| Message ID | 1373021097-32420-22-git-send-email-hdoyu@nvidia.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
On 07/05/2013 04:44 AM, Hiroshi Doyu wrote: > Support Multiple Address Space(AS). Tegra SMMU can have multiple > ASes. We reserve 2 of them for static assignment, AS[0] for system > default, AS[1] for AHB clusters as protected domain from others, where > there are many traditional pheripheral devices like USB, SD/MMC. They > should be isolated from some smart devices like host1x for system > robustness. Even if smart devices behaves wrongly, the traditional > devices(SD/MMC, USB) wouldn't be affected, and the system could > continue most likely. > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c > static int smmu_iommu_add_device(struct device *dev) > { > int err; > - struct dma_iommu_mapping *map = smmu_handle->map[SYSTEM_DEFAULT]; > + u64 swgroup; > + struct dma_iommu_mapping *map = NULL; > + > + swgroup = smmu_of_get_memory_client(dev); > + switch (swgroup) { > + case TEGRA_SWGROUP_BIT(PPCS): > + map = smmu_handle->map[SYSTEM_PROTECTED]; > + break; > + default: > + map = smmu_handle->map[SYSTEM_DEFAULT]; I already mentioned this, but just for completeness: What is smmu->num_as <= SYSTEM_DEFAULT? -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Stephen Warren <swarren@wwwdotorg.org> wrote @ Thu, 18 Jul 2013 22:43:06 +0200: > On 07/05/2013 04:44 AM, Hiroshi Doyu wrote: > > Support Multiple Address Space(AS). Tegra SMMU can have multiple > > ASes. We reserve 2 of them for static assignment, AS[0] for system > > default, AS[1] for AHB clusters as protected domain from others, where > > there are many traditional pheripheral devices like USB, SD/MMC. They > > should be isolated from some smart devices like host1x for system > > robustness. Even if smart devices behaves wrongly, the traditional > > devices(SD/MMC, USB) wouldn't be affected, and the system could > > continue most likely. > > > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c > > > static int smmu_iommu_add_device(struct device *dev) > > { > > int err; > > - struct dma_iommu_mapping *map = smmu_handle->map[SYSTEM_DEFAULT]; > > + u64 swgroup; > > + struct dma_iommu_mapping *map = NULL; > > + > > + swgroup = smmu_of_get_memory_client(dev); > > + switch (swgroup) { > > + case TEGRA_SWGROUP_BIT(PPCS): > > + map = smmu_handle->map[SYSTEM_PROTECTED]; > > + break; > > + default: > > + map = smmu_handle->map[SYSTEM_DEFAULT]; > > I already mentioned this, but just for completeness: What is > smmu->num_as <= SYSTEM_DEFAULT? I think that this belongs to the system operation policy. Which H/W should be configured to which Address Space(AS). This put all AHB clients(PPCS) into AS[1](SYSTEM_PROTECTED), and the rest into AS[0](SYSTEM_DEFAULT). AHB clients are mainly traditional H/Ws like USB and SD/MMC so that they should be kept separated from the smart IOMMU clients like host1x. Is there any place to configure this kind of board specific policy rather than here? -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 07/29/2013 04:31 AM, Hiroshi Doyu wrote: > Stephen Warren <swarren@wwwdotorg.org> wrote @ Thu, 18 Jul 2013 22:43:06 +0200: > >> On 07/05/2013 04:44 AM, Hiroshi Doyu wrote: >>> Support Multiple Address Space(AS). Tegra SMMU can have multiple >>> ASes. We reserve 2 of them for static assignment, AS[0] for system >>> default, AS[1] for AHB clusters as protected domain from others, where >>> there are many traditional pheripheral devices like USB, SD/MMC. They >>> should be isolated from some smart devices like host1x for system >>> robustness. Even if smart devices behaves wrongly, the traditional >>> devices(SD/MMC, USB) wouldn't be affected, and the system could >>> continue most likely. >> >>> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c >> >>> static int smmu_iommu_add_device(struct device *dev) >>> { >>> int err; >>> - struct dma_iommu_mapping *map = smmu_handle->map[SYSTEM_DEFAULT]; >>> + u64 