--- /dev/null
+--- ./crypto/cipher.c 2004-07-26 12:52:03.000000000 +0100
++++ ./crypto/cipher.c 2004-07-26 12:55:11.000000000 +0100
+@@ -88,12 +88,21 @@ static void scatterwalk_start(struct sca
+
+ walk->sg = sg;
+
++#if SMALL_SCATTERLIST
++ walk->page = sg->u.page.page;
++ walk->len_this_segment = sg->length;
++
++ rest_of_page = PAGE_CACHE_SIZE - (sg->u.page.offset & (PAGE_CACHE_SIZE - 1));
++ walk->len_this_page = min(sg->length, rest_of_page);
++ walk->offset = sg->u.page.offset;
++#else
+ walk->page = sg->page;
+ walk->len_this_segment = sg->length;
+
+ rest_of_page = PAGE_CACHE_SIZE - (sg->offset & (PAGE_CACHE_SIZE - 1));
+ walk->len_this_page = min(sg->length, rest_of_page);
+ walk->offset = sg->offset;
++#endif
+ }
+
+ static void scatterwalk_map(struct scatter_walk *walk, int out)
+--- ./crypto/digest.c 2004-07-26 12:52:03.000000000 +0100
++++ ./crypto/digest.c 2004-07-26 12:55:11.000000000 +0100
+@@ -29,7 +29,11 @@ static void update(struct crypto_tfm *tf
+ unsigned int i;
+
+ for (i = 0; i < nsg; i++) {
++#if SMALL_SCATTERLIST
++ char *p = crypto_kmap(sg[i].u.page.page, 0) + sg[i].u.page.offset;
++#else
+ char *p = crypto_kmap(sg[i].page, 0) + sg[i].offset;
++#endif
+ tfm->__crt_alg->cra_digest.dia_update(crypto_tfm_ctx(tfm),
+ p, sg[i].length);
+ crypto_kunmap(p, 0);
+@@ -50,7 +54,11 @@ static void digest(struct crypto_tfm *tf
+ tfm->crt_digest.dit_init(tfm);
+
+ for (i = 0; i < nsg; i++) {
++#if SMALL_SCATTERLIST
++ char *p = crypto_kmap(sg[i].u.page.page, 0) + sg[i].u.page.offset;
++#else
+ char *p = crypto_kmap(sg[i].page, 0) + sg[i].offset;
++#endif
+ tfm->__crt_alg->cra_digest.dia_update(crypto_tfm_ctx(tfm),
+ p, sg[i].length);
+ crypto_kunmap(p, 0);
+--- ./crypto/hmac.c 2004-07-26 12:52:03.000000000 +0100
++++ ./crypto/hmac.c 2004-07-26 12:55:11.000000000 +0100
+@@ -25,8 +25,14 @@ static void hash_key(struct crypto_tfm *
+ {
+ struct scatterlist tmp;
+
++#if SMALL_SCATTERLIST
++ tmp.ispaged = 1;
++ tmp.u.page.page = virt_to_page(key);
++ tmp.u.page.offset = ((long)key & ~PAGE_MASK);
++#else
+ tmp.page = virt_to_page(key);
+ tmp.offset = ((long)key & ~PAGE_MASK);
++#endif
+ tmp.length = keylen;
+ crypto_digest_digest(tfm, &tmp, 1, key);
+
+@@ -70,8 +76,14 @@ void crypto_hmac_init(struct crypto_tfm
+ for (i = 0; i < crypto_tfm_alg_blocksize(tfm); i++)
+ ipad[i] ^= 0x36;
+
++#if SMALL_SCATTERLIST
++ tmp.ispaged = 1;
++ tmp.u.page.page = virt_to_page(ipad);
++ tmp.u.page.offset = ((long)ipad & ~PAGE_MASK);
++#else
+ tmp.page = virt_to_page(ipad);
+ tmp.offset = ((long)ipad & ~PAGE_MASK);
++#endif
+ tmp.length = crypto_tfm_alg_blocksize(tfm);
