| /* |
| * PowerPC64 port by Mike Corrigan and Dave Engebretsen |
| * {mikejc|engebret}@us.ibm.com |
| * |
| * Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com> |
| * |
| * SMP scalability work: |
| * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM |
| * |
| * Module name: htab.c |
| * |
| * Description: |
| * PowerPC Hashed Page Table functions |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #undef DEBUG |
| #undef DEBUG_LOW |
| |
| #include <linux/spinlock.h> |
| #include <linux/errno.h> |
| #include <linux/sched.h> |
| #include <linux/proc_fs.h> |
| #include <linux/stat.h> |
| #include <linux/sysctl.h> |
| #include <linux/ctype.h> |
| #include <linux/cache.h> |
| #include <linux/init.h> |
| #include <linux/signal.h> |
| #include <linux/memblock.h> |
| |
| #include <asm/processor.h> |
| #include <asm/pgtable.h> |
| #include <asm/mmu.h> |
| #include <asm/mmu_context.h> |
| #include <asm/page.h> |
| #include <asm/types.h> |
| #include <asm/system.h> |
| #include <asm/uaccess.h> |
| #include <asm/machdep.h> |
| #include <asm/prom.h> |
| #include <asm/abs_addr.h> |
| #include <asm/tlbflush.h> |
| #include <asm/io.h> |
| #include <asm/eeh.h> |
| #include <asm/tlb.h> |
| #include <asm/cacheflush.h> |
| #include <asm/cputable.h> |
| #include <asm/sections.h> |
| #include <asm/spu.h> |
| #include <asm/udbg.h> |
| |
| #ifdef DEBUG |
| #define DBG(fmt...) udbg_printf(fmt) |
| #else |
| #define DBG(fmt...) |
| #endif |
| |
| #ifdef DEBUG_LOW |
| #define DBG_LOW(fmt...) udbg_printf(fmt) |
| #else |
| #define DBG_LOW(fmt...) |
| #endif |
| |
| #define KB (1024) |
| #define MB (1024*KB) |
| #define GB (1024L*MB) |
| |
| /* |
| * Note: pte --> Linux PTE |
| * HPTE --> PowerPC Hashed Page Table Entry |
| * |
| * Execution context: |
| * htab_initialize is called with the MMU off (of course), but |
| * the kernel has been copied down to zero so it can directly |
| * reference global data. At this point it is very difficult |
| * to print debug info. |
| * |
| */ |
| |
| #ifdef CONFIG_U3_DART |
| extern unsigned long dart_tablebase; |
| #endif /* CONFIG_U3_DART */ |
| |
| static unsigned long _SDR1; |
| struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT]; |
| |
| struct hash_pte *htab_address; |
| unsigned long htab_size_bytes; |
| unsigned long htab_hash_mask; |
| EXPORT_SYMBOL_GPL(htab_hash_mask); |
| int mmu_linear_psize = MMU_PAGE_4K; |
| int mmu_virtual_psize = MMU_PAGE_4K; |
| int mmu_vmalloc_psize = MMU_PAGE_4K; |
| #ifdef CONFIG_SPARSEMEM_VMEMMAP |
| int mmu_vmemmap_psize = MMU_PAGE_4K; |
| #endif |
| int mmu_io_psize = MMU_PAGE_4K; |
| int mmu_kernel_ssize = MMU_SEGSIZE_256M; |
| int mmu_highuser_ssize = MMU_SEGSIZE_256M; |
| u16 mmu_slb_size = 64; |
| EXPORT_SYMBOL_GPL(mmu_slb_size); |
| #ifdef CONFIG_HUGETLB_PAGE |
| unsigned int HPAGE_SHIFT; |
| #endif |
| #ifdef CONFIG_PPC_64K_PAGES |
| int mmu_ci_restrictions; |
| #endif |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| static u8 *linear_map_hash_slots; |
| static unsigned long linear_map_hash_count; |
| static DEFINE_SPINLOCK(linear_map_hash_lock); |
| #endif /* CONFIG_DEBUG_PAGEALLOC */ |
| |
| /* There are definitions of page sizes arrays to be used when none |
| * is provided by the firmware. |
| */ |
| |
| /* Pre-POWER4 CPUs (4k pages only) |
| */ |
| static struct mmu_psize_def mmu_psize_defaults_old[] = { |
| [MMU_PAGE_4K] = { |
| .shift = 12, |
| .sllp = 0, |
| .penc = 0, |
| .avpnm = 0, |
| .tlbiel = 0, |
| }, |
| }; |
| |
| /* POWER4, GPUL, POWER5 |
| * |
| * Support for 16Mb large pages |
| */ |
| static struct mmu_psize_def mmu_psize_defaults_gp[] = { |
| [MMU_PAGE_4K] = { |
| .shift = 12, |
| .sllp = 0, |
| .penc = 0, |
| .avpnm = 0, |
| .tlbiel = 1, |
| }, |
| [MMU_PAGE_16M] = { |
| .shift = 24, |
| .sllp = SLB_VSID_L, |
| .penc = 0, |
| .avpnm = 0x1UL, |
| .tlbiel = 0, |
| }, |
| }; |
| |
| static unsigned long htab_convert_pte_flags(unsigned long pteflags) |
| { |
| unsigned long rflags = pteflags & 0x1fa; |
| |
| /* _PAGE_EXEC -> NOEXEC */ |
| if ((pteflags & _PAGE_EXEC) == 0) |
| rflags |= HPTE_R_N; |
| |
| /* PP bits. PAGE_USER is already PP bit 0x2, so we only |
| * need to add in 0x1 if it's a read-only user page |
| */ |
| if ((pteflags & _PAGE_USER) && !((pteflags & _PAGE_RW) && |
| (pteflags & _PAGE_DIRTY))) |
| rflags |= 1; |
| |
| /* Always add C */ |
| return rflags | HPTE_R_C; |
| } |
| |
| int htab_bolt_mapping(unsigned long vstart, unsigned long vend, |
| unsigned long pstart, unsigned long prot, |
| int psize, int ssize) |
| { |
| unsigned long vaddr, paddr; |
| unsigned int step, shift; |
| int ret = 0; |
| |
| shift = mmu_psize_defs[psize].shift; |
| step = 1 << shift; |
| |
