[linux-2.6-block.git] / arch / powerpc / mm / ptdump / hashpagetable.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2016, Rashmica Gupta, IBM Corp.
 *
 * This traverses the kernel virtual memory and dumps the pages that are in
 * the hash pagetable, along with their flags to
 * /sys/kernel/debug/kernel_hash_pagetable.
 *
 * If radix is enabled then there is no hash page table and so no debugfs file
 * is generated.
 */
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/const.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/plpar_wrappers.h>
#include <linux/memblock.h>
#include <asm/firmware.h>

struct pg_state {
	struct seq_file *seq;
	const struct addr_marker *marker;
	unsigned long start_address;
	unsigned int level;
	u64 current_flags;
};

struct addr_marker {
	unsigned long start_address;
	const char *name;
};

static struct addr_marker address_markers[] = {
	{ 0,	"Start of kernel VM" },
	{ 0,	"vmalloc() Area" },
	{ 0,	"vmalloc() End" },
	{ 0,	"isa I/O start" },
	{ 0,	"isa I/O end" },
	{ 0,	"phb I/O start" },
	{ 0,	"phb I/O end" },
	{ 0,	"I/O remap start" },
	{ 0,	"I/O remap end" },
	{ 0,	"vmemmap start" },
	{ -1,	NULL },
};

struct flag_info {
	u64		mask;
	u64		val;
	const char	*set;
	const char	*clear;
	bool		is_val;
	int		shift;
};

static const struct flag_info v_flag_array[] = {
	{
		.mask   = SLB_VSID_B,
		.val    = SLB_VSID_B_256M,
		.set    = "ssize: 256M",
		.clear  = "ssize: 1T  ",
	}, {
		.mask	= HPTE_V_SECONDARY,
		.val	= HPTE_V_SECONDARY,
		.set	= "secondary",
		.clear	= "primary  ",
	}, {
		.mask	= HPTE_V_VALID,
		.val	= HPTE_V_VALID,
		.set	= "valid  ",
		.clear	= "invalid",
	}, {
		.mask	= HPTE_V_BOLTED,
		.val	= HPTE_V_BOLTED,
		.set	= "bolted",
		.clear	= "",
	}
};

static const struct flag_info r_flag_array[] = {
	{
		.mask	= HPTE_R_PP0 | HPTE_R_PP,
		.val	= PP_RWXX,
		.set	= "prot:RW--",
	}, {
		.mask	= HPTE_R_PP0 | HPTE_R_PP,
		.val	= PP_RWRX,
		.set	= "prot:RWR-",
	}, {
		.mask	= HPTE_R_PP0 | HPTE_R_PP,
		.val	= PP_RWRW,
		.set	= "prot:RWRW",
	}, {
		.mask	= HPTE_R_PP0 | HPTE_R_PP,
		.val	= PP_RXRX,
		.set	= "prot:R-R-",
	}, {
		.mask	= HPTE_R_PP0 | HPTE_R_PP,
		.val	= PP_RXXX,
		.set	= "prot:R---",
	}, {
		.mask	= HPTE_R_KEY_HI | HPTE_R_KEY_LO,
		.val	= HPTE_R_KEY_HI | HPTE_R_KEY_LO,
		.set	= "key",
		.clear	= "",
		.is_val = true,
	}, {
		.mask	= HPTE_R_R,
		.val	= HPTE_R_R,
		.set	= "ref",
		.clear	= "   ",
	}, {
		.mask	= HPTE_R_C,
		.val	= HPTE_R_C,
		.set	= "changed",
		.clear	= "       ",
	}, {
		.mask	= HPTE_R_N,
		.val	= HPTE_R_N,
		.set	= "no execute",
	}, {
		.mask	= HPTE_R_WIMG,
		.val	= HPTE_R_W,
		.set	= "writethru",
	}, {
		.mask	= HPTE_R_WIMG,
		.val	= HPTE_R_I,
		.set	= "no cache",
	}, {
		.mask	= HPTE_R_WIMG,
		.val	= HPTE_R_G,
		.set	= "guarded",
	}
};

static int calculate_pagesize(struct pg_state *st, int ps, char s[])
{
	static const char units[] = "BKMGTPE";
	const char *unit = units;

	while (ps > 9 && unit[1]) {
		ps -= 10;
		unit++;
	}
	seq_printf(st->seq, "  %s_ps: %i%c\t", s, 1<<ps, *unit);
	return ps;
}

static void dump_flag_info(struct pg_state *st, const struct flag_info
		*flag, u64 pte, int num)
{
	unsigned int i;

	for (i = 0; i < num; i++, flag++) {
		const char *s = NULL;
		u64 val;

