On Mon, Nov 18, 2019 at 11:02:30PM +0300, Dmitry Osipenko wrote: > All NVIDIA Tegra SoCs have identical topology in regards to memory > interconnection between memory clients and memory controllers. > The memory controller (MC) and external memory controller (EMC) are > providing memory clients with required memory bandwidth. The memory > controller performs arbitration between memory clients, while the > external memory controller transfers data from/to DRAM and pipes that > data from/to memory controller. Memory controller interconnect provider > aggregates bandwidth requests from memory clients and sends the aggregated > request to EMC provider that scales DRAM frequency in order to satisfy the > bandwidth requirement. Memory controller provider could adjust hardware > configuration for a more optimal arbitration depending on bandwidth > requirements from memory clients, but this is unimplemented for now. > > Signed-off-by: Dmitry Osipenko > --- > drivers/interconnect/Kconfig | 1 + > drivers/interconnect/Makefile | 1 + > drivers/interconnect/tegra/Kconfig | 6 + > drivers/interconnect/tegra/Makefile | 4 + > drivers/interconnect/tegra/tegra-icc-emc.c | 138 +++++++++++++++++++++ > drivers/interconnect/tegra/tegra-icc-mc.c | 130 +++++++++++++++++++ > include/soc/tegra/mc.h | 26 ++++ > 7 files changed, 306 insertions(+) > create mode 100644 drivers/interconnect/tegra/Kconfig > create mode 100644 drivers/interconnect/tegra/Makefile > create mode 100644 drivers/interconnect/tegra/tegra-icc-emc.c > create mode 100644 drivers/interconnect/tegra/tegra-icc-mc.c Why does this have to be separate from the memory controller driver in drivers/memory/tegra? It seems like this requires a bunch of boilerplate just so that this code can live in the drivers/interconnect directory. If Georgi doesn't insist, I'd prefer if we carried this code directly in the drivers/memory/tegra directory so that we don't have so many indirections. Also, and I already briefly mentioned this in another reply, I think we don't need two providers here. The only one we're really interested in is the memory-client to memory-controller paths. The MC to EMC path is static. Thierry > diff --git a/drivers/interconnect/Kconfig b/drivers/interconnect/Kconfig > index bfa4ca3ab7a9..b11ca09665bb 100644 > --- a/drivers/interconnect/Kconfig > +++ b/drivers/interconnect/Kconfig > @@ -12,5 +12,6 @@ menuconfig INTERCONNECT > if INTERCONNECT > > source "drivers/interconnect/qcom/Kconfig" > +source "drivers/interconnect/tegra/Kconfig" > > endif > diff --git a/drivers/interconnect/Makefile b/drivers/interconnect/Makefile > index 28f2ab0824d5..a37d419e262c 100644 > --- a/drivers/interconnect/Makefile > +++ b/drivers/interconnect/Makefile > @@ -4,3 +4,4 @@ icc-core-objs := core.o > > obj-$(CONFIG_INTERCONNECT) += icc-core.o > obj-$(CONFIG_INTERCONNECT_QCOM) += qcom/ > +obj-$(CONFIG_INTERCONNECT_TEGRA) += tegra/ > diff --git a/drivers/interconnect/tegra/Kconfig b/drivers/interconnect/tegra/Kconfig > new file mode 100644 > index 000000000000..b724781da71e > --- /dev/null > +++ b/drivers/interconnect/tegra/Kconfig > @@ -0,0 +1,6 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +config INTERCONNECT_TEGRA > + bool "NVIDIA Tegra interconnect drivers" > + depends on ARCH_TEGRA || COMPILE_TEST > + help > + Say Y here to enable support for NVIDIA Tegra interconnect drivers. > diff --git a/drivers/interconnect/tegra/Makefile b/drivers/interconnect/tegra/Makefile > new file mode 100644 > index 000000000000..74ff2e53dbdc > --- /dev/null > +++ b/drivers/interconnect/tegra/Makefile > @@ -0,0 +1,4 @@ > +# SPDX-License-Identifier: GPL-2.0 > + > +obj-$(CONFIG_INTERCONNECT_TEGRA) += tegra-icc-mc.o > +obj-$(CONFIG_INTERCONNECT_TEGRA) += tegra-icc-emc.o > diff --git a/drivers/interconnect/tegra/tegra-icc-emc.c b/drivers/interconnect/tegra/tegra-icc-emc.c > new file mode 100644 > index 000000000000..b594ce811153 > --- /dev/null > +++ b/drivers/interconnect/tegra/tegra-icc-emc.c > @@ -0,0 +1,138 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Author: Dmitry Osipenko > + * Copyright (C) 2019 GRATE-DRIVER project > + */ > + > +#include > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include > + > +struct tegra_emc_provider { > + struct icc_provider provider; > + struct clk *clk; > + unsigned int dram_data_bus_width_bytes; > +}; > + > +static inline struct tegra_emc_provider * > +to_tegra_emc_provider(struct icc_provider *provider) > +{ > + return container_of(provider, struct tegra_emc_provider, provider); > +} > + > +static struct icc_node * > +tegra_emc_of_icc_xlate_onecell(struct of_phandle_args *spec, void *data) > +{ > + struct icc_provider *provider = data; > + struct icc_node *node; > + > + list_for_each_entry(node, &provider->nodes, node_list) { > + if (node->id == spec->args[0]) > + return node; > + } > + > + return ERR_PTR(-EINVAL); > +} > + > +static int tegra_emc_icc_set(struct icc_node *src, struct icc_node *dst) > +{ > + struct tegra_emc_provider *emc = to_tegra_emc_provider(dst->provider); > + unsigned long long rate = icc_units_to_bps(dst->avg_bw); > + unsigned int ddr = 2; > + int err; > + > + do_div(rate, ddr * emc->dram_data_bus_width_bytes); > + rate = min_t(u64, rate, U32_MAX); > + > + err = clk_set_min_rate(emc->clk, rate); > + if (err) > + return err; > + > + err = clk_set_rate(emc->clk, rate); > + if (err) > + return err; > + > + return 0; > +} > + > +static int tegra_emc_icc_aggregate(struct icc_node *node, > + u32 tag, u32 avg_bw, u32 peak_bw, > + u32 *agg_avg, u32 *agg_peak) > +{ > + *agg_avg = min((u64)avg_bw + (*agg_avg), (u64)U32_MAX); > + *agg_peak = max(*agg_peak, peak_bw); > + > + return 0; > +} > + > +int tegra_icc_emc_setup_interconnect(struct device *emc_dev, > + unsigned int dram_data_bus_width_bytes) > +{ > + struct tegra_emc_provider *emc; > + struct icc_node *node, *tmp; > + int err; > + > + emc = devm_kzalloc(emc_dev, sizeof(*emc), GFP_KERNEL); > + if (!emc) > + return -ENOMEM; > + > + emc->clk = devm_clk_get(emc_dev, "emc"); > + err = PTR_ERR_OR_ZERO(emc->clk); > + if (err) > + return err; > + > + emc->dram_data_bus_width_bytes = dram_data_bus_width_bytes; > + > + emc->provider.dev = emc_dev; > + emc->provider.set = tegra_emc_icc_set; > + emc->provider.data = &emc->provider; > + emc->provider.xlate = tegra_emc_of_icc_xlate_onecell; > + emc->provider.aggregate = tegra_emc_icc_aggregate; > + > + err = icc_provider_add(&emc->provider); > + if (err) > + return err; > + > + /* create External Memory Controller node */ > + node = icc_node_create(TEGRA_ICC_EMC); > + err = PTR_ERR_OR_ZERO(node); > + if (err) > + goto del_provider; > + > + node->name = "EMC"; > + icc_node_add(node, &emc->provider); > + > + /* link External Memory Controller with External Memory */ > + err = icc_link_create(node, TEGRA_ICC_EMEM); > + if (err) > + goto destroy_nodes; > + > + /* create External Memory node */ > + node = icc_node_create(TEGRA_ICC_EMEM); > + err = PTR_ERR_OR_ZERO(node); > + if (err) > + goto destroy_nodes; > + > + node->name = "EMEM"; > + icc_node_add(node, &emc->provider); > + > + return 0; > + > +destroy_nodes: > + list_for_each_entry_safe(node, tmp, &emc->provider.nodes, node_list) { > + icc_node_del(node); > + icc_node_destroy(node->id); > + } > + > +del_provider: > + icc_provider_del(&emc->provider); > + > + return err; > +} > diff --git a/drivers/interconnect/tegra/tegra-icc-mc.c b/drivers/interconnect/tegra/tegra-icc-mc.c > new file mode 100644 > index 000000000000..f1ff8f98def3 > --- /dev/null > +++ b/drivers/interconnect/tegra/tegra-icc-mc.c > @@ -0,0 +1,130 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Author: Dmitry Osipenko > + * Copyright (C) 2019 GRATE-DRIVER project > + */ > + > +#include > + > +#include > +#include > +#include > +#include > + > +#include > + > +static struct icc_node * > +tegra_mc_of_icc_xlate_onecell(struct of_phandle_args *spec, void *data) > +{ > + struct icc_provider *provider = data; > + struct icc_node *node; > + > + list_for_each_entry(node, &provider->nodes, node_list) { > + if (node->id == spec->args[0]) > + return node; > + } > + > + return ERR_PTR(-EINVAL); > +} > + > +static int tegra_mc_icc_set(struct