| prot = htab_convert_pte_flags(prot); |
| |
| DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n", |
| vstart, vend, pstart, prot, psize, ssize); |
| |
| for (vaddr = vstart, paddr = pstart; vaddr < vend; |
| vaddr += step, paddr += step) { |
| unsigned long hash, hpteg; |
| unsigned long vsid = get_kernel_vsid(vaddr, ssize); |
| unsigned long va = hpt_va(vaddr, vsid, ssize); |
| unsigned long tprot = prot; |
| |
| /* Make kernel text executable */ |
| if (overlaps_kernel_text(vaddr, vaddr + step)) |
| tprot &= ~HPTE_R_N; |
| |
| hash = hpt_hash(va, shift, ssize); |
| hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP); |
| |
| BUG_ON(!ppc_md.hpte_insert); |
| ret = ppc_md.hpte_insert(hpteg, va, paddr, tprot, |
| HPTE_V_BOLTED, psize, ssize); |
| |
| if (ret < 0) |
| break; |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| if ((paddr >> PAGE_SHIFT) < linear_map_hash_count) |
| linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80; |
| #endif /* CONFIG_DEBUG_PAGEALLOC */ |
| } |
| return ret < 0 ? ret : 0; |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTPLUG |
| static int htab_remove_mapping(unsigned long vstart, unsigned long vend, |
| int psize, int ssize) |
| { |
| unsigned long vaddr; |
| unsigned int step, shift; |
| |
| shift = mmu_psize_defs[psize].shift; |
| step = 1 << shift; |
| |
| if (!ppc_md.hpte_removebolted) { |
| printk(KERN_WARNING "Platform doesn't implement " |
| "hpte_removebolted\n"); |
| return -EINVAL; |
| } |
| |
| for (vaddr = vstart; vaddr < vend; vaddr += step) |
| ppc_md.hpte_removebolted(vaddr, psize, ssize); |
| |
| return 0; |
| } |
| #endif /* CONFIG_MEMORY_HOTPLUG */ |
| |
| static int __init htab_dt_scan_seg_sizes(unsigned long node, |
| const char *uname, int depth, |
| void *data) |
| { |
| char *type = of_get_flat_dt_prop(node, "device_type", NULL); |
| u32 *prop; |
| unsigned long size = 0; |
| |
| /* We are scanning "cpu" nodes only */ |
| if (type == NULL || strcmp(type, "cpu") != 0) |
| return 0; |
| |
| prop = (u32 *)of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", |
| &size); |
| if (prop == NULL) |
| return 0; |
| for (; size >= 4; size -= 4, ++prop) { |
| if (prop[0] == 40) { |
| DBG("1T segment support detected\n"); |
| cur_cpu_spec->cpu_features |= CPU_FTR_1T_SEGMENT; |
| return 1; |
| } |
| } |
| cur_cpu_spec->cpu_features &= ~CPU_FTR_NO_SLBIE_B; |
| return 0; |
| } |
| |
| static void __init htab_init_seg_sizes(void) |
| { |
| of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL); |
| } |
| |
| static int __init htab_dt_scan_page_sizes(unsigned long node, |
| const char *uname, int depth, |
| void *data) |
| { |
| char *type = of_get_flat_dt_prop(node, "device_type", NULL); |
| u32 *prop; |
| unsigned long size = 0; |
| |
| /* We are scanning "cpu" nodes only */ |
| if (type == NULL || strcmp(type, "cpu") != 0) |
| return 0; |
| |
| prop = (u32 *)of_get_flat_dt_prop(node, |
| "ibm,segment-page-sizes", &size); |
| if (prop != NULL) { |
| DBG("Page sizes from device-tree:\n"); |
| size /= 4; |
| cur_cpu_spec->cpu_features &= ~(CPU_FTR_16M_PAGE); |
| while(size > 0) { |
| unsigned int shift = prop[0]; |
| unsigned int slbenc = prop[1]; |
| unsigned int lpnum = prop[2]; |
| unsigned int lpenc = 0; |
| struct mmu_psize_def *def; |
| int idx = -1; |
| |
| size -= 3; prop += 3; |
| while(size > 0 && lpnum) { |
| if (prop[0] == shift) |
| lpenc = prop[1]; |
| prop += 2; size -= 2; |
| lpnum--; |
| } |
| switch(shift) { |
| case 0xc: |
| idx = MMU_PAGE_4K; |
| break; |
| case 0x10: |
| idx = MMU_PAGE_64K; |
| break; |
| case 0x14: |
| idx = MMU_PAGE_1M; |
| break; |
| case 0x18: |
| idx = MMU_PAGE_16M; |
| cur_cpu_spec->cpu_features |= CPU_FTR_16M_PAGE; |
| break; |
| case 0x22: |
| idx = MMU_PAGE_16G; |
| break; |
| } |
| if (idx < 0) |
| continue; |
| def = &mmu_psize_defs[idx]; |
| def->shift = shift; |
| if (shift <= 23) |
| def->avpnm = 0; |
| else |
| def->avpnm = (1 << (shift - 23)) - 1; |
| def->sllp = slbenc; |
| def->penc = lpenc; |
| /* We don't know for sure what's up with tlbiel, so |
| * for now we only set it for 4K and 64K pages |
| */ |
| if (idx == MMU_PAGE_4K || idx == MMU_PAGE_64K) |
| def->tlbiel = 1; |
| else |
| def->tlbiel = 0; |
| |
| DBG(" %d: shift=%02x, sllp=%04lx, avpnm=%08lx, " |
| "tlbiel=%d, penc=%d\n", |
| idx, shift, def->sllp, def->avpnm, def->tlbiel, |
| def->penc); |
| } |
| return 1; |
| } |
| return 0; |
| } |
| |
| #ifdef CONFIG_HUGETLB_PAGE |
| /* Scan for 16G memory blocks that have been set aside for huge pages |
| * and reserve those blocks for 16G huge pages. |
| */ |
| static int __init htab_dt_scan_hugepage_blocks(unsigned long node, |
| const char *uname, int depth, |
