[PATCH 2/3] powerpc/mm: Allow more than 16 low slices
Christophe Leroy
christophe.leroy at c-s.fr
Sat Jan 6 04:29:51 AEDT 2018
While the implementation of the "slices" address space allows
a significant amount of high slices, it limits the number of
low slices to 16 due to the use of a single u64 low_slices element
in struct slice_mask.
In order to override this limitation, this patch switches the
handling of low_slices to BITMAPs as done already for high_slices.
Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>
---
arch/powerpc/include/asm/book3s/64/mmu.h | 2 +-
arch/powerpc/include/asm/mmu-8xx.h | 2 +-
arch/powerpc/include/asm/paca.h | 2 +-
arch/powerpc/kernel/paca.c | 3 +-
arch/powerpc/mm/hash_utils_64.c | 13 ++--
arch/powerpc/mm/slb_low.S | 8 ++-
arch/powerpc/mm/slice.c | 102 +++++++++++++++++--------------
7 files changed, 73 insertions(+), 59 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index c9448e19847a..27e7e9732ea1 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -91,7 +91,7 @@ typedef struct {
struct npu_context *npu_context;
#ifdef CONFIG_PPC_MM_SLICES
- u64 low_slices_psize; /* SLB page size encodings */
+ unsigned char low_slices_psize[8]; /* SLB page size encodings */
unsigned char high_slices_psize[SLICE_ARRAY_SIZE];
unsigned long slb_addr_limit;
#else
diff --git a/arch/powerpc/include/asm/mmu-8xx.h b/arch/powerpc/include/asm/mmu-8xx.h
index 5f89b6010453..d669d0062da4 100644
--- a/arch/powerpc/include/asm/mmu-8xx.h
+++ b/arch/powerpc/include/asm/mmu-8xx.h
@@ -171,7 +171,7 @@ typedef struct {
unsigned long vdso_base;
#ifdef CONFIG_PPC_MM_SLICES
u16 user_psize; /* page size index */
- u64 low_slices_psize; /* page size encodings */
+ unsigned char low_slices_psize[8]; /* 16 slices */
unsigned char high_slices_psize[0];
unsigned long slb_addr_limit;
#endif
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 3892db93b837..612017054825 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -141,7 +141,7 @@ struct paca_struct {
#ifdef CONFIG_PPC_BOOK3S
mm_context_id_t mm_ctx_id;
#ifdef CONFIG_PPC_MM_SLICES
- u64 mm_ctx_low_slices_psize;
+ unsigned char mm_ctx_low_slices_psize[8];
unsigned char mm_ctx_high_slices_psize[SLICE_ARRAY_SIZE];
unsigned long mm_ctx_slb_addr_limit;
#else
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index d6597038931d..8e1566bf82b8 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -264,7 +264,8 @@ void copy_mm_to_paca(struct mm_struct *mm)
#ifdef CONFIG_PPC_MM_SLICES
VM_BUG_ON(!mm->context.slb_addr_limit);
get_paca()->mm_ctx_slb_addr_limit = mm->context.slb_addr_limit;
- get_paca()->mm_ctx_low_slices_psize = context->low_slices_psize;
+ memcpy(&get_paca()->mm_ctx_low_slices_psize,
+ &context->low_slices_psize, sizeof(context->low_slices_psize));
memcpy(&get_paca()->mm_ctx_high_slices_psize,
&context->high_slices_psize, TASK_SLICE_ARRAY_SZ(mm));
#else /* CONFIG_PPC_MM_SLICES */
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 3266b3326088..2f0c6b527a83 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1097,19 +1097,18 @@ unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
#ifdef CONFIG_PPC_MM_SLICES
static unsigned int get_paca_psize(unsigned long addr)
{
