diff mbox

[-V3,07/11] arch/powerpc: Increase the slice range to 64TB

Message ID 1341839621-28332-8-git-send-email-aneesh.kumar@linux.vnet.ibm.com (mailing list archive)
State Changes Requested
Delegated to: Benjamin Herrenschmidt
Headers show

Commit Message

Aneesh Kumar K.V July 9, 2012, 1:13 p.m. UTC
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

This patch makes the high psizes mask as an unsigned char array
so that we can have more than 16TB. Currently we support upto
64TB

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/mmu-hash64.h |    6 ++-
 arch/powerpc/include/asm/page_64.h    |    6 ++-
 arch/powerpc/mm/hash_utils_64.c       |   15 +++---
 arch/powerpc/mm/slb_low.S             |   35 ++++++++----
 arch/powerpc/mm/slice.c               |   95 +++++++++++++++++++++------------
 5 files changed, 107 insertions(+), 50 deletions(-)

Comments

Paul Mackerras July 23, 2012, midnight UTC | #1
On Mon, Jul 09, 2012 at 06:43:37PM +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> 
> This patch makes the high psizes mask as an unsigned char array
> so that we can have more than 16TB. Currently we support upto
> 64TB

Some comments inline...

> @@ -804,16 +804,19 @@ unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
>  #ifdef CONFIG_PPC_MM_SLICES
>  unsigned int get_paca_psize(unsigned long addr)
>  {
> -	unsigned long index, slices;
> +	u64 lpsizes;
> +	unsigned char *hpsizes;
> +	unsigned long index, mask_index;
>  
>  	if (addr < SLICE_LOW_TOP) {
> -		slices = get_paca()->context.low_slices_psize;
> +		lpsizes = 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 (lpsizes >> (index * 4)) & 0xF;
>  	}
> -	return (slices >> (index * 4)) & 0xF;
> +	hpsizes = get_paca()->context.high_slices_psize;
> +	index = GET_HIGH_SLICE_INDEX(addr) >> 1;
> +	mask_index = GET_HIGH_SLICE_INDEX(addr) - (index << 1);
> +	return (hpsizes[index] >> (mask_index * 4)) & 0xF;

The last 3 lines here feel awkward.  How about:

> +	index = GET_HIGH_SLICE_INDEX(addr);
> +	mask_index = index & 1;
> +	return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF;

>  static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize)
>  {
> +	unsigned char *hpsizes;
> +	int index, mask_index;
>  	struct slice_mask ret = { 0, 0 };
>  	unsigned long i;
> -	u64 psizes;
> +	u64 lpsizes;
>  
> -	psizes = mm->context.low_slices_psize;
> +	lpsizes = mm->context.low_slices_psize;
>  	for (i = 0; i < SLICE_NUM_LOW; i++)
> -		if (((psizes >> (i * 4)) & 0xf) == psize)
> +		if (((lpsizes >> (i * 4)) & 0xf) == psize)
>  			ret.low_slices |= 1u << i;
>  
> -	psizes = mm->context.high_slices_psize;
> -	for (i = 0; i < SLICE_NUM_HIGH; i++)
> -		if (((psizes >> (i * 4)) & 0xf) == psize)
> +	hpsizes = mm->context.high_slices_psize;
> +	for (i = 0; i < SLICE_NUM_HIGH; i++) {
> +		index = i >> 1;
> +		mask_index = i - (index << 1);

Again, seems like a complicated way to do mask_index = i & 1 (or
even i % 2, if you prefer, but then make i an unsigned type).

Paul.
Aneesh Kumar K.V July 23, 2012, 7:13 a.m. UTC | #2
Paul Mackerras <paulus@samba.org> writes:

> On Mon, Jul 09, 2012 at 06:43:37PM +0530, Aneesh Kumar K.V wrote:
>> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>> 
>> This patch makes the high psizes mask as an unsigned char array
>> so that we can have more than 16TB. Currently we support upto
>> 64TB
>
> Some comments inline...
>
>> @@ -804,16 +804,19 @@ unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
>>  #ifdef CONFIG_PPC_MM_SLICES
>>  unsigned int get_paca_psize(unsigned long addr)
>>  {
>> -	unsigned long index, slices;
>> +	u64 lpsizes;
>> +	unsigned char *hpsizes;
>> +	unsigned long index, mask_index;
>>  
>>  	if (addr < SLICE_LOW_TOP) {
>> -		slices = get_paca()->context.low_slices_psize;
>> +		lpsizes = 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 (lpsizes >> (index * 4)) & 0xF;
>>  	}
>> -	return (slices >> (index * 4)) & 0xF;
>> +	hpsizes = get_paca()->context.high_slices_psize;
>> +	index = GET_HIGH_SLICE_INDEX(addr) >> 1;
>> +	mask_index = GET_HIGH_SLICE_INDEX(addr) - (index << 1);
>> +	return (hpsizes[index] >> (mask_index * 4)) & 0xF;
>
> The last 3 lines here feel awkward.  How about:
>
	index = GET_HIGH_SLICE_INDEX(addr);
	mask_index = index & 1;
	return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF;


