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Commit 0c7b1df6 authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: SH-4A Privileged Space Mapping Buffer (PMB) support. 



Add support for 32-bit physical addressing through the SH-4A
Privileged Space Mapping Buffer (PMB).

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent a09749dd

arch/sh/mm/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -23,3 +23,4 @@ obj-$(CONFIG_SH7705_CACHE_32KB) += pg-sh7705.o 
endif



obj-$(CONFIG_SH7705_CACHE_32KB)	+= cache-sh7705.o

obj-$(CONFIG_32BIT)		+= pmb.o

arch/sh/mm/pmb.c

0 → 100644
+269 −0
Original line number Diff line number Diff line 
/*

 * arch/sh/mm/pmb.c

 *

 * Privileged Space Mapping Buffer (PMB) Support.

 *

 * Copyright (C) 2005 Paul Mundt

 *

 * P1/P2 Section mapping definitions from map32.h, which was:

 *

 *	Copyright 2003 (c) Lineo Solutions,Inc.

 *

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 */

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/bitops.h>

#include <linux/debugfs.h>

#include <linux/fs.h>

#include <linux/seq_file.h>

#include <linux/err.h>

#include <asm/system.h>

#include <asm/uaccess.h>

#include <asm/mmu.h>

#include <asm/io.h>



#define NR_PMB_ENTRIES	16



static kmem_cache_t *pmb_cache;

static unsigned long pmb_map;



static struct pmb_entry pmb_init_map[] = {

	/* vpn         ppn         flags (ub/sz/c/wt) */



	/* P1 Section Mappings */

	{ 0x80000000, 0x00000000, PMB_SZ_64M  | PMB_C, },

	{ 0x84000000, 0x04000000, PMB_SZ_64M  | PMB_C, },

	{ 0x88000000, 0x08000000, PMB_SZ_128M | PMB_C, },

	{ 0x90000000, 0x10000000, PMB_SZ_64M  | PMB_C, },

	{ 0x94000000, 0x14000000, PMB_SZ_64M  | PMB_C, },

	{ 0x98000000, 0x18000000, PMB_SZ_64M  | PMB_C, },



	/* P2 Section Mappings */

	{ 0xa0000000, 0x00000000, PMB_UB | PMB_SZ_64M  | PMB_WT, },

	{ 0xa4000000, 0x04000000, PMB_UB | PMB_SZ_64M  | PMB_WT, },

	{ 0xa8000000, 0x08000000, PMB_UB | PMB_SZ_128M | PMB_WT, },

	{ 0xb0000000, 0x10000000, PMB_UB | PMB_SZ_64M  | PMB_WT, },

	{ 0xb4000000, 0x14000000, PMB_UB | PMB_SZ_64M  | PMB_WT, },

	{ 0xb8000000, 0x18000000, PMB_UB | PMB_SZ_64M  | PMB_WT, },

};



static inline unsigned long mk_pmb_entry(unsigned int entry)

{

	return (entry & PMB_E_MASK) << PMB_E_SHIFT;

}



static inline unsigned long mk_pmb_addr(unsigned int entry)

{

	return mk_pmb_entry(entry) | PMB_ADDR;

}



static inline unsigned long mk_pmb_data(unsigned int entry)

{

	return mk_pmb_entry(entry) | PMB_DATA;

}



struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,

			    unsigned long flags)

{

	struct pmb_entry *pmbe;



	pmbe = kmem_cache_alloc(pmb_cache, GFP_KERNEL);

	if (!pmbe)

		return ERR_PTR(-ENOMEM);



	pmbe->vpn	= vpn;

	pmbe->ppn	= ppn;

	pmbe->flags	= flags;



	return pmbe;

}



void pmb_free(struct pmb_entry *pmbe)

{

	kmem_cache_free(pmb_cache, pmbe);

}



/*

 * Must be in P2 for __set_pmb_entry()

 */

int __set_pmb_entry(unsigned long vpn, unsigned long ppn,

		    unsigned long flags, int *entry)

{

	unsigned int pos = *entry;



	if (unlikely(pos == PMB_NO_ENTRY))

		pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);



repeat:

	if (unlikely(pos > NR_PMB_ENTRIES))

		return -ENOSPC;



	if (test_and_set_bit(pos, &pmb_map)) {

		pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);

		goto repeat;

	}



	ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos));



#ifdef CONFIG_SH_WRITETHROUGH

	/*

	 * When we are in 32-bit address extended mode, CCR.CB becomes

	 * invalid, so care must be taken to manually adjust cacheable

	 * translations.

	 */

	if (likely(flags & PMB_C))

		flags |= PMB_WT;

#endif



	ctrl_outl(ppn | flags | PMB_V, mk_pmb_data(pos));



	*entry = pos;



	return 0;

}



void set_pmb_entry(struct pmb_entry *pmbe)

{

	jump_to_P2();

	__set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry);

	back_to_P1();

}



void clear_pmb_entry(struct pmb_entry *pmbe)

{

	unsigned int entry = pmbe->entry;

	unsigned long addr;



	/*

	 * Don't allow clearing of wired init entries, P1 or P2 access

	 * without a corresponding mapping in the PMB will lead to reset

	 * by the TLB.

