This patchset enhances MTRR checks for the kernel huge I/O mapping, which was enabled by the patchset below: https://lkml.org/lkml/2015/3/3/589 The following functional changes are made in patch 5/5. - Allow pud_set_huge() and pmd_set_huge() to create a huge page mapping to a range covered by a single MTRR entry of any memory type. - Log a pr_warn() message when a specified PMD map range spans more than a single MTRR entry. Drivers should make a mapping request aligned to a single MTRR entry when the range is covered by MTRRs. Patch 1/5 addresses other review comments to the mapping funcs for better code read-ability. Patch 2/5 - 4/5 are bug fixes and clean up to mtrr_type_lookup(). The patchset is based on the -mm tree. --- v3: - Add patch 3/5 to fix a bug in MTRR state checks. - Update patch 4/5 to create separate functions for the fixed and variable entries. (Ingo Molnar) v2: - Update change logs and comments per review comments. (Ingo Molnar) - Add patch 3/4 to clean up mtrr_type_lookup(). (Ingo Molnar) --- Toshi Kani (5): 1/5 mm, x86: Document return values of mapping funcs 2/5 mtrr, x86: Fix MTRR lookup to handle inclusive entry 3/5 mtrr, x86: Fix MTRR state checks in mtrr_type_lookup() 4/5 mtrr, x86: Clean up mtrr_type_lookup() 5/5 mtrr, mm, x86: Enhance MTRR checks for KVA huge page mapping --- arch/x86/Kconfig | 2 +- arch/x86/include/asm/mtrr.h | 5 +- arch/x86/include/uapi/asm/mtrr.h | 4 + arch/x86/kernel/cpu/mtrr/generic.c | 181 ++++++++++++++++++++++++------------- arch/x86/mm/pat.c | 4 +- arch/x86/mm/pgtable.c | 53 ++++++++--- 6 files changed, 165 insertions(+), 84 deletions(-) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>