		/* flag not defined so don't check it */
		if (flag->mask == 0)
			continue;
		/* Some 'flags' are actually values */
		if (flag->is_val) {
			val = pte & flag->val;
			if (flag->shift)
				val = val >> flag->shift;
			seq_printf(st->seq, "  %s:%llx", flag->set, val);
		} else {
			if ((pte & flag->mask) == flag->val)
				s = flag->set;
			else
				s = flag->clear;
			if (s)
				seq_printf(st->seq, "  %s", s);
		}
	}
}

static void dump_hpte_info(struct pg_state *st, unsigned long ea, u64 v, u64 r,
		unsigned long rpn, int bps, int aps, unsigned long lp)
{
	int aps_index;

	while (ea >= st->marker[1].start_address) {
		st->marker++;
		seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
	}
	seq_printf(st->seq, "0x%lx:\t", ea);
	seq_printf(st->seq, "AVPN:%llx\t", HPTE_V_AVPN_VAL(v));
	dump_flag_info(st, v_flag_array, v, ARRAY_SIZE(v_flag_array));
	seq_printf(st->seq, "  rpn: %lx\t", rpn);
	dump_flag_info(st, r_flag_array, r, ARRAY_SIZE(r_flag_array));

	calculate_pagesize(st, bps, "base");
	aps_index = calculate_pagesize(st, aps, "actual");
	if (aps_index != 2)
		seq_printf(st->seq, "LP enc: %lx", lp);
	seq_putc(st->seq, '\n');
}


static int native_find(unsigned long ea, int psize, bool primary, u64 *v, u64
		*r)
{
	struct hash_pte *hptep;
	unsigned long hash, vsid, vpn, hpte_group, want_v, hpte_v;
	int i, ssize = mmu_kernel_ssize;
	unsigned long shift = mmu_psize_defs[psize].shift;

	/* calculate hash */
	vsid = get_kernel_vsid(ea, ssize);
	vpn  = hpt_vpn(ea, vsid, ssize);
	hash = hpt_hash(vpn, shift, ssize);
	want_v = hpte_encode_avpn(vpn, psize, ssize);

	/* to check in the secondary hash table, we invert the hash */
	if (!primary)
		hash = ~hash;
	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
	for (i = 0; i < HPTES_PER_GROUP; i++) {
		hptep = htab_address + hpte_group;
		hpte_v = be64_to_cpu(hptep->v);

		if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID)) {
			/* HPTE matches */
			*v = be64_to_cpu(hptep->v);
			*r = be64_to_cpu(hptep->r);
			return 0;
		}
		++hpte_group;
	}
	return -1;
}

static int pseries_find(unsigned long ea, int psize, bool primary, u64 *v, u64 *r)
{
	struct hash_pte ptes[4];
	unsigned long vsid, vpn, hash, hpte_group, want_v;
	int i, j, ssize = mmu_kernel_ssize;
	long lpar_rc = 0;
	unsigned long shift = mmu_psize_defs[psize].shift;

	/* calculate hash */
	vsid = get_kernel_vsid(ea, ssize);
	vpn  = hpt_vpn(ea, vsid, ssize);
	hash = hpt_hash(vpn, shift, ssize);
	want_v = hpte_encode_avpn(vpn, psize, ssize);

	/* to check in the secondary hash table, we invert the hash */
	if (!primary)
		hash = ~hash;
	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
	/* see if we can find an entry in the hpte with this hash */
	for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) {
		lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes);

		if (lpar_rc != H_SUCCESS)
			continue;
		for (j = 0; j < 4; j++) {
			if (HPTE_V_COMPARE(ptes[j].v, want_v) &&
					(ptes[j].v & HPTE_V_VALID)) {
				/* HPTE matches */
				*v = ptes[j].v;
				*r = ptes[j].r;
				return 0;
			}
		}
	}
	return -1;
}

static void decode_r(int bps, unsigned long r, unsigned long *rpn, int *aps,
		unsigned long *lp_bits)
{
	struct mmu_psize_def entry;
	unsigned long arpn, mask, lp;
	int penc = -2, idx = 0, shift;