That is much simpler. I updated the patch, changing to the above format in
all the location.

>
>>  static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize)
>>  {
>> +	unsigned char *hpsizes;
>> +	int index, mask_index;
>>  	struct slice_mask ret = { 0, 0 };
>>  	unsigned long i;
>> -	u64 psizes;
>> +	u64 lpsizes;
>>  
>> -	psizes = mm->context.low_slices_psize;
>> +	lpsizes = mm->context.low_slices_psize;
>>  	for (i = 0; i < SLICE_NUM_LOW; i++)
>> -		if (((psizes >> (i * 4)) & 0xf) == psize)
>> +		if (((lpsizes >> (i * 4)) & 0xf) == psize)
>>  			ret.low_slices |= 1u << i;
>>  
>> -	psizes = mm->context.high_slices_psize;
>> -	for (i = 0; i < SLICE_NUM_HIGH; i++)
>> -		if (((psizes >> (i * 4)) & 0xf) == psize)
>> +	hpsizes = mm->context.high_slices_psize;
>> +	for (i = 0; i < SLICE_NUM_HIGH; i++) {
>> +		index = i >> 1;
>> +		mask_index = i - (index << 1);
>
> Again, seems like a complicated way to do mask_index = i & 1 (or
> even i % 2, if you prefer, but then make i an unsigned type).
>
> Paul.


-aneesh
diff mbox

Patch

diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
index a085de2..35b74e8 100644
--- a/arch/powerpc/include/asm/mmu-hash64.h
+++ b/arch/powerpc/include/asm/mmu-hash64.h
@@ -463,7 +463,11 @@  typedef struct {
 
 #ifdef CONFIG_PPC_MM_SLICES
 	u64 low_slices_psize;	/* SLB page size encodings */
-	u64 high_slices_psize;  /* 4 bits per slice for now */
+	/*
+	 * Right now we support 64TB and 4 bits for each
+	 * 1TB slice we need 32 bytes for 64TB.
+	 */
+	unsigned char high_slices_psize[32];  /* 4 bits per slice for now */
 #else
 	u16 sllp;		/* SLB page size encoding */
 #endif
diff --git a/arch/powerpc/include/asm/page_64.h b/arch/powerpc/include/asm/page_64.h
index fed85e6..6c9bef4 100644
--- a/arch/powerpc/include/asm/page_64.h
+++ b/arch/powerpc/include/asm/page_64.h
@@ -82,7 +82,11 @@  extern u64 ppc64_pft_size;
 
 struct slice_mask {
 	u16 low_slices;
-	u16 high_slices;
+	/*
+	 * This should be derived out of PGTABLE_RANGE. For the current
+	 * max 64TB, u64 should be ok.
+	 */
+	u64 high_slices;
 };
 
 struct mm_struct;
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 0d8c4b8..eb4a3ac 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -804,16 +804,19 @@  unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
 #ifdef CONFIG_PPC_MM_SLICES
 unsigned int get_paca_psize(unsigned long addr)
 {
-	unsigned long index, slices;
+	u64 lpsizes;
+	unsigned char *hpsizes;
+	unsigned long index, mask_index;
 
 	if (addr < SLICE_LOW_TOP) {
-		slices = get_paca()->context.low_slices_psize;
+		lpsizes = 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 (lpsizes >> (index * 4)) & 0xF;
 	}
-	return (slices >> (index * 4)) & 0xF;
+	hpsizes = get_paca()->context.high_slices_psize;
+	index = GET_HIGH_SLICE_INDEX(addr) >> 1;
+	mask_index = GET_HIGH_SLICE_INDEX(addr) - (index << 1);
+	return (hpsizes[index] >> (mask_index * 4)) & 0xF;
 }
 
