Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933676Ab3CLXQg (ORCPT ); Tue, 12 Mar 2013 19:16:36 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60151 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755823Ab3CLWc4 (ORCPT ); Tue, 12 Mar 2013 18:32:56 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Emmanuel Grumbach , Johannes Berg Subject: [ 031/100] iwlwifi: always copy first 16 bytes of commands Date: Tue, 12 Mar 2013 15:31:16 -0700 Message-Id: <20130312223126.381565711@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130312223122.884099393@linuxfoundation.org> References: <20130312223122.884099393@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8008 Lines: 247 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg commit 8a964f44e01ad3bbc208c3e80d931ba91b9ea786 upstream. The FH hardware will always write back to the scratch field in commands, even host commands not just TX commands, which can overwrite parts of the command. This is problematic if the command is re-used (with IWL_HCMD_DFL_NOCOPY) and can cause calibration issues. Address this problem by always putting at least the first 16 bytes into the buffer we also use for the command header and therefore make the DMA engine write back into this. For commands that are smaller than 16 bytes also always map enough memory for the DMA engine to write back to. Reviewed-by: Emmanuel Grumbach Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/iwlwifi/iwl-devtrace.h | 10 +-- drivers/net/wireless/iwlwifi/pcie/internal.h | 9 +++ drivers/net/wireless/iwlwifi/pcie/tx.c | 75 ++++++++++++++++++++------- 3 files changed, 71 insertions(+), 23 deletions(-) --- a/drivers/net/wireless/iwlwifi/iwl-devtrace.h +++ b/drivers/net/wireless/iwlwifi/iwl-devtrace.h @@ -349,25 +349,23 @@ TRACE_EVENT(iwlwifi_dev_rx_data, TRACE_EVENT(iwlwifi_dev_hcmd, TP_PROTO(const struct device *dev, struct iwl_host_cmd *cmd, u16 total_size, - const void *hdr, size_t hdr_len), - TP_ARGS(dev, cmd, total_size, hdr, hdr_len), + struct iwl_cmd_header *hdr), + TP_ARGS(dev, cmd, total_size, hdr), TP_STRUCT__entry( DEV_ENTRY __dynamic_array(u8, hcmd, total_size) __field(u32, flags) ), TP_fast_assign( - int i, offset = hdr_len; + int i, offset = sizeof(*hdr); DEV_ASSIGN; __entry->flags = cmd->flags; - memcpy(__get_dynamic_array(hcmd), hdr, hdr_len); + memcpy(__get_dynamic_array(hcmd), hdr, sizeof(*hdr)); for (i = 0; i < IWL_MAX_CMD_TFDS; i++) { if (!cmd->len[i]) continue; - if (!(cmd->dataflags[i] & IWL_HCMD_DFL_NOCOPY)) - continue; memcpy((u8 *)__get_dynamic_array(hcmd) + offset, cmd->data[i], cmd->len[i]); offset += cmd->len[i]; --- a/drivers/net/wireless/iwlwifi/pcie/internal.h +++ b/drivers/net/wireless/iwlwifi/pcie/internal.h @@ -182,6 +182,15 @@ struct iwl_queue { #define TFD_TX_CMD_SLOTS 256 #define TFD_CMD_SLOTS 32 +/* + * The FH will write back to the first TB only, so we need + * to copy some data into the buffer regardless of whether + * it should be mapped or not. This indicates how much to + * copy, even for HCMDs it must be big enough to fit the + * DRAM scratch from the TX cmd, at least 16 bytes. + */ +#define IWL_HCMD_MIN_COPY_SIZE 16 + struct iwl_pcie_txq_entry { struct iwl_device_cmd *cmd; struct iwl_device_cmd *copy_cmd; --- a/drivers/net/wireless/iwlwifi/pcie/tx.c +++ b/drivers/net/wireless/iwlwifi/pcie/tx.c @@ -1131,10 +1131,12 @@ static int iwl_pcie_enqueue_hcmd(struct void *dup_buf = NULL; dma_addr_t phys_addr; int idx; - u16 copy_size, cmd_size; + u16 copy_size, cmd_size, dma_size; bool had_nocopy = false; int i; u32 cmd_pos; + const u8 *cmddata[IWL_MAX_CMD_TFDS]; + u16 cmdlen[IWL_MAX_CMD_TFDS]; copy_size = sizeof(out_cmd->hdr); cmd_size = sizeof(out_cmd->hdr); @@ -1143,8 +1145,23 @@ static int iwl_pcie_enqueue_hcmd(struct BUILD_BUG_ON(IWL_MAX_CMD_TFDS > IWL_NUM_OF_TBS - 1); for (i = 0; i < IWL_MAX_CMD_TFDS; i++) { + cmddata[i] = cmd->data[i]; + cmdlen[i] = cmd->len[i]; + if (!cmd->len[i]) continue; + + /* need