[RFC PATCH v6 0/9] Add external dma support for Synopsys MSHC

Shawn Lin
2015-08-20T08:44:13Z

Synopsys DesignWare mobile storage host controller supports three
types of transfer mode: pio, internal dma and external dma. However,
dw_mmc can only supports pio and internal dma now. Thus some platforms
using dw-mshc integrated with generic dma can't work in dma mode. So we
submit this patch to achieve it.

And the config option, CONFIG_MMC_DW_IDMAC, was added by Will Newton
(commit:f95f3850) for the first version of dw_mmc and never be touched since
then. At that time dt-bindings hadn't been introduced into dw_mmc yet means
we should select CONFIG_MMC_DW_IDMAC to enable internal dma mode at compile
time. Nowadays, device-tree helps us to support a variety of boards with one
kernel. That's why we need to remove it and decide the transfer mode by reading
dw_mmc's HCON reg at runtime.

This RFC patch needs lots of ACKs. I know it's hard, but it does need someone
to make the running.

Patch does the following things:
- remove CONFIG_MMC_DW_IDMAC config option
- add bindings for edmac used by synopsys-dw-mshc
at runtime
- add edmac support for synopsys-dw-mshc

Patch v1~v4 is based on next of git://git.linaro.org/people/ulf.hansson/mmc
Patch v5~v6 is rebased on dw-mmc-for-ulf-v4.2 of https://github.com/jh80chung/dw-mmc.git

Test emmc throughput on my platform with edmac support and without edmac support(pio only)
iozone -L64 -S32 -azecwI -+n -r4k -r64k -r128k -s1g -i0 -i1 -i2 -f datafile -Rb out.xls > /mnt/result.txt
(light cpu loading, Direct IO, fixed line size, all pattern recycle, 1GB data in total)
___________________________________________________________
| external dma mode |
|-----------------------------------------------------------|
|blksz | Random Read | Random Write | Seq Read | Seq Write|
|-----------------------------------------------------------|
|4kB | 13953kB/s | 8602kB/s | 13672kB/s | 9785kB/s|
|-----------------------------------------------------------|
|64kB | 46058kB/s | 24794kB/s | 48058kB/s | 25418kB/s|
|-----------------------------------------------------------|
|128kB | 57026kB/s | 35117kB/s | 57375kB/s | 35183kB/s|
|-----------------------------------------------------------|
VS
___________________________________________________________
| pio mode |
|-----------------------------------------------------------|
|blksz | Random Read | Random Write | Seq Read | Seq Write|
|-----------------------------------------------------------|
|4kB | 11720kB/s | 8644kB/s | 11549kB/s | 9624kB/s|
|-----------------------------------------------------------|
|64kB | 21869kB/s | 24414kB/s | 22031kB/s | 27986kB/s|
|-----------------------------------------------------------|
|128kB | 23718kB/s | 34495kB/s | 24698kB/s | 34637kB/s|
|-----------------------------------------------------------|

Changes in v6:
- add trans_mode condition for IDMAC initialization
suggested by Heiko
- re-test my patch on rk3188 platform and update commit msg
- update performance of pio vs edmac in cover letter

Changes in v5:
- add the title of cover letter
- fix typo of comment
- add macro for reading HCON register
- add "Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>" for exynos_defconfig patch
- add "Acked-by: Vineet Gupta <vgupta@synopsys.com>" for axs10x_defconfig patch
- add "Acked-by: Govindraj Raja <govindraj.raja@imgtec.com>" and
"Acked-by: Ralf Baechle <ralf@linux-mips.org>" for pistachio_defconfig patch
- add "Acked-by: Joachim Eastwood <manabian@gmail.com>" for lpc18xx_defconfig patch
- add "Acked-by: Wei Xu <xuwei5@hisilicon.com>" for hisi_defconfig patch
- rebase on "https://github.com/jh80chung/dw-mmc.git tags/dw-mmc-for-ulf-v4.2" for merging easily

Changes in v4:
- remove "host->trans_mode" and use "host->use_dma" to indicate
transfer mode.
- remove all bt-bindings' changes since we don't need new properities.
- check transfer mode at runtime by reading HCON reg
- spilt defconfig changes for each sub-architecture
- fix the title of cover letter
- reuse some code for reducing code size

Changes in v3:
- choose transfer mode at runtime
- remove all CONFIG_MMC_DW_IDMAC config option
- add supports-idmac property for some platforms

Changes in v2:
- Fix typo of dev_info msg
- remove unused dmach from declaration of dw_mci_dma_slave

Shawn Lin (9):
mmc: dw_mmc: Add external dma interface support
Documentation: synopsys-dw-mshc: add bindings for idmac and edmac
mips: pistachio_defconfig: remove CONFIG_MMC_DW_IDMAC
arc: axs10x_defconfig: remove CONFIG_MMC_DW_IDMAC
arm: exynos_defconfig: remove CONFIG_MMC_DW_IDMAC
arm: hisi_defconfig: remove CONFIG_MMC_DW_IDMAC
arm: lpc18xx_defconfig: remove CONFIG_MMC_DW_IDMAC
arm: multi_v7_defconfig: remove CONFIG_MMC_DW_IDMAC
arm: zx_defconfig: remove CONFIG_MMC_DW_IDMAC

.../devicetree/bindings/mmc/synopsys-dw-mshc.txt | 25 ++
arch/arc/configs/axs101_defconfig | 1 -
arch/arc/configs/axs103_defconfig | 1 -
arch/arc/configs/axs103_smp_defconfig | 1 -
arch/arm/configs/exynos_defconfig | 1 -
arch/arm/configs/hisi_defconfig | 1 -
arch/arm/configs/lpc18xx_defconfig | 1 -
arch/arm/configs/multi_v7_defconfig | 1 -
arch/arm/configs/zx_defconfig | 1 -
arch/mips/configs/pistachio_defconfig | 1 -
drivers/mmc/host/Kconfig | 11 +-
drivers/mmc/host/dw_mmc-pltfm.c | 2 +
drivers/mmc/host/dw_mmc.c | 264 +++++++++++++++++----
drivers/mmc/host/dw_mmc.h | 5 +
include/linux/mmc/dw_mmc.h | 27 ++-
15 files changed, 267 insertions(+), 76 deletions(-)

--
2.3.7