| void *data) { |
| char *type = of_get_flat_dt_prop(node, "device_type", NULL); |
| unsigned long *addr_prop; |
| u32 *page_count_prop; |
| unsigned int expected_pages; |
| long unsigned int phys_addr; |
| long unsigned int block_size; |
| |
| /* We are scanning "memory" nodes only */ |
| if (type == NULL || strcmp(type, "memory") != 0) |
| return 0; |
| |
| /* This property is the log base 2 of the number of virtual pages that |
| * will represent this memory block. */ |
| page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL); |
| if (page_count_prop == NULL) |
| return 0; |
| expected_pages = (1 << page_count_prop[0]); |
| addr_prop = of_get_flat_dt_prop(node, "reg", NULL); |
| if (addr_prop == NULL) |
| return 0; |
| phys_addr = addr_prop[0]; |
| block_size = addr_prop[1]; |
| if (block_size != (16 * GB)) |
| return 0; |
| printk(KERN_INFO "Huge page(16GB) memory: " |
| "addr = 0x%lX size = 0x%lX pages = %d\n", |
| phys_addr, block_size, expected_pages); |
| if (phys_addr + (16 * GB) <= memblock_end_of_DRAM()) { |
| memblock_reserve(phys_addr, block_size * expected_pages); |
| add_gpage(phys_addr, block_size, expected_pages); |
| } |
| return 0; |
| } |
| #endif /* CONFIG_HUGETLB_PAGE */ |
| |
| static void __init htab_init_page_sizes(void) |
| { |
| int rc; |
| |
| /* Default to 4K pages only */ |
| memcpy(mmu_psize_defs, mmu_psize_defaults_old, |
| sizeof(mmu_psize_defaults_old)); |
| |
| /* |
| * Try to find the available page sizes in the device-tree |
| */ |
| rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL); |
| if (rc != 0) /* Found */ |
| goto found; |
| |
| /* |
| * Not in the device-tree, let's fallback on known size |
| * list for 16M capable GP & GR |
| */ |
| if (cpu_has_feature(CPU_FTR_16M_PAGE)) |
| memcpy(mmu_psize_defs, mmu_psize_defaults_gp, |
| sizeof(mmu_psize_defaults_gp)); |
| found: |
| #ifndef CONFIG_DEBUG_PAGEALLOC |
| /* |
| * Pick a size for the linear mapping. Currently, we only support |
| * 16M, 1M and 4K which is the default |
| */ |
| if (mmu_psize_defs[MMU_PAGE_16M].shift) |
| mmu_linear_psize = MMU_PAGE_16M; |
| else if (mmu_psize_defs[MMU_PAGE_1M].shift) |
| mmu_linear_psize = MMU_PAGE_1M; |
| #endif /* CONFIG_DEBUG_PAGEALLOC */ |
| |
| #ifdef CONFIG_PPC_64K_PAGES |
| /* |
| * Pick a size for the ordinary pages. Default is 4K, we support |
| * 64K for user mappings and vmalloc if supported by the processor. |
| * We only use 64k for ioremap if the processor |
| * (and firmware) support cache-inhibited large pages. |
| * If not, we use 4k and set mmu_ci_restrictions so that |
| * hash_page knows to switch processes that use cache-inhibited |
| * mappings to 4k pages. |
| */ |
| if (mmu_psize_defs[MMU_PAGE_64K].shift) { |
| mmu_virtual_psize = MMU_PAGE_64K; |
| mmu_vmalloc_psize = MMU_PAGE_64K; |
| if (mmu_linear_psize == MMU_PAGE_4K) |
| mmu_linear_psize = MMU_PAGE_64K; |
| if (cpu_has_feature(CPU_FTR_CI_LARGE_PAGE)) { |
| /* |
| * Don't use 64k pages for ioremap on pSeries, since |
| * that would stop us accessing the HEA ethernet. |
| */ |
| if (!machine_is(pseries)) |
| mmu_io_psize = MMU_PAGE_64K; |
| } else |
| mmu_ci_restrictions = 1; |
| } |
| #endif /* CONFIG_PPC_64K_PAGES */ |
| |
| #ifdef CONFIG_SPARSEMEM_VMEMMAP |
| /* We try to use 16M pages for vmemmap if that is supported |
| * and we have at least 1G of RAM at boot |
| */ |
| if (mmu_psize_defs[MMU_PAGE_16M].shift && |
| memblock_phys_mem_size() >= 0x40000000) |
| mmu_vmemmap_psize = MMU_PAGE_16M; |
| else if (mmu_psize_defs[MMU_PAGE_64K].shift) |
| mmu_vmemmap_psize = MMU_PAGE_64K; |
| else |
| mmu_vmemmap_psize = MMU_PAGE_4K; |
| #endif /* CONFIG_SPARSEMEM_VMEMMAP */ |
| |
| printk(KERN_DEBUG "Page orders: linear mapping = %d, " |
| "virtual = %d, io = %d" |
| #ifdef CONFIG_SPARSEMEM_VMEMMAP |
| ", vmemmap = %d" |
| #endif |
| "\n", |
| mmu_psize_defs[mmu_linear_psize].shift, |
| mmu_psize_defs[mmu_virtual_psize].shift, |
| mmu_psize_defs[mmu_io_psize].shift |
| #ifdef CONFIG_SPARSEMEM_VMEMMAP |
| ,mmu_psize_defs[mmu_vmemmap_psize].shift |
| #endif |
| ); |
| |
| #ifdef CONFIG_HUGETLB_PAGE |
| /* Reserve 16G huge page memory sections for huge pages */ |
| of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL); |
| #endif /* CONFIG_HUGETLB_PAGE */ |
| } |
| |
| static int __init htab_dt_scan_pftsize(unsigned long node, |
| const char *uname, int depth, |
| void *data) |
| { |
| char *type = of_get_flat_dt_prop(node, "device_type", NULL); |
| u32 *prop; |
| |
| /* We are scanning "cpu" nodes only */ |
| if (type == NULL || strcmp(type, "cpu") != 0) |
| return 0; |
| |
| prop = (u32 *)of_get_flat_dt_prop(node, "ibm,pft-size", NULL); |
| if (prop != NULL) { |
| /* pft_size[0] is the NUMA CEC cookie */ |