 #else
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index b9ee79ce..c355af6 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -108,17 +108,34 @@  END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
 	 * between 4k and 64k standard page size
 	 */
 #ifdef CONFIG_PPC_MM_SLICES
+	/* r10 have esid */
 	cmpldi	r10,16
-
-	/* Get the slice index * 4 in r11 and matching slice size mask in r9 */
-	ld	r9,PACALOWSLICESPSIZE(r13)
-	sldi	r11,r10,2
+	/* below SLICE_LOW_TOP */
 	blt	5f
-	ld	r9,PACAHIGHSLICEPSIZE(r13)
-	srdi	r11,r10,(SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT - 2)
-	andi.	r11,r11,0x3c
-
-5:	/* Extract the psize and multiply to get an array offset */
+	/*
+	 * Handle hpsizes,
+	 * r9 is get_paca()->context.high_slices_psize[index], r11 is mask_index
+	 * We use r10 here, later we restore it to esid.
+	 * Can we use other register instead of r10 ?
+	 */
+	srdi    r10,r10,(SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT) /* index */
+	srdi	r11,r10,1			/* r11 is array index */
+	addi	r9,r11,PACAHIGHSLICEPSIZE
+	lbzx	r9,r9,r13			/* r9 is hpsizes[r11] */
+	sldi    r11,r11,1
+	subf	r11,r11,r10	/* mask_index = index - (array_index << 1) */
+	srdi	r10,r3,28	/* restore r10 with esid */
+	b	6f
+5:
+	/*
+	 * Handle lpsizes
+	 * r9 is get_paca()->context.low_slices_psize, r11 is index
+	 */
+	ld	r9,PACALOWSLICESPSIZE(r13)
+	mr	r11,r10
+6:
+	sldi	r11,r11,2  /* index * 4 */
+	/* Extract the psize and multiply to get an array offset */
 	srd	r9,r9,r11
 	andi.	r9,r9,0xf
 	mulli	r9,r9,MMUPSIZEDEFSIZE
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index 73709f7..302a481 100644
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -42,7 +42,7 @@  int _slice_debug = 1;
 
 static void slice_print_mask(const char *label, struct slice_mask mask)
 {
-	char	*p, buf[16 + 3 + 16 + 1];
+	char	*p, buf[16 + 3 + 64 + 1];
 	int	i;
 
 	if (!_slice_debug)
@@ -142,19 +142,24 @@  static struct slice_mask slice_mask_for_free(struct mm_struct *mm)
 
 static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize)
 {
+	unsigned char *hpsizes;
+	int index, mask_index;
 	struct slice_mask ret = { 0, 0 };
 	unsigned long i;
-	u64 psizes;
+	u64 lpsizes;
 
-	psizes = mm->context.low_slices_psize;
+	lpsizes = mm->context.low_slices_psize;
 	for (i = 0; i < SLICE_NUM_LOW; i++)
-		if (((psizes >> (i * 4)) & 0xf) == psize)
+		if (((lpsizes >> (i * 4)) & 0xf) == psize)
 			ret.low_slices |= 1u << i;
 
-	psizes = mm->context.high_slices_psize;
-	for (i = 0; i < SLICE_NUM_HIGH; i++)
-		if (((psizes >> (i * 4)) & 0xf) == psize)
+	hpsizes = mm->context.high_slices_psize;
+	for (i = 0; i < SLICE_NUM_HIGH; i++) {
+		index = i >> 1;
+		mask_index = i - (index << 1);
+		if (((hpsizes[index] >> (mask_index * 4)) & 0xf) == psize)
 			ret.high_slices |= 1u << i;
+	}
 
 	return ret;
 }
@@ -183,8 +188,10 @@  static void slice_flush_segments(void *parm)
 
 static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psize)
 {
+	int index, mask_index;
 	/* Write the new slice psize bits */
-	u64 lpsizes, hpsizes;
+	unsigned char *hpsizes;
+	u64 lpsizes;
 	unsigned long i, flags;
 
 	slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize);
@@ -201,14 +208,18 @@  static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psiz
 			lpsizes = (lpsizes & ~(0xful << (i * 4))) |
 				(((unsigned long)psize) << (i * 4));
 
