[mirror_ubuntu-focal-kernel.git] / arch / s390 / include / asm / idals.h

/* SPDX-License-Identifier: GPL-2.0 */
/* 
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * Copyright IBM Corp. 2000
 *
 * History of changes
 * 07/24/00 new file
 * 05/04/02 code restructuring.
 */

#ifndef _S390_IDALS_H
#define _S390_IDALS_H

#include <linux/errno.h>
#include <linux/err.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <asm/cio.h>
#include <linux/uaccess.h>

#define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */
#define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG)

/*
 * Test if an address/length pair needs an idal list.
 */
static inline int
idal_is_needed(void *vaddr, unsigned int length)
{
	return ((__pa(vaddr) + length - 1) >> 31) != 0;
}


/*
 * Return the number of idal words needed for an address/length pair.
 */
static inline unsigned int idal_nr_words(void *vaddr, unsigned int length)
{
	return ((__pa(vaddr) & (IDA_BLOCK_SIZE-1)) + length +
		(IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
}

/*
 * Create the list of idal words for an address/length pair.
 */
static inline unsigned long *idal_create_words(unsigned long *idaws,
					       void *vaddr, unsigned int length)
{
	unsigned long paddr;
	unsigned int cidaw;

	paddr = __pa(vaddr);
	cidaw = ((paddr & (IDA_BLOCK_SIZE-1)) + length + 
		 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
	*idaws++ = paddr;
	paddr &= -IDA_BLOCK_SIZE;
	while (--cidaw > 0) {
		paddr += IDA_BLOCK_SIZE;
		*idaws++ = paddr;
	}
	return idaws;
}

/*
 * Sets the address of the data in CCW.
 * If necessary it allocates an IDAL and sets the appropriate flags.
 */
static inline int
set_normalized_cda(struct ccw1 * ccw, void *vaddr)
{
	unsigned int nridaws;
	unsigned long *idal;

	if (ccw->flags & CCW_FLAG_IDA)
		return -EINVAL;
	nridaws = idal_nr_words(vaddr, ccw->count);
	if (nridaws > 0) {
		idal = kmalloc(nridaws * sizeof(unsigned long),
			       GFP_ATOMIC | GFP_DMA );
		if (idal == NULL)
			return -ENOMEM;
		idal_create_words(idal, vaddr, ccw->count);
		ccw->flags |= CCW_FLAG_IDA;
		vaddr = idal;
	}
	ccw->cda = (__u32)(unsigned long) vaddr;
	return 0;
}

/*
 * Releases any allocated IDAL related to the CCW.
 */
static inline void
clear_normalized_cda(struct ccw1 * ccw)
{
	if (ccw->flags & CCW_FLAG_IDA) {
		kfree((void *)(unsigned long) ccw->cda);
		ccw->flags &= ~CCW_FLAG_IDA;
	}
	ccw->cda = 0;
}

/*
 * Idal buffer extension
 */
struct idal_buffer {
	size_t size;
	size_t page_order;
	void *data[0];
};

/*
 * Allocate an idal buffer
 */
static inline struct idal_buffer *
idal_buffer_alloc(size_t size, int page_order)
{
	struct idal_buffer *ib;
	int nr_chunks, nr_ptrs, i;

	nr_ptrs = (size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
	nr_chunks = (4096 << page_order) >> IDA_SIZE_LOG;
	ib = kmalloc(sizeof(struct idal_buffer) + nr_ptrs*sizeof(void *),
		     GFP_DMA | GFP_KERNEL);
	if (ib == NULL)
		return ERR_PTR(-ENOMEM);
	ib->size = size;
	ib->page_order = page_order;
	for (i = 0; i < nr_ptrs; i++) {
		if ((i & (nr_chunks - 1)) != 0) {
			ib->data[i] = ib->data[i-1] + IDA_BLOCK_SIZE;
			continue;
		}
		ib->data[i] = (void *)
			__get_free_pages(GFP_KERNEL, page_order);
		if (ib->data[i] != NULL)
			continue;
		// Not enough memory
		while (i >= nr_chunks) {
			i -= nr_chunks;
			free_pages((unsigned long) ib->data[i],
				   ib->page_order);
		}
		kfree(ib);
		return ERR_PTR(-ENOMEM);
	}
	return ib;
}