- u64 lpsizes;
- unsigned char *hpsizes;
+ unsigned char *psizes;
unsigned long index, mask_index;
if (addr <= SLICE_LOW_TOP) {
- lpsizes = get_paca()->mm_ctx_low_slices_psize;
+ psizes = get_paca()->mm_ctx_low_slices_psize;
index = GET_LOW_SLICE_INDEX(addr);
- return (lpsizes >> (index * 4)) & 0xF;
+ } else {
+ psizes = get_paca()->mm_ctx_high_slices_psize;
+ index = GET_HIGH_SLICE_INDEX(addr);
}
- hpsizes = get_paca()->mm_ctx_high_slices_psize;
- index = GET_HIGH_SLICE_INDEX(addr);
mask_index = index & 0x1;
- return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF;
+ return (psizes[index >> 1] >> (mask_index * 4)) & 0xF;
}
#else
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index 2cf5ef3fc50d..2c7c717fd2ea 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -200,10 +200,12 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
5:
/*
* Handle lpsizes
- * r9 is get_paca()->context.low_slices_psize, r11 is index
+ * r9 is get_paca()->context.low_slices_psize[index], r11 is mask_index
*/
- ld r9,PACALOWSLICESPSIZE(r13)
- mr r11,r10
+ srdi r11,r10,1 /* index */
+ addi r9,r11,PACALOWSLICESPSIZE
+ lbzx r9,r13,r9 /* r9 is lpsizes[r11] */
+ rldicl r11,r10,0,63 /* r11 = r10 & 0x1 */
6:
sldi r11,r11,2 /* index * 4 */
/* Extract the psize and multiply to get an array offset */
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index 1a66fafc3e45..e01ea72f21c6 100644
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -43,7 +43,7 @@ static DEFINE_SPINLOCK(slice_convert_lock);
* in 1TB size.
*/
struct slice_mask {
- u64 low_slices;
+ DECLARE_BITMAP(low_slices, SLICE_NUM_LOW);
DECLARE_BITMAP(high_slices, SLICE_NUM_HIGH);
};
@@ -54,7 +54,8 @@ static void slice_print_mask(const char *label, struct slice_mask mask)
{
if (!_slice_debug)
return;
- pr_devel("%s low_slice: %*pbl\n", label, (int)SLICE_NUM_LOW, &mask.low_slices);
+ pr_devel("%s low_slice: %*pbl\n", label, (int)SLICE_NUM_LOW,
+ mask.low_slices);
pr_devel("%s high_slice: %*pbl\n", label, (int)SLICE_NUM_HIGH, mask.high_slices);
}
@@ -72,15 +73,18 @@ static void slice_range_to_mask(unsigned long start, unsigned long len,
{
unsigned long end = start + len - 1;
- ret->low_slices = 0;
+ bitmap_zero(ret->low_slices, SLICE_NUM_LOW);
if (SLICE_NUM_HIGH)
bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
if (start <= SLICE_LOW_TOP) {
unsigned long mend = min(end, SLICE_LOW_TOP);
+ unsigned long start_index = GET_LOW_SLICE_INDEX(start);
+ unsigned long align_end = ALIGN(mend, (1UL << SLICE_LOW_SHIFT));
+ unsigned long count = GET_LOW_SLICE_INDEX(align_end) -
+ start_index;
- ret->low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
- - (1u << GET_LOW_SLICE_INDEX(start));
+ bitmap_set(ret->low_slices, start_index, count);
}
if ((start + len) > SLICE_LOW_TOP) {
@@ -128,13 +132,13 @@ static void slice_mask_for_free(struct mm_struct *mm, struct slice_mask *ret,
{
unsigned long i;
- ret->low_slices = 0;
+ bitmap_zero(ret->low_slices, SLICE_NUM_LOW);
if (SLICE_NUM_HIGH)
bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
for (i = 0; i < SLICE_NUM_LOW; i++)
if (!slice_low_has_vma(mm, i))
- ret->low_slices |= 1u << i;
+ __set_bit(i, ret->low_slices);
if (high_limit <= SLICE_LOW_TOP)
