diff options
author | Andy Grover <agrover@redhat.com> | 2012-01-16 16:57:08 -0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-02-29 16:31:09 -0800 |
commit | d2227f84ba0e97906153ac83db13213fb2e3938d (patch) | |
tree | bc965679916c94fc5ee2fb6e694b83f7f3c07f43 /drivers/target/target_core_transport.c | |
parent | 2ab9cc5409e9871927ef2799b41af3288cf7114c (diff) |
target: Allow control CDBs with data > 1 page
commit 4949314c7283ea4f9ade182ca599583b89f7edd6 upstream.
We need to handle >1 page control cdbs, so extend the code to do a vmap
if bigger than 1 page. It seems like kmap() is still preferable if just
a page, fewer TLB shootdowns(?), so keep using that when possible.
Rename function pair for their new scope.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/target/target_core_transport.c')
-rw-r--r-- | drivers/target/target_core_transport.c | 45 |
1 files changed, 34 insertions, 11 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 861628eb2da2..e4ddb93a827a 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -3053,11 +3053,6 @@ static int transport_generic_cmd_sequencer( (cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB))) goto out_unsupported_cdb; - /* Let's limit control cdbs to a page, for simplicity's sake. */ - if ((cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB) && - size > PAGE_SIZE) - goto out_invalid_cdb_field; - transport_set_supported_SAM_opcode(cmd); return ret; @@ -3435,9 +3430,11 @@ int transport_generic_map_mem_to_cmd( } EXPORT_SYMBOL(transport_generic_map_mem_to_cmd); -void *transport_kmap_first_data_page(struct se_cmd *cmd) +void *transport_kmap_data_sg(struct se_cmd *cmd) { struct scatterlist *sg = cmd->t_data_sg; + struct page **pages; + int i; BUG_ON(!sg); /* @@ -3445,15 +3442,41 @@ void *transport_kmap_first_data_page(struct se_cmd *cmd) * tcm_loop who may be using a contig buffer from the SCSI midlayer for * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd() */ - return kmap(sg_page(sg)) + sg->offset; + if (!cmd->t_data_nents) + return NULL; + else if (cmd->t_data_nents == 1) + return kmap(sg_page(sg)) + sg->offset; + + /* >1 page. use vmap */ + pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL); + if (!pages) + return NULL; + + /* convert sg[] to pages[] */ + for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) { + pages[i] = sg_page(sg); + } + + cmd->t_data_vmap = vmap(pages, cmd->t_data_nents, VM_MAP, PAGE_KERNEL); + kfree(pages); + if (!cmd->t_data_vmap) + return NULL; + + return cmd->t_data_vmap + cmd->t_data_sg[0].offset; } -EXPORT_SYMBOL(transport_kmap_first_data_page); +EXPORT_SYMBOL(transport_kmap_data_sg); -void transport_kunmap_first_data_page(struct se_cmd *cmd) +void transport_kunmap_data_sg(struct se_cmd *cmd) { - kunmap(sg_page(cmd->t_data_sg)); + if (!cmd->t_data_nents) + return; + else if (cmd->t_data_nents == 1) + kunmap(sg_page(cmd->t_data_sg)); + + vunmap(cmd->t_data_vmap); + cmd->t_data_vmap = NULL; } -EXPORT_SYMBOL(transport_kunmap_first_data_page); +EXPORT_SYMBOL(transport_kunmap_data_sg); static int transport_generic_get_mem(struct se_cmd *cmd) |