/*
 * Free an idal buffer.
 */
static inline void
idal_buffer_free(struct idal_buffer *ib)
{
	int nr_chunks, nr_ptrs, i;

	nr_ptrs = (ib->size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
	nr_chunks = (4096 << ib->page_order) >> IDA_SIZE_LOG;
	for (i = 0; i < nr_ptrs; i += nr_chunks)
		free_pages((unsigned long) ib->data[i], ib->page_order);
	kfree(ib);
}

/*
 * Test if a idal list is really needed.
 */
static inline int
__idal_buffer_is_needed(struct idal_buffer *ib)
{
	return ib->size > (4096ul << ib->page_order) ||
		idal_is_needed(ib->data[0], ib->size);
}

/*
 * Set channel data address to idal buffer.
 */
static inline void
idal_buffer_set_cda(struct idal_buffer *ib, struct ccw1 *ccw)
{
	if (__idal_buffer_is_needed(ib)) {
		// setup idals;
		ccw->cda = (u32)(addr_t) ib->data;
		ccw->flags |= CCW_FLAG_IDA;
	} else
		// we do not need idals - use direct addressing
		ccw->cda = (u32)(addr_t) ib->data[0];
	ccw->count = ib->size;
}

/*
 * Copy count bytes from an idal buffer to user memory
 */
static inline size_t
idal_buffer_to_user(struct idal_buffer *ib, void __user *to, size_t count)
{
	size_t left;
	int i;

	BUG_ON(count > ib->size);
	for (i = 0; count > IDA_BLOCK_SIZE; i++) {
		left = copy_to_user(to, ib->data[i], IDA_BLOCK_SIZE);
		if (left)
			return left + count - IDA_BLOCK_SIZE;
		to = (void __user *) to + IDA_BLOCK_SIZE;
		count -= IDA_BLOCK_SIZE;
	}
	return copy_to_user(to, ib->data[i], count);
}

/*
 * Copy count bytes from user memory to an idal buffer
 */
static inline size_t
idal_buffer_from_user(struct idal_buffer *ib, const void __user *from, size_t count)
{
	size_t left;
	int i;

	BUG_ON(count > ib->size);
	for (i = 0; count > IDA_BLOCK_SIZE; i++) {
		left = copy_from_user(ib->data[i], from, IDA_BLOCK_SIZE);
		if (left)
			return left + count - IDA_BLOCK_SIZE;
		from = (void __user *) from + IDA_BLOCK_SIZE;
		count -= IDA_BLOCK_SIZE;
	}
	return copy_from_user(ib->data[i], from, count);
}