+
+ crypto_digest_init(tfm);
+@@ -104,15 +116,27 @@ void crypto_hmac_final(struct crypto_tfm
+ for (i = 0; i < crypto_tfm_alg_blocksize(tfm); i++)
+ opad[i] ^= 0x5c;
+
++#if SMALL_SCATTERLIST
++ tmp.ispaged = 1;
++ tmp.u.page.page = virt_to_page(opad);
++ tmp.u.page.offset = ((long)opad & ~PAGE_MASK);
++#else
+ tmp.page = virt_to_page(opad);
+ tmp.offset = ((long)opad & ~PAGE_MASK);
++#endif
+ tmp.length = crypto_tfm_alg_blocksize(tfm);
+
+ crypto_digest_init(tfm);
+ crypto_digest_update(tfm, &tmp, 1);
+
++#if SMALL_SCATTERLIST
++ tmp.ispaged = 1;
++ tmp.u.page.page = virt_to_page(out);
++ tmp.u.page.offset = ((long)out & ~PAGE_MASK);
++#else
+ tmp.page = virt_to_page(out);
+ tmp.offset = ((long)out & ~PAGE_MASK);
++#endif
+ tmp.length = crypto_tfm_alg_digestsize(tfm);
+
+ crypto_digest_update(tfm, &tmp, 1);
+--- ./drivers/ide/ide-dma.c 2004-07-26 12:52:17.000000000 +0100
++++ ./drivers/ide/ide-dma.c 2004-07-26 12:55:11.000000000 +0100
+@@ -281,14 +281,25 @@ static int ide_build_sglist (ide_hwif_t
+ memset(&sg[nents], 0, sizeof(*sg));
+
+ if (bh->b_page) {
++#if SMALL_SCATTERLIST
++ sg[nents].ispaged = 1;
++ sg[nents].u.page.page = bh->b_page;
++ sg[nents].u.page.offset = bh_offset(bh);
++#else
+ sg[nents].page = bh->b_page;
+ sg[nents].offset = bh_offset(bh);
++#endif
+ lastdataend = bh_phys(bh) + bh->b_size;
+ } else {
+ if ((unsigned long) bh->b_data < PAGE_SIZE)
+ BUG();
+
++#if SMALL_SCATTERLIST
++ sg[nents].ispaged = 0;
++ sg[nents].u.address = bh->b_data;
++#else
+ sg[nents].address = bh->b_data;
++#endif
+ lastdataend = (unsigned long) bh->b_data + bh->b_size;
+ }
+
+@@ -329,14 +340,24 @@ static int ide_raw_build_sglist (ide_hwi
+ #if 1
+ if (sector_count > 128) {
+ memset(&sg[nents], 0, sizeof(*sg));
++#if SMALL_SCATTERLIST
++ sg[nents].ispaged = 0;
++ sg[nents].u.address = virt_addr;
++#else
+ sg[nents].address = virt_addr;
++#endif
+ sg[nents].length = 128 * SECTOR_SIZE;
+ nents++;
+ virt_addr = virt_addr + (128 * SECTOR_SIZE);
+ sector_count -= 128;
+ }
+ memset(&sg[nents], 0, sizeof(*sg));
++#if SMALL_SCATTERLIST
++ sg[nents].ispaged = 0;
++ sg[nents].u.address = virt_addr;
++#else
+ sg[nents].address = virt_addr;
++#endif
+ sg[nents].length = sector_count * SECTOR_SIZE;
+ nents++;
+ #else
+--- ./drivers/scsi/dpt_i2o.c 2004-07-26 12:52:39.000000000 +0100
++++ ./drivers/scsi/dpt_i2o.c 2004-07-26 12:55:11.000000000 +0100
+@@ -2151,7 +2151,13 @@ static s32 adpt_scsi_to_i2o(adpt_hba* pH
+ for(i = 0 ; i < cmd->use_sg; i++) {
+ *mptr++ = direction|0x10000000|sg->length;
+ len+=sg->length;
++#if SMALL_SCATTERLIST
++ if (sg->ispaged)