| ppc64_pft_size = prop[1]; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static unsigned long __init htab_get_table_size(void) |
| { |
| unsigned long mem_size, rnd_mem_size, pteg_count, psize; |
| |
| /* If hash size isn't already provided by the platform, we try to |
| * retrieve it from the device-tree. If it's not there neither, we |
| * calculate it now based on the total RAM size |
| */ |
| if (ppc64_pft_size == 0) |
| of_scan_flat_dt(htab_dt_scan_pftsize, NULL); |
| if (ppc64_pft_size) |
| return 1UL << ppc64_pft_size; |
| |
| /* round mem_size up to next power of 2 */ |
| mem_size = memblock_phys_mem_size(); |
| rnd_mem_size = 1UL << __ilog2(mem_size); |
| if (rnd_mem_size < mem_size) |
| rnd_mem_size <<= 1; |
| |
| /* # pages / 2 */ |
| psize = mmu_psize_defs[mmu_virtual_psize].shift; |
| pteg_count = max(rnd_mem_size >> (psize + 1), 1UL << 11); |
| |
| return pteg_count << 7; |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTPLUG |
| void create_section_mapping(unsigned long start, unsigned long end) |
| { |
| BUG_ON(htab_bolt_mapping(start, end, __pa(start), |
| pgprot_val(PAGE_KERNEL), mmu_linear_psize, |
| mmu_kernel_ssize)); |
| } |
| |
| int remove_section_mapping(unsigned long start, unsigned long end) |
| { |
| return htab_remove_mapping(start, end, mmu_linear_psize, |
| mmu_kernel_ssize); |
| } |
| #endif /* CONFIG_MEMORY_HOTPLUG */ |
| |
| static inline void make_bl(unsigned int *insn_addr, void *func) |
| { |
| unsigned long funcp = *((unsigned long *)func); |
| int offset = funcp - (unsigned long)insn_addr; |
| |
| *insn_addr = (unsigned int)(0x48000001 | (offset & 0x03fffffc)); |
| flush_icache_range((unsigned long)insn_addr, 4+ |
| (unsigned long)insn_addr); |
| } |
| |
| static void __init htab_finish_init(void) |
| { |
| extern unsigned int *htab_call_hpte_insert1; |
| extern unsigned int *htab_call_hpte_insert2; |
| extern unsigned int *htab_call_hpte_remove; |
| extern unsigned int *htab_call_hpte_updatepp; |
| |
| #ifdef CONFIG_PPC_HAS_HASH_64K |
| extern unsigned int *ht64_call_hpte_insert1; |
| extern unsigned int *ht64_call_hpte_insert2; |
| extern unsigned int *ht64_call_hpte_remove; |
| extern unsigned int *ht64_call_hpte_updatepp; |
| |
| make_bl(ht64_call_hpte_insert1, ppc_md.hpte_insert); |
| make_bl(ht64_call_hpte_insert2, ppc_md.hpte_insert); |
| make_bl(ht64_call_hpte_remove, ppc_md.hpte_remove); |
| make_bl(ht64_call_hpte_updatepp, ppc_md.hpte_updatepp); |
| #endif /* CONFIG_PPC_HAS_HASH_64K */ |
| |
| make_bl(htab_call_hpte_insert1, ppc_md.hpte_insert); |
| make_bl(htab_call_hpte_insert2, ppc_md.hpte_insert); |
| make_bl(htab_call_hpte_remove, ppc_md.hpte_remove); |
| make_bl(htab_call_hpte_updatepp, ppc_md.hpte_updatepp); |
| } |
| |
| static void __init htab_initialize(void) |
| { |
| unsigned long table; |
| unsigned long pteg_count; |
| unsigned long prot; |
| unsigned long base = 0, size = 0, limit; |
| struct memblock_region *reg; |
| |
| DBG(" -> htab_initialize()\n"); |
| |
| /* Initialize segment sizes */ |
| htab_init_seg_sizes(); |
| |
| /* Initialize page sizes */ |
| htab_init_page_sizes(); |
| |
| if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) { |
| mmu_kernel_ssize = MMU_SEGSIZE_1T; |
| mmu_highuser_ssize = MMU_SEGSIZE_1T; |
| printk(KERN_INFO "Using 1TB segments\n"); |
| } |
| |
| /* |
| * Calculate the required size of the htab. We want the number of |
| * PTEGs to equal one half the number of real pages. |
| */ |
| htab_size_bytes = htab_get_table_size(); |
| pteg_count = htab_size_bytes >> 7; |
| |
| htab_hash_mask = pteg_count - 1; |
| |
| if (firmware_has_feature(FW_FEATURE_LPAR)) { |
| /* Using a hypervisor which owns the htab */ |
| htab_address = NULL; |
| _SDR1 = 0; |
| } else { |
| /* Find storage for the HPT. Must be contiguous in |
| * the absolute address space. On cell we want it to be |
| * in the first 2 Gig so we can use it for IOMMU hacks. |
| */ |
| if (machine_is(cell)) |
| limit = 0x80000000; |
| else |
| limit = MEMBLOCK_ALLOC_ANYWHERE; |
| |
| table = memblock_alloc_base(htab_size_bytes, htab_size_bytes, limit); |
| |
| DBG("Hash table allocated at %lx, size: %lx\n", table, |
| htab_size_bytes); |
| |
| htab_address = abs_to_virt(table); |
| |
| /* htab absolute addr + encoded htabsize */ |
| _SDR1 = table + __ilog2(pteg_count) - 11; |
| |
| /* Initialize the HPT with no entries */ |
| memset((void *)table, 0, htab_size_bytes); |
| |
| /* Set SDR1 */ |
| mtspr(SPRN_SDR1, _SDR1); |
| } |
| |
| prot = pgprot_val(PAGE_KERNEL); |
| |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT; |
| linear_map_hash_slots = __va(memblock_alloc_base(linear_map_hash_count, |
| 1, ppc64_rma_size)); |
