| Message ID | 148897092335.16106.10892669490439039957.sendpatchset@little-apple (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
Hi Magnus, On Wed, Mar 8, 2017 at 12:02 PM, Magnus Damm <magnus.damm@gmail.com> wrote: > From: Magnus Damm <damm+renesas@opensource.se> > > Hook up IOMMU_OF_DECLARE() support in case CONFIG_IOMMU_DMA > is enabled. The only current supported case for 32-bit ARM > is disabled, however for 64-bit ARM usage of OF is required. > > Signed-off-by: Magnus Damm <damm+renesas@opensource.se While I'm not such a big fan of *_OF_DECLARE() (it doesn't support deferred probing, which is needed for any device with dependencies, like clocks and power domains), what's the rationale for not using IOMMU_OF_DECLARE() on arm32, and thus the need for setup_done? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Hi Geert, On Wed, Mar 8, 2017 at 10:52 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote: > Hi Magnus, > > On Wed, Mar 8, 2017 at 12:02 PM, Magnus Damm <magnus.damm@gmail.com> wrote: >> From: Magnus Damm <damm+renesas@opensource.se> >> >> Hook up IOMMU_OF_DECLARE() support in case CONFIG_IOMMU_DMA >> is enabled. The only current supported case for 32-bit ARM >> is disabled, however for 64-bit ARM usage of OF is required. >> >> Signed-off-by: Magnus Damm <damm+renesas@opensource.se > > While I'm not such a big fan of *_OF_DECLARE() (it doesn't support deferred > probing, which is needed for any device with dependencies, like clocks and > power domains), what's the rationale for not using IOMMU_OF_DECLARE() > on arm32, and thus the need for setup_done? ARM32 could (and should) be converted over to IOMMU_OF_DECLARE(), but it is just a matter of timing. If we try to do it before ARM32 is converted over to CONFIG_IOMMU_DMA=y then we have to handle all the hairy legacy implementation details of IOMMU support in case of CONFIG_IOMMU_DMA=n _and_ deal with just moving over the init order bits to OF. Testing and keeping all the combinations working is a lot of work. I prefer to kill two birds with one stone and do a larger feature jump and move over ARM32 to same state of ARM64 (with OF init) once CONFIG_IOMMU_DMA=y is ready for 32-bit ARM. Just changing the init order bits to OF while keeping legacy CONFIG_IOMMU_DMA=n code is introducing potential errors with not much upside. Unless there is some other reason to do it that I can't see that is. =) Cheers, / magnus
--- 0012/drivers/iommu/ipmmu-vmsa.c +++ work/drivers/iommu/ipmmu-vmsa.c 2017-03-08 19:08:31.610607110 +0900 @@ -19,6 +19,7 @@ #include <linux/iommu.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/of_iommu.h> #include <linux/platform_device.h> #include <linux/sizes.h> #include <linux/slab.h> @@ -41,6 +42,7 @@ struct ipmmu_features { struct ipmmu_vmsa_device { struct device *dev; void __iomem *base; + struct iommu_device iommu; struct list_head list; const struct ipmmu_features *features; bool is_leaf; @@ -1161,6 +1163,25 @@ static int ipmmu_probe(struct platform_d ipmmu_device_reset(mmu); } +#if defined(CONFIG_IOMMU_DMA) + /* + * Register the IPMMU to the IOMMU subsystem in the following cases: + * - R-Car Gen2 IPMMU (all devices registered) + * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device) + */ + if (!mmu->features->has_cache_leaf_nodes || mmu->is_leaf) { + ret = iommu_device_register(&mmu->iommu); + if (ret) + return ret; + + iommu_device_set_ops(&mmu->iommu, &ipmmu_ops); + iommu_device_set_fwnode(&mmu->iommu, + &pdev->dev.of_node->fwnode); + + if (!iommu_present(&platform_bus_type)) + bus_set_iommu(&platform_bus_type, &ipmmu_ops); + } +#endif /* * We can't create the ARM mapping here as it requires the bus to have * an IOMMU, which only happens when bus_set_iommu() is called in @@ -1204,15 +1225,22 @@ static struct platform_driver ipmmu_driv static int __init ipmmu_init(void) { + static bool setup_done; int ret; + if (setup_done) + return 0; + ret = platform_driver_register(&ipmmu_driver); if (ret < 0) return ret; +#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA) if (!iommu_present(&platform_bus_type)) bus_set_iommu(&platform_bus_type, &ipmmu_ops); +#endif + setup_done = true; return 0; } @@ -1224,6 +1252,17 @@ static void __exit ipmmu_exit(void) subsys_initcall(ipmmu_init); module_exit(ipmmu_exit); +#ifdef CONFIG_IOMMU_DMA +static int __init ipmmu_vmsa_iommu_of_setup(struct device_node *np) +{ + ipmmu_init(); + return 0; +} + +IOMMU_OF_DECLARE(ipmmu_vmsa_iommu_of, "renesas,ipmmu-vmsa", + ipmmu_vmsa_iommu_of_setup); +#endif + MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU"); MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); MODULE_LICENSE("GPL v2");