++ BUG();
++ *mptr++ = virt_to_bus(sg->u.address);
++#else
+ *mptr++ = virt_to_bus(sg->address);
++#endif
+ sg++;
+ }
+ /* Make this an end of list */
+--- ./drivers/scsi/scsi_debug.c 2004-07-26 12:52:40.000000000 +0100
++++ ./drivers/scsi/scsi_debug.c 2004-07-26 12:55:11.000000000 +0100
+@@ -186,7 +186,13 @@ int scsi_debug_queuecommand(Scsi_Cmnd *
+ struct scatterlist *sgpnt = (struct scatterlist *)
+ SCpnt->request_buffer;
+
++#if SMALL_SCATTERLIST
++ if (sgpnt[0].ispaged)
++ BUG();
++ buff = sgpnt[0].u.address;
++#else
+ buff = sgpnt[0].address;
++#endif
+ bufflen = sgpnt[0].length;
+ /* READ and WRITE process scatterlist themselves */
+ }
+@@ -672,7 +678,13 @@ static int resp_read(Scsi_Cmnd * SCpnt,
+ if (SCpnt->use_sg) {
+ sgcount = 0;
+ sgpnt = (struct scatterlist *) buff;
++#if SMALL_SCATTERLIST
++ if (sgpnt[sgcount].ispaged)
++ BUG();
++ buff = sgpnt[sgcount].u.address;
++#else
+ buff = sgpnt[sgcount].address;
++#endif
+ bufflen = sgpnt[sgcount].length;
+ }
+ do {
+@@ -682,7 +694,13 @@ static int resp_read(Scsi_Cmnd * SCpnt,
+ block += bufflen >> POW2_SECT_SIZE;
+ sgcount++;
+ if (nbytes) {
++#if SMALL_SCATTERLIST
++ if (sgpnt[sgcount].ispaged)
++ BUG();
++ buff = sgpnt[sgcount].u.address;
++#else
+ buff = sgpnt[sgcount].address;
++#endif
+ bufflen = sgpnt[sgcount].length;
+ }
+ } else if (nbytes > 0)
+@@ -713,7 +731,13 @@ static int resp_write(Scsi_Cmnd * SCpnt,
+ if (SCpnt->use_sg) {
+ sgcount = 0;
+ sgpnt = (struct scatterlist *) buff;
++#if SMALL_SCATTERLIST
++ if (sgpnt[sgcount].ispaged)
++ BUG();
++ buff = sgpnt[sgcount].u.address;
++#else
+ buff = sgpnt[sgcount].address;
++#endif
+ bufflen = sgpnt[sgcount].length;
+ }
+ do {
+@@ -724,7 +748,13 @@ static int resp_write(Scsi_Cmnd * SCpnt,
+ block += bufflen >> POW2_SECT_SIZE;
+ sgcount++;
+ if (nbytes) {
++#if SMALL_SCATTERLIST
++ if (sgpnt[sgcount].ispaged)
++ BUG();
++ buff = sgpnt[sgcount].u.address;
++#else
+ buff = sgpnt[sgcount].address;
++#endif
+ bufflen = sgpnt[sgcount].length;
+ }
+ } else if (nbytes > 0)
+--- ./drivers/scsi/scsi_lib.c 2004-07-26 12:52:40.000000000 +0100
++++ ./drivers/scsi/scsi_lib.c 2004-07-26 12:55:11.000000000 +0100
+@@ -549,7 +549,13 @@ static void scsi_release_buffers(Scsi_Cm
+ if (bbpnt) {
+ for (i = 0; i < SCpnt->use_sg; i++) {
+ if (bbpnt[i])
++#if SMALL_SCATTERLIST
++ if (sgpnt[i].ispaged)
++ BUG();
++ scsi_free(sgpnt[i].u.address, sgpnt[i].length);
++#else
+ scsi_free(sgpnt[i].address, sgpnt[i].length);
++#endif
+ }
+ }
+ scsi_free(SCpnt->request_buffer, SCpnt->sglist_len);
+@@ -625,12 +631,23 @@ void scsi_io_completion(Scsi_Cmnd * SCpn