#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4	2	/*
1da177e4 LT	3	* Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
	4	* Martin Schwidefsky <schwidefsky@de.ibm.com>
	5	* Bugreports.to..: <Linux390@de.ibm.com>
a53c8fab HC	6	* Copyright IBM Corp. 2000
a53c8fab HC	7	*
1da177e4 LT	8	* History of changes
	9	* 07/24/00 new file
	10	* 05/04/02 code restructuring.
	11	*/
	12
	13	#ifndef _S390_IDALS_H
	14	#define _S390_IDALS_H
	15
1da177e4 LT	16	#include <linux/errno.h>
	17	#include <linux/err.h>
	18	#include <linux/types.h>
	19	#include <linux/slab.h>
	20	#include <asm/cio.h>
7c0f6ba6	21	#include <linux/uaccess.h>
1da177e4	22
1da177e4	23	#define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */
1da177e4 LT	24	#define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG)
	25
	26	/*
	27	* Test if an address/length pair needs an idal list.
	28	*/
	29	static inline int
	30	idal_is_needed(void *vaddr, unsigned int length)
	31	{
1da177e4	32	return ((__pa(vaddr) + length - 1) >> 31) != 0;
1da177e4 LT	33	}
	34
	35
	36	/*
	37	* Return the number of idal words needed for an address/length pair.
	38	*/
f3eb5384	39	static inline unsigned int idal_nr_words(void *vaddr, unsigned int length)
1da177e4	40	{
f3eb5384 SW	41	return ((__pa(vaddr) & (IDA_BLOCK_SIZE-1)) + length +
f3eb5384 SW	42	(IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
1da177e4 LT	43	}
	44
	45	/*
	46	* Create the list of idal words for an address/length pair.
	47	*/
f3eb5384 SW	48	static inline unsigned long idal_create_words(unsigned long idaws,
f3eb5384 SW	49	void *vaddr, unsigned int length)
1da177e4	50	{
1da177e4 LT	51	unsigned long paddr;
	52	unsigned int cidaw;
	53
	54	paddr = __pa(vaddr);
	55	cidaw = ((paddr & (IDA_BLOCK_SIZE-1)) + length +
	56	(IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
	57	*idaws++ = paddr;
	58	paddr &= -IDA_BLOCK_SIZE;
	59	while (--cidaw > 0) {
	60	paddr += IDA_BLOCK_SIZE;
	61	*idaws++ = paddr;
	62	}
1da177e4 LT	63	return idaws;
	64	}
	65
	66	/*
	67	* Sets the address of the data in CCW.
	68	* If necessary it allocates an IDAL and sets the appropriate flags.
	69	*/
	70	static inline int
	71	set_normalized_cda(struct ccw1 * ccw, void *vaddr)
	72	{
1da177e4 LT	73	unsigned int nridaws;
	74	unsigned long *idal;
	75
	76	if (ccw->flags & CCW_FLAG_IDA)
	77	return -EINVAL;
	78	nridaws = idal_nr_words(vaddr, ccw->count);
	79	if (nridaws > 0) {
	80	idal = kmalloc(nridaws * sizeof(unsigned long),
	81	GFP_ATOMIC \| GFP_DMA );
	82	if (idal == NULL)
	83	return -ENOMEM;
	84	idal_create_words(idal, vaddr, ccw->count);
	85	ccw->flags \|= CCW_FLAG_IDA;
	86	vaddr = idal;
	87	}
1da177e4 LT	88	ccw->cda = (__u32)(unsigned long) vaddr;
	89	return 0;
	90	}
	91
	92	/*
	93	* Releases any allocated IDAL related to the CCW.
	94	*/
	95	static inline void
	96	clear_normalized_cda(struct ccw1 * ccw)
	97	{
1da177e4 LT	98	if (ccw->flags & CCW_FLAG_IDA) {
	99	kfree((void *)(unsigned long) ccw->cda);
	100	ccw->flags &= ~CCW_FLAG_IDA;
	101	}
1da177e4 LT	102	ccw->cda = 0;
	103	}
	104
	105	/*
	106	* Idal buffer extension
	107	*/
	108	struct idal_buffer {
	109	size_t size;
	110	size_t page_order;
	111	void *data[0];
	112	};
	113
	114	/*
	115	* Allocate an idal buffer
	116	*/
	117	static inline struct idal_buffer *