	/*.
	 * The LP field has 8 bits. Depending on the actual page size, some of
	 * these bits are concatenated with the APRN to get the RPN. The rest
	 * of the bits in the LP field is the LP value and is an encoding for
	 * the base page size and the actual page size.
	 *
	 *  -	find the mmu entry for our base page size
	 *  -	go through all page encodings and use the associated mask to
	 *	find an encoding that matches our encoding in the LP field.
	 */
	arpn = (r & HPTE_R_RPN) >> HPTE_R_RPN_SHIFT;
	lp = arpn & 0xff;

	entry = mmu_psize_defs[bps];
	while (idx < MMU_PAGE_COUNT) {
		penc = entry.penc[idx];
		if ((penc != -1) && (mmu_psize_defs[idx].shift)) {
			shift = mmu_psize_defs[idx].shift -  HPTE_R_RPN_SHIFT;
			mask = (0x1 << (shift)) - 1;
			if ((lp & mask) == penc) {
				*aps = mmu_psize_to_shift(idx);
				*lp_bits = lp & mask;
				*rpn = arpn >> shift;
				return;
			}
		}
		idx++;
	}
}

static int base_hpte_find(unsigned long ea, int psize, bool primary, u64 *v,
			  u64 *r)
{
	if (IS_ENABLED(CONFIG_PPC_PSERIES) && firmware_has_feature(FW_FEATURE_LPAR))
		return pseries_find(ea, psize, primary, v, r);

	return native_find(ea, psize, primary, v, r);
}

static unsigned long hpte_find(struct pg_state *st, unsigned long ea, int psize)
{
	unsigned long slot;
	u64 v  = 0, r = 0;
	unsigned long rpn, lp_bits;
	int base_psize = 0, actual_psize = 0;

	if (ea < PAGE_OFFSET)
		return -1;

	/* Look in primary table */
	slot = base_hpte_find(ea, psize, true, &v, &r);

	/* Look in secondary table */
	if (slot == -1)
		slot = base_hpte_find(ea, psize, false, &v, &r);

	/* No entry found */
	if (slot == -1)
		return -1;

	/*
	 * We found an entry in the hash page table:
	 *  - check that this has the same base page
	 *  - find the actual page size
	 *  - find the RPN
	 */
	base_psize = mmu_psize_to_shift(psize);

	if ((v & HPTE_V_LARGE) == HPTE_V_LARGE) {
		decode_r(psize, r, &rpn, &actual_psize, &lp_bits);
	} else {
		/* 4K actual page size */
		actual_psize = 12;
		rpn = (r & HPTE_R_RPN) >> HPTE_R_RPN_SHIFT;
		/* In this case there are no LP bits */
		lp_bits = -1;
	}
	/*
	 * We didn't find a matching encoding, so the PTE we found isn't for
	 * this address.
	 */
	if (actual_psize == -1)
		return -1;

	dump_hpte_info(st, ea, v, r, rpn, base_psize, actual_psize, lp_bits);
	return 0;
}

static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start)
{
	pte_t *pte = pte_offset_kernel(pmd, 0);
	unsigned long addr, pteval, psize;
	int i, status;

	for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
		addr = start + i * PAGE_SIZE;
		pteval = pte_val(*pte);

		if (addr < VMALLOC_END)
			psize = mmu_vmalloc_psize;
		else
			psize = mmu_io_psize;

		/* check for secret 4K mappings */
		if (IS_ENABLED(CONFIG_PPC_64K_PAGES) &&
		    ((pteval & H_PAGE_COMBO) == H_PAGE_COMBO ||
		     (pteval & H_PAGE_4K_PFN) == H_PAGE_4K_PFN))
			psize = mmu_io_psize;

		/* check for hashpte */
		status = hpte_find(st, addr, psize);

		if (((pteval & H_PAGE_HASHPTE) != H_PAGE_HASHPTE)
				&& (status != -1)) {
		/* found a hpte that is not in the linux page tables */
			seq_printf(st->seq, "page probably bolted before linux"
				" pagetables were set: addr:%lx, pteval:%lx\n",
				addr, pteval);
		}
	}
}

static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start)
{
	pmd_t *pmd = pmd_offset(pud, 0);
	unsigned long addr;
	unsigned int i;

	for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
		addr = start + i * PMD_SIZE;
		if (!pmd_none(*pmd))
			/* pmd exists */
			walk_pte(st, pmd, addr);
	}
}

static void walk_pud(struct pg_state *st, p4d_t *p4d, unsigned long start)
{
	pud_t *pud = pud_offset(p4d, 0);
	unsigned long addr;
	unsigned int i;

	for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
		addr = start + i * PUD_SIZE;
		if (!pud_none(*pud))
			/* pud exists */
			walk_pmd(st, pud, addr);
	}
}

static void walk_p4d(struct pg_state *st, pgd_t *pgd, unsigned long start)
{
	p4d_t *p4d = p4d_offset(pgd, 0);
	unsigned long addr;
	unsigned int i;

	for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
		addr = start + i * P4D_SIZE;
		if (!p4d_none(*p4d))
			/* p4d exists */
			walk_pud(st, p4d, addr);
	}
}

static void walk_pagetables(struct pg_state *st)
{
	pgd_t *pgd = pgd_offset_k(0UL);
	unsigned int i;
	unsigned long addr;