| memset(linear_map_hash_slots, 0, linear_map_hash_count); |
| #endif /* CONFIG_DEBUG_PAGEALLOC */ |
| |
| /* On U3 based machines, we need to reserve the DART area and |
| * _NOT_ map it to avoid cache paradoxes as it's remapped non |
| * cacheable later on |
| */ |
| |
| /* create bolted the linear mapping in the hash table */ |
| for_each_memblock(memory, reg) { |
| base = (unsigned long)__va(reg->base); |
| size = reg->size; |
| |
| DBG("creating mapping for region: %lx..%lx (prot: %lx)\n", |
| base, size, prot); |
| |
| #ifdef CONFIG_U3_DART |
| /* Do not map the DART space. Fortunately, it will be aligned |
| * in such a way that it will not cross two memblock regions and |
| * will fit within a single 16Mb page. |
| * The DART space is assumed to be a full 16Mb region even if |
| * we only use 2Mb of that space. We will use more of it later |
| * for AGP GART. We have to use a full 16Mb large page. |
| */ |
| DBG("DART base: %lx\n", dart_tablebase); |
| |
| if (dart_tablebase != 0 && dart_tablebase >= base |
| && dart_tablebase < (base + size)) { |
| unsigned long dart_table_end = dart_tablebase + 16 * MB; |
| if (base != dart_tablebase) |
| BUG_ON(htab_bolt_mapping(base, dart_tablebase, |
| __pa(base), prot, |
| mmu_linear_psize, |
| mmu_kernel_ssize)); |
| if ((base + size) > dart_table_end) |
| BUG_ON(htab_bolt_mapping(dart_tablebase+16*MB, |
| base + size, |
| __pa(dart_table_end), |
| prot, |
| mmu_linear_psize, |
| mmu_kernel_ssize)); |
| continue; |
| } |
| #endif /* CONFIG_U3_DART */ |
| BUG_ON(htab_bolt_mapping(base, base + size, __pa(base), |
| prot, mmu_linear_psize, mmu_kernel_ssize)); |
| } |
| memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); |
| |
| /* |
| * If we have a memory_limit and we've allocated TCEs then we need to |
| * explicitly map the TCE area at the top of RAM. We also cope with the |
| * case that the TCEs start below memory_limit. |
| * tce_alloc_start/end are 16MB aligned so the mapping should work |
| * for either 4K or 16MB pages. |
| */ |
| if (tce_alloc_start) { |
| 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; |
| |
| BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end, |
| __pa(tce_alloc_start), prot, |
| mmu_linear_psize, mmu_kernel_ssize)); |
| } |
| |
| htab_finish_init(); |
| |
| DBG(" <- htab_initialize()\n"); |
| } |
| #undef KB |
| #undef MB |
| |
| void __init early_init_mmu(void) |
| { |
| /* Setup initial STAB address in the PACA */ |
| get_paca()->stab_real = __pa((u64)&initial_stab); |
| get_paca()->stab_addr = (u64)&initial_stab; |
| |
| /* Initialize the MMU Hash table and create the linear mapping |
| * of memory. Has to be done before stab/slb initialization as |
| * this is currently where the page size encoding is obtained |
| */ |
| htab_initialize(); |
| |
| /* Initialize stab / SLB management except on iSeries |
| */ |
| if (cpu_has_feature(CPU_FTR_SLB)) |
| slb_initialize(); |
| else if (!firmware_has_feature(FW_FEATURE_ISERIES)) |
| stab_initialize(get_paca()->stab_real); |
| } |
| |
| #ifdef CONFIG_SMP |
| void __cpuinit early_init_mmu_secondary(void) |
| { |
| /* Initialize hash table for that CPU */ |
| if (!firmware_has_feature(FW_FEATURE_LPAR)) |
| mtspr(SPRN_SDR1, _SDR1); |
| |
| /* Initialize STAB/SLB. We use a virtual address as it works |
| * in real mode on pSeries and we want a virutal address on |
| * iSeries anyway |
| */ |
| if (cpu_has_feature(CPU_FTR_SLB)) |
| slb_initialize(); |
| else |
| stab_initialize(get_paca()->stab_addr); |
| } |
| #endif /* CONFIG_SMP */ |
| |
| /* |
| * Called by asm hashtable.S for doing lazy icache flush |
| */ |
| unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap) |
| { |
| struct page *page; |
| |
| if (!pfn_valid(pte_pfn(pte))) |
| return pp; |
| |
| page = pte_page(pte); |
| |
| /* page is dirty */ |
| if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) { |
| if (trap == 0x400) { |
| flush_dcache_icache_page(page); |
| set_bit(PG_arch_1, &page->flags); |
| } else |
| pp |= HPTE_R_N; |
| } |
| return pp; |
| } |
| |
| #ifdef CONFIG_PPC_MM_SLICES |
| unsigned int get_paca_psize(unsigned long addr) |
| { |
| unsigned long index, slices; |
| |
| if (addr < SLICE_LOW_TOP) { |
| slices = get_paca()->context.low_slices_psize; |
| index = GET_LOW_SLICE_INDEX(addr); |
| } else { |
| slices = get_paca()->context.high_slices_psize; |
| index = GET_HIGH_SLICE_INDEX(addr); |
| } |
| return (slices >> (index * 4)) & 0xF; |
| } |
| |
| #else |
| unsigned int get_paca_psize(unsigned long addr) |
| { |
| return get_paca()->context.user_psize; |
| } |
| #endif |
| |
| /* |
| * Demote a segment to using 4k pages. |
| * For now this makes the whole process use 4k pages. |
