Re: [PATCH 1/1] arm/dts: Tegra30: Add device tree support for SMMU
From: Hiroshi Doyu <hidden>
Date: 2012-04-18 09:18:24
Also in:
linux-arm-kernel, linux-iommu, linux-tegra
Subsystem:
open firmware and flattened device tree, the rest · Maintainers:
Rob Herring, Saravana Kannan, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2012-04-18 · Re: [PATCH 1/1] arm/dts: Tegra30: Add device tree support for SMMU · Stephen Warren <hidden>
- 2012-04-18 · Re: [PATCH 1/1] arm/dts: Tegra30: Add device tree support for SMMU · Thierry Reding <hidden>
- 2012-04-18 · Re: [PATCH 1/1] arm/dts: Tegra30: Add device tree support for SMMU · Arnd Bergmann <hidden>
- 2012-04-18 · Re: [PATCH 1/1] arm/dts: Tegra30: Add device tree support for SMMU · Hiroshi Doyu <hidden>
- 2012-04-18 · Re: [PATCH 1/1] arm/dts: Tegra30: Add device tree support for SMMU · Thierry Reding <hidden>
From: Arnd Bergmann <redacted> Subject: Re: [PATCH 1/1] arm/dts: Tegra30: Add device tree support for SMMU Date: Wed, 18 Apr 2012 09:31:53 +0200 Message-ID: [off-list ref]
On Wednesday 18 April 2012, Hiroshi Doyu wrote:quoted
If we can consider IOMMU as one of the implementation of DMA(Direct Memory Access), the prefix "dma-(window)" may make sense here. Then, we don't have to introduce a new concept "IO virtual address(iova)" in addition to the existing "bus address"(?) Anyway, either name would be ok for me;)I would just use dma-window, without the "ibm," prefix but following the same conventions. Note that the of_parse_dma_window function is currently only defined in powerpc specific code, and should get moved to drivers/of from arch/powerpc/kernel/prom_parse.c.
Something like below? At least, I verified that this works with "tegra-smmu".
From 67c1dd493637c9e972d04e061a8e67049687021a Mon Sep 17 00:00:00 2001
From: Hiroshi DOYU <redacted> Date: Wed, 18 Apr 2012 12:09:03 +0300 Subject: [PATCH 1/1] dt: Add general DMA window parser This code was stolen from: "arch/microblaze/kernel/prom_parse.c" "arch/powerpc/kernel/prom_parse.c" Once "ibm," prefix is removed from dts file. This generic one could replace the originals. Signed-off-by: Hiroshi DOYU <redacted> --- drivers/of/Kconfig | 4 ++++ drivers/of/Makefile | 1 + drivers/of/of_dma.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/of_address.h | 10 ++++++++++ 4 files changed, 50 insertions(+), 0 deletions(-)
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index dfba3e6..3b0298b 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig@@ -83,4 +83,8 @@ config OF_MTD depends on MTD def_bool y +config OF_DMA + depends on HAS_DMA + def_bool y + endmenu # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index e027f44..711ff5b 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile@@ -11,3 +11,4 @@ obj-$(CONFIG_OF_MDIO) += of_mdio.o obj-$(CONFIG_OF_PCI) += of_pci.o obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o obj-$(CONFIG_OF_MTD) += of_mtd.o +obj-$(CONFIG_OF_DMA) += of_dma.o
diff --git a/drivers/of/of_dma.c b/drivers/of/of_dma.c
new file mode 100644
index 0000000..1db1ccd
--- /dev/null
+++ b/drivers/of/of_dma.c@@ -0,0 +1,35 @@ +/* + * Stealed from: + * "arch/microblaze/kernel/prom_parse.c" + * "arch/powerpc/kernel/prom_parse.c" + */ + +#include <linux/of_address.h> + +void of_parse_dma_window(struct device_node *dn, const void *dma_window_prop, + unsigned long *busno, unsigned long *phys, unsigned long *size) +{ + const u32 *dma_window; + u32 cells; + const unsigned char *prop; + + dma_window = dma_window_prop; + + /* busno is always one cell */ + if (busno) + *busno = *(dma_window++); + + prop = of_get_property(dn, "#dma-address-cells", NULL); + if (!prop) + prop = of_get_property(dn, "#address-cells", NULL); + + cells = prop ? *(u32 *)prop : of_n_addr_cells(dn); + *phys = of_read_number(dma_window, cells); + + dma_window += cells; + + prop = of_get_property(dn, "#dma-size-cells", NULL); + cells = prop ? *(u32 *)prop : of_n_size_cells(dn); + *size = of_read_number(dma_window, cells); +} +
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 01b925a..2a0f7c6 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h@@ -21,6 +21,10 @@ extern void __iomem *of_iomap(struct device_node *device, int index); extern const u32 *of_get_address(struct device_node *dev, int index, u64 *size, unsigned int *flags); +extern void of_parse_dma_window(struct device_node *dn, + const void *dma_window_prop, unsigned long *busno, + unsigned long *phys, unsigned long *size); + #ifndef pci_address_to_pio static inline unsigned long pci_address_to_pio(phys_addr_t addr) { return -1; } #define pci_address_to_pio pci_address_to_pio
@@ -48,6 +52,12 @@ static inline const u32 *of_get_address(struct device_node *dev, int index, { return NULL; } + +static inline void of_parse_dma_window(struct device_node *dn, + const void *dma_window_prop, unsigned long *busno, + unsigned long *phys, unsigned long *size) +{ +} #endif /* CONFIG_OF_ADDRESS */
--
1.7.5.4