From b5beae5e224f1c72c4482b0ab36fc3d89481a6b2 Mon Sep 17 00:00:00 2001 From: Oliver O'Halloran Date: Mon, 15 Oct 2018 10:18:28 +1100 Subject: [PATCH] powerpc/pseries: Add driver for PAPR SCM regions Adds a driver that implements support for enabling and accessing PAPR SCM regions. Unfortunately due to how the PAPR interface works we can't use the existing of_pmem driver (yet) because: a) The guest is required to use the H_SCM_BIND_MEM h-call to add add the SCM region to it's physical address space, and b) There is currently no mechanism for relating a bare of_pmem region to the backing DIMM (or not-a-DIMM for our case). Both of these are easily handled by rolling the functionality into a seperate driver so here we are... Acked-by: Dan Williams Signed-off-by: Oliver O'Halloran Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/pseries/Kconfig | 7 + arch/powerpc/platforms/pseries/Makefile | 1 + arch/powerpc/platforms/pseries/papr_scm.c | 345 ++++++++++++++++++++++ 3 files changed, 353 insertions(+) create mode 100644 arch/powerpc/platforms/pseries/papr_scm.c diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index 39032d9b316c..2e4bd32154b5 100644 --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -138,3 +138,10 @@ config IBMEBUS bool "Support for GX bus based adapters" help Bus device driver for GX bus based adapters. + +config PAPR_SCM + depends on PPC_PSERIES && MEMORY_HOTPLUG + select LIBNVDIMM + tristate "Support for the PAPR Storage Class Memory interface" + help + Enable access to hypervisor provided storage class memory. diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile index 892b27ced973..a43ec843c8e2 100644 --- a/arch/powerpc/platforms/pseries/Makefile +++ b/arch/powerpc/platforms/pseries/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_IO_EVENT_IRQ) += io_event_irq.o obj-$(CONFIG_LPARCFG) += lparcfg.o obj-$(CONFIG_IBMVIO) += vio.o obj-$(CONFIG_IBMEBUS) += ibmebus.o +obj-$(CONFIG_PAPR_SCM) += papr_scm.o ifdef CONFIG_PPC_PSERIES obj-$(CONFIG_SUSPEND) += suspend.o diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c new file mode 100644 index 000000000000..ee9372b65ca5 --- /dev/null +++ b/arch/powerpc/platforms/pseries/papr_scm.c @@ -0,0 +1,345 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define pr_fmt(fmt) "papr-scm: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define BIND_ANY_ADDR (~0ul) + +#define PAPR_SCM_DIMM_CMD_MASK \ + ((1ul << ND_CMD_GET_CONFIG_SIZE) | \ + (1ul << ND_CMD_GET_CONFIG_DATA) | \ + (1ul << ND_CMD_SET_CONFIG_DATA)) + +struct papr_scm_priv { + struct platform_device *pdev; + struct device_node *dn; + uint32_t drc_index; + uint64_t blocks; + uint64_t block_size; + int metadata_size; + + uint64_t bound_addr; + + struct nvdimm_bus_descriptor bus_desc; + struct nvdimm_bus *bus; + struct nvdimm *nvdimm; + struct resource res; + struct nd_region *region; + struct nd_interleave_set nd_set; +}; + +static int drc_pmem_bind(struct papr_scm_priv *p) +{ + unsigned long ret[PLPAR_HCALL_BUFSIZE]; + uint64_t rc, token; + + /* + * When the hypervisor cannot map all the requested memory in a single + * hcall it returns H_BUSY and we call again with the token until + * we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS + * leave the system in an undefined state, so we wait. + */ + token = 0; + + do { + rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0, + p->blocks, BIND_ANY_ADDR, token); + token = be64_to_cpu(ret[0]); + cond_resched(); + } while (rc == H_BUSY); + + if (rc) { + dev_err(&p->pdev->dev, "bind err: %lld\n", rc); + return -ENXIO; + } + + p->bound_addr = be64_to_cpu(ret[1]); + + dev_dbg(&p->pdev->dev, "bound drc %x to %pR\n", p->drc_index, &p->res); + + return 0; +} + +static int drc_pmem_unbind(struct papr_scm_priv *p) +{ + unsigned long ret[PLPAR_HCALL_BUFSIZE]; + uint64_t rc, token; + + token = 0; + + /* NB: unbind has the same retry requirements mentioned above */ + do { + rc = plpar_hcall(H_SCM_UNBIND_MEM, ret, p->drc_index, + p->bound_addr, p->blocks, token); + token = be64_to_cpu(ret); + cond_resched(); + } while (rc == H_BUSY); + + if (rc) + dev_err(&p->pdev->dev, "unbind error: %lld\n", rc); + + return !!rc; +} + +static int papr_scm_meta_get(struct papr_scm_priv *p, + struct nd_cmd_get_config_data_hdr *hdr) +{ + unsigned long data[PLPAR_HCALL_BUFSIZE]; + int64_t ret; + + if (hdr->in_offset >= p->metadata_size || hdr->in_length != 1) + return -EINVAL; + + ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index, + hdr->in_offset, 1); + + if (ret == H_PARAMETER) /* bad DRC index */ + return -ENODEV; + if (ret) + return -EINVAL; /* other invalid parameter */ + + hdr->out_buf[0] = data[0] & 0xff; + + return 