1.1 --- a/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c	Fri Oct 06 08:09:52 2006 +0100
     1.2 +++ b/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c	Fri Oct 06 10:30:43 2006 +0100
     1.3 @@ -186,16 +186,18 @@ static inline unsigned int RTN_PEND_IDX(
     1.4  
     1.5  #define BLKBACK_INVALID_HANDLE (~0)
     1.6  
     1.7 -typedef struct mmap_page {
     1.8 -	unsigned long start;
     1.9 -	struct page *mpage;
    1.10 -} mmap_page_t;
    1.11 +static struct page **foreign_pages[MAX_DYNAMIC_MEM];
    1.12 +static inline unsigned long idx_to_kaddr(
    1.13 +	unsigned int mmap_idx, unsigned int req_idx, unsigned int sg_idx)
    1.14 +{
    1.15 +	unsigned int arr_idx = req_idx*BLKIF_MAX_SEGMENTS_PER_REQUEST + sg_idx;
    1.16 +	unsigned long pfn = page_to_pfn(foreign_pages[mmap_idx][arr_idx]);
    1.17 +	return (unsigned long)pfn_to_kaddr(pfn);
    1.18 +}
    1.19  
    1.20 -static mmap_page_t mmap_start[MAX_DYNAMIC_MEM];
    1.21  static unsigned short mmap_alloc = 0;
    1.22  static unsigned short mmap_lock = 0;
    1.23  static unsigned short mmap_inuse = 0;
    1.24 -static unsigned long *pending_addrs[MAX_DYNAMIC_MEM];
    1.25  
    1.26  /******************************************************************
    1.27   * GRANT HANDLES
    1.28 @@ -726,63 +728,33 @@ static void make_response(blkif_t *blkif
    1.29  static int req_increase(void)
    1.30  {
    1.31  	int i, j;
    1.32 -	struct page *page;
    1.33 -	int ret;
    1.34 -
    1.35 -	ret = -EINVAL;
    1.36 -	if (mmap_alloc >= MAX_PENDING_REQS || mmap_lock) 
    1.37 -		goto done;
    1.38 +	struct page **pages = NULL;
    1.39  
    1.40 -#ifdef __ia64__
    1.41 -	extern unsigned long alloc_empty_foreign_map_page_range(
    1.42 -		unsigned long pages);
    1.43 -	mmap_start[mmap_alloc].start = (unsigned long)
    1.44 -		alloc_empty_foreign_map_page_range(mmap_pages);
    1.45 -#else /* ! ia64 */
    1.46 -	page = balloon_alloc_empty_page_range(mmap_pages);
    1.47 -	ret = -ENOMEM;
    1.48 -	if (page == NULL) {
    1.49 -		printk("%s balloon_alloc_empty_page_range gave NULL\n", __FUNCTION__);
    1.50 -		goto done;
    1.51 +	if (mmap_alloc >= MAX_PENDING_REQS || mmap_lock) 
    1.52 +		return -EINVAL;
    1.53 +
    1.54 +	pending_reqs[mmap_alloc] = kzalloc(sizeof(pending_req_t) *
    1.55 +					   blkif_reqs, GFP_KERNEL);
    1.56 +	pages = kmalloc(sizeof(pages[0]) * mmap_pages, GFP_KERNEL);
    1.57 +
    1.58 +	if (!pending_reqs[mmap_alloc] || !pages)
    1.59 +		goto out_of_memory;
    1.60 +
    1.61 +	for (i = 0; i < mmap_pages; i++) {
    1.62 +		pages[i] = balloon_alloc_empty_page();
    1.63 +		if (!pages[i]) {
    1.64 +			while (--i >= 0)
    1.65 +				balloon_free_empty_page(pages[i]);
    1.66 +			goto out_of_memory;
    1.67 +		}
    1.68  	}
    1.69  
    1.70 -	/* Pin all of the pages. */