+ if (bbpnt) {
+ for (i = 0; i < SCpnt->use_sg; i++) {
+ if (bbpnt[i]) {
++#if SMALL_SCATTERLIST
++ if (sgpnt[i].ispaged)
++ BUG();
++ if (req->cmd == READ) {
++ memcpy(bbpnt[i],
++ sgpnt[i].u.address,
++ sgpnt[i].length);
++ }
++ scsi_free(sgpnt[i].u.address, sgpnt[i].length);
++#else
+ if (req->cmd == READ) {
+ memcpy(bbpnt[i],
+ sgpnt[i].address,
+ sgpnt[i].length);
+ }
+ scsi_free(sgpnt[i].address, sgpnt[i].length);
++#endif
+ }
+ }
+ }
+--- ./drivers/scsi/scsi_merge.c 2004-07-26 12:52:40.000000000 +0100
++++ ./drivers/scsi/scsi_merge.c 2004-07-26 13:06:01.000000000 +0100
+@@ -144,11 +144,21 @@ static void dma_exhausted(Scsi_Cmnd * SC
+ */
+ for(jj=0; jj < SCpnt->use_sg; jj++)
+ {
++#if SMALL_SCATTERLIST
++ if (sgpnt[jj].ispaged)
++ BUG();
++ printk("[%d]\tlen:%d\taddr:%p\tbounce:%p\n",
++ jj,
++ sgpnt[jj].length,
++ sgpnt[jj].u.address,
++ (bbpnt ? bbpnt[jj] : NULL));
++#else
+ printk("[%d]\tlen:%d\taddr:%p\tbounce:%p\n",
+ jj,
+ sgpnt[jj].length,
+ sgpnt[jj].address,
+ (bbpnt ? bbpnt[jj] : NULL));
++#endif
+ if (bbpnt && bbpnt[jj])
+ consumed += sgpnt[jj].length;
+ }
+@@ -612,6 +622,9 @@ __inline static int __scsi_merge_request
+ max_segments = scsi_max_sg;
+
+ #ifdef DMA_CHUNK_SIZE
++# if SMALL_SCATTERLIST
++# error "This defeats the purpose of SMALL_SCATTERLIST"
++# endif
+ if (max_segments > 64)
+ max_segments = 64;
+
+@@ -929,15 +942,26 @@ __inline static int __init_io(Scsi_Cmnd
+ }
+
+ if (SCpnt->host->highmem_io) {
++#if SMALL_SCATTERLIST
++ sgpnt[count].ispaged = 1;
++ sgpnt[count].u.page.page = bh->b_page;
++ sgpnt[count].u.page.offset = bh_offset(bh);
++#else
+ sgpnt[count].page = bh->b_page;
+ sgpnt[count].offset = bh_offset(bh);
+ sgpnt[count].address = NULL;
++#endif
+ } else {
+ if (PageHighMem(bh->b_page))
+ BUG();
+
++#if SMALL_SCATTERLIST
++ sgpnt[count].ispaged = 0;
++ sgpnt[count].u.address = bh->b_data;
++#else
+ sgpnt[count].page = NULL;
+ sgpnt[count].address = bh->b_data;
++#endif
+ }
+
+ sgpnt[count].length = bh->b_size;
+@@ -972,6 +996,50 @@ __inline static int __init_io(Scsi_Cmnd
+ * only done for dma_host, in which case .page is not
+ * set since it's guarenteed to be a low memory page
+ */
++#if SMALL_SCATTERLIST
++ if (sgpnt[i].ispaged)
++ BUG();
++ if (virt_to_phys(sgpnt[i].u.address) + sgpnt[i].length - 1 >
++ ISA_DMA_THRESHOLD) {
++ if( scsi_dma_free_sectors - sectors <= 10 ) {
++ /*
++ * If this would nearly drain the DMA
++ * pool empty, then let's stop here.
++ * Don't make this request any larger.
++ * This is kind of a safety valve that
++ * we use - we could get screwed later
++ * on if we run out completely.