return;
@@ -147,19 +151,21 @@ static void slice_mask_for_free(struct mm_struct *mm, struct slice_mask *ret,
static void slice_mask_for_size(struct mm_struct *mm, int psize, struct slice_mask *ret,
unsigned long high_limit)
{
- unsigned char *hpsizes;
+ unsigned char *hpsizes, *lpsizes;
int index, mask_index;
unsigned long i;
- u64 lpsizes;
- ret->low_slices = 0;
+ bitmap_zero(ret->low_slices, SLICE_NUM_LOW);
if (SLICE_NUM_HIGH)
bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
lpsizes = mm->context.low_slices_psize;
- for (i = 0; i < SLICE_NUM_LOW; i++)
- if (((lpsizes >> (i * 4)) & 0xf) == psize)
- ret->low_slices |= 1u << i;
+ for (i = 0; i < SLICE_NUM_LOW; i++) {
+ mask_index = i & 0x1;
+ index = i >> 1;
+ if (((lpsizes[index] >> (mask_index * 4)) & 0xf) == psize)
+ __set_bit(i, ret->low_slices);
+ }
if (high_limit <= SLICE_LOW_TOP)
return;
@@ -176,6 +182,7 @@ static void slice_mask_for_size(struct mm_struct *mm, int psize, struct slice_ma
static int slice_check_fit(struct mm_struct *mm,
struct slice_mask mask, struct slice_mask available)
{
+ DECLARE_BITMAP(result_low, SLICE_NUM_LOW);
DECLARE_BITMAP(result, SLICE_NUM_HIGH);
/*
* Make sure we just do bit compare only to the max
@@ -183,11 +190,13 @@ static int slice_check_fit(struct mm_struct *mm,
*/
unsigned long slice_count = GET_HIGH_SLICE_INDEX(mm->context.slb_addr_limit);
+ bitmap_and(result_low, mask.low_slices,
+ available.low_slices, SLICE_NUM_LOW);
if (SLICE_NUM_HIGH)
bitmap_and(result, mask.high_slices,
available.high_slices, slice_count);
- return (mask.low_slices & available.low_slices) == mask.low_slices &&
+ return bitmap_equal(result_low, mask.low_slices, SLICE_NUM_LOW) &&
(!slice_count ||
bitmap_equal(result, mask.high_slices, slice_count));
}
@@ -213,8 +222,7 @@ static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psiz
{
int index, mask_index;
/* Write the new slice psize bits */
- unsigned char *hpsizes;
- u64 lpsizes;
+ unsigned char *hpsizes, *lpsizes;
unsigned long i, flags;
slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize);
@@ -226,13 +234,14 @@ static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psiz
spin_lock_irqsave(&slice_convert_lock, flags);
lpsizes = mm->context.low_slices_psize;
- for (i = 0; i < SLICE_NUM_LOW; i++)
- if (mask.low_slices & (1u << i))
- lpsizes = (lpsizes & ~(0xful << (i * 4))) |
- (((unsigned long)psize) << (i * 4));
-
- /* Assign the value back */
- mm->context.low_slices_psize = lpsizes;
+ for (i = 0; i < SLICE_NUM_LOW; i++) {
+ mask_index = i & 0x1;
+ index = i >> 1;
+ if (test_bit(i, mask.low_slices))
+ lpsizes[index] = (lpsizes[index] &
+ ~(0xf << (mask_index * 4))) |
+ (((unsigned long)psize) << (mask_index * 4));
+ }
hpsizes = mm->context.high_slices_psize;
for (i = 0; i < GET_HIGH_SLICE_INDEX(mm->context.slb_addr_limit); i++) {
@@ -269,7 +278,7 @@ static bool slice_scan_available(unsigned long addr,
if (addr <= SLICE_LOW_TOP) {
slice = GET_LOW_SLICE_INDEX(addr);
*boundary_addr = (slice + end) << SLICE_LOW_SHIFT;
- return !!(available.low_slices & (1u << slice));
+ return !!test_bit(slice, available.low_slices);
} else {
slice = GET_HIGH_SLICE_INDEX(addr);
*boundary_addr = (slice + end) ?
