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Commit 4f93d21d authored by David S. Miller's avatar David S. Miller
Browse files

sparc64: Support 2GB and 16GB page sizes for kernel linear mappings. 



SPARC-T4 supports 2GB pages.

So convert kpte_linear_bitmap into an array of 2-bit values which
index into kern_linear_pte_xor.

Now kern_linear_pte_xor is used for 4 page size aligned regions,
4MB, 256MB, 2GB, and 16GB respectively.

Enabling 2GB pages is currently hardcoded using a check against
sun4v_chip_type.  In the future this will be done more cleanly
by interrogating the machine description which is the correct
way to determine this kind of thing.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 699871bc

arch/sparc/kernel/ktlb.S

+10 −15
Original line number Diff line number Diff line
@@ -188,31 +188,26 @@ valid_addr_bitmap_patch: 
	be,pn		%xcc, kvmap_dtlb_longpath



2:	 sethi		%hi(kpte_linear_bitmap), %g2

	or		%g2, %lo(kpte_linear_bitmap), %g2



	/* Get the 256MB physical address index. */

	sllx		%g4, 21, %g5

	mov		1, %g7

	or		%g2, %lo(kpte_linear_bitmap), %g2

	srlx		%g5, 21 + 28, %g5

	and		%g5, (32 - 1), %g7



	/* Don't try this at home kids... this depends upon srlx

	 * only taking the low 6 bits of the shift count in %g5.

	 */

	sllx		%g7, %g5, %g7



	/* Divide by 64 to get the offset into the bitmask.  */

	srlx		%g5, 6, %g5

	/* Divide by 32 to get the offset into the bitmask.  */

	srlx		%g5, 5, %g5

	add		%g7, %g7, %g7

	sllx		%g5, 3, %g5



	/* kern_linear_pte_xor[((mask & bit) ? 1 : 0)] */

	/* kern_linear_pte_xor[(mask >> shift) & 3)] */

	ldx		[%g2 + %g5], %g2

	andcc		%g2, %g7, %g0

	srlx		%g2, %g7, %g7

	sethi		%hi(kern_linear_pte_xor), %g5

	and		%g7, 3, %g7

	or		%g5, %lo(kern_linear_pte_xor), %g5

	bne,a,pt	%xcc, 1f

	 add		%g5, 8, %g5



1:	ldx		[%g5], %g2

	sllx		%g7, 3, %g7

	ldx		[%g5 + %g7], %g2



	.globl		kvmap_linear_patch

kvmap_linear_patch:

arch/sparc/mm/init_64.c

+110 −27
Original line number Diff line number Diff line
@@ -51,18 +51,34 @@ 


#include "init_64.h"



unsigned long kern_linear_pte_xor[2] __read_mostly;

unsigned long kern_linear_pte_xor[4] __read_mostly;



/* A bitmap, one bit for every 256MB of physical memory.  If the bit

 * is clear, we should use a 4MB page (via kern_linear_pte_xor[0]) else

 * if set we should use a 256MB page (via kern_linear_pte_xor[1]).

/* A bitmap, two bits for every 256MB of physical memory.  These two

 * bits determine what page size we use for kernel linear

 * translations.  They form an index into kern_linear_pte_xor[].  The

 * value in the indexed slot is XOR'd with the TLB miss virtual

 * address to form the resulting TTE.  The mapping is:

 *

 *	0	==>	4MB

 *	1	==>	256MB

 *	2	==>	2GB

 *	3	==>	16GB

 *

 * All sun4v chips support 256MB pages.  Only SPARC-T4 and later

 * support 2GB pages, and hopefully future cpus will support the 16GB

 * pages as well.  For slots 2 and 3, we encode a 256MB TTE xor there

 * if these larger page sizes are not supported by the cpu.

 *

 * It would be nice to determine this from the machine description

 * 'cpu' properties, but we need to have this table setup before the

 * MDESC is initialized.

 */

unsigned long kpte_linear_bitmap[KPTE_BITMAP_BYTES / sizeof(unsigned long)];



#ifndef CONFIG_DEBUG_PAGEALLOC

/* A special kernel TSB for 4MB and 256MB linear mappings.

