| Message ID | 20160920115433.14772.84308.sendpatchset@little-apple (mailing list archive) |
|---|---|
| State | Under Review |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
Hi Magnus, On 2016-09-20 20:54:33 +0900, Magnus Damm wrote: > From: Magnus Damm <damm+renesas@opensource.se> > > Here's some prototype code that works around the lack of software > support for mapping I/O devices to the SYS-DMAC hardware via the > DMA Engine framework when using IOMMU. > > The code itself is one big layering violation that goes through > the DT and unconditionally maps I/O devices using DMACs via the > IPMMU device instance into iova space with a 1:1 mapping. > > This very short term prototype will for instance automatically make > the SCIF serial port function with the IPMMU hardware in case the > SYS-DMAC is hooked up to the IPMMU device. > > Not to be confused with the more long term solution to allow the > DMA Engine framework to map I/O device memory dynamically. Good news, Vinod queued the dma_{map,unmap}_resource API and rcar-dmac usage of it yesterday \o/. > > Not-Yet-Signed-off-by: Magnus Damm <damm+renesas@opensource.se> > --- > > Applies on top of: renesas-drivers-2016-09-13-v4.8-rc6 > > drivers/iommu/ipmmu-vmsa.c | 75 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 75 insertions(+) > > --- 0001/drivers/iommu/ipmmu-vmsa.c > +++ work/drivers/iommu/ipmmu-vmsa.c 2016-09-20 20:03:37.620607110 +0900 > @@ -19,6 +19,7 @@ > #include <linux/iommu.h> > #include <linux/module.h> > #include <linux/of.h> > +#include <linux/of_address.h> > #include <linux/of_iommu.h> > #include <linux/platform_device.h> > #include <linux/sizes.h> > @@ -625,6 +626,78 @@ static void ipmmu_domain_free(struct iom > kfree(domain); > } > > +static void ipmmu_workaround_map(struct iommu_domain *io_domain, > + struct device *dma_dev, struct resource *res) > +{ > + phys_addr_t phys_addr; > + > + dev_info(dma_dev, "map %pr\n", res); > + > + phys_addr = iommu_iova_to_phys(io_domain, res->start); > + if (phys_addr) > + return; > + > + iommu_map(io_domain, res->start, res->start, > + ALIGN(resource_size(res), SZ_4K), > + IOMMU_READ | IOMMU_WRITE); > +} > + > +static void ipmmu_workaround_dt(struct iommu_domain *io_domain, > + struct device *dev, > + void (*match)(struct iommu_domain *io_domain, > + struct device *dma_dev, > + struct resource *res)) > +{ > + struct device_node *np = NULL; > + struct of_phandle_args dma_spec; > + struct resource r; > + int i, cnt; > + bool found; > + > + /* Locate I/O devices using the DMAC and map their registers */ > + while ((np = of_find_all_nodes(np))) { > + if (!of_find_property(np, "dmas", NULL)) > + continue; > + > + cnt = of_property_count_strings(np, "dma-names"); > + if (cnt < 0) > + continue; > + > + found = false; > + for (i = 0; i < cnt; i++) { > + if (of_parse_phandle_with_args(np, "dmas", > + "#dma-cells", i, > + &dma_spec)) > + continue; > + > + if (dma_spec.np == dev->of_node) > + found = true; > + > + of_node_put(dma_spec.np); > + } > + > + if (!found) > + continue; > + > + i = 0; > + while (!of_address_to_resource(np, i, &r)) { > + match(io_domain, dev, &r); > + i++; > + } > + } > +} > + > +static void ipmmu_workaround(struct iommu_domain *io_domain, > + struct device *dev) > +{ > + /* only apply workaround for DMA controllers */ > + if (!strstr(dev_name(dev), "dma-controller")) > + return; > + > + dev_info(dev, "Adding iommu workaround to map I/O devices for DMACs\n"); > + ipmmu_workaround_dt(io_domain, dev, ipmmu_workaround_map); > +} > + > static int ipmmu_attach_device(struct iommu_domain *io_domain, > struct device *dev) > { > @@ -678,6 +751,8 @@ static int ipmmu_attach_device(struct io > if (ret < 0) > return ret; > > + ipmmu_workaround(io_domain, dev); > + > for (i = 0; i < archdata->num_utlbs; ++i) > ipmmu_utlb_enable(domain, archdata->utlbs[i]); >
