For address above 512TB we allocate additional mmu context. To make it all
easy, address above 512TB is handled with IR/DR=1 and with stack frame setup.
The mmu_context_t is also updated to track the new extended_ids. To support
upto 4PB we need a total 8 contexts.
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/book3s/64/hash-4k.h | 6 ++
arch/powerpc/include/asm/book3s/64/hash-64k.h | 6 ++
arch/powerpc/include/asm/book3s/64/mmu.h | 31 +++++++-
arch/powerpc/include/asm/mmu_context.h | 38 +++++++++
arch/powerpc/include/asm/processor.h | 6 ++
arch/powerpc/kernel/exceptions-64s.S | 11 ++-
arch/powerpc/kernel/traps.c | 12 ---
arch/powerpc/mm/copro_fault.c | 2 +-
arch/powerpc/mm/hash_utils_64.c | 4 +-
arch/powerpc/mm/mmu_context_book3s64.c | 15 +++-
arch/powerpc/mm/pgtable-hash64.c | 2 +-
arch/powerpc/mm/slb.c | 108 ++++++++++++++++++++++++++
arch/powerpc/mm/slb_low.S | 8 +-
arch/powerpc/mm/slice.c | 15 +++-
arch/powerpc/mm/tlb_hash64.c | 2 +-
15 files changed, 239 insertions(+), 27 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h
b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index 67c5475311ee..1a35eb944481 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -11,6 +11,12 @@
#define H_PUD_INDEX_SIZE 9
#define H_PGD_INDEX_SIZE 9
+/*
+ * Each context is 512TB. But on 4k we restrict our max TASK size to 64TB
+ * Hence also limit max EA bits to 64TB.
+ */
+#define MAX_EA_BITS_PER_CONTEXT 46
+
#ifndef __ASSEMBLY__
#define H_PTE_TABLE_SIZE (sizeof(pte_t) << H_PTE_INDEX_SIZE)
#define H_PMD_TABLE_SIZE (sizeof(pmd_t) << H_PMD_INDEX_SIZE)
diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h
b/arch/powerpc/include/asm/book3s/64/hash-64k.h
index 3bcf269f8f55..8d0cbbb31023 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
@@ -7,6 +7,12 @@
#define H_PUD_INDEX_SIZE 7
#define H_PGD_INDEX_SIZE 8
+/*
+ * Each context is 512TB size. SLB miss for first context/default context
+ * is handled in the hotpath.
+ */
+#define MAX_EA_BITS_PER_CONTEXT 49
+
/*
* 64k aligned address free up few of the lower bits of RPN for us
* We steal that here. For more deatils look at pte_pfn/pfn_pte()
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h
b/arch/powerpc/include/asm/book3s/64/mmu.h
index 777778579305..33ba81d69bd1 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -91,7 +91,18 @@ struct slice_mask {
};
typedef struct {
- mm_context_id_t id;
+ union {
+ /*
+ * We use id as the PIDR content for radix. On hash we can use
+ * more than one id. The extended ids are used when we start
+ * having address above 512TB. We allocate one extended id
+ * for each 512TB. The new id is then used with the 49 bit
+ * EA to build a new VA. We always use ESID_BITS_1T_MASK bits
+ * from EA and new context ids to build the new VAs.
+ */
+ mm_context_id_t id;
+ mm_context_id_t extended_id[TASK_SIZE_USER64/TASK_CONTEXT_SIZE];
+ };
u16 user_psize; /* page size index */
/* Number of bits in the mm_cpumask */
@@ -193,5 +204,23 @@ extern void radix_init_pseries(void);
static inline void radix_init_pseries(void) { };
#endif
+static inline int get_ea_context(mm_context_t *ctx, unsigned long ea)
+{
+ int index = ea >> MAX_EA_BITS_PER_CONTEXT;
+
+ if (likely(index < ARRAY_SIZE(ctx->extended_id)))
+ return ctx->extended_id[index];
+ /* should never happen */
+ BUG();
+}
+
+static inline unsigned long get_user_vsid(mm_context_t *ctx,
+ unsigned long ea, int ssize)
+{
+ unsigned long context = get_ea_context(ctx, ea);
+
+ return get_vsid(context, ea, ssize);
+}
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_BOOK3S_64_MMU_H_ */
diff --git a/arch/powerpc/include/asm/mmu_context.h
b/arch/powerpc/include/asm/mmu_context.h
index 051b3d63afe3..61d96b4a03b9 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -60,12 +60,50 @@ extern int hash__alloc_context_id(void);
extern void hash__reserve_context_id(int id);
extern void __destroy_context(int context_id);