 * Space is allocated for this right after the trap table

 * in arch/sparc64/kernel/head.S

/* A special kernel TSB for 4MB, 256MB, 2GB and 16GB linear mappings.

 * Space is allocated for this right after the trap table in

 * arch/sparc64/kernel/head.S

 */

extern struct tsb swapper_4m_tsb[KERNEL_TSB4M_NENTRIES];

#endif
@@ -1358,32 +1374,75 @@ static unsigned long __ref kernel_map_range(unsigned long pstart, 
extern unsigned int kvmap_linear_patch[1];

#endif /* CONFIG_DEBUG_PAGEALLOC */



static void __init mark_kpte_bitmap(unsigned long start, unsigned long end)

static void __init kpte_set_val(unsigned long index, unsigned long val)

{

	const unsigned long shift_256MB = 28;

	const unsigned long mask_256MB = ((1UL << shift_256MB) - 1UL);

	const unsigned long size_256MB = (1UL << shift_256MB);

	unsigned long *ptr = kpte_linear_bitmap;



	while (start < end) {

		long remains;

	val <<= ((index % (BITS_PER_LONG / 2)) * 2);

	ptr += (index / (BITS_PER_LONG / 2));



		remains = end - start;

		if (remains < size_256MB)

			break;

	*ptr |= val;

}



		if (start & mask_256MB) {

			start = (start + size_256MB) & ~mask_256MB;

			continue;

static const unsigned long kpte_shift_min = 28; /* 256MB */

static const unsigned long kpte_shift_max = 34; /* 16GB */

static const unsigned long kpte_shift_incr = 3;



static unsigned long kpte_mark_using_shift(unsigned long start, unsigned long end,

					   unsigned long shift)

{

	unsigned long size = (1UL << shift);

	unsigned long mask = (size - 1UL);

	unsigned long remains = end - start;

	unsigned long val;



	if (remains < size || (start & mask))

		return start;



	/* VAL maps:

	 *

	 *	shift 28 --> kern_linear_pte_xor index 1

	 *	shift 31 --> kern_linear_pte_xor index 2

	 *	shift 34 --> kern_linear_pte_xor index 3

	 */

	val = ((shift - kpte_shift_min) / kpte_shift_incr) + 1;



	remains &= ~mask;

	if (shift != kpte_shift_max)

		remains = size;



	while (remains) {

		unsigned long index = start >> kpte_shift_min;



		kpte_set_val(index, val);



		start += 1UL << kpte_shift_min;

		remains -= 1UL << kpte_shift_min;

	}



		while (remains >= size_256MB) {

			unsigned long index = start >> shift_256MB;

	return start;

}



			__set_bit(index, kpte_linear_bitmap);

static void __init mark_kpte_bitmap(unsigned long start, unsigned long end)

{

	unsigned long smallest_size, smallest_mask;

	unsigned long s;



	smallest_size = (1UL << kpte_shift_min);

	smallest_mask = (smallest_size - 1UL);



	while (start < end) {

		unsigned long orig_start = start;



		for (s = kpte_shift_max; s >= kpte_shift_min; s -= kpte_shift_incr) {

			start = kpte_mark_using_shift(start, end, s);



			start += size_256MB;

			remains -= size_256MB;

			if (start != orig_start)

				break;

		}



		if (start == orig_start)

			start = (start + smallest_size) & ~smallest_mask;

	}

}
@@ -1577,13 +1636,15 @@ static void __init sun4v_ktsb_init(void) 
	ktsb_descr[0].resv = 0;



#ifndef CONFIG_DEBUG_PAGEALLOC

	/* Second KTSB for 4MB/256MB mappings.  */

	/* Second KTSB for 4MB/256MB/2GB/16GB mappings.  */

	ktsb_pa = (kern_base +

		   ((unsigned long)&swapper_4m_tsb[0] - KERNBASE));



	ktsb_descr[1].pgsz_idx = HV_PGSZ_IDX_4MB;

	ktsb_descr[1].pgsz_mask = (HV_PGSZ_MASK_4MB |

				   HV_PGSZ_MASK_256MB);

	if (sun4v_chip_type == SUN4V_CHIP_NIAGARA4)

		ktsb_descr[1].pgsz_mask |= HV_PGSZ_MASK_2GB;

	ktsb_descr[1].assoc = 1;

	ktsb_descr[1].num_ttes = KERNEL_TSB4M_NENTRIES;

	ktsb_descr[1].ctx_idx = 0;
@@ -2110,6 +2171,7 @@ static void __init sun4u_pgprot_init(void) 
{

	unsigned long page_none, page_shared, page_copy, page_readonly;

	unsigned long page_exec_bit;

	int i;