    1.71 -	for (i=0; i<mmap_pages; i++)
    1.72 -		get_page(&page[i]);
    1.73 -
    1.74 -	mmap_start[mmap_alloc].start = 
    1.75 -		(unsigned long)pfn_to_kaddr(page_to_pfn(page));
    1.76 -	mmap_start[mmap_alloc].mpage = page;
    1.77 -
    1.78 -#endif
    1.79 -
    1.80 -	pending_reqs[mmap_alloc]  = kzalloc(sizeof(pending_req_t) *
    1.81 -					blkif_reqs, GFP_KERNEL);
    1.82 -	pending_addrs[mmap_alloc] = kzalloc(sizeof(unsigned long) *
    1.83 -					mmap_pages, GFP_KERNEL);
    1.84 +	foreign_pages[mmap_alloc] = pages;
    1.85  
    1.86 -	ret = -ENOMEM;
    1.87 -	if (!pending_reqs[mmap_alloc] || !pending_addrs[mmap_alloc]) {
    1.88 -		kfree(pending_reqs[mmap_alloc]);
    1.89 -		kfree(pending_addrs[mmap_alloc]);
    1.90 -		WPRINTK("%s: out of memory\n", __FUNCTION__);
    1.91 -		ret = -ENOMEM;
    1.92 -		goto done;
    1.93 -	}
    1.94 -
    1.95 -	ret = 0;
    1.96 +	DPRINTK("%s: reqs=%d, pages=%d\n",
    1.97 +		__FUNCTION__, blkif_reqs, mmap_pages);
    1.98  
    1.99 -	DPRINTK("%s: reqs=%d, pages=%d, mmap_vstart=0x%lx\n",
   1.100 -	        __FUNCTION__, blkif_reqs, mmap_pages, 
   1.101 -	       mmap_start[mmap_alloc].start);
   1.102 -
   1.103 -	BUG_ON(mmap_start[mmap_alloc].start == 0);
   1.104 -
   1.105 -	for (i = 0; i < mmap_pages; i++) 
   1.106 -		pending_addrs[mmap_alloc][i] = 
   1.107 -			mmap_start[mmap_alloc].start + (i << PAGE_SHIFT);
   1.108 -
   1.109 -	for (i = 0; i < MAX_PENDING_REQS ; i++) {
   1.110 +	for (i = 0; i < MAX_PENDING_REQS; i++) {
   1.111  		list_add_tail(&pending_reqs[mmap_alloc][i].free_list, 
   1.112  			      &pending_free);
   1.113  		pending_reqs[mmap_alloc][i].mem_idx = mmap_alloc;
   1.114 @@ -793,30 +765,27 @@ static int req_increase(void)
   1.115  
   1.116  	mmap_alloc++;
   1.117  	DPRINTK("# MMAPs increased to %d\n",mmap_alloc);
   1.118 -done:
   1.119 -	return ret;
   1.120 +	return 0;
   1.121 +
   1.122 + out_of_memory:
   1.123 +	kfree(pages);
   1.124 +	kfree(pending_reqs[mmap_alloc]);
   1.125 +	WPRINTK("%s: out of memory\n", __FUNCTION__);
   1.126 +	return -ENOMEM;
   1.127  }
   1.128  
   1.129  static void mmap_req_del(int mmap)
   1.130  {
   1.131  	int i;
   1.132 -	struct page *page;
   1.133 -
   1.134 -	/*Spinlock already acquired*/
   1.135 -	kfree(pending_reqs[mmap]);
   1.136 -	kfree(pending_addrs[mmap]);
   1.137  
   1.138 -#ifdef __ia64__
   1.139 -	/*Not sure what goes here yet!*/
   1.140 -#else
   1.141 +	BUG_ON(!spin_is_locked(&pending_free_lock));
   1.142  
   1.143 -	/* Unpin all of the pages. */
   1.144 -	page = mmap_start[mmap].mpage;
   1.145 -	for (i=0; i<mmap_pages; i++)
   1.146 -		put_page(&page[i]);
   1.147 +	kfree(pending_reqs[mmap]);
   1.148  
   1.149 -	balloon_dealloc_empty_page_range(mmap_start[mmap].mpage, mmap_pages);
   1.150 -#endif
   1.151 +	for (i = 0; i < mmap_pages; i++)