static inline void mmu_context_init(void) { }
+
+static inline int alloc_extended_context(struct mm_struct *mm,
+ unsigned long ea)
+{
+ int context_id;
+
+ int index = ea >> MAX_EA_BITS_PER_CONTEXT;
+
+ context_id = hash__alloc_context_id();
+ if (context_id < 0)
+ return context_id;
+
+ VM_WARN_ON(mm->context.extended_id[index]);
+ mm->context.extended_id[index] = context_id;
+ return context_id;
+}
+
+static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
+{
+ int context_id;
+ context_id = get_ea_context(&mm->context, ea);
+ if (!context_id)
+ return true;
+ return false;
+}
+
#else
extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk);
extern unsigned long __init_new_context(void);
extern void __destroy_context(unsigned long context_id);
extern void mmu_context_init(void);
+static inline int alloc_extended_context(struct mm_struct *mm,
+ unsigned long ea)
+{
+ /* non book3s_64 should never find this called */
+ WARN_ON(1);
+ return -ENOMEM;
+}
+
+static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
+{
+ return false;
+}
#endif
#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
diff --git a/arch/powerpc/include/asm/processor.h
b/arch/powerpc/include/asm/processor.h
index 01299cdc9806..75b084486ce1 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -119,9 +119,15 @@ void release_thread(struct task_struct *);
*/
#define TASK_SIZE_USER64 TASK_SIZE_512TB
#define DEFAULT_MAP_WINDOW_USER64 TASK_SIZE_128TB
+#define TASK_CONTEXT_SIZE TASK_SIZE_512TB
#else
#define TASK_SIZE_USER64 TASK_SIZE_64TB
#define DEFAULT_MAP_WINDOW_USER64 TASK_SIZE_64TB
+/*
+ * We don't need to allocate extended context ids for 4K page size, because
+ * we limit the max effective address on this config to 64TB.
+ */
+#define TASK_CONTEXT_SIZE TASK_SIZE_64TB
#endif
/*
diff --git a/arch/powerpc/kernel/exceptions-64s.S
b/arch/powerpc/kernel/exceptions-64s.S
index 3ac87e53b3da..2b1d79900b0a 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -621,7 +621,10 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
lwz r9,PACA_EXSLB+EX_CCR(r13) /* get saved CR */
mtlr r10
- beq- 8f /* if bad address, make full stack frame */
+ /*
+ * Large address, check whether we have to allocate new contexts.
+ */
+ beq- 8f
bne- cr5,2f /* if unrecoverable exception, oops */
@@ -685,7 +688,7 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
mr r3,r12
mfspr r11,SPRN_SRR0
mfspr r12,SPRN_SRR1
- LOAD_HANDLER(r10,bad_addr_slb)
+ LOAD_HANDLER(r10, large_addr_slb)
mtspr SPRN_SRR0,r10
ld r10,PACAKMSR(r13)
mtspr SPRN_SRR1,r10
@@ -700,7 +703,7 @@ EXC_COMMON_BEGIN(unrecov_slb)
bl unrecoverable_exception
b 1b
-EXC_COMMON_BEGIN(bad_addr_slb)
+EXC_COMMON_BEGIN(large_addr_slb)
EXCEPTION_PROLOG_COMMON(0x380, PACA_EXSLB)
RECONCILE_IRQ_STATE(r10, r11)
ld r3, PACA_EXSLB+EX_DAR(r13)
@@ -710,7 +713,7 @@ EXC_COMMON_BEGIN(bad_addr_slb)
std r10, _TRAP(r1)
2: bl save_nvgprs
addi r3, r1, STACK_FRAME_OVERHEAD
- bl slb_miss_bad_addr
+ bl slb_miss_large_addr
b ret_from_except
EXC_REAL_BEGIN(hardware_interrupt, 0x500, 0x100)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 1e48d157196a..f200bfd98b17 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1495,18 +1495,6 @@ void alignment_exception(struct pt_regs *regs)
exception_exit(prev_state);
}
-void slb_miss_bad_addr(struct pt_regs *regs)
-{
- enum ctx_state prev_state = exception_enter();
-
- if (user_mode(regs))
- _exception(SIGSEGV, regs, SEGV_BNDERR, regs->dar);
- else
- bad_page_fault(regs, regs->dar, SIGSEGV);
-
- exception_exit(prev_state);
-}
-
void StackOverflow(struct pt_regs *regs)
{
printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_fault.c
index 697b70ad1195..7d0945bd3a61 100644
--- a/arch/powerpc/mm/copro_fault.c
+++ b/arch/powerpc/mm/copro_fault.c
@@ -112,7 +112,7 @@ int copro_calculate_slb(struct mm_struct *mm, u64 ea,
struct copro_slb *slb)
return 1;
psize = get_slice_psize(mm, ea);
