| Message ID | 1355678760-27357-3-git-send-email-laurent.pinchart+renesas@ideasonboard.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Laurent, On 2012/12/17 2:25, Laurent Pinchart wrote: > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > --- > arch/arm/mach-shmobile/Kconfig | 6 ------ > arch/arm/mach-shmobile/Makefile | 3 --- > drivers/iommu/Kconfig | 6 ++++++ > drivers/iommu/Makefile | 1 + > .../ipmmu.c => drivers/iommu/shmobile-ipmmu.c | 0 > 5 files changed, 7 insertions(+), 9 deletions(-) > rename arch/arm/mach-shmobile/ipmmu.c => drivers/iommu/shmobile-ipmmu.c (100%) I agree that arch/arm is not a good place, but I'm not completely sure that ipmmu.c belongs in drivers/iommu. The reason is because of the PMB functionality provided by the IPMMU. The PMB provides a fixed address remapping capability that is completely unrelated to the IOMMU functionality. Since this remapping is done by writing the IPMMU registers directly, instead of via a page table it doesn't really fit in well with the IOMMU API (it also supports things like tiled/linear address translation, which require some other method to set up). Since the PMB and the IOMMU functions of the IPPMU share the same register address space, we would like to have one driver to handle the register accesses of both of these functions. That driver is ipmmu.c. So if ipmmu.c is in drivers/iommu, the entire IOMMU subsystem must be enabled in order to use the PMB functionality. So maybe it might be better to treat the IPMMU like a multifuction device, with a core driver (ipmmu.c) in one location and the function implementations in their own respective directories. Does drivers/mfd sound like a good place for it? Thanks, Damian. -- Damian Hobson-Garcia IGEL Co.,Ltd http://www.igel.co.jp
Hi Damian, (CC'ing iommu@lists.linux-foundation.org) On Monday 17 December 2012 12:10:28 Damian Hobson-Garcia wrote: > On 2012/12/17 2:25, Laurent Pinchart wrote: > > Signed-off-by: Laurent Pinchart > > <laurent.pinchart+renesas@ideasonboard.com> > > --- > > > > arch/arm/mach-shmobile/Kconfig | 6 ------ > > arch/arm/mach-shmobile/Makefile | 3 --- > > drivers/iommu/Kconfig | 6 ++++++ > > drivers/iommu/Makefile | 1 + > > .../ipmmu.c => drivers/iommu/shmobile-ipmmu.c | 0 > > 5 files changed, 7 insertions(+), 9 deletions(-) > > rename arch/arm/mach-shmobile/ipmmu.c => drivers/iommu/shmobile-ipmmu.c > > (100%) > > I agree that arch/arm is not a good place, but I'm not completely sure that > ipmmu.c belongs in drivers/iommu. The reason is because of the PMB > functionality provided by the IPMMU. The PMB provides a fixed address > remapping capability that is completely unrelated to the IOMMU > functionality. Since this remapping is done by writing the IPMMU registers > directly, instead of via a page table it doesn't really fit in well with the > IOMMU API (it also supports things like tiled/linear address translation, > which require some other method to set up). Since the PMB and the IOMMU > functions of the IPPMU share the same register address space, we would like > to have one driver to handle the register accesses of both of these > functions. That driver is ipmmu.c. So if ipmmu.c is in drivers/iommu, the > entire IOMMU subsystem must be enabled in order to use the PMB > functionality. So maybe it might be better to treat the IPMMU like a > multifuction device, with a core driver (ipmmu.c) in one location and the > function implementations in their own respective directories. Does > drivers/mfd sound like a good place for it? I've thought about this as well. The IPMMU indeed provides two different functions, so drivers/mfd/ could be a candidate. This being said, both the IOMMU function and the PMB function are related to virtual memory space management, so they're not totally unrelated. I agree that the PMB function isn't really an IOMMU in the sense that it will likely not be exposed through the existing IOMMU API. However, drivers/iommu/ seems to me like a more natural place to store the IPMMU driver compared to drivers/mfd/. Enabling IOMMU support (CONFIG_IOMMU_SUPPORT) doesn't mean the IOMMU core (CONFIG_IOMMU_API) will be compiled in. There would thus be no extra code compiled in if the IOMMU function of the IPMMU is disabled.
diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig index de69ab3..8ae100c 100644 --- a/arch/arm/mach-shmobile/Kconfig +++ b/arch/arm/mach-shmobile/Kconfig @@ -210,12 +210,6 @@ endmenu config SH_CLK_CPG bool -config SHMOBILE_IPMMU - bool - -config SHMOBILE_IPMMU_TLB - bool - source "drivers/sh/Kconfig" endif diff --git a/arch/arm/mach-shmobile/Makefile b/arch/arm/mach-shmobile/Makefile index 4ffba9d..fe2c97c 100644 --- a/arch/arm/mach-shmobile/Makefile +++ b/arch/arm/mach-shmobile/Makefile @@ -60,6 +60,3 @@ obj-$(CONFIG_MACH_KZM9G) += board-kzm9g.o # Framework support obj-$(CONFIG_SMP) += $(smp-y) obj-$(CONFIG_GENERIC_GPIO) += $(pfc-y) - -# IPMMU/IPMMUI -obj-$(CONFIG_SHMOBILE_IPMMU) += ipmmu.o diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 265829f..cb2a3e8 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -187,6 +187,12 @@ config EXYNOS_IOMMU_DEBUG Say N unless you need kernel log message for IOMMU debugging +config SHMOBILE_IPMMU + bool + +config SHMOBILE_IPMMU_TLB + bool + config SHMOBILE_IOMMU bool "IOMMU for Renesas IPMMU/IPMMUI" default n diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 62cf917..e65384f 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_TEGRA_IOMMU_GART) += tegra-gart.o obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o obj-$(CONFIG_SHMOBILE_IOMMU) += shmobile-iommu.o +obj-$(CONFIG_SHMOBILE_IPMMU) += shmobile-ipmmu.o
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> --- arch/arm/mach-shmobile/Kconfig | 6 ------ arch/arm/mach-shmobile/Makefile | 3 --- drivers/iommu/Kconfig | 6 ++++++ drivers/iommu/Makefile | 1 + .../ipmmu.c => drivers/iommu/shmobile-ipmmu.c | 0 5 files changed, 7 insertions(+), 9 deletions(-) rename arch/arm/mach-shmobile/ipmmu.c => drivers/iommu/shmobile-ipmmu.c (100%) diff --git a/arch/arm/mach-shmobile/ipmmu.c b/drivers/iommu/shmobile-ipmmu.c similarity index 100% rename from arch/arm/mach-shmobile/ipmmu.c rename to drivers/iommu/shmobile-ipmmu.c