	/*
	 * Traverse the linux pagetable structure and dump pages that are in
	 * the hash pagetable.
	 */
	for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
		addr = KERN_VIRT_START + i * PGDIR_SIZE;
		if (!pgd_none(*pgd))
			/* pgd exists */
			walk_p4d(st, pgd, addr);
	}
}


static void walk_linearmapping(struct pg_state *st)
{
	unsigned long addr;

	/*
	 * Traverse the linear mapping section of virtual memory and dump pages
	 * that are in the hash pagetable.
	 */
	unsigned long psize = 1 << mmu_psize_defs[mmu_linear_psize].shift;

	for (addr = PAGE_OFFSET; addr < PAGE_OFFSET +
			memblock_end_of_DRAM(); addr += psize)
		hpte_find(st, addr, mmu_linear_psize);
}

static void walk_vmemmap(struct pg_state *st)
{
	struct vmemmap_backing *ptr = vmemmap_list;

	if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP))
		return;
	/*
	 * Traverse the vmemmaped memory and dump pages that are in the hash
	 * pagetable.
	 */
	while (ptr->list) {
		hpte_find(st, ptr->virt_addr, mmu_vmemmap_psize);
		ptr = ptr->list;
	}
	seq_puts(st->seq, "---[ vmemmap end ]---\n");
}

static void populate_markers(void)
{
	address_markers[0].start_address = PAGE_OFFSET;
	address_markers[1].start_address = VMALLOC_START;
	address_markers[2].start_address = VMALLOC_END;
	address_markers[3].start_address = ISA_IO_BASE;
	address_markers[4].start_address = ISA_IO_END;
	address_markers[5].start_address = PHB_IO_BASE;
	address_markers[6].start_address = PHB_IO_END;
	address_markers[7].start_address = IOREMAP_BASE;
	address_markers[8].start_address = IOREMAP_END;
	address_markers[9].start_address =  H_VMEMMAP_START;
}

static int ptdump_show(struct seq_file *m, void *v)
{
	struct pg_state st = {
		.seq = m,
		.start_address = PAGE_OFFSET,
		.marker = address_markers,
	};
	/*
	 * Traverse the 0xc, 0xd and 0xf areas of the kernel virtual memory and
	 * dump pages that are in the hash pagetable.
	 */
	walk_linearmapping(&st);
	walk_pagetables(&st);
	walk_vmemmap(&st);
	return 0;
}

static int ptdump_open(struct inode *inode, struct file *file)
{
	return single_open(file, ptdump_show, NULL);
}