icc_node *src, struct icc_node *dst) > +{ > + return 0; > +} > + > +static int tegra_mc_icc_aggregate(struct icc_node *node, > + u32 tag, u32 avg_bw, u32 peak_bw, > + u32 *agg_avg, u32 *agg_peak) > +{ > + *agg_avg = min((u64)avg_bw + (*agg_avg), (u64)U32_MAX); > + *agg_peak = max(*agg_peak, peak_bw); > + > + return 0; > +} > + > +/* > + * Memory Controller (MC) has few Memory Clients that are issuing memory > + * bandwidth allocation requests to the MC interconnect provider. The MC > + * provider aggregates the requests and then sends the aggregated request > + * up to the External Memory Controller (EMC) interconnect provider which > + * re-configures hardware interface to External Memory (EMEM) in accordance > + * to the required bandwidth. > + * > + * Memory interconnect topology: > + * > + * +----+ > + * +-----+ | | > + * | GPU +---->+ | > + * +-----+ | | > + * | | +-----+ +------+ > + * ... | MC +---->+ EMC +---->+ EMEM | > + * | | +-----+ +------+ > + * +------+ | | > + * | DISP +---->+ | > + * +------+ | | > + * +----+ > + */ > +int tegra_icc_mc_setup_interconnect(struct tegra_mc *mc) > +{ > + struct icc_provider *provider; > + struct icc_node *node, *tmp; > + unsigned int i; > + int err; > + > + provider = devm_kzalloc(mc->dev, sizeof(*provider), GFP_KERNEL); > + if (!provider) > + return -ENOMEM; > + > + provider->dev = mc->dev; > + provider->set = tegra_mc_icc_set; > + provider->data = provider; > + provider->xlate = tegra_mc_of_icc_xlate_onecell; > + provider->aggregate = tegra_mc_icc_aggregate; > + > + err = icc_provider_add(provider); > + if (err) > + return err; > + > + /* create Memory Controller node */ > + node = icc_node_create(TEGRA_ICC_MC); > + err = PTR_ERR_OR_ZERO(node); > + if (err) > + goto del_provider; > + > + node->name = "MC"; > + icc_node_add(node, provider); > + > + /* link Memory Controller with External Memory Controller */ > + err = icc_link_create(node, TEGRA_ICC_EMC); > + if (err) > + goto destroy_nodes; > + > + for (i = 0; i < mc->soc->num_icc_nodes; i++) { > + /* create MC client node */ > + node = icc_node_create(mc->soc->icc_nodes[i].id); > + err = PTR_ERR_OR_ZERO(node); > + if (err) > + goto destroy_nodes; > + > + node->name = mc->soc->icc_nodes[i].name; > + icc_node_add(node, provider); > + > + /* link Memory Client with Memory Controller */ > + err = icc_link_create(node, TEGRA_ICC_MC); > + if (err) > + goto destroy_nodes; > + } > + > + return 0; > + > +destroy_nodes: > + list_for_each_entry_safe(node, tmp, &provider->nodes, node_list) { > + icc_node_del(node); > + icc_node_destroy(node->id); > + } > + > +del_provider: > + icc_provider_del(provider); > + > + return err; > +} > diff --git a/include/soc/tegra/mc.h b/include/soc/tegra/mc.h > index 1238e35653d1..593954324259 100644 > --- a/include/soc/tegra/mc.h > +++ b/include/soc/tegra/mc.h > @@ -141,6 +141,11 @@ struct tegra_mc_reset_ops { > const struct tegra_mc_reset *rst); > }; > > +struct tegra_mc_icc_node { > + const char *name; > + unsigned int id; > +}; > + > struct tegra_mc_soc { > const struct tegra_mc_client *clients; > unsigned int num_clients; > @@ -160,6 +165,9 @@ struct tegra_mc_soc { > const struct tegra_mc_reset_ops *reset_ops; > const struct tegra_mc_reset *resets; > unsigned int num_resets; > + > + const struct tegra_mc_icc_node *icc_nodes; > + unsigned int num_icc_nodes; > }; > > struct tegra_mc { > @@ -184,4 +192,22 @@ struct tegra_mc { > int tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long rate); > unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc); > > +#ifdef CONFIG_INTERCONNECT_TEGRA > +int tegra_icc_mc_setup_interconnect(struct tegra_mc *mc); > +int tegra_icc_emc_setup_interconnect(struct device *emc_dev, > + unsigned int dram_data_bus_width_bytes); > +#else > +static inline int tegra_icc_mc_setup_interconnect(struct tegra_mc *mc); > +{ > + return 0; > +} > + > +static inline int > +tegra_icc_emc_setup_interconnect(struct device *emc_dev, > + unsigned int dram_data_bus_width_bytes) > +{ > + return 0; > +} > +#endif > + > #endif /* __SOC_TEGRA_MC_H__ */ > -- > 2.23.0 >