From 4f93d21d2563353df813ee049f6489f340389aab Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 6 Sep 2012 18:13:58 -0700 Subject: 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: David S. Miller --- arch/sparc/mm/init_64.c | 137 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 110 insertions(+), 27 deletions(-) (limited to 'arch/sparc/mm/init_64.c') diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index d58edf5fefd..c0fc25be0c5 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -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; - while (remains >= size_256MB) { - unsigned long index = start >> shift_256MB; +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; - __set_bit(index, kpte_linear_bitmap); + if (remains < size || (start & mask)) + return start; - start += size_256MB; - remains -= size_256MB; + /* 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; + } + + return start; +} + +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); + + 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); -- cgit v1.2.3