	PAGE_KERNEL = __pgprot (_PAGE_PRESENT_4U | _PAGE_VALID |

				_PAGE_CACHE_4U | _PAGE_P_4U |
@@ -2138,7 +2200,8 @@ static void __init sun4u_pgprot_init(void) 
				   _PAGE_P_4U | _PAGE_W_4U);



	/* XXX Should use 256MB on Panther. XXX */

	kern_linear_pte_xor[1] = kern_linear_pte_xor[0];

	for (i = 1; i < 4; i++)

		kern_linear_pte_xor[i] = kern_linear_pte_xor[0];



	_PAGE_SZBITS = _PAGE_SZBITS_4U;

	_PAGE_ALL_SZ_BITS =  (_PAGE_SZ4MB_4U | _PAGE_SZ512K_4U |
@@ -2164,6 +2227,7 @@ static void __init sun4v_pgprot_init(void) 
{

	unsigned long page_none, page_shared, page_copy, page_readonly;

	unsigned long page_exec_bit;

	int i;



	PAGE_KERNEL = __pgprot (_PAGE_PRESENT_4V | _PAGE_VALID |

				_PAGE_CACHE_4V | _PAGE_P_4V |
@@ -2195,6 +2259,25 @@ static void __init sun4v_pgprot_init(void) 
	kern_linear_pte_xor[1] |= (_PAGE_CP_4V | _PAGE_CV_4V |

				   _PAGE_P_4V | _PAGE_W_4V);



	i = 2;



	if (sun4v_chip_type == SUN4V_CHIP_NIAGARA4) {

#ifdef CONFIG_DEBUG_PAGEALLOC

		kern_linear_pte_xor[2] = (_PAGE_VALID | _PAGE_SZBITS_4V) ^

			0xfffff80000000000UL;

#else

		kern_linear_pte_xor[2] = (_PAGE_VALID | _PAGE_SZ2GB_4V) ^

			0xfffff80000000000UL;

#endif

		kern_linear_pte_xor[2] |= (_PAGE_CP_4V | _PAGE_CV_4V |

					   _PAGE_P_4V | _PAGE_W_4V);



		i = 3;

	}



	for (; i < 4; i++)

		kern_linear_pte_xor[i] = kern_linear_pte_xor[i - 1];



	pg_iobits = (_PAGE_VALID | _PAGE_PRESENT_4V | __DIRTY_BITS_4V |

		     __ACCESS_BITS_4V | _PAGE_E_4V);

arch/sparc/mm/init_64.h

+2 −2
Original line number Diff line number Diff line
@@ -8,12 +8,12 @@ 
#define MAX_PHYS_ADDRESS	(1UL << 41UL)

#define KPTE_BITMAP_CHUNK_SZ		(256UL * 1024UL * 1024UL)

#define KPTE_BITMAP_BYTES	\

	((MAX_PHYS_ADDRESS / KPTE_BITMAP_CHUNK_SZ) / 8)

	((MAX_PHYS_ADDRESS / KPTE_BITMAP_CHUNK_SZ) / 4)

#define VALID_ADDR_BITMAP_CHUNK_SZ	(4UL * 1024UL * 1024UL)

#define VALID_ADDR_BITMAP_BYTES	\

	((MAX_PHYS_ADDRESS / VALID_ADDR_BITMAP_CHUNK_SZ) / 8)



extern unsigned long kern_linear_pte_xor[2];

extern unsigned long kern_linear_pte_xor[4];

extern unsigned long kpte_linear_bitmap[KPTE_BITMAP_BYTES / sizeof(unsigned long)];

extern unsigned int sparc64_highest_unlocked_tlb_ent;

extern unsigned long sparc64_kern_pri_context;