SPARC architecture supports 16G hugepages but the kernel did not support them. This patch series adds support for it and also cleanes up some page walk/alloc functions. Patch 1/3: get_user_pages() etc. are used for direct IO. These functions were not aware of hugepages at the PUD level and would try to continue walking page tables beyond the PUD level. Since 16G hugepages have page tables allocated till PUD level only, these accesses would result in invalid access. This patch adds the case for PUD huge pages to these functions. Patch 2/3: Core changes needed to add 16G hugepage support: To map a single 16G hugepage, two PUD entries are used. Each PUD entry maps 8G portion of a 16G page. This page table encoding scheme is same as that used for hugepages at PMD level (8M, 256M and 2G pages) where each PMD entry points successively to 8M regions within a page. No page table entries below the PUD level are allocated for 16G hugepage since those are not required. TSB entries for a 16G page are created at every 4M boundary since the HUGE_TSB is used for these pages which is configured with page size of 4M. When walking page tables (on a TSB miss), bits [32:22] are transferred from vaddr to PUD to resolve addresses at 4M boundary. The resolved address mapping is then stored in HUGE_TSB. Patch 3/3: Patch 2 added the case of PUD entry being huge in page table walk and alloc functions. This new case further increased nesting in these functions and made them harder to follow. This patch flattens these functions for better readability. Cc: Nitin Gupta <nitin.m.gupta@xxxxxxxxxx> Cc: sparclinux@xxxxxxxxxxxxxxx Nitin Gupta (3): sparc64: Support huge PUD case in get_user_pages sparc64: Add 16GB hugepage support sparc64: Cleanup hugepage table walk functions arch/sparc/include/asm/page_64.h | 3 +- arch/sparc/include/asm/pgtable_64.h | 20 ++++++- arch/sparc/include/asm/tsb.h | 30 +++++++++++ arch/sparc/kernel/tsb.S | 2 +- arch/sparc/mm/gup.c | 47 ++++++++++++++++- arch/sparc/mm/hugetlbpage.c | 102 +++++++++++++++++++++--------------- arch/sparc/mm/init_64.c | 41 ++++++++++++--- 7 files changed, 191 insertions(+), 54 deletions(-) -- 2.9.2 -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
