From mboxrd@z Thu Jan 1 00:00:00 1970 From: robherring2@gmail.com (Rob Herring) Date: Fri, 8 Aug 2014 10:23:24 -0500 Subject: [PATCH] ARM: expand fixmap region to 3MB Message-ID: <1407511404-11997-1-git-send-email-robherring2@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Rob Herring With commit a05e54c103b0b8 "ARM: 8031/2: change fixmap mapping region to support 32 CPUs", the fixmap region was expanded to 2MB, but it precluded any other uses of the fixmap region in order to support up to 32 CPUs. In order to support other uses the fixmap region needs to be expanded beyond 2MB. Fortunately, the adjacent 1MB range 0xffe00000-0xfff00000 is availabe to use. Remove fixmap_page_table ptr and lookup the page table via the virtual address so that the fixmap region can span more that one pmd. The 2nd pmd is already created since it is shared with the vector page. Cc: Leif Lindholm Cc: Kees Cook Cc: Russell King Signed-off-by: Rob Herring --- This patch can come before or after the generic fixmap.h. There's a single line conflict with the ending address This worked for earlycon, but I've not done any highmem specific testing. My full series is available here: git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git fixmap Rob Documentation/arm/memory.txt | 2 +- arch/arm/include/asm/fixmap.h | 2 +- arch/arm/mm/highmem.c | 15 ++++++++------- arch/arm/mm/mmu.c | 2 +- 4 files changed, 11 insertions(+), 10 deletions(-) diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt index 38dc06d..4178ebd 100644 --- a/Documentation/arm/memory.txt +++ b/Documentation/arm/memory.txt @@ -41,7 +41,7 @@ fffe8000 fffeffff DTCM mapping area for platforms with fffe0000 fffe7fff ITCM mapping area for platforms with ITCM mounted inside the CPU. -ffc00000 ffdfffff Fixmap mapping region. Addresses provided +ffc00000 ffefffff Fixmap mapping region. Addresses provided by fix_to_virt() will be located here. fee00000 feffffff Mapping of PCI I/O space. This is a static diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index 74124b0..cb50cee 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -2,7 +2,7 @@ #define _ASM_FIXMAP_H #define FIXADDR_START 0xffc00000UL -#define FIXADDR_TOP 0xffe00000UL +#define FIXADDR_TOP 0xfff00000UL #define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START) #define FIX_KMAP_NR_PTES (FIXADDR_SIZE >> PAGE_SHIFT) diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c index 45aeaac..ac2938f 100644 --- a/arch/arm/mm/highmem.c +++ b/arch/arm/mm/highmem.c @@ -18,19 +18,20 @@ #include #include "mm.h" -pte_t *fixmap_page_table; - static inline void set_fixmap_pte(int idx, pte_t pte) { unsigned long vaddr = __fix_to_virt(idx); - set_pte_ext(fixmap_page_table + idx, pte, 0); + pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr); + + set_pte_ext(ptep, pte, 0); local_flush_tlb_kernel_page(vaddr); } static inline pte_t get_fixmap_pte(unsigned long vaddr) { - unsigned long idx = __virt_to_fix(vaddr); - return *(fixmap_page_table + idx); + pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr); + + return *ptep; } void *kmap(struct page *page) @@ -84,7 +85,7 @@ void *kmap_atomic(struct page *page) * With debugging enabled, kunmap_atomic forces that entry to 0. * Make sure it was indeed properly unmapped. */ - BUG_ON(!pte_none(*(fixmap_page_table + idx))); + BUG_ON(!pte_none(*get_fixmap_pte(vaddr))); #endif /* * When debugging is off, kunmap_atomic leaves the previous mapping @@ -134,7 +135,7 @@ void *kmap_atomic_pfn(unsigned long pfn) idx = type + KM_TYPE_NR * smp_processor_id(); vaddr = __fix_to_virt(idx); #ifdef CONFIG_DEBUG_HIGHMEM - BUG_ON(!pte_none(*(fixmap_page_table + idx))); + BUG_ON(!pte_none(*get_fixmap_pte(vaddr))); #endif set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot)); diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 8348ed6..5e5d0ba 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1327,7 +1327,7 @@ static void __init kmap_init(void) pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE), PKMAP_BASE, _PAGE_KERNEL_TABLE); - fixmap_page_table = early_pte_alloc(pmd_off_k(FIXADDR_START), + early_pte_alloc(pmd_off_k(FIXADDR_START), FIXADDR_START, _PAGE_KERNEL_TABLE); #endif } -- 1.9.1