static const struct file_operations ptdump_fops = {
	.open		= ptdump_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int ptdump_init(void)
{
	if (!radix_enabled()) {
		populate_markers();
		debugfs_create_file("kernel_hash_pagetable", 0400, NULL, NULL,
				    &ptdump_fops);
	}
	return 0;
}
device_initcall(ptdump_init);
Commit	Line	Data
b886d83c	1	// SPDX-License-Identifier: GPL-2.0-only
1515ab93 RG	2	/*
	3	* Copyright 2016, Rashmica Gupta, IBM Corp.
	4	*
	5	* This traverses the kernel virtual memory and dumps the pages that are in
	6	* the hash pagetable, along with their flags to
	7	* /sys/kernel/debug/kernel_hash_pagetable.
	8	*
	9	* If radix is enabled then there is no hash page table and so no debugfs file
	10	* is generated.
1515ab93 RG	11	*/
	12	#include <linux/debugfs.h>
	13	#include <linux/fs.h>
	14	#include <linux/io.h>
	15	#include <linux/mm.h>
	16	#include <linux/sched.h>
	17	#include <linux/seq_file.h>
1515ab93 RG	18	#include <linux/const.h>
	19	#include <asm/page.h>
	20	#include <asm/pgalloc.h>
	21	#include <asm/plpar_wrappers.h>
	22	#include <linux/memblock.h>
	23	#include <asm/firmware.h>
	24
	25	struct pg_state {
	26	struct seq_file *seq;
	27	const struct addr_marker *marker;
	28	unsigned long start_address;
	29	unsigned int level;
	30	u64 current_flags;
	31	};
	32
	33	struct addr_marker {
	34	unsigned long start_address;
	35	const char *name;
	36	};
	37
	38	static struct addr_marker address_markers[] = {
	39	{ 0, "Start of kernel VM" },
	40	{ 0, "vmalloc() Area" },
	41	{ 0, "vmalloc() End" },
	42	{ 0, "isa I/O start" },
	43	{ 0, "isa I/O end" },
	44	{ 0, "phb I/O start" },
	45	{ 0, "phb I/O end" },
	46	{ 0, "I/O remap start" },
	47	{ 0, "I/O remap end" },
	48	{ 0, "vmemmap start" },
	49	{ -1, NULL },
	50	};
	51
	52	struct flag_info {
	53	u64 mask;
	54	u64 val;
	55	const char *set;
	56	const char *clear;
	57	bool is_val;
	58	int shift;
	59	};
	60
	61	static const struct flag_info v_flag_array[] = {
	62	{
	63	.mask = SLB_VSID_B,
	64	.val = SLB_VSID_B_256M,
	65	.set = "ssize: 256M",
	66	.clear = "ssize: 1T ",
	67	}, {
	68	.mask = HPTE_V_SECONDARY,
	69	.val = HPTE_V_SECONDARY,
	70	.set = "secondary",
	71	.clear = "primary ",
	72	}, {
	73	.mask = HPTE_V_VALID,
	74	.val = HPTE_V_VALID,
	75	.set = "valid ",
	76	.clear = "invalid",
	77	}, {
	78	.mask = HPTE_V_BOLTED,
	79	.val = HPTE_V_BOLTED,
	80	.set = "bolted",
	81	.clear = "",
82	}
83	};
84
85	static const struct flag_info r_flag_array[] = {
86	{
87	.mask = HPTE_R_PP0 \| HPTE_R_PP,
88	.val = PP_RWXX,
89	.set = "prot:RW--",
90	}, {
91	.mask = HPTE_R_PP0 \| HPTE_R_PP,
92	.val = PP_RWRX,
93	.set = "prot:RWR-",
94	}, {
95	.mask = HPTE_R_PP0 \| HPTE_R_PP,
96	.val = PP_RWRW,
97	.set = "prot:RWRW",
98	}, {
99	.mask = HPTE_R_PP0 \| HPTE_R_PP,
100	.val = PP_RXRX,
101	.set = "prot:R-R-",
102	}, {
103	.mask = HPTE_R_PP0 \| HPTE_R_PP,
104	.val = PP_RXXX,
105	.set = "prot:R---",
106	}, {
107	.mask = HPTE_R_KEY_HI \| HPTE_R_KEY_LO,
108	.val = HPTE_R_KEY_HI \| HPTE_R_KEY_LO,
109	.set = "key",
110	.clear = "",
111	.is_val = true,
112	}, {
113	.mask = HPTE_R_R,
114	.val = HPTE_R_R,
115	.set = "ref",
116	.clear = " ",
117	}, {
118	.mask = HPTE_R_C,
119	.val = HPTE_R_C,
120	.set = "changed",
121	.clear = " ",
122	}, {
123	.mask = HPTE_R_N,
124	.val = HPTE_R_N,
125	.set = "no execute",
126	}, {
127	.mask = HPTE_R_WIMG,
128	.val = HPTE_R_W,
129	.set = "writethru",
130	}, {
131	.mask = HPTE_R_WIMG,
132	.val = HPTE_R_I,
133	.set = "no cache",
134	}, {
135	.mask = HPTE_R_WIMG,
136	.val = HPTE_R_G,
137	.set = "guarded",
138	}
139	};
140
141	static int calculate_pagesize(struct pg_state *st, int ps, char s[])
142	{
143	static const char units[] = "BKMGTPE";
144	const char *unit = units;
145
146	while (ps > 9 && unit[1]) {
147	ps -= 10;
148	unit++;
149	}
150	seq_printf(st->seq, " %s_ps: %i%c\t", s, 1<<ps, *unit);
151	return ps;
152	}
153
154	static void dump_flag_info(struct pg_state *st, const struct flag_info
155	*flag, u64 pte, int num)
156	{