++ */
++ SCpnt->request_bufflen -= sgpnt[i].length;
++ SCpnt->use_sg = i;
++ if (i == 0) {
++ goto big_trouble;
++ }
++ break;
++ }
++
++ bbpnt[i] = sgpnt[i].u.address;
++ sgpnt[i].u.address =
++ (char *) scsi_malloc(sgpnt[i].length);
++ /*
++ * If we cannot allocate memory for this DMA bounce
++ * buffer, then queue just what we have done so far.
++ */
++ if (sgpnt[i].u.address == NULL) {
++ printk("Warning - running low on DMA memory\n");
++ SCpnt->request_bufflen -= sgpnt[i].length;
++ SCpnt->use_sg = i;
++ if (i == 0) {
++ goto big_trouble;
++ }
++ break;
++ }
++ if (req->cmd == WRITE) {
++ memcpy(sgpnt[i].u.address, bbpnt[i],
++ sgpnt[i].length);
++ }
++ }
++#else
+ if (virt_to_phys(sgpnt[i].address) + sgpnt[i].length - 1 >
+ ISA_DMA_THRESHOLD) {
+ if( scsi_dma_free_sectors - sectors <= 10 ) {
+@@ -1012,6 +1080,7 @@ __inline static int __init_io(Scsi_Cmnd
+ sgpnt[i].length);
+ }
+ }
++#endif
+ }
+ return 1;
+
+--- ./drivers/scsi/sg.c 2004-07-26 12:52:40.000000000 +0100
++++ ./drivers/scsi/sg.c 2004-07-26 12:55:12.000000000 +0100
+@@ -1068,7 +1068,11 @@ static void sg_rb_correct4mmap(Sg_scatte
+
+ for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
+ for (m = PAGE_SIZE; m < sclp->length; m += PAGE_SIZE) {
++#if SMALL_SCATTERLIST
++ page_ptr = (unsigned char *)sclp->u.address + m;
++#else
+ page_ptr = (unsigned char *)sclp->address + m;
++#endif
+ page = virt_to_page(page_ptr);
+ if (startFinish)
+ get_page(page); /* increment page count */
+@@ -1121,7 +1125,11 @@ static struct page * sg_vma_nopage(struc
+ len = vma->vm_end - sa;
+ len = (len < sclp->length) ? len : sclp->length;
+ if (offset < len) {
++#if SMALL_SCATTERLIST
++ page_ptr = (unsigned char *)sclp->u.address + offset;
++#else
+ page_ptr = (unsigned char *)sclp->address + offset;
++#endif
+ page = virt_to_page(page_ptr);
+ get_page(page); /* increment page count */
+ break;
+@@ -1166,8 +1174,13 @@ static int sg_mmap(struct file * filp, s
+
+ for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
+ ++k, ++sclp) {
++#if SMALL_SCATTERLIST
++ if ((unsigned long)sclp->u.address & (PAGE_SIZE - 1))
++ return -EFAULT; /* non page aligned memory ?? */
++#else
+ if ((unsigned long)sclp->address & (PAGE_SIZE - 1))
+ return -EFAULT; /* non page aligned memory ?? */
++#endif
+ len = vma->vm_end - sa;
+ len = (len < sclp->length) ? len : sclp->length;
+ sa += len;
+@@ -1716,16 +1729,27 @@ static int sg_build_dir(Sg_request * srp
+ offset = (0 == k) ? kp->offset : 0;
+ num = (rem_sz > (PAGE_SIZE - offset)) ? (PAGE_SIZE - offset) :
+ rem_sz;
++#if SMALL_SCATTERLIST
++ sclp->u.address = page_address(kp->maplist[k]) + offset;
++ sclp->ispaged = 0;
++#else
+ sclp->address = page_address(kp->maplist[k]) + offset;
+ #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,13)
+ sclp->page = NULL;
+ #endif
++#endif
+ sclp->length = num;