+	/* Assign the value back */
+	mm->context.low_slices_psize = lpsizes;
+
 	hpsizes = mm->context.high_slices_psize;
-	for (i = 0; i < SLICE_NUM_HIGH; i++)
+	for (i = 0; i < SLICE_NUM_HIGH; i++) {
+		index = i >> 1;
+		mask_index = i - (index << 1);
 		if (mask.high_slices & (1u << i))
-			hpsizes = (hpsizes & ~(0xful << (i * 4))) |
-				(((unsigned long)psize) << (i * 4));
-
-	mm->context.low_slices_psize = lpsizes;
-	mm->context.high_slices_psize = hpsizes;
+			hpsizes[index] = (hpsizes[index] &
+					  ~(0xf << (mask_index * 4))) |
+				(((unsigned long)psize) << (mask_index * 4));
+	}
 
 	slice_dbg(" lsps=%lx, hsps=%lx\n",
 		  mm->context.low_slices_psize,
@@ -587,18 +598,19 @@  unsigned long arch_get_unmapped_area_topdown(struct file *filp,
 
 unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
 {
-	u64 psizes;
-	int index;
+	unsigned char *hpsizes;
+	int index, mask_index;
 
 	if (addr < SLICE_LOW_TOP) {
-		psizes = mm->context.low_slices_psize;
+		u64 lpsizes;
+		lpsizes = mm->context.low_slices_psize;
 		index = GET_LOW_SLICE_INDEX(addr);
-	} else {
-		psizes = mm->context.high_slices_psize;
-		index = GET_HIGH_SLICE_INDEX(addr);
+		return (lpsizes >> (index * 4)) & 0xf;
 	}
-
-	return (psizes >> (index * 4)) & 0xf;
+	hpsizes = mm->context.high_slices_psize;
+	index = GET_HIGH_SLICE_INDEX(addr) >> 1;
+	mask_index = GET_HIGH_SLICE_INDEX(addr) - (index << 1);
+	return (hpsizes[index] >> (mask_index * 4)) & 0xf;
 }
 EXPORT_SYMBOL_GPL(get_slice_psize);
 
@@ -618,7 +630,9 @@  EXPORT_SYMBOL_GPL(get_slice_psize);
  */
 void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
 {
-	unsigned long flags, lpsizes, hpsizes;
+	int index, mask_index;
+	unsigned char *hpsizes;
+	unsigned long flags, lpsizes;
 	unsigned int old_psize;
 	int i;
 
@@ -639,15 +653,21 @@  void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
 		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;
 
 	hpsizes = mm->context.high_slices_psize;
-	for (i = 0; i < SLICE_NUM_HIGH; i++)
-		if (((hpsizes >> (i * 4)) & 0xf) == old_psize)
-			hpsizes = (hpsizes & ~(0xful << (i * 4))) |
-				(((unsigned long)psize) << (i * 4));
+	for (i = 0; i < SLICE_NUM_HIGH; i++) {
+		index = i >> 1;
+		mask_index = i - (index << 1);
+		if (((hpsizes[index] >> (mask_index * 4)) & 0xf) == old_psize)
+			hpsizes[index] = (hpsizes[index] &
+					  ~(0xf << (mask_index * 4))) |
+				(((unsigned long)psize) << (mask_index * 4));
+	}
+
+
 
-	mm->context.low_slices_psize = lpsizes;
-	mm->context.high_slices_psize = hpsizes;
 
 	slice_dbg(" lsps=%lx, hsps=%lx\n",
 		  mm->context.low_slices_psize,
@@ -660,18 +680,27 @@  void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
 void slice_set_psize(struct mm_struct *mm, unsigned long address,
 		     unsigned int psize)
 {
+	unsigned char *hpsizes;
 	unsigned long i, flags;
-	u64 *p;
+	u64 *lpsizes;
 
 	spin_lock_irqsave(&slice_convert_lock, flags);
 	if (address < SLICE_LOW_TOP) {
 		i = GET_LOW_SLICE_INDEX(address);
-		p = &mm->context.low_slices_psize;
+		lpsizes = &mm->context.low_slices_psize;
+		*lpsizes = (*lpsizes & ~(0xful << (i * 4))) |
+			((unsigned long) psize << (i * 4));
 	} else {
+		int index, mask_index;
 		i = GET_HIGH_SLICE_INDEX(address);
-		p = &mm->context.high_slices_psize;
+		hpsizes = mm->context.high_slices_psize;
+		index = i >> 1;
+		mask_index = i - (index << 1);
+		hpsizes[index] = (hpsizes[index] &
+				  ~(0xf << (mask_index * 4))) |
+			(((unsigned long)psize) << (mask_index * 4));
 	}
-	*p = (*p & ~(0xful << (i * 4))) | ((unsigned long) psize << (i * 4));
+
 	spin_unlock_irqrestore(&slice_convert_lock, flags);
 
 #ifdef CONFIG_SPU_BASE