157	unsigned int i;
158
159	for (i = 0; i < num; i++, flag++) {
160	const char *s = NULL;
161	u64 val;
162
163	/* flag not defined so don't check it */
164	if (flag->mask == 0)
165	continue;
166	/* Some 'flags' are actually values */
167	if (flag->is_val) {
168	val = pte & flag->val;
169	if (flag->shift)
170	val = val >> flag->shift;
171	seq_printf(st->seq, " %s:%llx", flag->set, val);
172	} else {
173	if ((pte & flag->mask) == flag->val)
174	s = flag->set;
175	else
176	s = flag->clear;
177	if (s)
178	seq_printf(st->seq, " %s", s);
179	}
180	}
181	}
182
183	static void dump_hpte_info(struct pg_state *st, unsigned long ea, u64 v, u64 r,
184	unsigned long rpn, int bps, int aps, unsigned long lp)
185	{
186	int aps_index;
187
188	while (ea >= st->marker[1].start_address) {
189	st->marker++;
190	seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
191	}
192	seq_printf(st->seq, "0x%lx:\t", ea);
193	seq_printf(st->seq, "AVPN:%llx\t", HPTE_V_AVPN_VAL(v));
194	dump_flag_info(st, v_flag_array, v, ARRAY_SIZE(v_flag_array));
195	seq_printf(st->seq, " rpn: %lx\t", rpn);
196	dump_flag_info(st, r_flag_array, r, ARRAY_SIZE(r_flag_array));
197
198	calculate_pagesize(st, bps, "base");
199	aps_index = calculate_pagesize(st, aps, "actual");
200	if (aps_index != 2)
201	seq_printf(st->seq, "LP enc: %lx", lp);
aae85e3c	202	seq_putc(st->seq, '\n');
1515ab93 RG	203	}
	204
	205
	206	static int native_find(unsigned long ea, int psize, bool primary, u64 *v, u64
	207	*r)
	208	{
	209	struct hash_pte *hptep;
	210	unsigned long hash, vsid, vpn, hpte_group, want_v, hpte_v;
	211	int i, ssize = mmu_kernel_ssize;
	212	unsigned long shift = mmu_psize_defs[psize].shift;
	213
	214	/* calculate hash */
	215	vsid = get_kernel_vsid(ea, ssize);
	216	vpn = hpt_vpn(ea, vsid, ssize);
	217	hash = hpt_hash(vpn, shift, ssize);
	218	want_v = hpte_encode_avpn(vpn, psize, ssize);
	219
	220	/* to check in the secondary hash table, we invert the hash */
	221	if (!primary)
	222	hash = ~hash;
	223	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
	224	for (i = 0; i < HPTES_PER_GROUP; i++) {
	225	hptep = htab_address + hpte_group;
	226	hpte_v = be64_to_cpu(hptep->v);
	227
	228	if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID)) {
	229	/* HPTE matches */
	230	*v = be64_to_cpu(hptep->v);
	231	*r = be64_to_cpu(hptep->r);
	232	return 0;
	233	}
	234	++hpte_group;
	235	}
	236	return -1;
	237	}
	238
1515ab93 RG	239	static int pseries_find(unsigned long ea, int psize, bool primary, u64 v, u64 r)
	240	{
	241	struct hash_pte ptes[4];
	242	unsigned long vsid, vpn, hash, hpte_group, want_v;
	243	int i, j, ssize = mmu_kernel_ssize;
	244	long lpar_rc = 0;
	245	unsigned long shift = mmu_psize_defs[psize].shift;
	246
	247	/* calculate hash */
	248	vsid = get_kernel_vsid(ea, ssize);
	249	vpn = hpt_vpn(ea, vsid, ssize);
	250	hash = hpt_hash(vpn, shift, ssize);
	251	want_v = hpte_encode_avpn(vpn, psize, ssize);
	252
	253	/* to check in the secondary hash table, we invert the hash */
	254	if (!primary)
	255	hash = ~hash;
1531cff4	256	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1515ab93 RG	257	/* see if we can find an entry in the hpte with this hash */
	258	for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) {
	259	lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes);
	260
	261	if (lpar_rc != H_SUCCESS)
	262	continue;
	263	for (j = 0; j < 4; j++) {
	264	if (HPTE_V_COMPARE(ptes[j].v, want_v) &&
	265	(ptes[j].v & HPTE_V_VALID)) {
	266	/* HPTE matches */
	267	*v = ptes[j].v;
	268	*r = ptes[j].r;
	269	return 0;
	270	}
	271	}
	272	}
	273	return -1;
	274	}
1515ab93 RG	275
	276	static void decode_r(int bps, unsigned long r, unsigned long rpn, int aps,
	277	unsigned long *lp_bits)
	278	{
	279	struct mmu_psize_def entry;
	280	unsigned long arpn, mask, lp;
	281	int penc = -2, idx = 0, shift;
	282
	283	/*.
	284	* The LP field has 8 bits. Depending on the actual page size, some of
	285	* these bits are concatenated with the APRN to get the RPN. The rest
