diff options
Diffstat (limited to 'target/linux/layerscape/patches-4.14/825-vfio-fsl-mc-Improve-send-mc-command-and-read-respons.patch')
| -rw-r--r-- | target/linux/layerscape/patches-4.14/825-vfio-fsl-mc-Improve-send-mc-command-and-read-respons.patch | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/target/linux/layerscape/patches-4.14/825-vfio-fsl-mc-Improve-send-mc-command-and-read-respons.patch b/target/linux/layerscape/patches-4.14/825-vfio-fsl-mc-Improve-send-mc-command-and-read-respons.patch new file mode 100644 index 0000000000..c04fef044c --- /dev/null +++ b/target/linux/layerscape/patches-4.14/825-vfio-fsl-mc-Improve-send-mc-command-and-read-respons.patch @@ -0,0 +1,48 @@ +From 703b2ca94467a029942fa478a38f0a14c8109766 Mon Sep 17 00:00:00 2001 +From: Bharat Bhushan <bharat.bhushan@nxp.com> +Date: Fri, 1 Mar 2019 13:33:58 +0800 +Subject: [PATCH] vfio/fsl-mc: Improve send mc-command and read response + +Actually there is no ordering need when reading response +from mc-portal. Similarly when writing the mc-command, +ordering needed before command is submitted. + +This patch removes un-necessary barriers, response is read +relaxed and maintain ordering when submit command. This also +fixes compilation issue with newer kernel. + +Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com> +Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> +--- + drivers/vfio/fsl-mc/vfio_fsl_mc.c | 13 +++++++------ + 1 file changed, 7 insertions(+), 6 deletions(-) + +--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c ++++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c +@@ -331,9 +331,7 @@ static int vfio_fsl_mc_dprc_wait_for_res + u64 header; + struct mc_cmd_header *resp_hdr; + +- __iormb(); +- header = readq(ioaddr); +- __iormb(); ++ header = cpu_to_le64(readq_relaxed(ioaddr)); + + resp_hdr = (struct mc_cmd_header *)&header; + status = (enum mc_cmd_status)resp_hdr->status; +@@ -353,9 +351,12 @@ static int vfio_fsl_mc_send_command(void + { + int i; + +- /* Write at command header in the end */ +- for (i = 7; i >= 0; i--) +- writeq(cmd_data[i], ioaddr + i * sizeof(uint64_t)); ++ /* Write at command parameter into portal */ ++ for (i = 7; i >= 1; i--) ++ writeq_relaxed(cmd_data[i], ioaddr + i * sizeof(uint64_t)); ++ ++ /* Write command header in the end */ ++ writeq(cmd_data[0], ioaddr); + + /* Wait for response before returning to user-space + * This can be optimized in future to even prepare response |