| */ |
| #ifdef CONFIG_PPC_64K_PAGES |
| void demote_segment_4k(struct mm_struct *mm, unsigned long addr) |
| { |
| if (get_slice_psize(mm, addr) == MMU_PAGE_4K) |
| return; |
| slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K); |
| #ifdef CONFIG_SPU_BASE |
| spu_flush_all_slbs(mm); |
| #endif |
| if (get_paca_psize(addr) != MMU_PAGE_4K) { |
| get_paca()->context = mm->context; |
| slb_flush_and_rebolt(); |
| } |
| } |
| #endif /* CONFIG_PPC_64K_PAGES */ |
| |
| #ifdef CONFIG_PPC_SUBPAGE_PROT |
| /* |
| * This looks up a 2-bit protection code for a 4k subpage of a 64k page. |
| * Userspace sets the subpage permissions using the subpage_prot system call. |
| * |
| * Result is 0: full permissions, _PAGE_RW: read-only, |
| * _PAGE_USER or _PAGE_USER|_PAGE_RW: no access. |
| */ |
| static int subpage_protection(struct mm_struct *mm, unsigned long ea) |
| { |
| struct subpage_prot_table *spt = &mm->context.spt; |
| u32 spp = 0; |
| u32 **sbpm, *sbpp; |
| |
| if (ea >= spt->maxaddr) |
| return 0; |
| if (ea < 0x100000000) { |
| /* addresses below 4GB use spt->low_prot */ |
| sbpm = spt->low_prot; |
| } else { |
| sbpm = spt->protptrs[ea >> SBP_L3_SHIFT]; |
| if (!sbpm) |
| return 0; |
| } |
| sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)]; |
| if (!sbpp) |
| return 0; |
| spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)]; |
| |
| /* extract 2-bit bitfield for this 4k subpage */ |
| spp >>= 30 - 2 * ((ea >> 12) & 0xf); |
| |
| /* turn 0,1,2,3 into combination of _PAGE_USER and _PAGE_RW */ |
| spp = ((spp & 2) ? _PAGE_USER : 0) | ((spp & 1) ? _PAGE_RW : 0); |
| return spp; |
| } |
| |
| #else /* CONFIG_PPC_SUBPAGE_PROT */ |
| static inline int subpage_protection(struct mm_struct *mm, unsigned long ea) |
| { |
| return 0; |
| } |
| #endif |
| |
| void hash_failure_debug(unsigned long ea, unsigned long access, |
| unsigned long vsid, unsigned long trap, |
| int ssize, int psize, unsigned long pte) |
| { |
| if (!printk_ratelimit()) |
| return; |
| pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n", |
| ea, access, current->comm); |
| pr_info(" trap=0x%lx vsid=0x%lx ssize=%d psize=%d pte=0x%lx\n", |
| trap, vsid, ssize, psize, pte); |
| } |
| |
| /* Result code is: |
| * 0 - handled |
| * 1 - normal page fault |
| * -1 - critical hash insertion error |
| * -2 - access not permitted by subpage protection mechanism |
| */ |
| int hash_page(unsigned long ea, unsigned long access, unsigned long trap) |
| { |
| pgd_t *pgdir; |
| unsigned long vsid; |
| struct mm_struct *mm; |
| pte_t *ptep; |
| unsigned hugeshift; |
| const struct cpumask *tmp; |
| int rc, user_region = 0, local = 0; |
| int psize, ssize; |
| |
| DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n", |
| ea, access, trap); |
| |
| if ((ea & ~REGION_MASK) >= PGTABLE_RANGE) { |
| DBG_LOW(" out of pgtable range !\n"); |
| return 1; |
| } |
| |
| /* Get region & vsid */ |
| switch (REGION_ID(ea)) { |
| case USER_REGION_ID: |
| user_region = 1; |
| mm = current->mm; |
| if (! mm) { |
| DBG_LOW(" user region with no mm !\n"); |
| return 1; |
| } |
| psize = get_slice_psize(mm, ea); |
| ssize = user_segment_size(ea); |
| vsid = get_vsid(mm->context.id, ea, ssize); |
| break; |
| case VMALLOC_REGION_ID: |
| mm = &init_mm; |
| vsid = get_kernel_vsid(ea, mmu_kernel_ssize); |
| if (ea < VMALLOC_END) |
| psize = mmu_vmalloc_psize; |
| else |
| psize = mmu_io_psize; |
| ssize = mmu_kernel_ssize; |
| break; |
| default: |
| /* Not a valid range |
| * Send the problem up to do_page_fault |
| */ |
| return 1; |
| } |
| DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid); |
| |
| /* Get pgdir */ |
| pgdir = mm->pgd; |
| if (pgdir == NULL) |
| return 1; |
| |
| /* Check CPU locality */ |
| tmp = cpumask_of(smp_processor_id()); |
| if (user_region && cpumask_equal(mm_cpumask(mm), tmp)) |
| local = 1; |
| |
| #ifndef CONFIG_PPC_64K_PAGES |
| /* If we use 4K pages and our psize is not 4K, then we might |
| * be hitting a special driver mapping, and need to align the |
| * address before we fetch the PTE. |
| * |
| * It could also be a hugepage mapping, in which case this is |
| * not necessary, but it's not harmful, either. |
| */ |
| if (psize != MMU_PAGE_4K) |
| ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1); |
| #endif /* CONFIG_PPC_64K_PAGES */ |
| |
| /* Get PTE and page size from page tables */ |
| ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugeshift); |
| if (ptep == NULL || !pte_present(*ptep)) { |
| DBG_LOW(" no PTE !\n"); |
| return 1; |
| } |
| |
| /* Add _PAGE_PRESENT to the required access perm */ |
| access |= _PAGE_PRESENT; |
| |
| /* Pre-check access permissions (will be re-checked atomically |
