From 325f8a0a31df567dbafafc48f8e60f3c1f101a46 Mon Sep 17 00:00:00 2001 From: David Daney Date: Fri, 4 Dec 2009 13:52:36 -0800 Subject: MIPS: Two-level pagetables for 64-bit kernels with 64KB pages. For 64-bit kernels with 64KB pages and two level page tables, there are 42 bits worth of virtual address space This is larger than the 40 bits of virtual address space obtained with the default 4KB Page size and three levels, so there are no draw backs for using two level tables with this configuration. Signed-off-by: David Daney Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/761/ Signed-off-by: Ralf Baechle --- arch/mips/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/mips/mm/init.c') diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index 1651942f7feb..3c5b7de10af5 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -477,7 +477,7 @@ unsigned long pgd_current[NR_CPUS]; * will officially be retired. */ pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER); -#ifdef CONFIG_64BIT +#ifndef __PAGETABLE_PMD_FOLDED pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER); #endif pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER); -- cgit v1.2.3 From 6dd9344cfc41bcc60a01cdc828cb278be7a10e01 Mon Sep 17 00:00:00 2001 From: David Daney Date: Wed, 10 Feb 2010 15:12:47 -0800 Subject: MIPS: Implement Read Inhibit/eXecute Inhibit The SmartMIPS ASE specifies how Read Inhibit (RI) and eXecute Inhibit (XI) bits in the page tables work. The upper two bits of EntryLo{0,1} are RI and XI when the feature is enabled in the PageGrain register. SmartMIPS only covers 32-bit systems. Cavium Octeon+ extends this to 64-bit systems by continuing to place the RI and XI bits in the top of EntryLo even when EntryLo is 64-bits wide. Because we need to carry the RI and XI bits in the PTE, the layout of the PTE is changed. There is a two instruction overhead in the TLB refill hot path to get the EntryLo bits into the proper position. Also the TLB load exception has to probe the TLB to check if RI or XI caused the exception. Also of note is that the layout of the PTE bits is done at compile and runtime rather than statically. In the 32-bit case this allows for the same number of PFN bits as before the patch as the _PAGE_HUGE is not supported in 32-bit kernels (we have _PAGE_NO_EXEC and _PAGE_NO_READ instead of _PAGE_READ and _PAGE_HUGE). The patch is tested on Cavium Octeon+, but should also work on 32-bit systems with the Smart-MIPS ASE. Signed-off-by: David Daney To: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/952/ Patchwork: http://patchwork.linux-mips.org/patch/956/ Patchwork: http://patchwork.linux-mips.org/patch/962/ Signed-off-by: Ralf Baechle --- arch/mips/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/mips/mm/init.c') diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index 3c5b7de10af5..f34c26439a32 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -143,7 +143,7 @@ void *kmap_coherent(struct page *page, unsigned long addr) #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32) entrylo = pte.pte_high; #else - entrylo = pte_val(pte) >> 6; + entrylo = pte_to_entrylo(pte_val(pte)); #endif ENTER_CRITICAL(flags); -- cgit v1.2.3