diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-14 10:06:41 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-14 10:06:41 -0800 |
commit | 694a20dae6efc3803740971fa9f7c86b8c8d4685 (patch) | |
tree | a2d39f89dc01b7527ec5ecd7340a72a427a6cac4 /arch/powerpc/mm/pgtable-radix.c | |
parent | 61f14c015f5be9151ba25e638d349f4d40cb7cd4 (diff) | |
parent | ecdf06e1ea5376bba03c155751f6869d3dfaa210 (diff) |
Merge tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"A larger batch of fixes than we'd like. Roughly 1/3 fixes for new
code, 1/3 fixes for stable and 1/3 minor things.
There's four commits fixing bugs when using 16GB huge pages on hash,
caused by some of the preparatory changes for pkeys.
Two fixes for bugs in the enhanced IRQ soft masking for local_t, one
of which broke KVM in some circumstances.
Four fixes for Power9. The most bizarre being a bug where futexes
stopped working because a NULL pointer dereference didn't trap during
early boot (it aliased the kernel mapping). A fix for memory hotplug
when using the Radix MMU, and a fix for live migration of guests using
the Radix MMU.
Two fixes for hotplug on pseries machines. One where we weren't
correctly updating NUMA info when CPUs are added and removed. And the
other fixes crashes/hangs seen when doing memory hot remove during
boot, which is apparently a thing people do.
Finally a handful of build fixes for obscure configs and other minor
fixes.
Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Balbir Singh, Colin
Ian King, Daniel Henrique Barboza, Florian Weimer, Guenter Roeck,
Harish, Laurent Vivier, Madhavan Srinivasan, Mauricio Faria de
Oliveira, Nathan Fontenot, Nicholas Piggin, Sam Bobroff"
* tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Fix to use ucontext_t instead of struct ucontext
powerpc/kdump: Fix powernv build break when KEXEC_CORE=n
powerpc/pseries: Fix build break for SPLPAR=n and CPU hotplug
powerpc/mm/hash64: Zero PGD pages on allocation
powerpc/mm/hash64: Store the slot information at the right offset for hugetlb
powerpc/mm/hash64: Allocate larger PMD table if hugetlb config is enabled
powerpc/mm: Fix crashes with 16G huge pages
powerpc/mm: Flush radix process translations when setting MMU type
powerpc/vas: Don't set uses_vas for kernel windows
powerpc/pseries: Enable RAS hotplug events later
powerpc/mm/radix: Split linear mapping on hot-unplug
powerpc/64s/radix: Boot-time NULL pointer protection using a guard-PID
ocxl: fix signed comparison with less than zero
powerpc/64s: Fix may_hard_irq_enable() for PMI soft masking
powerpc/64s: Fix MASKABLE_RELON_EXCEPTION_HV_OOL macro
powerpc/numa: Invalidate numa_cpu_lookup_table on cpu remove
Diffstat (limited to 'arch/powerpc/mm/pgtable-radix.c')
-rw-r--r-- | arch/powerpc/mm/pgtable-radix.c | 117 |
1 files changed, 95 insertions, 22 deletions
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c index 573a9a2ee455..2e10a964e290 100644 --- a/arch/powerpc/mm/pgtable-radix.c +++ b/arch/powerpc/mm/pgtable-radix.c @@ -17,9 +17,11 @@ #include <linux/of_fdt.h> #include <linux/mm.h> #include <linux/string_helpers.h> +#include <linux/stop_machine.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> +#include <asm/mmu_context.h> #include <asm/dma.h> #include <asm/machdep.h> #include <asm/mmu.h> @@ -333,6 +335,22 @@ static void __init radix_init_pgtable(void) "r" (TLBIEL_INVAL_SET_LPID), "r" (0)); asm volatile("eieio; tlbsync; ptesync" : : : "memory"); trace_tlbie(0, 0, TLBIEL_INVAL_SET_LPID, 0, 2, 1, 1); + + /* + * The init_mm context is given the first available (non-zero) PID, + * which is the "guard PID" and contains no page table. PIDR should + * never be set to zero because that duplicates the kernel address + * space at the 0x0... offset (quadrant 0)! + * + * An arbitrary PID that may later be allocated by the PID allocator + * for userspace processes must not be used either, because that + * would cause stale user mappings for that PID on CPUs outside of + * the TLB invalidation scheme (because it won't be in mm_cpumask). + * + * So permanently carve out one PID for the purpose of a guard PID. + */ + init_mm.context.id = mmu_base_pid; + mmu_base_pid++; } static