| * in __hash_page_XX but this pre-check is a fast path |
| */ |
| if (access & ~pte_val(*ptep)) { |
| DBG_LOW(" no access !\n"); |
| return 1; |
| } |
| |
| #ifdef CONFIG_HUGETLB_PAGE |
| if (hugeshift) |
| return __hash_page_huge(ea, access, vsid, ptep, trap, local, |
| ssize, hugeshift, psize); |
| #endif /* CONFIG_HUGETLB_PAGE */ |
| |
| #ifndef CONFIG_PPC_64K_PAGES |
| DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep)); |
| #else |
| DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep), |
| pte_val(*(ptep + PTRS_PER_PTE))); |
| #endif |
| /* Do actual hashing */ |
| #ifdef CONFIG_PPC_64K_PAGES |
| /* If _PAGE_4K_PFN is set, make sure this is a 4k segment */ |
| if ((pte_val(*ptep) & _PAGE_4K_PFN) && psize == MMU_PAGE_64K) { |
| demote_segment_4k(mm, ea); |
| psize = MMU_PAGE_4K; |
| } |
| |
| /* If this PTE is non-cacheable and we have restrictions on |
| * using non cacheable large pages, then we switch to 4k |
| */ |
| if (mmu_ci_restrictions && psize == MMU_PAGE_64K && |
| (pte_val(*ptep) & _PAGE_NO_CACHE)) { |
| if (user_region) { |
| demote_segment_4k(mm, ea); |
| psize = MMU_PAGE_4K; |
| } else if (ea < VMALLOC_END) { |
| /* |
| * some driver did a non-cacheable mapping |
| * in vmalloc space, so switch vmalloc |
| * to 4k pages |
| */ |
| printk(KERN_ALERT "Reducing vmalloc segment " |
| "to 4kB pages because of " |
| "non-cacheable mapping\n"); |
| psize = mmu_vmalloc_psize = MMU_PAGE_4K; |
| #ifdef CONFIG_SPU_BASE |
| spu_flush_all_slbs(mm); |
| #endif |
| } |
| } |
| if (user_region) { |
| if (psize != get_paca_psize(ea)) { |
| get_paca()->context = mm->context; |
| slb_flush_and_rebolt(); |
| } |
| } else if (get_paca()->vmalloc_sllp != |
| mmu_psize_defs[mmu_vmalloc_psize].sllp) { |
| get_paca()->vmalloc_sllp = |
| mmu_psize_defs[mmu_vmalloc_psize].sllp; |
| slb_vmalloc_update(); |
| } |
| #endif /* CONFIG_PPC_64K_PAGES */ |
| |
| #ifdef CONFIG_PPC_HAS_HASH_64K |
| if (psize == MMU_PAGE_64K) |
| rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize); |
| else |
| #endif /* CONFIG_PPC_HAS_HASH_64K */ |
| { |
| int spp = subpage_protection(mm, ea); |
| if (access & spp) |
| rc = -2; |
| else |
| rc = __hash_page_4K(ea, access, vsid, ptep, trap, |
| local, ssize, spp); |
| } |
| |
| /* Dump some info in case of hash insertion failure, they should |
| * never happen so it is really useful to know if/when they do |
| */ |
| if (rc == -1) |
| hash_failure_debug(ea, access, vsid, trap, ssize, psize, |
| pte_val(*ptep)); |
| #ifndef CONFIG_PPC_64K_PAGES |
| DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep)); |
| #else |
| DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep), |
| pte_val(*(ptep + PTRS_PER_PTE))); |
| #endif |
| DBG_LOW(" -> rc=%d\n", rc); |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(hash_page); |
| |
| void hash_preload(struct mm_struct *mm, unsigned long ea, |
| unsigned long access, unsigned long trap) |
| { |
| unsigned long vsid; |
| void *pgdir; |
| pte_t *ptep; |
| unsigned long flags; |
| int rc, ssize, local = 0; |
| |
| BUG_ON(REGION_ID(ea) != USER_REGION_ID); |
| |
| #ifdef CONFIG_PPC_MM_SLICES |
| /* We only prefault standard pages for now */ |
| if (unlikely(get_slice_psize(mm, ea) != mm->context.user_psize)) |
| return; |
| #endif |
| |
| DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx," |
| " trap=%lx\n", mm, mm->pgd, ea, access, trap); |
| |
| /* Get Linux PTE if available */ |
| pgdir = mm->pgd; |
| if (pgdir == NULL) |
| return; |
| ptep = find_linux_pte(pgdir, ea); |
| if (!ptep) |
| return; |
| |
| #ifdef CONFIG_PPC_64K_PAGES |
| /* If either _PAGE_4K_PFN or _PAGE_NO_CACHE is set (and we are on |
| * a 64K kernel), then we don't preload, hash_page() will take |
| * care of it once we actually try to access the page. |
| * That way we don't have to duplicate all of the logic for segment |
| * page size demotion here |
| */ |
| if (pte_val(*ptep) & (_PAGE_4K_PFN | _PAGE_NO_CACHE)) |
| return; |
| #endif /* CONFIG_PPC_64K_PAGES */ |
| |
| /* Get VSID */ |
| ssize = user_segment_size(ea); |
| vsid = get_vsid(mm->context.id, ea, ssize); |
| |
| /* Hash doesn't like irqs */ |
| local_irq_save(flags); |
| |
| /* Is that local to this CPU ? */ |
| if (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) |
| local = 1; |
| |
| /* Hash it in */ |
| #ifdef CONFIG_PPC_HAS_HASH_64K |
| if (mm->context.user_psize == MMU_PAGE_64K) |
| rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize); |
| else |
| #endif /* CONFIG_PPC_HAS_HASH_64K */ |
| rc = __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize, |
| subpage_protection(pgdir, ea)); |
| |
| /* Dump some info in case of hash insertion failure, they should |
