's patch
 - Improve OF dma-ranges parsing function
 - Add unit test for OF function
 - Address small changes
 - Move crashkernel reservation later in boot process

Changes since v1:
 - Parse dma-ranges instead of using machine compatible string

Ard Biesheuvel (1):
  arm64: mm: Set ZONE_DMA size based on early IORT scan

Nicolas Saenz Julienne (7):
  arm64: mm: Move reserve_crashkernel() into mem_init()
  arm64: mm: Move zone_dma_bits initialization into zone_sizes_init()
  of/address: Introduce of_dma_get_max_cpu_address()
  of: unittest: Add test for of_dma_get_max_cpu_address()
  dma-direct: Turn zone_dma_bits default value into a define
  arm64: mm: Set ZONE_DMA size based on devicetree's dma-ranges
  mm: Update DMA zones description

 arch/arm64/include/asm/processor.h |  1 +
 arch/arm64/mm/init.c               | 20 ++++++------
 drivers/acpi/arm64/iort.c          | 51 ++++++++++++++++++++++++++++++
 drivers/of/address.c               | 42 ++++++++++++++++++++++++
 drivers/of/unittest.c              | 20 ++++++++++++
 include/linux/acpi_iort.h          |  4 +++
 include/linux/dma-direct.h         |  3 ++
 include/linux/mmzone.h             |  5 +--
 include/linux/of.h                 |  7 ++++
 kernel/dma/direct.c                |  2 +-
 10 files changed, 143 insertions(+), 12 deletions(-)

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2.28.0