+ mem_src_arr[k] = SG_USER_MEM;
+ rem_sz -= num;
++#if SMALL_SCATTERLIST
++ SCSI_LOG_TIMEOUT(5,
++ printk("sg_build_dir: k=%d, a=0x%p, len=%d, ms=%d\n",
++ k, sclp->u.address, num, mem_src_arr[k]));
++#else
+ SCSI_LOG_TIMEOUT(5,
+ printk("sg_build_dir: k=%d, a=0x%p, len=%d, ms=%d\n",
+ k, sclp->address, num, mem_src_arr[k]));
++#endif
+ }
+ schp->k_use_sg = k;
+ SCSI_LOG_TIMEOUT(5,
+@@ -1805,16 +1829,27 @@ static int sg_build_indi(Sg_scatter_hold
+ if (! p)
+ break;
+ }
++#if SMALL_SCATTERLIST
++ sclp->u.address = p;
++ sclp->ispaged = 0;
++#else
+ sclp->address = p;
+ #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,13)
+ sclp->page = NULL;
+ #endif
++#endif
+ sclp->length = ret_sz;
+ mem_src_arr[k] = mem_src;
+
++#if SMALL_SCATTERLIST
++ SCSI_LOG_TIMEOUT(5,
++ printk("sg_build_build: k=%d, a=0x%p, len=%d, ms=%d\n",
++ k, sclp->u.address, ret_sz, mem_src));
++#else
+ SCSI_LOG_TIMEOUT(5,
+ printk("sg_build_build: k=%d, a=0x%p, len=%d, ms=%d\n",
+ k, sclp->address, ret_sz, mem_src));
++#endif
+ } /* end of for loop */
+ schp->k_use_sg = k;
+ SCSI_LOG_TIMEOUT(5,
+@@ -1879,13 +1914,21 @@ static int sg_write_xfer(Sg_request * sr
+ struct scatterlist * sclp = (struct scatterlist *)schp->buffer;
+ char * mem_src_arr = sg_get_sgat_msa(schp);
+ ksglen = (int)sclp->length;
++#if SMALL_SCATTERLIST
++ p = sclp->u.address;
++#else
+ p = sclp->address;
++#endif
+
+ for (j = 0, k = 0; j < onum; ++j) {
+ res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
+ if (res) return res;
+
++#if SMALL_SCATTERLIST
++ for ( ; p; ++sclp, ksglen = (int)sclp->length, p = sclp->u.address) {
++#else
+ for ( ; p; ++sclp, ksglen = (int)sclp->length, p = sclp->address) {
++#endif
+ ok = (SG_USER_MEM != mem_src_arr[k]);
+ if (usglen <= 0)
+ break;
+@@ -1962,6 +2005,18 @@ static void sg_remove_scat(Sg_scatter_ho
+ struct scatterlist * sclp = (struct scatterlist *)schp->buffer;
+ char * mem_src_arr = sg_get_sgat_msa(schp);
+
++#if SMALL_SCATTERLIST
++ for (k = 0; (k < schp->k_use_sg) && sclp->u.address; ++k, ++sclp) {
++ mem_src = mem_src_arr[k];
++ SCSI_LOG_TIMEOUT(5,
++ printk("sg_remove_scat: k=%d, a=0x%p, len=%d, ms=%d\n",
++ k, sclp->u.address, sclp->length, mem_src));
++ sg_free(sclp->u.address, sclp->length, mem_src);
++ sclp->u.address = NULL;
++ sclp->ispaged = 0;
++ sclp->length = 0;
++ }
++#else
+ for (k = 0; (k < schp->k_use_sg) && sclp->address; ++k, ++sclp) {
+ mem_src = mem_src_arr[k];
+ SCSI_LOG_TIMEOUT(5,
+@@ -1974,6 +2029,7 @@ static void sg_remove_scat(Sg_scatter_ho
+ #endif
+ sclp->length = 0;
+ }
++#endif
+ sg_free(schp->buffer, schp->sglist_len, schp->buffer_mem_src);
+ }
+ else if (schp->buffer)
+@@ -2034,13 +2090,21 @@ static int sg_read_xfer(Sg_request * srp
+ struct scatterlist * sclp = (struct scatterlist *)schp->buffer;
+ char * mem_src_arr = sg_get_sgat_msa(schp);