| * never happen so it is really useful to know if/when they do |
| */ |
| if (rc == -1) |
| hash_failure_debug(ea, access, vsid, trap, ssize, |
| mm->context.user_psize, pte_val(*ptep)); |
| |
| local_irq_restore(flags); |
| } |
| |
| /* WARNING: This is called from hash_low_64.S, if you change this prototype, |
| * do not forget to update the assembly call site ! |
| */ |
| void flush_hash_page(unsigned long va, real_pte_t pte, int psize, int ssize, |
| int local) |
| { |
| unsigned long hash, index, shift, hidx, slot; |
| |
| DBG_LOW("flush_hash_page(va=%016lx)\n", va); |
| pte_iterate_hashed_subpages(pte, psize, va, index, shift) { |
| hash = hpt_hash(va, shift, ssize); |
| hidx = __rpte_to_hidx(pte, index); |
| if (hidx & _PTEIDX_SECONDARY) |
| hash = ~hash; |
| slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; |
| slot += hidx & _PTEIDX_GROUP_IX; |
| DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx); |
| ppc_md.hpte_invalidate(slot, va, psize, ssize, local); |
| } pte_iterate_hashed_end(); |
| } |
| |
| void flush_hash_range(unsigned long number, int local) |
| { |
| if (ppc_md.flush_hash_range) |
| ppc_md.flush_hash_range(number, local); |
| else { |
| int i; |
| struct ppc64_tlb_batch *batch = |
| &__get_cpu_var(ppc64_tlb_batch); |
| |
| for (i = 0; i < number; i++) |
| flush_hash_page(batch->vaddr[i], batch->pte[i], |
| batch->psize, batch->ssize, local); |
| } |
| } |
| |
| /* |
| * low_hash_fault is called when we the low level hash code failed |
| * to instert a PTE due to an hypervisor error |
| */ |
| void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc) |
| { |
| if (user_mode(regs)) { |
| #ifdef CONFIG_PPC_SUBPAGE_PROT |
| if (rc == -2) |
| _exception(SIGSEGV, regs, SEGV_ACCERR, address); |
| else |
| #endif |
| _exception(SIGBUS, regs, BUS_ADRERR, address); |
| } else |
| bad_page_fault(regs, address, SIGBUS); |
| } |
| |
| #ifdef CONFIG_DEBUG_PAGEALLOC |
| static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi) |
| { |
| unsigned long hash, hpteg; |
| unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize); |
| unsigned long va = hpt_va(vaddr, vsid, mmu_kernel_ssize); |
| unsigned long mode = htab_convert_pte_flags(PAGE_KERNEL); |
| int ret; |
| |
| hash = hpt_hash(va, PAGE_SHIFT, mmu_kernel_ssize); |
| hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP); |
| |
| ret = ppc_md.hpte_insert(hpteg, va, __pa(vaddr), |
| mode, HPTE_V_BOLTED, |
| mmu_linear_psize, mmu_kernel_ssize); |
| BUG_ON (ret < 0); |
| spin_lock(&linear_map_hash_lock); |
| BUG_ON(linear_map_hash_slots[lmi] & 0x80); |
| linear_map_hash_slots[lmi] = ret | 0x80; |
| spin_unlock(&linear_map_hash_lock); |
| } |
| |
| static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi) |
| { |
| unsigned long hash, hidx, slot; |
| unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize); |
| unsigned long va = hpt_va(vaddr, vsid, mmu_kernel_ssize); |
| |
| hash = hpt_hash(va, PAGE_SHIFT, mmu_kernel_ssize); |
| spin_lock(&linear_map_hash_lock); |
| BUG_ON(!(linear_map_hash_slots[lmi] & 0x80)); |
| hidx = linear_map_hash_slots[lmi] & 0x7f; |
| linear_map_hash_slots[lmi] = 0; |
| spin_unlock(&linear_map_hash_lock); |
| if (hidx & _PTEIDX_SECONDARY) |
| hash = ~hash; |
| slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; |
| slot += hidx & _PTEIDX_GROUP_IX; |
| ppc_md.hpte_invalidate(slot, va, mmu_linear_psize, mmu_kernel_ssize, 0); |
| } |
| |
| void kernel_map_pages(struct page *page, int numpages, int enable) |
| { |
| unsigned long flags, vaddr, lmi; |
| int i; |
| |
| local_irq_save(flags); |
| for (i = 0; i < numpages; i++, page++) { |
| vaddr = (unsigned long)page_address(page); |
| lmi = __pa(vaddr) >> PAGE_SHIFT; |
| if (lmi >= linear_map_hash_count) |
| continue; |
| if (enable) |
| kernel_map_linear_page(vaddr, lmi); |
| else |
| kernel_unmap_linear_page(vaddr, lmi); |
| } |
| local_irq_restore(flags); |
| } |
| #endif /* CONFIG_DEBUG_PAGEALLOC */ |
| |
| void setup_initial_memory_limit(phys_addr_t first_memblock_base, |
| phys_addr_t first_memblock_size) |
| { |
| /* We don't currently support the first MEMBLOCK not mapping 0 |
| * physical on those processors |
| */ |
| BUG_ON(first_memblock_base != 0); |
| |
| /* On LPAR systems, the first entry is our RMA region, |
| * non-LPAR 64-bit hash MMU systems don't have a limitation |
| * on real mode access, but using the first entry works well |
| * enough. We also clamp it to 1G to avoid some funky things |
| * such as RTAS bugs etc... |
| */ |
| ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000); |
| |
| /* Finally limit subsequent allocations */ |
| memblock_set_current_limit(ppc64_rma_size); |
| } |