swgroup; >>> + struct dma_iommu_mapping *map = NULL; >>> + >>> + swgroup = smmu_of_get_memory_client(dev); >>> + switch (swgroup) { >>> + case TEGRA_SWGROUP_BIT(PPCS): >>> + map = smmu_handle->map[SYSTEM_PROTECTED]; >>> + break; >>> + default: >>> + map = smmu_handle->map[SYSTEM_DEFAULT]; >> >> I already mentioned this, but just for completeness: What is >> smmu->num_as <= SYSTEM_DEFAULT? > > I think that this belongs to the system operation policy. Which H/W > should be configured to which Address Space(AS). This put all AHB > clients(PPCS) into AS[1](SYSTEM_PROTECTED), and the rest into > AS[0](SYSTEM_DEFAULT). AHB clients are mainly traditional H/Ws like > USB and SD/MMC so that they should be kept separated from the smart > IOMMU clients like host1x. > > Is there any place to configure this kind of board specific policy > rather than here? I'm not sure that answers the question I asked. I mean that the driver expects that two AS always exist; SYSTEM_PROTECTED and SYSTEM_DEFAULT. However, the set of extant ASs is IIRC defined by the DT content. What if the DT doesn't define two ASs? Shouldn't there at least be an error-check for this case, so the driver doesn't just blindly continue and access smmu_handle->map[1] when the map[] array only has 1 entry? -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 29 Jul 2013 19:41:23 +0200 Stephen Warren <swarren@wwwdotorg.org> wrote: ... > > I think that this belongs to the system operation policy. Which H/W > > should be configured to which Address Space(AS). This put all AHB > > clients(PPCS) into AS[1](SYSTEM_PROTECTED), and the rest into > > AS[0](SYSTEM_DEFAULT). AHB clients are mainly traditional H/Ws like > > USB and SD/MMC so that they should be kept separated from the smart > > IOMMU clients like host1x. > > > > Is there any place to configure this kind of board specific policy > > rather than here? > > I'm not sure that answers the question I asked. > > I mean that the driver expects that two AS always exist; > SYSTEM_PROTECTED and SYSTEM_DEFAULT. However, the set of extant ASs is > IIRC defined by the DT content. What if the DT doesn't define two ASs? > Shouldn't there at least be an error-check for this case, so the driver > doesn't just blindly continue and access smmu_handle->map[1] when the > map[] array only has 1 entry? OK, now I got it. We can create multiple maps on the same AS in theory. So the limitation is only for how many maps S/W creaed. This can/should be checked only within kernel side. No constraints from DT. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c index 8a9434e..1945815 100644 --- a/drivers/iommu/tegra-smmu.c +++ b/drivers/iommu/tegra-smmu.c @@ -904,7 +904,18 @@ enum { static int smmu_iommu_add_device(struct device *dev) { int err; - struct dma_iommu_mapping *map = smmu_handle->map[SYSTEM_DEFAULT]; + u64 swgroup; + struct dma_iommu_mapping *map = NULL; + + swgroup = smmu_of_get_memory_client(dev); + switch (swgroup) { + case TEGRA_SWGROUP_BIT(PPCS): + map = smmu_handle->map[SYSTEM_PROTECTED]; + break; + default: + map = smmu_handle->map[SYSTEM_DEFAULT]; + break; + } if (!map) goto out; @@ -915,7 +926,7 @@ static int smmu_iommu_add_device(struct device *dev) return err; } out: - dev_dbg(dev, "Attached to map %p\n", map); + dev_dbg(dev, "Attached to map %p, swgroup:%08llx\n", map, swgroup); return 0; }
Support Multiple Address Space(AS). Tegra SMMU can have multiple ASes. We reserve 2 of them for static assignment, AS[0] for system default, AS[1] for AHB clusters as protected domain from others, where there are many traditional pheripheral devices like USB, SD/MMC. They should be isolated from some smart devices like host1x for system robustness. Even if smart devices behaves wrongly, the traditional devices(SD/MMC, USB) wouldn't be affected, and the system could continue most likely. Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com> --- drivers/iommu/tegra-smmu.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)