ssize = user_segment_size(ea);
- vsid = get_vsid(mm->context.id, ea, ssize);
+ vsid = get_user_vsid(&mm->context, ea, ssize);
vsidkey = SLB_VSID_USER;
break;
case VMALLOC_REGION_ID:
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index b578148d89e6..f62325d4f5f5 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1261,7 +1261,7 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
}
psize = get_slice_psize(mm, ea);
ssize = user_segment_size(ea);
- vsid = get_vsid(mm->context.id, ea, ssize);
+ vsid = get_user_vsid(&mm->context, ea, ssize);
break;
case VMALLOC_REGION_ID:
vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
@@ -1526,7 +1526,7 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
/* Get VSID */
ssize = user_segment_size(ea);
- vsid = get_vsid(mm->context.id, ea, ssize);
+ vsid = get_user_vsid(&mm->context, ea, ssize);
if (!vsid)
return;
/*
diff --git a/arch/powerpc/mm/mmu_context_book3s64.c
b/arch/powerpc/mm/mmu_context_book3s64.c
index 80acad52b006..d3acc9d9352a 100644
--- a/arch/powerpc/mm/mmu_context_book3s64.c
+++ b/arch/powerpc/mm/mmu_context_book3s64.c
@@ -178,6 +178,19 @@ void __destroy_context(int context_id)
}
EXPORT_SYMBOL_GPL(__destroy_context);
+static void destroy_contexts(mm_context_t *ctx)
+{
+ int index, context_id;
+
+ spin_lock(&mmu_context_lock);
+ for (index = 0; index < ARRAY_SIZE(ctx->extended_id); index++) {
+ context_id = ctx->extended_id[index];
+ if (context_id)
+ ida_remove(&mmu_context_ida, context_id);
+ }
+ spin_unlock(&mmu_context_lock);
+}
+
#ifdef CONFIG_PPC_64K_PAGES
static void destroy_pagetable_page(struct mm_struct *mm)
{
@@ -216,7 +229,7 @@ void destroy_context(struct mm_struct *mm)
else
subpage_prot_free(mm);
destroy_pagetable_page(mm);
- __destroy_context(mm->context.id);
+ destroy_contexts(&mm->context);
mm->context.id = MMU_NO_CONTEXT;
}
diff --git a/arch/powerpc/mm/pgtable-hash64.c b/arch/powerpc/mm/pgtable-hash64.c
index 469808e77e58..a87b18cf6749 100644
--- a/arch/powerpc/mm/pgtable-hash64.c
+++ b/arch/powerpc/mm/pgtable-hash64.c
@@ -320,7 +320,7 @@ void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned
long addr,
if (!is_kernel_addr(addr)) {
ssize = user_segment_size(addr);
- vsid = get_vsid(mm->context.id, addr, ssize);
+ vsid = get_user_vsid(&mm->context, addr, ssize);
WARN_ON(vsid == 0);
} else {
vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 13cfe413b40d..a94c3cd97c95 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -22,6 +22,7 @@
#include <asm/cacheflush.h>
#include <asm/smp.h>
#include <linux/compiler.h>
+#include <linux/context_tracking.h>
#include <linux/mm_types.h>
#include <asm/udbg.h>
@@ -340,3 +341,110 @@ void slb_initialize(void)
asm volatile("isync":::"memory");
}
+
+static void insert_slb_entry(unsigned long vsid, unsigned long ea,
+ int bpsize, int ssize)
+{
+ int slb_cache_index;
+ unsigned long flags;
+ enum slb_index index;
+ unsigned long vsid_data, esid_data;
+
+ /*
+ * We are irq disabled, hence should be safe to access PACA.
+ */
+ index = get_paca()->stab_rr;
+
+ /*
+ * simple round-robin replacement of slb starting at SLB_NUM_BOLTED.
+ */
+ if (index < mmu_slb_size)
+ index++;
+ else
+ index = SLB_NUM_BOLTED;
+
+ get_paca()->stab_rr = index;
+
+ flags = SLB_VSID_USER | mmu_psize_defs[bpsize].sllp;
+ vsid_data = (vsid << slb_vsid_shift(ssize)) | flags |
+ ((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
+ esid_data = mk_esid_data(ea, ssize, index);
+
+ asm volatile("slbmte %0, %1" : : "r" (vsid_data), "r" (esid_data)
+ : "memory");
+
+ /*
+ * Now update slb cache entries
+ */
+ slb_cache_index = get_paca()->slb_cache_ptr;
+ if (slb_cache_index < SLB_CACHE_ENTRIES) {
+ /*
+ * We have space in slb cache for optimized switch_slb().
+ * Top 36 bits from esid_data as per ISA
+ */
+ get_paca()->slb_cache[slb_cache_index++] = esid_data >> 28;
+ }
+
+ /*
+ * if we are full, just increment and return.