void __init radix_init_partition_table(void) @@ -535,6 +553,7 @@ void __init radix__early_init_mmu(void) __pmd_index_size = RADIX_PMD_INDEX_SIZE; __pud_index_size = RADIX_PUD_INDEX_SIZE; __pgd_index_size = RADIX_PGD_INDEX_SIZE; + __pud_cache_index = RADIX_PUD_INDEX_SIZE; __pmd_cache_index = RADIX_PMD_INDEX_SIZE; __pte_table_size = RADIX_PTE_TABLE_SIZE; __pmd_table_size = RADIX_PMD_TABLE_SIZE; @@ -579,7 +598,8 @@ void __init radix__early_init_mmu(void) radix_init_iamr(); radix_init_pgtable(); - + /* Switch to the guard PID before turning on MMU */ + radix__switch_mmu_context(NULL, &init_mm); if (cpu_has_feature(CPU_FTR_HVMODE)) tlbiel_all(); } @@ -604,6 +624,7 @@ void radix__early_init_mmu_secondary(void) } radix_init_iamr(); + radix__switch_mmu_context(NULL, &init_mm); if (cpu_has_feature(CPU_FTR_HVMODE)) tlbiel_all(); } @@ -666,6 +687,30 @@ static void free_pmd_table(pmd_t *pmd_start, pud_t *pud) pud_clear(pud); } +struct change_mapping_params { + pte_t *pte; + unsigned long start; + unsigned long end; + unsigned long aligned_start; + unsigned long aligned_end; +}; + +static int stop_machine_change_mapping(void *data) +{ + struct change_mapping_params *params = + (struct change_mapping_params *)data; + + if (!data) + return -1; + + spin_unlock(&init_mm.page_table_lock); + pte_clear(&init_mm, params->aligned_start, params->pte); + create_physical_mapping(params->aligned_start, params->start); + create_physical_mapping(params->end, params->aligned_end); + spin_lock(&init_mm.page_table_lock); + return 0; +} + static void remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end) { @@ -694,6 +739,52 @@ static void remove_pte_table(pte_t *pte_start, unsigned long addr, } } +/* + * clear the pte and potentially split the mapping helper + */ +static void split_kernel_mapping(unsigned long addr, unsigned long end, + unsigned long size, pte_t *pte) +{ + unsigned long mask = ~(size - 1); + unsigned long aligned_start = addr & mask; + unsigned long aligned_end = addr + size; + struct change_mapping_params params; + bool split_region = false; + + if ((end - addr) < size) { + /* + * We're going to clear the PTE, but not flushed + * the mapping, time to remap and flush. The + * effects if visible outside the processor or + * if we are running in code close to the + * mapping we cleared, we are in trouble. + */ + if (overlaps_kernel_text(aligned_start, addr) || + overlaps_kernel_text(end, aligned_end)) { + /* + * Hack, just return, don't pte_clear + */ + WARN_ONCE(1, "Linear mapping %lx->%lx overlaps kernel " + "text, not splitting\n", addr, end); + return; + } + split_region = true; + } + + if (split_region) { + params.pte = pte; + params.start = addr; + params.end = end; + params.aligned_start = addr & ~(size - 1); + params.aligned_end = min_t(unsigned long, aligned_end, + (unsigned long)__va(memblock_end_of_DRAM())); + stop_machine(stop_machine_change_mapping, ¶ms, NULL); + return; + } + + pte_clear(&init_mm, addr, pte); +} + static void remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end) { @@ -709,13 +800,7 @@ static void remove_pmd_table(pmd_t *pmd_start, unsigned long addr, continue; if (pmd_huge(*pmd)) { - if (!IS_ALIGNED(addr, PMD_SIZE) || - !IS_ALIGNED(next, PMD_SIZE)) { - WARN_ONCE(1, "%s: unaligned range\n", __func__); - continue; - } - - pte_clear(&init_mm, addr, (pte_t *)pmd); + split_kernel_mapping(addr, end, PMD_SIZE, (pte_t *)pmd); continue; } @@ -740,13 +825,7 @@ static void remove_pud_table(pud_t *pud_start, unsigned long addr, continue; if (pud_huge(*pud)) { - if (!IS_ALIGNED(addr, PUD_SIZE) || - !IS_ALIGNED(next, PUD_SIZE)) { - WARN_ONCE(1, "%s: unaligned range\n", __func__); - continue; - } - - pte_clear(&init_mm, addr, (pte_t *)pud); + split_kernel_mapping(addr, end, PUD_SIZE, (pte_t *)pud); continue; } @@ -772,13 +851,7 @@ static void remove_pagetable(unsigned long start, unsigned long end) continue; if (pgd_huge(*pgd)) { - if (!IS_ALIGNED(addr, PGDIR_SIZE) || - !IS_ALIGNED(next, PGDIR_SIZE)) { - WARN_ONCE(1, "%s: unaligned range\n", __func__); - continue; - } - - pte_clear(&init_mm, addr, (pte_t *)pgd); + split_kernel_mapping(addr, end, PGDIR_SIZE, (pte_t *)pgd); continue; } |