linux/include
Pratyush Yadav (Google) 23c346727b kho: make radix max key width more obvious
The KHO radix tree constants are somewhat hard to understand. The tree
depth essentially comes from the max key width. The max key width comes
from the need to store a 52-bit PFN plus one more bit for the order.

All this is very obscure with the corrent code. The PFN width is defined
as KHO_ORDER_0_LOG2, which makes very little sense to a new reader not
already familiar with what the value means. Then the fact that an extra
bit is needed is hidden in the KHO_TREE_MAX_DEPTH calculation.

Simplify this by removing KHO_ORDER_0_LOG2 and replace it with
KHO_RADIX_KEY_WIDTH. Update the comment to explain why this value is
used. This moves the +1 from KHO_TREE_MAX_DEPTH to KHO_RADIX_KEY_WIDTH,
making things clearer.

Update kho_{encode,decode}_radix_key() to not use KHO_ORDER_0_LOG2.
Instead, refactor the code and comments to make it clearer how the
encoding and decoding is done.

In kho_encode_radix_key(), add a new variable for the shift for physical
address. Use that in calculating where the order bit goes and in
calculating the shifted PFN. Update comments to make this clearer.

In kho_radix_decode_key(), turn order_bit to 0-indexed to simplify the
eventual calculation for order. Touch up comments to make the
computation clearer.

Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Link: https://patch.msgid.link/20260801084833.1897543-3-pratyush@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-08-03 21:53:54 +03:00
..
acpi ACPICA: Define acpi_ut_safe_strncpy() as strscpy_pad() alias 2026-07-01 12:29:24 +02:00
asm-generic Merge branch 'mm-stable-6d098029de09' of https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm into kho-scratch 2026-07-30 10:53:28 +03:00
clocksource
crypto Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
cxl cxl/region: Introduce devm_cxl_probe_mem() 2026-06-12 13:47:30 -07:00
drm drm-misc-fixes for v7.2-rc5: 2026-07-24 18:30:29 +10:00
dt-bindings SoC fixes for 7.2 2026-07-17 08:52:09 -07:00
hyperv
keys keys: Pin request_key_auth payload in instantiate paths 2026-06-15 15:19:13 +03:00
kunit linux_kselftest-kunit-7.2-rc1 2026-06-16 16:33:57 +05:30
kvm Merge branch kvm-arm64/vgic-v5-PPI-fixes into kvmarm-master/next 2026-06-12 09:08:31 +01:00
linux kho: make radix max key width more obvious 2026-08-03 21:53:54 +03:00
math-emu
media
memory
misc
net tcp: challenge ACK for non-exact RST in SYN-RECEIVED 2026-07-23 08:27:22 -07:00
pcmcia Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (headers) 2026-07-03 07:38:16 +02:00
ras
rdma RDMA v7.2 merge window 2026-06-18 08:16:21 -07:00
rv
scsi scsi: core: wake eh reliably when using scsi_schedule_eh 2026-07-12 22:21:22 -04:00
soc soc/tegra: pmc: Fixes for v7.2 2026-07-10 14:40:52 +02:00
sound Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (headers) 2026-07-03 07:38:16 +02:00
target
trace mm: use enum migrate_reason instead of int for migration reason parameters 2026-07-28 21:11:50 -07:00
uapi io_uring-7.2-20260724 2026-07-24 19:58:03 -07:00
ufs Merge branch 7.1/scsi-fixes into 7.2/scsi-staging 2026-06-15 21:01:30 -04:00
vdso
video
xen xen: Replace __ASSEMBLY__ with __ASSEMBLER__ in header files 2026-07-01 09:49:52 +02:00
Kbuild