From f4ad2df2209acac66f3df47d847f1f714283feab Mon Sep 17 00:00:00 2001 From: "Suren A. Chilingaryan" Date: Thu, 14 Jul 2011 06:01:27 +0200 Subject: First iteration of work to preserve DMA state between executions --- driver/kmem.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 55 insertions(+), 1 deletion(-) (limited to 'driver/kmem.c') diff --git a/driver/kmem.c b/driver/kmem.c index 95a5487..ed2a2af 100644 --- a/driver/kmem.c +++ b/driver/kmem.c @@ -35,6 +35,26 @@ int pcidriver_kmem_alloc(pcidriver_privdata_t *privdata, kmem_handle_t *kmem_han pcidriver_kmem_entry_t *kmem_entry; void *retptr; + privdata->kmem_cur = NULL; + + if (kmem_handle->reuse) { +/* kmem_entry = pcidriver_kmem_find_entry_use(privdata, kmem_handle->use, kmem_handle->item); + if (kmem_entry) { + if (kmem_handle->type != kmem_entry->type) return EINVAL; + + if (kmem_handle->type == PCILIB_KMEM_TYPE_PAGE) kmem_handle->size = kmem_entry->size; + else if (kmem_handle->size != kmem_entry->size) return EINVAL; + + kmem_handle->handle_id = kmem_entry->id; + kmem_handle->pa = (unsigned long)(kmem_entry->dma_handle); + + privdata->kmem_cur = kmem_entry; + + return 0; + }*/ + kmem_handle->reuse = 0; + } + /* First, allocate zeroed memory for the kmem_entry */ if ((kmem_entry = kcalloc(1, sizeof(pcidriver_kmem_entry_t), GFP_KERNEL)) == NULL) goto kmem_alloc_entry_fail; @@ -42,6 +62,7 @@ int pcidriver_kmem_alloc(pcidriver_privdata_t *privdata, kmem_handle_t *kmem_han /* Initialize the kmem_entry */ kmem_entry->id = atomic_inc_return(&privdata->kmem_count) - 1; kmem_entry->use = kmem_handle->use; + kmem_entry->item = kmem_handle->item; kmem_entry->type = kmem_handle->type; kmem_handle->handle_id = kmem_entry->id; @@ -102,6 +123,11 @@ int pcidriver_kmem_free( pcidriver_privdata_t *privdata, kmem_handle_t *kmem_han { pcidriver_kmem_entry_t *kmem_entry; + if (kmem_handle->reuse) { + // just mark free + return 0; + } + /* Find the associated kmem_entry for this buffer */ if ((kmem_entry = pcidriver_kmem_find_entry(privdata, kmem_handle)) == NULL) return -EINVAL; /* kmem_handle is not valid */ @@ -193,6 +219,8 @@ int pcidriver_kmem_sync( pcidriver_privdata_t *privdata, kmem_sync_t *kmem_sync */ int pcidriver_kmem_free_entry(pcidriver_privdata_t *privdata, pcidriver_kmem_entry_t *kmem_entry) { + privdata->kmem_cur = NULL; + pcidriver_sysfs_remove(privdata, &(kmem_entry->sysfs_attr)); /* Go over the pages of the kmem buffer, and mark them as not reserved */ @@ -297,6 +325,31 @@ pcidriver_kmem_entry_t *pcidriver_kmem_find_entry_id(pcidriver_privdata_t *privd return result; } +/** + * + * find the corresponding kmem_entry for the given use and item. + * + */ +pcidriver_kmem_entry_t *pcidriver_kmem_find_entry_use(pcidriver_privdata_t *privdata, unsigned long use, unsigned long item) +{ + struct list_head *ptr; + pcidriver_kmem_entry_t *entry, *result = NULL; + + spin_lock(&(privdata->kmemlist_lock)); + list_for_each(ptr, &(privdata->kmem_list)) { + entry = list_entry(ptr, pcidriver_kmem_entry_t, list); + + if ((entry->use == use)&&(entry->item == item)) { + result = entry; + break; + } + } + + spin_unlock(&(privdata->kmemlist_lock)); + return result; +} + + /** * * mmap() kernel memory to userspace. @@ -318,7 +371,8 @@ int pcidriver_mmap_kmem(pcidriver_privdata_t *privdata, struct vm_area_struct *v mod_info("Trying to mmap a kernel memory buffer without creating it first!\n"); return -EFAULT; } - kmem_entry = list_entry(privdata->kmem_list.prev, pcidriver_kmem_entry_t, list); + if (privdata->kmem_cur) kmem_entry = privdata->kmem_cur; + else kmem_entry = list_entry(privdata->kmem_list.prev, pcidriver_kmem_entry_t, list); spin_unlock(&(privdata->kmemlist_lock)); mod_info_dbg("Got kmem_entry with id: %d\n", kmem_entry->id); -- cgit v1.2.3