	286	* of the bits in the LP field is the LP value and is an encoding for
	287	* the base page size and the actual page size.
	288	*
	289	* - find the mmu entry for our base page size
	290	* - go through all page encodings and use the associated mask to
	291	* find an encoding that matches our encoding in the LP field.
	292	*/
	293	arpn = (r & HPTE_R_RPN) >> HPTE_R_RPN_SHIFT;
	294	lp = arpn & 0xff;
	295
	296	entry = mmu_psize_defs[bps];
	297	while (idx < MMU_PAGE_COUNT) {
	298	penc = entry.penc[idx];
	299	if ((penc != -1) && (mmu_psize_defs[idx].shift)) {
	300	shift = mmu_psize_defs[idx].shift - HPTE_R_RPN_SHIFT;
	301	mask = (0x1 << (shift)) - 1;
	302	if ((lp & mask) == penc) {
	303	*aps = mmu_psize_to_shift(idx);
	304	*lp_bits = lp & mask;
	305	*rpn = arpn >> shift;
	306	return;
	307	}
	308	}
	309	idx++;
	310	}
	311	}
	312
	313	static int base_hpte_find(unsigned long ea, int psize, bool primary, u64 *v,
	314	u64 *r)
	315	{
65e701b2	316	if (IS_ENABLED(CONFIG_PPC_PSERIES) && firmware_has_feature(FW_FEATURE_LPAR))
1515ab93	317	return pseries_find(ea, psize, primary, v, r);
65e701b2	318
1515ab93 RG	319	return native_find(ea, psize, primary, v, r);
	320	}
	321
	322	static unsigned long hpte_find(struct pg_state *st, unsigned long ea, int psize)
	323	{
	324	unsigned long slot;
	325	u64 v = 0, r = 0;
	326	unsigned long rpn, lp_bits;
	327	int base_psize = 0, actual_psize = 0;
	328
e63739b1	329	if (ea < PAGE_OFFSET)
1515ab93 RG	330	return -1;
	331
	332	/* Look in primary table */
	333	slot = base_hpte_find(ea, psize, true, &v, &r);
	334
	335	/* Look in secondary table */
	336	if (slot == -1)
790845e2	337	slot = base_hpte_find(ea, psize, false, &v, &r);
1515ab93 RG	338
	339	/* No entry found */
	340	if (slot == -1)
	341	return -1;
	342
	343	/*
	344	* We found an entry in the hash page table:
	345	* - check that this has the same base page
	346	* - find the actual page size
	347	* - find the RPN
	348	*/
	349	base_psize = mmu_psize_to_shift(psize);
	350
	351	if ((v & HPTE_V_LARGE) == HPTE_V_LARGE) {
	352	decode_r(psize, r, &rpn, &actual_psize, &lp_bits);
	353	} else {
	354	/* 4K actual page size */
	355	actual_psize = 12;
	356	rpn = (r & HPTE_R_RPN) >> HPTE_R_RPN_SHIFT;
	357	/* In this case there are no LP bits */
	358	lp_bits = -1;
	359	}
	360	/*
	361	* We didn't find a matching encoding, so the PTE we found isn't for
	362	* this address.
	363	*/
	364	if (actual_psize == -1)
	365	return -1;
	366
	367	dump_hpte_info(st, ea, v, r, rpn, base_psize, actual_psize, lp_bits);
	368	return 0;
	369	}
	370
	371	static void walk_pte(struct pg_state st, pmd_t pmd, unsigned long start)
	372	{
	373	pte_t *pte = pte_offset_kernel(pmd, 0);
	374	unsigned long addr, pteval, psize;
	375	int i, status;
	376
	377	for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
	378	addr = start + i * PAGE_SIZE;
	379	pteval = pte_val(*pte);
	380
	381	if (addr < VMALLOC_END)
	382	psize = mmu_vmalloc_psize;
	383	else
	384	psize = mmu_io_psize;
65e701b2	385
1515ab93	386	/* check for secret 4K mappings */
65e701b2 CL	387	if (IS_ENABLED(CONFIG_PPC_64K_PAGES) &&
	388	((pteval & H_PAGE_COMBO) == H_PAGE_COMBO \|\|
	389	(pteval & H_PAGE_4K_PFN) == H_PAGE_4K_PFN))
1515ab93	390	psize = mmu_io_psize;
65e701b2	391
1515ab93 RG	392	/* check for hashpte */
	393	status = hpte_find(st, addr, psize);
	394
	395	if (((pteval & H_PAGE_HASHPTE) != H_PAGE_HASHPTE)
	396	&& (status != -1)) {
	397	/* found a hpte that is not in the linux page tables */
	398	seq_printf(st->seq, "page probably bolted before linux"
	399	" pagetables were set: addr:%lx, pteval:%lx\n",
	400	addr, pteval);
	401	}
	402	}
	403	}
	404
	405	static void walk_pmd(struct pg_state st, pud_t pud, unsigned long start)
	406	{
	407	pmd_t *pmd = pmd_offset(pud, 0);
	408	unsigned long addr;
	409	unsigned int i;
	410
	411	for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
	412	addr = start + i * PMD_SIZE;
	413	if (!pmd_none(*pmd))
	414	/* pmd exists */
	415	walk_pte(st, pmd, addr);