Hi Niklas, On Tue, Sep 27, 2016 at 3:20 PM, Niklas Söderlund <niklas.soderlund@ragnatech.se> wrote: > Hi Magnus, > > On 2016-09-20 20:54:33 +0900, Magnus Damm wrote: >> From: Magnus Damm <damm+renesas@opensource.se> >> >> Here's some prototype code that works around the lack of software >> support for mapping I/O devices to the SYS-DMAC hardware via the >> DMA Engine framework when using IOMMU. >> >> The code itself is one big layering violation that goes through >> the DT and unconditionally maps I/O devices using DMACs via the >> IPMMU device instance into iova space with a 1:1 mapping. >> >> This very short term prototype will for instance automatically make >> the SCIF serial port function with the IPMMU hardware in case the >> SYS-DMAC is hooked up to the IPMMU device. >> >> Not to be confused with the more long term solution to allow the >> DMA Engine framework to map I/O device memory dynamically. > > Good news, Vinod queued the dma_{map,unmap}_resource API and rcar-dmac > usage of it yesterday \o/. Excellent. Are the DMA Engine slave devices supposed to work out of the box with the IPMMU then, or is some other component missing? Cheers, / magnus
--- 0001/drivers/iommu/ipmmu-vmsa.c +++ work/drivers/iommu/ipmmu-vmsa.c 2016-09-20 20:03:37.620607110 +0900 @@ -19,6 +19,7 @@ #include <linux/iommu.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/of_iommu.h> #include <linux/platform_device.h> #include <linux/sizes.h> @@ -625,6 +626,78 @@ static void ipmmu_domain_free(struct iom kfree(domain); } +static void ipmmu_workaround_map(struct iommu_domain *io_domain, + struct device *dma_dev, struct resource *res) +{ + phys_addr_t phys_addr; + + dev_info(dma_dev, "map %pr\n", res); + + phys_addr = iommu_iova_to_phys(io_domain, res->start); + if (phys_addr) + return; + + iommu_map(io_domain, res->start, res->start, + ALIGN(resource_size(res), SZ_4K), + IOMMU_READ | IOMMU_WRITE); +} + +static void ipmmu_workaround_dt(struct iommu_domain *io_domain, + struct device *dev, + void (*match)(struct iommu_domain *io_domain, + struct device *dma_dev, + struct resource *res)) +{ + struct device_node *np = NULL; + struct of_phandle_args dma_spec; + struct resource r; + int i, cnt; + bool found; + + /* Locate I/O devices using the DMAC and map their registers */ + while ((np = of_find_all_nodes(np))) { + if (!of_find_property(np, "dmas", NULL)) + continue; + + cnt = of_property_count_strings(np, "dma-names"); + if (cnt < 0) + continue; + + found = false; + for (i = 0; i < cnt; i++) { + if (of_parse_phandle_with_args(np, "dmas", + "#dma-cells", i, + &dma_spec)) + continue; + + if (dma_spec.np == dev->of_node) + found = true; + + of_node_put(dma_spec.np); + } + + if (!found) + continue; + + i = 0; + while (!of_address_to_resource(np, i, &r)) { + match(io_domain, dev, &r); + i++; + } + } +} + +static void ipmmu_workaround(struct iommu_domain *io_domain, + struct device *dev) +{ + /* only apply workaround for DMA controllers */ + if (!strstr(dev_name(dev), "dma-controller")) + return; + + dev_info(dev, "Adding iommu workaround to map I/O devices for DMACs\n"); + ipmmu_workaround_dt(io_domain, dev, ipmmu_workaround_map); +} + static int ipmmu_attach_device(struct iommu_domain *io_domain, struct device *dev) { @@ -678,6 +751,8 @@ static int ipmmu_attach_device(struct io if (ret < 0) return ret; + ipmmu_workaround(io_domain, dev); + for (i = 0; i < archdata->num_utlbs; ++i) ipmmu_utlb_enable(domain, archdata->utlbs[i]);
From: Magnus Damm <damm+renesas@opensource.se> Here's some prototype code that works around the lack of software support for mapping I/O devices to the SYS-DMAC hardware via the DMA Engine framework when using IOMMU. The code itself is one big layering violation that goes through the DT and unconditionally maps I/O devices using DMACs via the IPMMU device instance into iova space with a 1:1 mapping. This very short term prototype will for instance automatically make the SCIF serial port function with the IPMMU hardware in case the SYS-DMAC is hooked up to the IPMMU device. Not to be confused with the more long term solution to allow the DMA Engine framework to map I/O device memory dynamically. Not-Yet-Signed-off-by: Magnus Damm <damm+renesas@opensource.se> --- Applies on top of: renesas-drivers-2016-09-13-v4.8-rc6 drivers/iommu/ipmmu-vmsa.c | 75 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+)