+ ksglen = (int)sclp->length;
++#if SMALL_SCATTERLIST
++ p = sclp->u.address;
++#else
+ p = sclp->address;
++#endif
+
+ for (j = 0, k = 0; j < onum; ++j) {
+ res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
+ if (res) return res;
+
++#if SMALL_SCATTERLIST
++ for ( ; p; ++sclp, ksglen = (int)sclp->length, p = sclp->u.address) {
++#else
+ for ( ; p; ++sclp, ksglen = (int)sclp->length, p = sclp->address) {
++#endif
+ ok = (SG_USER_MEM != mem_src_arr[k]);
+ if (usglen <= 0)
+ break;
+@@ -2084,14 +2148,26 @@ static void sg_read_oxfer(Sg_request * s
+ int k, num;
+ struct scatterlist * sclp = (struct scatterlist *)schp->buffer;
+
++#if SMALL_SCATTERLIST
++ for (k = 0; (k < schp->k_use_sg) && sclp->u.address; ++k, ++sclp) {
++#else
+ for (k = 0; (k < schp->k_use_sg) && sclp->address; ++k, ++sclp) {
++#endif
+ num = (int)sclp->length;
+ if (num > num_read_xfer) {
++#if SMALL_SCATTERLIST
++ __copy_to_user(outp, sclp->u.address, num_read_xfer);
++#else
+ __copy_to_user(outp, sclp->address, num_read_xfer);
++#endif
+ break;
+ }
+ else {
++#if SMALL_SCATTERLIST
++ __copy_to_user(outp, sclp->u.address, num);
++#else
+ __copy_to_user(outp, sclp->address, num);
++#endif
+ num_read_xfer -= num;
+ if (num_read_xfer <= 0)
+ break;
+@@ -2137,7 +2213,11 @@ static void sg_link_reserve(Sg_fd * sfp,
+ if (rem <= num) {
+ if (0 == k) {
+ req_schp->k_use_sg = 0;
++#if SMALL_SCATTERLIST
++ req_schp->buffer = sclp->u.address;
++#else
+ req_schp->buffer = sclp->address;
++#endif
+ }
+ else {
+ sfp->save_scat_len = num;
+--- ./drivers/scsi/sr.c 2004-07-26 12:52:40.000000000 +0100
++++ ./drivers/scsi/sr.c 2004-07-26 12:55:12.000000000 +0100
+@@ -343,7 +343,12 @@ static int sr_scatter_pad(Scsi_Cmnd *SCp
+
+ i = 0;
+ if (fsize) {
++#if SMALL_SCATTERLIST
++ sg[0].ispaged = 0;
++ sg[0].u.address = bbpnt[0] = front;
++#else
+ sg[0].address = bbpnt[0] = front;
++#endif
+ sg[0].length = fsize;
+ i++;
+ }
+@@ -354,7 +359,12 @@ static int sr_scatter_pad(Scsi_Cmnd *SCp
+ scsi_free(old_sg, (((SCpnt->use_sg * sizeof(struct scatterlist)) +
+ (SCpnt->use_sg * sizeof(void *))) + 511) & ~511);
+ } else {
++#if SMALL_SCATTERLIST
++ sg[i].ispaged = 0;
++ sg[i].u.address = SCpnt->request_buffer;
++#else
+ sg[i].address = SCpnt->request_buffer;
++#endif
+ sg[i].length = SCpnt->request_bufflen;
+ }
+
+@@ -364,7 +374,12 @@ static int sr_scatter_pad(Scsi_Cmnd *SCp
+ SCpnt->use_sg += i;
+
+ if (bsize) {
++#if SMALL_SCATTERLIST
++ sg[SCpnt->use_sg].ispaged = 0;
++ sg[SCpnt->use_sg].u.address = back;
++#else
+ sg[SCpnt->use_sg].address = back;
++#endif
+ bbpnt[SCpnt->use_sg] = back;
+ sg[SCpnt->use_sg].length = bsize;
+ SCpnt->use_sg++;
+--- ./include/asm-i386/pci.h 2004-07-26 12:52:59.000000000 +0100
++++ ./include/asm-i386/pci.h 2004-07-26 12:55:12.000000000 +0100
+@@ -157,6 +157,17 @@ static inline int pci_map_sg(struct pci_