	416	}
	417	}
	418
2fb47060	419	static void walk_pud(struct pg_state st, p4d_t p4d, unsigned long start)
1515ab93	420	{
2fb47060	421	pud_t *pud = pud_offset(p4d, 0);
1515ab93 RG	422	unsigned long addr;
	423	unsigned int i;
	424
	425	for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
	426	addr = start + i * PUD_SIZE;
	427	if (!pud_none(*pud))
	428	/* pud exists */
	429	walk_pmd(st, pud, addr);
	430	}
	431	}
	432
2fb47060 MR	433	static void walk_p4d(struct pg_state st, pgd_t pgd, unsigned long start)
	434	{
	435	p4d_t *p4d = p4d_offset(pgd, 0);
	436	unsigned long addr;
	437	unsigned int i;
	438
	439	for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
	440	addr = start + i * P4D_SIZE;
	441	if (!p4d_none(*p4d))
	442	/* p4d exists */
	443	walk_pud(st, p4d, addr);
	444	}
	445	}
	446
1515ab93 RG	447	static void walk_pagetables(struct pg_state *st)
	448	{
	449	pgd_t *pgd = pgd_offset_k(0UL);
	450	unsigned int i;
	451	unsigned long addr;
	452
	453	/*
	454	* Traverse the linux pagetable structure and dump pages that are in
	455	* the hash pagetable.
	456	*/
	457	for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
	458	addr = KERN_VIRT_START + i * PGDIR_SIZE;
	459	if (!pgd_none(*pgd))
	460	/* pgd exists */
2fb47060	461	walk_p4d(st, pgd, addr);
1515ab93 RG	462	}
	463	}
	464
	465
	466	static void walk_linearmapping(struct pg_state *st)
	467	{
	468	unsigned long addr;
	469
	470	/*
	471	* Traverse the linear mapping section of virtual memory and dump pages
	472	* that are in the hash pagetable.
	473	*/
	474	unsigned long psize = 1 << mmu_psize_defs[mmu_linear_psize].shift;
	475
	476	for (addr = PAGE_OFFSET; addr < PAGE_OFFSET +
9e4114b3	477	memblock_end_of_DRAM(); addr += psize)
1515ab93 RG	478	hpte_find(st, addr, mmu_linear_psize);
	479	}
	480
	481	static void walk_vmemmap(struct pg_state *st)
	482	{
1515ab93 RG	483	struct vmemmap_backing *ptr = vmemmap_list;
1515ab93 RG	484
65e701b2 CL	485	if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP))
65e701b2 CL	486	return;
1515ab93 RG	487	/*
	488	* Traverse the vmemmaped memory and dump pages that are in the hash
	489	* pagetable.
	490	*/
	491	while (ptr->list) {
	492	hpte_find(st, ptr->virt_addr, mmu_vmemmap_psize);
	493	ptr = ptr->list;
	494	}
	495	seq_puts(st->seq, "---[ vmemmap end ]---\n");
1515ab93 RG	496	}
	497
	498	static void populate_markers(void)
	499	{
	500	address_markers[0].start_address = PAGE_OFFSET;
	501	address_markers[1].start_address = VMALLOC_START;
	502	address_markers[2].start_address = VMALLOC_END;
	503	address_markers[3].start_address = ISA_IO_BASE;
	504	address_markers[4].start_address = ISA_IO_END;
	505	address_markers[5].start_address = PHB_IO_BASE;
	506	address_markers[6].start_address = PHB_IO_END;
	507	address_markers[7].start_address = IOREMAP_BASE;
	508	address_markers[8].start_address = IOREMAP_END;
0034d395	509	address_markers[9].start_address = H_VMEMMAP_START;
1515ab93 RG	510	}
	511
	512	static int ptdump_show(struct seq_file m, void v)
	513	{
	514	struct pg_state st = {
	515	.seq = m,
	516	.start_address = PAGE_OFFSET,
	517	.marker = address_markers,
	518	};
	519	/*
	520	* Traverse the 0xc, 0xd and 0xf areas of the kernel virtual memory and
	521	* dump pages that are in the hash pagetable.
	522	*/
	523	walk_linearmapping(&st);
	524	walk_pagetables(&st);
	525	walk_vmemmap(&st);
	526	return 0;
	527	}
	528
	529	static int ptdump_open(struct inode inode, struct file file)
	530	{
	531	return single_open(file, ptdump_show, NULL);
	532	}
	533
	534	static const struct file_operations ptdump_fops = {
	535	.open = ptdump_open,
	536	.read = seq_read,
	537	.llseek = seq_lseek,
	538	.release = single_release,
	539	};
	540
	541	static int ptdump_init(void)
	542	{
1515ab93 RG	543	if (!radix_enabled()) {
1515ab93 RG	544	populate_markers();
f3c05201 GKH	545	debugfs_create_file("kernel_hash_pagetable", 0400, NULL, NULL,
f3c05201 GKH	546	&ptdump_fops);
1515ab93 RG	547	}
	548	return 0;
	549	}
	550	device_initcall(ptdump_init);