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Diffstat (limited to 'arch/s390/include/asm/idals.h')
| -rw-r--r-- | arch/s390/include/asm/idals.h | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/arch/s390/include/asm/idals.h b/arch/s390/include/asm/idals.h new file mode 100644 index 000000000..15578fd76 --- /dev/null +++ b/arch/s390/include/asm/idals.h @@ -0,0 +1,233 @@ +/* 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 |