   1.152 +		balloon_free_empty_page(foreign_pages[mmap][i]);
   1.153 +	kfree(foreign_pages[mmap]);
   1.154 +	foreign_pages[mmap] = NULL;
   1.155  
   1.156  	mmap_lock = 0;
   1.157  	DPRINTK("# MMAPs decreased to %d\n",mmap_alloc);
   1.158 @@ -887,7 +856,7 @@ static void fast_flush_area(pending_req_
   1.159  	mmap_idx = req->mem_idx;
   1.160  
   1.161  	for (i = 0; i < req->nr_pages; i++) {
   1.162 -		kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, k_idx, i);
   1.163 +		kvaddr = idx_to_kaddr(mmap_idx, k_idx, i);
   1.164  		uvaddr = MMAP_VADDR(info->user_vstart, u_idx, i);
   1.165  
   1.166  		khandle = &pending_handle(mmap_idx, k_idx, i);
   1.167 @@ -896,7 +865,7 @@ static void fast_flush_area(pending_req_
   1.168  			continue;
   1.169  		}
   1.170  		gnttab_set_unmap_op(&unmap[invcount], 
   1.171 -			MMAP_VADDR(mmap_start[mmap_idx].start, k_idx, i), 
   1.172 +				    idx_to_kaddr(mmap_idx, k_idx, i), 
   1.173  				    GNTMAP_host_map, khandle->kernel);
   1.174  		invcount++;
   1.175  
   1.176 @@ -1030,9 +999,8 @@ static int blktap_read_ufe_ring(tap_blki
   1.177  			struct page *pg;
   1.178  			int offset;
   1.179  
   1.180 -			uvaddr  = MMAP_VADDR(info->user_vstart, usr_idx, j);
   1.181 -			kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, 
   1.182 -					    pending_idx, j);
   1.183 +			uvaddr = MMAP_VADDR(info->user_vstart, usr_idx, j);
   1.184 +			kvaddr = idx_to_kaddr(mmap_idx, pending_idx, j);
   1.185  
   1.186  			pg = pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT);
   1.187  			ClearPageReserved(pg);
   1.188 @@ -1214,8 +1182,7 @@ static void dispatch_rw_block_io(blkif_t
   1.189  		uint32_t flags;
   1.190  
   1.191  		uvaddr = MMAP_VADDR(info->user_vstart, usr_idx, i);
   1.192 -		kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, 
   1.193 -				    pending_idx, i);
   1.194 +		kvaddr = idx_to_kaddr(mmap_idx, pending_idx, i);
   1.195  		page = virt_to_page(kvaddr);
   1.196  
   1.197  		sector = req->sector_number + (8*i);
   1.198 @@ -1267,8 +1234,7 @@ static void dispatch_rw_block_io(blkif_t
   1.199  		struct page *pg;
   1.200  
   1.201  		uvaddr = MMAP_VADDR(info->user_vstart, usr_idx, i/2);
   1.202 -		kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, 
   1.203 -				    pending_idx, i/2);
   1.204 +		kvaddr = idx_to_kaddr(mmap_idx, pending_idx, i/2);
   1.205  
   1.206  		if (unlikely(map[i].status != 0)) {
   1.207  			WPRINTK("invalid kernel buffer -- "
   1.208 @@ -1298,8 +1264,7 @@ static void dispatch_rw_block_io(blkif_t
   1.209  		unsigned long kvaddr;
   1.210  		struct page *pg;
   1.211  
   1.212 -		kvaddr = MMAP_VADDR(mmap_start[mmap_idx].start, 
   1.213 -				    pending_idx, i);
   1.214 +		kvaddr = idx_to_kaddr(mmap_idx, pending_idx, i);
   1.215  		pg = pfn_to_page(__pa(kvaddr) >> PAGE_SHIFT);
   1.216  		SetPageReserved(pg);
   1.217  	}