	 */

	if (unlikely(entry < ARRAY_SIZE(pmb_init_map) ||

		     entry >= NR_PMB_ENTRIES))

		return;



	jump_to_P2();



	/* Clear V-bit */

	addr = mk_pmb_addr(entry);

	ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);



	addr = mk_pmb_data(entry);

	ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);



	back_to_P1();



	clear_bit(entry, &pmb_map);

}



static void pmb_cache_ctor(void *pmb, kmem_cache_t *cachep, unsigned long flags)

{

	memset(pmb, 0, sizeof(struct pmb_entry));



	((struct pmb_entry *)pmb)->entry = PMB_NO_ENTRY;

}



static int __init pmb_init(void)

{

	unsigned int nr_entries = ARRAY_SIZE(pmb_init_map);

	unsigned int entry;



	BUG_ON(unlikely(nr_entries >= NR_PMB_ENTRIES));



	pmb_cache = kmem_cache_create("pmb", sizeof(struct pmb_entry),

				      0, 0, pmb_cache_ctor, NULL);

	BUG_ON(!pmb_cache);



	jump_to_P2();



	/*

	 * Ordering is important, P2 must be mapped in the PMB before we

	 * can set PMB.SE, and P1 must be mapped before we jump back to

	 * P1 space.

	 */

	for (entry = 0; entry < nr_entries; entry++) {

		struct pmb_entry *pmbe = pmb_init_map + entry;



		__set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &entry);

	}



	ctrl_outl(0, PMB_IRMCR);



	/* PMB.SE and UB[7] */

	ctrl_outl((1 << 31) | (1 << 7), PMB_PASCR);



	back_to_P1();



	return 0;

}



arch_initcall(pmb_init);



#ifdef CONFIG_DEBUG_FS

static int pmb_seq_show(struct seq_file *file, void *iter)

{

	int i;



	seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"

			 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n");

	seq_printf(file, "ety   vpn  ppn  size   flags\n");



	for (i = 0; i < NR_PMB_ENTRIES; i++) {

		unsigned long addr, data;

		unsigned int size;

		char *sz_str = NULL;



		addr = ctrl_inl(mk_pmb_addr(i));

		data = ctrl_inl(mk_pmb_data(i));



		size = data & PMB_SZ_MASK;

		sz_str = (size == PMB_SZ_16M)  ? " 16MB":

			 (size == PMB_SZ_64M)  ? " 64MB":

			 (size == PMB_SZ_128M) ? "128MB":

					         "512MB";



		/* 02: V 0x88 0x08 128MB C CB  B */

		seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",

			   i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',

			   (addr >> 24) & 0xff, (data >> 24) & 0xff,

			   sz_str, (data & PMB_C) ? 'C' : ' ',

			   (data & PMB_WT) ? "WT" : "CB",

			   (data & PMB_UB) ? "UB" : " B");

	}



	return 0;

}



static int pmb_debugfs_open(struct inode *inode, struct file *file)

{

	return single_open(file, pmb_seq_show, NULL);

}



static struct file_operations pmb_debugfs_fops = {

	.owner		= THIS_MODULE,

	.open		= pmb_debugfs_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= seq_release,

};



static int __init pmb_debugfs_init(void)

{

	struct dentry *dentry;



	dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,

				     NULL, NULL, &pmb_debugfs_fops);

	if (IS_ERR(dentry))

		return PTR_ERR(dentry);



	return 0;

}



postcore_initcall(pmb_debugfs_init);

#endif

include/asm-sh/mmu.h

+47 −1
Original line number Diff line number Diff line
@@ -25,5 +25,51 @@ typedef struct { 
typedef unsigned long mm_context_t;



#endif /* CONFIG_MMU */

#endif /* __MMH_H */



/*

 * Privileged Space Mapping Buffer (PMB) definitions

 */

#define PMB_PASCR		0xff000070

#define PMB_IRMCR		0xff000078



#define PMB_ADDR		0xf6100000

#define PMB_DATA		0xf7100000

#define PMB_ENTRY_MAX		16

#define PMB_E_MASK		0x0000000f

#define PMB_E_SHIFT		8



#define PMB_SZ_16M		0x00000000

#define PMB_SZ_64M		0x00000010

#define PMB_SZ_128M		0x00000080

#define PMB_SZ_512M		0x00000090

#define PMB_SZ_MASK		PMB_SZ_512M

#define PMB_C			0x00000008

#define PMB_WT			0x00000001

#define PMB_UB			0x00000200

#define PMB_V			0x00000100



#define PMB_NO_ENTRY		(-1)



struct pmb_entry {

	unsigned long vpn;

	unsigned long ppn;

	unsigned long flags;



	/*

	 * 0 .. NR_PMB_ENTRIES for specific entry selection, or

	 * PMB_NO_ENTRY to search for a free one

	 */

	int entry;

};



/* arch/sh/mm/pmb.c */

int __set_pmb_entry(unsigned long vpn, unsigned long ppn,

		    unsigned long flags, int *entry);

void set_pmb_entry(struct pmb_entry *pmbe);

void clear_pmb_entry(struct pmb_entry *pmbe);

struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,

			    unsigned long flags);

void pmb_free(struct pmb_entry *pmbe);



#endif /* __MMU_H */