	118	idal_buffer_alloc(size_t size, int page_order)
	119	{
	120	struct idal_buffer *ib;
	121	int nr_chunks, nr_ptrs, i;
	122
	123	nr_ptrs = (size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
	124	nr_chunks = (4096 << page_order) >> IDA_SIZE_LOG;
	125	ib = kmalloc(sizeof(struct idal_buffer) + nr_ptrssizeof(void ),
	126	GFP_DMA \| GFP_KERNEL);
	127	if (ib == NULL)
	128	return ERR_PTR(-ENOMEM);
	129	ib->size = size;
	130	ib->page_order = page_order;
	131	for (i = 0; i < nr_ptrs; i++) {
	132	if ((i & (nr_chunks - 1)) != 0) {
	133	ib->data[i] = ib->data[i-1] + IDA_BLOCK_SIZE;
	134	continue;
	135	}
	136	ib->data[i] = (void *)
	137	__get_free_pages(GFP_KERNEL, page_order);
	138	if (ib->data[i] != NULL)
	139	continue;
	140	// Not enough memory
	141	while (i >= nr_chunks) {
	142	i -= nr_chunks;
	143	free_pages((unsigned long) ib->data[i],
	144	ib->page_order);
	145	}
	146	kfree(ib);
	147	return ERR_PTR(-ENOMEM);
	148	}
	149	return ib;
	150	}
	151
	152	/*
	153	* Free an idal buffer.
	154	*/
	155	static inline void
	156	idal_buffer_free(struct idal_buffer *ib)
	157	{
	158	int nr_chunks, nr_ptrs, i;
	159
	160	nr_ptrs = (ib->size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
	161	nr_chunks = (4096 << ib->page_order) >> IDA_SIZE_LOG;
	162	for (i = 0; i < nr_ptrs; i += nr_chunks)
	163	free_pages((unsigned long) ib->data[i], ib->page_order);
	164	kfree(ib);
	165	}
166
167	/*
168	* Test if a idal list is really needed.
169	*/
170	static inline int
171	__idal_buffer_is_needed(struct idal_buffer *ib)
172	{
1da177e4 LT	173	return ib->size > (4096ul << ib->page_order) \|\|
1da177e4 LT	174	idal_is_needed(ib->data[0], ib->size);
1da177e4 LT	175	}
	176
	177	/*
	178	* Set channel data address to idal buffer.
	179	*/
	180	static inline void
	181	idal_buffer_set_cda(struct idal_buffer ib, struct ccw1 ccw)
	182	{
	183	if (__idal_buffer_is_needed(ib)) {
	184	// setup idals;
	185	ccw->cda = (u32)(addr_t) ib->data;
	186	ccw->flags \|= CCW_FLAG_IDA;
	187	} else
	188	// we do not need idals - use direct addressing
	189	ccw->cda = (u32)(addr_t) ib->data[0];
	190	ccw->count = ib->size;
	191	}
	192
	193	/*
	194	* Copy count bytes from an idal buffer to user memory
	195	*/
	196	static inline size_t
	197	idal_buffer_to_user(struct idal_buffer ib, void __user to, size_t count)
	198	{
	199	size_t left;
	200	int i;
	201
	202	BUG_ON(count > ib->size);
	203	for (i = 0; count > IDA_BLOCK_SIZE; i++) {
	204	left = copy_to_user(to, ib->data[i], IDA_BLOCK_SIZE);
	205	if (left)
	206	return left + count - IDA_BLOCK_SIZE;
	207	to = (void __user *) to + IDA_BLOCK_SIZE;
	208	count -= IDA_BLOCK_SIZE;
	209	}
	210	return copy_to_user(to, ib->data[i], count);
	211	}
	212
	213	/*
	214	* Copy count bytes from user memory to an idal buffer
	215	*/
	216	static inline size_t
	217	idal_buffer_from_user(struct idal_buffer ib, const void __user from, size_t count)
	218	{
	219	size_t left;
	220	int i;
	221
	222	BUG_ON(count > ib->size);
	223	for (i = 0; count > IDA_BLOCK_SIZE; i++) {
	224	left = copy_from_user(ib->data[i], from, IDA_BLOCK_SIZE);
	225	if (left)
	226	return left + count - IDA_BLOCK_SIZE;
	227	from = (void __user *) from + IDA_BLOCK_SIZE;
	228	count -= IDA_BLOCK_SIZE;
	229	}
	230	return copy_from_user(ib->data[i], from, count);
	231	}
	232
	233	#endif