at least IWL_HCMD_MIN_COPY_SIZE copied */ + if (copy_size < IWL_HCMD_MIN_COPY_SIZE) { + int copy = IWL_HCMD_MIN_COPY_SIZE - copy_size; + + if (copy > cmdlen[i]) + copy = cmdlen[i]; + cmdlen[i] -= copy; + cmddata[i] += copy; + copy_size += copy; + } + if (cmd->dataflags[i] & IWL_HCMD_DFL_NOCOPY) { had_nocopy = true; if (WARN_ON(cmd->dataflags[i] & IWL_HCMD_DFL_DUP)) { @@ -1164,7 +1181,7 @@ static int iwl_pcie_enqueue_hcmd(struct goto free_dup_buf; } - dup_buf = kmemdup(cmd->data[i], cmd->len[i], + dup_buf = kmemdup(cmddata[i], cmdlen[i], GFP_ATOMIC); if (!dup_buf) return -ENOMEM; @@ -1174,7 +1191,7 @@ static int iwl_pcie_enqueue_hcmd(struct idx = -EINVAL; goto free_dup_buf; } - copy_size += cmd->len[i]; + copy_size += cmdlen[i]; } cmd_size += cmd->len[i]; } @@ -1221,14 +1238,31 @@ static int iwl_pcie_enqueue_hcmd(struct /* and copy the data that needs to be copied */ cmd_pos = offsetof(struct iwl_device_cmd, payload); + copy_size = sizeof(out_cmd->hdr); for (i = 0; i < IWL_MAX_CMD_TFDS; i++) { - if (!cmd->len[i]) + int copy = 0; + + if (!cmd->len) continue; - if (cmd->dataflags[i] & (IWL_HCMD_DFL_NOCOPY | - IWL_HCMD_DFL_DUP)) - break; - memcpy((u8 *)out_cmd + cmd_pos, cmd->data[i], cmd->len[i]); - cmd_pos += cmd->len[i]; + + /* need at least IWL_HCMD_MIN_COPY_SIZE copied */ + if (copy_size < IWL_HCMD_MIN_COPY_SIZE) { + copy = IWL_HCMD_MIN_COPY_SIZE - copy_size; + + if (copy > cmd->len[i]) + copy = cmd->len[i]; + } + + /* copy everything if not nocopy/dup */ + if (!(cmd->dataflags[i] & (IWL_HCMD_DFL_NOCOPY | + IWL_HCMD_DFL_DUP))) + copy = cmd->len[i]; + + if (copy) { + memcpy((u8 *)out_cmd + cmd_pos, cmd->data[i], copy); + cmd_pos += copy; + copy_size += copy; + } } WARN_ON_ONCE(txq->entries[idx].copy_cmd); @@ -1254,7 +1288,14 @@ static int iwl_pcie_enqueue_hcmd(struct out_cmd->hdr.cmd, le16_to_cpu(out_cmd->hdr.sequence), cmd_size, q->write_ptr, idx, trans_pcie->cmd_queue); - phys_addr = dma_map_single(trans->dev, &out_cmd->hdr, copy_size, + /* + * If the entire command is smaller than IWL_HCMD_MIN_COPY_SIZE, we must + * still map at least that many bytes for the hardware to write back to. + * We have enough space, so that's not a problem. + */ + dma_size = max_t(u16, copy_size, IWL_HCMD_MIN_COPY_SIZE); + + phys_addr = dma_map_single(trans->dev, &out_cmd->hdr, dma_size, DMA_BIDIRECTIONAL); if (unlikely(dma_mapping_error(trans->dev, phys_addr))) { idx = -ENOMEM; @@ -1262,14 +1303,15 @@ static int iwl_pcie_enqueue_hcmd(struct } dma_unmap_addr_set(out_meta, mapping, phys_addr); - dma_unmap_len_set(out_meta, len, copy_size); + dma_unmap_len_set(out_meta, len, dma_size); iwl_pcie_txq_build_tfd(trans, txq, phys_addr, copy_size, 1); + /* map the remaining (adjusted) nocopy/dup fragments */ for (i = 0; i < IWL_MAX_CMD_TFDS; i++) { - const void *data = cmd->data[i]; + const void *data = cmddata[i]; - if (!cmd->len[i]) + if (!cmdlen[i]) continue; if (!(cmd->dataflags[i] & (IWL_HCMD_DFL_NOCOPY | IWL_HCMD_DFL_DUP))) @@ -1277,7 +1319,7 @@ static int iwl_pcie_enqueue_hcmd(struct if (cmd->dataflags[i] & IWL_HCMD_DFL_DUP) data = dup_buf; phys_addr = dma_map_single(trans->dev, (void *)data, - cmd->len[i], DMA_BIDIRECTIONAL); + cmdlen[i], DMA_BIDIRECTIONAL); if (dma_mapping_error(trans->dev, phys_addr)) { iwl_pcie_tfd_unmap(trans, out_meta, &txq->tfds[q->write_ptr], @@ -1286,7 +1328,7 @@ static int iwl_pcie_enqueue_hcmd(struct goto out; } - iwl_pcie_txq_build_tfd(trans, txq, phys_addr, cmd->len[i], 0); + iwl_pcie_txq_build_tfd(trans, txq, phys_addr, cmdlen[i], 0); } out_meta->flags = cmd->flags; @@ -1296,8 +1338,7 @@ static int iwl_pcie_enqueue_hcmd(struct txq->need_update = 1; - trace_iwlwifi_dev_hcmd(trans->dev, cmd, cmd_size, - &out_cmd->hdr, copy_size); + trace_iwlwifi_dev_hcmd(trans->dev, cmd, cmd_size, &out_cmd->hdr); /* start timer if queue currently empty */ if (q->read_ptr == q->write_ptr && trans_pcie->wd_timeout) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/