+ */
+ get_paca()->slb_cache_ptr++;
+}
+
+static void handle_multi_context_slb_miss(int context_id, unsigned long ea)
+{
+ int bpsize;
+ unsigned long vsid;
+ struct mm_struct *mm = current->mm;
+
+ /*
+ * We are always above 1TB, hence use high user segment size.
+ */
+ vsid = get_vsid(context_id, ea, mmu_highuser_ssize);
+ bpsize = get_slice_psize(mm, ea);
+ insert_slb_entry(vsid, ea, bpsize, mmu_highuser_ssize);
+}
+
+void slb_miss_large_addr(struct pt_regs *regs)
+{
+ int context;
+ enum ctx_state prev_state = exception_enter();
+ unsigned long ea = regs->dar;
+
+ if (REGION_ID(ea) != USER_REGION_ID)
+ goto slb_bad_addr;
+
+ /*
+ * Are we beyound what the page table layout supports ?
+ */
+ if ((ea & ~REGION_MASK) >= H_PGTABLE_RANGE)
+ goto slb_bad_addr;
+
+ /* Lower address should have been handled by asm code */
+ if (ea < (1UL << MAX_EA_BITS_PER_CONTEXT))
+ goto slb_bad_addr;
+
+#ifdef CONFIG_PPC_MM_SLICES
+ /*
+ * consider this as bad access if we take a SLB miss
+ * on an address above addr limit.
+ */
+ if (ea >= current->mm->context.slb_addr_limit)
+ goto slb_bad_addr;
+#endif
+
+ context = get_ea_context(¤t->mm->context, ea);
+ if (!context)
+ goto slb_bad_addr;
+
+ handle_multi_context_slb_miss(context, ea);
+ exception_exit(prev_state);
+ return;
+
+slb_bad_addr:
+ if (user_mode(regs))
+ _exception(SIGSEGV, regs, SEGV_BNDERR, ea);
+ else
+ bad_page_fault(regs, ea, SIGSEGV);
+ exception_exit(prev_state);
+}
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index 2c7c717fd2ea..7cf006228e2e 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -74,11 +74,13 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_68_BIT_VA)
* No other registers are examined or changed.
*/
_GLOBAL(slb_allocate)
- /*
- * check for bad kernel/user address
+ /*
+ * Check for address range for which we need to handle multi context.
For
+ * the default context we allocate the slb via the fast path. For large
+ * address we branch out to C-code and look at additional context
allocated.
* (ea & ~REGION_MASK) >= PGTABLE_RANGE
*/
- rldicr. r9,r3,4,(63 - H_PGTABLE_EADDR_SIZE - 4)
+ rldicr. r9,r3,4,(63 - MAX_EA_BITS_PER_CONTEXT - 4)
bne- 8f
srdi r9,r3,60 /* get region */
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index f64bfe8bae57..dbb534eff2c3 100644
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -659,6 +659,15 @@ unsigned long slice_get_unmapped_area(unsigned long addr,
unsigned long len,
slice_print_mask(" mask", &potential_mask);
convert:
+ /*
+ * Try to allocate the context before we do slice convert
+ * so that we handle the context allocation failure gracefully.
+ */
+ if (need_extra_context(mm, newaddr)) {
+ if (alloc_extended_context(mm, newaddr) < 0)
+ return -ENOMEM;
+ }
+
slice_andnot_mask(&potential_mask, &potential_mask, &good_mask,
high_slices);
if (compat_maskp && !fixed)
slice_andnot_mask(&potential_mask, &potential_mask,
compat_maskp, high_slices);
@@ -669,10 +678,14 @@ unsigned long slice_get_unmapped_area(unsigned long addr,
unsigned long len,
if (psize > MMU_PAGE_BASE)
on_each_cpu(slice_flush_segments, mm, 1);
}
+ return newaddr;
return_addr:
+ if (need_extra_context(mm, newaddr)) {
+ if (alloc_extended_context(mm, newaddr) < 0)
+ return -ENOMEM;
+ }
return newaddr;
-
}
EXPORT_SYMBOL_GPL(slice_get_unmapped_area);
diff --git a/arch/powerpc/mm/tlb_hash64.c b/arch/powerpc/mm/tlb_hash64.c
index 9b23f12e863c..87d71dd25441 100644
--- a/arch/powerpc/mm/tlb_hash64.c
+++ b/arch/powerpc/mm/tlb_hash64.c
@@ -89,7 +89,7 @@ void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
/* Build full vaddr */
if (!is_kernel_addr(addr)) {
ssize = user_segment_size(addr);
- vsid = get_vsid(mm->context.id, addr, ssize);
+ vsid = get_user_vsid(&mm->context, addr, ssize);
} else {
vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
ssize = mmu_kernel_ssize;
--
2.14.3