+ * temporary 2.4 hack
+ */
+ for (i = 0; i < nents; i++ ) {
++#if SMALL_SCATTERLIST
++ if (sg[i].ispaged) {
++ if (!sg[i].u.page.page)
++ out_of_line_bug();
++ sg[i].dma_address = page_to_bus(sg[i].u.page.page) + sg[i].u.page.offset;
++ } else {
++ if (!sg[i].u.address)
++ out_of_line_bug();
++ sg[i].dma_address = virt_to_bus(sg[i].u.address);
++ }
++#else
+ if (sg[i].address && sg[i].page)
+ out_of_line_bug();
+ else if (!sg[i].address && !sg[i].page)
+@@ -166,6 +177,7 @@ static inline int pci_map_sg(struct pci_
+ sg[i].dma_address = virt_to_bus(sg[i].address);
+ else
+ sg[i].dma_address = page_to_bus(sg[i].page) + sg[i].offset;
++#endif
+ }
+
+ flush_write_buffers();
+--- ./include/asm-i386/scatterlist.h 2004-07-26 12:52:59.000000000 +0100
++++ ./include/asm-i386/scatterlist.h 2004-07-26 13:45:04.000000000 +0100
+@@ -19,7 +19,25 @@
+ *
+ * and that's it. There's no excuse for not highmem enabling YOUR driver. /jens
+ */
++
++/* Define SMALL_SCATTERLIST non-zero if you want to compress scatter/gather
++ descriptors to fit in 1 page. NB this file is arch-specific, so we only
++ define this where we actually need/want it */
++#define SMALL_SCATTERLIST 1
++
+ struct scatterlist {
++#if SMALL_SCATTERLIST
++ union {
++ char *address; /* mapped address... */
++ struct {
++ struct page *page; /* ...or page + offset... */
++ unsigned int offset;
++ } page;
++ } u;
++ dma_addr_t dma_address;
++ unsigned int length:31; /* ...steal 1 bit from the length */
++ unsigned int ispaged:1; /* to discriminate */
++#else
+ char * address; /* Location data is to be transferred to, NULL for
+ * highmem page */
+ struct page * page; /* Location for highmem page, if any */
+@@ -27,6 +45,7 @@ struct scatterlist {
+
+ dma_addr_t dma_address;
+ unsigned int length;
++#endif
+ };
+
+ #define ISA_DMA_THRESHOLD (0x00ffffff)
+--- ./net/xfrm/xfrm_algo.c 2004-07-26 12:53:25.000000000 +0100
++++ ./net/xfrm/xfrm_algo.c 2004-07-26 12:55:12.000000000 +0100
+@@ -487,9 +487,14 @@ void skb_icv_walk(const struct sk_buff *
+ if (copy > 0) {
+ if (copy > len)
+ copy = len;
+-
++#if SMALL_SCATTERLIST
++ sg.ispaged = 1;
++ sg.u.page.page = virt_to_page(skb->data + offset);
++ sg.u.page.offset = (unsigned long)(skb->data + offset) % PAGE_SIZE;
++#else
+ sg.page = virt_to_page(skb->data + offset);
+ sg.offset = (unsigned long)(skb->data + offset) % PAGE_SIZE;
++#endif
+ sg.length = copy;
+
+ icv_update(tfm, &sg, 1);
+@@ -511,8 +516,14 @@ void skb_icv_walk(const struct sk_buff *
+ if (copy > len)
+ copy = len;
+
++#if SMALL_SCATTERLIST
++ sg.ispaged = 1;
++ sg.u.page.page = frag->page;
++ sg.u.page.offset = frag->page_offset + offset-start;
++#else
+ sg.page = frag->page;
+ sg.offset = frag->page_offset + offset-start;
++#endif
+ sg.length = copy;
+
+ icv_update(tfm, &sg, 1);
git://git.whamcloud.com / fs / lustre-release.git / commitdiff