From b5666f70395016a55cc9d57826508b8a346398d0 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Mon, 5 Dec 2005 10:24:33 -0600 Subject: [PATCH] [PATCH] powerpc: Separate usage of KERNELBASE and PAGE_OFFSET This patch separates usage of KERNELBASE and PAGE_OFFSET. I haven't looked at any of the PPC32 code, if we ever want to support Kdump on PPC we'll have to do another audit, ditto for iSeries. This patch makes PAGE_OFFSET the constant, it'll always be 0xC * 1 gazillion for 64-bit. To get a physical address from a virtual one you subtract PAGE_OFFSET, _not_ KERNELBASE. KERNELBASE is the virtual address of the start of the kernel, it's often the same as PAGE_OFFSET, but _might not be_. If you want to know something's offset from the start of the kernel you should subtract KERNELBASE. Signed-off-by: Michael Ellerman Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/btext.c | 4 ++-- arch/powerpc/kernel/entry_64.S | 4 ++-- arch/powerpc/kernel/lparmap.c | 6 +++--- arch/powerpc/kernel/machine_kexec_64.c | 5 ++--- arch/powerpc/mm/hash_utils_64.c | 6 +++--- arch/powerpc/mm/slb.c | 4 ++-- arch/powerpc/mm/slb_low.S | 6 +++--- arch/powerpc/mm/stab.c | 10 +++++----- include/asm-powerpc/page.h | 16 +++++++++++++++- 9 files changed, 37 insertions(+), 24 deletions(-) diff --git a/arch/powerpc/kernel/btext.c b/arch/powerpc/kernel/btext.c index 893dd24a9f..5de0d80ca2 100644 --- a/arch/powerpc/kernel/btext.c +++ b/arch/powerpc/kernel/btext.c @@ -60,7 +60,7 @@ int force_printk_to_btext = 0; * * The display is mapped to virtual address 0xD0000000, rather * than 1:1, because some some CHRP machines put the frame buffer - * in the region starting at 0xC0000000 (KERNELBASE). + * in the region starting at 0xC0000000 (PAGE_OFFSET). * This mapping is temporary and will disappear as soon as the * setup done by MMU_Init() is applied. * @@ -71,7 +71,7 @@ int force_printk_to_btext = 0; */ void __init btext_prepare_BAT(void) { - unsigned long vaddr = KERNELBASE + 0x10000000; + unsigned long vaddr = PAGE_OFFSET + 0x10000000; unsigned long addr; unsigned long lowbits; diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 7b93971697..aacebb33e9 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -690,7 +690,7 @@ _GLOBAL(enter_rtas) /* Setup our real return addr */ SET_REG_TO_LABEL(r4,.rtas_return_loc) - SET_REG_TO_CONST(r9,KERNELBASE) + SET_REG_TO_CONST(r9,PAGE_OFFSET) sub r4,r4,r9 mtlr r4 @@ -718,7 +718,7 @@ _GLOBAL(enter_rtas) _STATIC(rtas_return_loc) /* relocation is off at this point */ mfspr r4,SPRN_SPRG3 /* Get PACA */ - SET_REG_TO_CONST(r5, KERNELBASE) + SET_REG_TO_CONST(r5, PAGE_OFFSET) sub r4,r4,r5 /* RELOC the PACA base pointer */ mfmsr r6 diff --git a/arch/powerpc/kernel/lparmap.c b/arch/powerpc/kernel/lparmap.c index 5a05a79748..8a53d436ad 100644 --- a/arch/powerpc/kernel/lparmap.c +++ b/arch/powerpc/kernel/lparmap.c @@ -16,8 +16,8 @@ const struct LparMap __attribute__((__section__(".text"))) xLparMap = { .xSegmentTableOffs = STAB0_PAGE, .xEsids = { - { .xKernelEsid = GET_ESID(KERNELBASE), - .xKernelVsid = KERNEL_VSID(KERNELBASE), }, + { .xKernelEsid = GET_ESID(PAGE_OFFSET), + .xKernelVsid = KERNEL_VSID(PAGE_OFFSET), }, { .xKernelEsid = GET_ESID(VMALLOCBASE), .xKernelVsid = KERNEL_VSID(VMALLOCBASE), }, }, @@ -25,7 +25,7 @@ const struct LparMap __attribute__((__section__(".text"))) xLparMap = { .xRanges = { { .xPages = HvPagesToMap, .xOffset = 0, - .xVPN = KERNEL_VSID(KERNELBASE) << (SID_SHIFT - HW_PAGE_SHIFT), + .xVPN = KERNEL_VSID(PAGE_OFFSET) << (SID_SHIFT - HW_PAGE_SHIFT), }, }, }; diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c index ec0f06bfc2..0b0fa47689 100644 --- a/arch/powerpc/kernel/machine_kexec_64.c +++ b/arch/powerpc/kernel/machine_kexec_64.c @@ -153,9 +153,8 @@ void kexec_copy_flush(struct kimage *image) * including ones that were in place on the original copy */ for (i = 0; i < nr_segments; i++) - flush_icache_range(ranges[i].mem + KERNELBASE, - ranges[i].mem + KERNELBASE + - ranges[i].memsz); + flush_icache_range((unsigned long)__va(ranges[i].mem), + (unsigned long)__va(ranges[i].mem + ranges[i].memsz)); } #ifdef CONFIG_SMP diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 846a1894cf..5bb433cbe4 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -456,7 +456,7 @@ void __init htab_initialize(void) /* create bolted the linear mapping in the hash table */ for (i=0; i < lmb.memory.cnt; i++) { - base = lmb.memory.region[i].base + KERNELBASE; + base = (unsigned long)__va(lmb.memory.region[i].base); size = lmb.memory.region[i].size; DBG("creating mapping for region: %lx : %lx\n", base, size); @@ -498,8 +498,8 @@ void __init htab_initialize(void) * for either 4K or 16MB pages. */ if (tce_alloc_start) { - tce_alloc_start += KERNELBASE; - tce_alloc_end += KERNELBASE; + tce_alloc_start = (unsigned long)__va(tce_alloc_start); + tce_alloc_end = (unsigned long)__va(tce_alloc_end); if (base + size >= tce_alloc_start) tce_alloc_start = base + size + 1; diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c index a47b273600..cc22570856 100644 --- a/arch/powerpc/mm/slb.c +++ b/arch/powerpc/mm/slb.c @@ -75,7 +75,7 @@ static void slb_flush_and_rebolt(void) vflags = SLB_VSID_KERNEL | virtual_llp; ksp_esid_data = mk_esid_data(get_paca()->kstack, 2); - if ((ksp_esid_data & ESID_MASK) == KERNELBASE) + if ((ksp_esid_data & ESID_MASK) == PAGE_OFFSET) ksp_esid_data &= ~SLB_ESID_V; /* We need to do this all in asm, so we're sure we don't touch @@ -213,7 +213,7 @@ void slb_initialize(void) asm volatile("isync":::"memory"); asm volatile("slbmte %0,%0"::"r" (0) : "memory"); asm volatile("isync; slbia; isync":::"memory"); - create_slbe(KERNELBASE, lflags, 0); + create_slbe(PAGE_OFFSET, lflags, 0); /* VMALLOC space has 4K pages always for now */ create_slbe(VMALLOCBASE, vflags, 1); diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S index 950ffc5848..d1acee38f1 100644 --- a/arch/powerpc/mm/slb_low.S +++ b/arch/powerpc/mm/slb_low.S @@ -37,9 +37,9 @@ _GLOBAL(slb_allocate_realmode) srdi r9,r3,60 /* get region */ srdi r10,r3,28 /* get esid */ - cmpldi cr7,r9,0xc /* cmp KERNELBASE for later use */ + cmpldi cr7,r9,0xc /* cmp PAGE_OFFSET for later use */ - /* r3 = address, r10 = esid, cr7 = <>KERNELBASE */ + /* r3 = address, r10 = esid, cr7 = <> PAGE_OFFSET */ blt cr7,0f /* user or kernel? */ /* kernel address: proto-VSID = ESID */ @@ -166,7 +166,7 @@ _GLOBAL(slb_allocate_user) /* * Finish loading of an SLB entry and return * - * r3 = EA, r10 = proto-VSID, r11 = flags, clobbers r9, cr7 = <>KERNELBASE + * r3 = EA, r10 = proto-VSID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET */ slb_finish_load: ASM_VSID_SCRAMBLE(r10,r9) diff --git a/arch/powerpc/mm/stab.c b/arch/powerpc/mm/stab.c index a18dab0d6b..82e4951826 100644 --- a/arch/powerpc/mm/stab.c +++ b/arch/powerpc/mm/stab.c @@ -40,7 +40,7 @@ static int make_ste(unsigned long stab, unsigned long esid, unsigned long vsid) unsigned long entry, group, old_esid, castout_entry, i; unsigned int global_entry; struct stab_entry *ste, *castout_ste; - unsigned long kernel_segment = (esid << SID_SHIFT) >= KERNELBASE; + unsigned long kernel_segment = (esid << SID_SHIFT) >= PAGE_OFFSET; vsid_data = vsid << STE_VSID_SHIFT; esid_data = esid << SID_SHIFT | STE_ESID_KP | STE_ESID_V; @@ -83,7 +83,7 @@ static int make_ste(unsigned long stab, unsigned long esid, unsigned long vsid) } /* Dont cast out the first kernel segment */ - if ((castout_ste->esid_data & ESID_MASK) != KERNELBASE) + if ((castout_ste->esid_data & ESID_MASK) != PAGE_OFFSET) break; castout_entry = (castout_entry + 1) & 0xf; @@ -251,7 +251,7 @@ void stabs_alloc(void) panic("Unable to allocate segment table for CPU %d.\n", cpu); - newstab += KERNELBASE; + newstab = (unsigned long)__va(newstab); memset((void *)newstab, 0, HW_PAGE_SIZE); @@ -270,11 +270,11 @@ void stabs_alloc(void) */ void stab_initialize(unsigned long stab) { - unsigned long vsid = get_kernel_vsid(KERNELBASE); + unsigned long vsid = get_kernel_vsid(PAGE_OFFSET); unsigned long stabreal; asm volatile("isync; slbia; isync":::"memory"); - make_ste(stab, GET_ESID(KERNELBASE), vsid); + make_ste(stab, GET_ESID(PAGE_OFFSET), vsid); /* Order update */ asm volatile("sync":::"memory"); diff --git a/include/asm-powerpc/page.h b/include/asm-powerpc/page.h index 94905ba2cf..4696bdbcc0 100644 --- a/include/asm-powerpc/page.h +++ b/include/asm-powerpc/page.h @@ -37,6 +37,20 @@ */ #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) +/* + * KERNELBASE is the virtual address of the start of the kernel, it's often + * the same as PAGE_OFFSET, but _might not be_. + * + * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET. + * + * To get a physical address from a virtual one you subtract PAGE_OFFSET, + * _not_ KERNELBASE. + * + * If you want to know something's offset from the start of the kernel you + * should subtract KERNELBASE. + * + * If you want to test if something's a kernel address, use is_kernel_addr(). + */ #define PAGE_OFFSET ASM_CONST(CONFIG_KERNEL_START) #define KERNELBASE PAGE_OFFSET @@ -56,7 +70,7 @@ #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) -#define __va(x) ((void *)((unsigned long)(x) + KERNELBASE)) +#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET)) #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET) /* -- 2.39.5