@@ -397,7 +406,8 @@ static inline void slice_or_mask(struct slice_mask *dst, struct slice_mask *src)
{
DECLARE_BITMAP(result, SLICE_NUM_HIGH);
- dst->low_slices |= src->low_slices;
+ bitmap_or(dst->low_slices, dst->low_slices, src->low_slices,
+ SLICE_NUM_LOW);
if (SLICE_NUM_HIGH) {
bitmap_or(result, dst->high_slices, src->high_slices,
SLICE_NUM_HIGH);
@@ -409,7 +419,8 @@ static inline void slice_andnot_mask(struct slice_mask *dst, struct slice_mask *
{
DECLARE_BITMAP(result, SLICE_NUM_HIGH);
- dst->low_slices &= ~src->low_slices;
+ bitmap_andnot(dst->low_slices, dst->low_slices, src->low_slices,
+ SLICE_NUM_LOW);
if (SLICE_NUM_HIGH) {
bitmap_andnot(result, dst->high_slices, src->high_slices,
@@ -464,16 +475,16 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
/*
* init different masks
*/
- mask.low_slices = 0;
+ bitmap_zero(mask.low_slices, SLICE_NUM_LOW);
if (SLICE_NUM_HIGH)
bitmap_zero(mask.high_slices, SLICE_NUM_HIGH);
/* silence stupid warning */;
- potential_mask.low_slices = 0;
+ bitmap_zero(potential_mask.low_slices, SLICE_NUM_LOW);
if (SLICE_NUM_HIGH)
bitmap_zero(potential_mask.high_slices, SLICE_NUM_HIGH);
- compat_mask.low_slices = 0;
+ bitmap_zero(compat_mask.low_slices, SLICE_NUM_LOW);
if (SLICE_NUM_HIGH)
bitmap_zero(compat_mask.high_slices, SLICE_NUM_HIGH);
@@ -613,7 +624,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
convert:
slice_andnot_mask(&mask, &good_mask);
slice_andnot_mask(&mask, &compat_mask);
- if (mask.low_slices ||
+ if (!bitmap_empty(mask.low_slices, SLICE_NUM_LOW) ||
(SLICE_NUM_HIGH &&
!bitmap_empty(mask.high_slices, SLICE_NUM_HIGH))) {
slice_convert(mm, mask, psize);
@@ -647,7 +658,7 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
{
- unsigned char *hpsizes;
+ unsigned char *psizes;
int index, mask_index;
/*
@@ -661,15 +672,14 @@ unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
#endif
}
if (addr <= SLICE_LOW_TOP) {
- u64 lpsizes;
- lpsizes = mm->context.low_slices_psize;
+ psizes = mm->context.low_slices_psize;
index = GET_LOW_SLICE_INDEX(addr);
- return (lpsizes >> (index * 4)) & 0xf;
+ } else {
+ psizes = mm->context.high_slices_psize;
+ index = GET_HIGH_SLICE_INDEX(addr);
}
- hpsizes = mm->context.high_slices_psize;
- index = GET_HIGH_SLICE_INDEX(addr);
mask_index = index & 0x1;
- return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xf;
+ return (psizes[index >> 1] >> (mask_index * 4)) & 0xf;
}
EXPORT_SYMBOL_GPL(get_slice_psize);
@@ -690,8 +700,8 @@ EXPORT_SYMBOL_GPL(get_slice_psize);
void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
{
int index, mask_index;
- unsigned char *hpsizes;
- unsigned long flags, lpsizes;
+ unsigned char *hpsizes, *lpsizes;
+ unsigned long flags;
unsigned int old_psize;
int i;
@@ -709,12 +719,14 @@ void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
wmb();
lpsizes = mm->context.low_slices_psize;
- for (i = 0; i < SLICE_NUM_LOW; i++)
- if (((lpsizes >> (i * 4)) & 0xf) == old_psize)
- lpsizes = (lpsizes & ~(0xful << (i * 4))) |
- (((unsigned long)psize) << (i * 4));
- /* Assign the value back */
- mm->context.low_slices_psize = lpsizes;
+ for (i = 0; i < SLICE_NUM_LOW; i++) {
+ mask_index = i & 0x1;
+ index = i >> 1;
+ if (((lpsizes[index] >> (mask_index * 4)) & 0xf) == old_psize)
+ lpsizes[index] = (lpsizes[index] &
+ ~(0xf << (mask_index * 4))) |
+ (((unsigned long)psize) << (mask_index * 4));
+ }
hpsizes = mm->context.high_slices_psize;
for (i = 0; i < SLICE_NUM_HIGH; i++) {
--
2.13.3
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