0; +} + +static int papr_scm_meta_set(struct papr_scm_priv *p, + struct nd_cmd_set_config_hdr *hdr) +{ + int64_t ret; + + if (hdr->in_offset >= p->metadata_size || hdr->in_length != 1) + return -EINVAL; + + ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, + p->drc_index, hdr->in_offset, hdr->in_buf[0], 1); + + if (ret == H_PARAMETER) /* bad DRC index */ + return -ENODEV; + if (ret) + return -EINVAL; /* other invalid parameter */ + + return 0; +} + +int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, + unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc) +{ + struct nd_cmd_get_config_size *get_size_hdr; + struct papr_scm_priv *p; + + /* Only dimm-specific calls are supported atm */ + if (!nvdimm) + return -EINVAL; + + p = nvdimm_provider_data(nvdimm); + + switch (cmd) { + case ND_CMD_GET_CONFIG_SIZE: + get_size_hdr = buf; + + get_size_hdr->status = 0; + get_size_hdr->max_xfer = 1; + get_size_hdr->config_size = p->metadata_size; + *cmd_rc = 0; + break; + + case ND_CMD_GET_CONFIG_DATA: + *cmd_rc = papr_scm_meta_get(p, buf); + break; + + case ND_CMD_SET_CONFIG_DATA: + *cmd_rc = papr_scm_meta_set(p, buf); + break; + + default: + return -EINVAL; + } + + dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc); + + return 0; +} + +static const struct attribute_group *region_attr_groups[] = { + &nd_region_attribute_group, + &nd_device_attribute_group, + &nd_mapping_attribute_group, + &nd_numa_attribute_group, + NULL, +}; + +static const struct attribute_group *bus_attr_groups[] = { + &nvdimm_bus_attribute_group, + NULL, +}; + +static const struct attribute_group *papr_scm_dimm_groups[] = { + &nvdimm_attribute_group, + &nd_device_attribute_group, + NULL, +}; + +static int papr_scm_nvdimm_init(struct papr_scm_priv *p) +{ + struct device *dev = &p->pdev->dev; + struct nd_mapping_desc mapping; + struct nd_region_desc ndr_desc; + unsigned long dimm_flags; + + p->bus_desc.ndctl = papr_scm_ndctl; + p->bus_desc.module = THIS_MODULE; + p->bus_desc.of_node = p->pdev->dev.of_node; + p->bus_desc.attr_groups = bus_attr_groups; + p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL); + + if (!p->bus_desc.provider_name) + return -ENOMEM; + + p->bus = nvdimm_bus_register(NULL, &p->bus_desc); + if (!p->bus) { + dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn); + return -ENXIO; + } + + dimm_flags = 0; + set_bit(NDD_ALIASING, &dimm_flags); + + p->nvdimm = nvdimm_create(p->bus, p, papr_scm_dimm_groups, + dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL); + if (!p->nvdimm) { + dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn); + goto err; + } + + /* now add the region */ + + memset(&mapping, 0, sizeof(mapping)); + mapping.nvdimm = p->nvdimm; + mapping.start = 0; + mapping.size = p->blocks * p->block_size; // XXX: potential overflow? + + memset(&ndr_desc, 0, sizeof(ndr_desc)); + ndr_desc.attr_groups = region_attr_groups; + ndr_desc.numa_node = dev_to_node(&p->pdev->dev); + ndr_desc.res = &p->res; + ndr_desc.of_node = p->dn; + ndr_desc.provider_data = p; + ndr_desc.mapping = &mapping; + ndr_desc.num_mappings = 1; + ndr_desc.nd_set = &p->nd_set; + set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags); + + p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc); + if (!p->region) { + dev_err(dev, "Error registering region %pR from %pOF\n", + ndr_desc.res, p->dn); + goto err; + } + + return 0; + +err: nvdimm_bus_unregister(p->bus); + kfree(p->bus_desc.provider_name); + return -ENXIO; +} + +static int papr_scm_probe(struct platform_device *pdev) +{ + uint32_t drc_index, metadata_size, unit_cap[2]; + struct device_node *dn = pdev->dev.of_node; + struct papr_scm_priv *p; + int rc; + + /* check we have all the required DT properties */ + if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) { + dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn); + return -ENODEV; + } + + if (of_property_read_u32_array(dn, "ibm,unit-capacity", unit_cap, 2)) { + dev_err(&pdev->dev, "%pOF: missing unit-capacity!\n", dn); + return -ENODEV; + } + + p = kzalloc(sizeof(*p), GFP_KERNEL); + if (!p) + return -ENOMEM; + + /* optional DT properties */ + of_property_read_u32(dn, "ibm,metadata-size", &metadata_size); + + p->dn = dn; + p->drc_index = drc_index; + p->block_size = unit_cap[0]; + p->blocks = unit_cap[1]; + + /* might be zero */ + p->metadata_size = metadata_size; + p->pdev = pdev; + + /* request the hypervisor to bind this region to somewhere in memory */ + rc = drc_pmem_bind(p); + if (rc) + goto err; + + /* setup the resource for the newly bound range */ + p->res.start = p->bound_addr; + p->res.end = p->bound_addr + p->blocks * p->block_size; + p->res.name = pdev->name; + p->res.flags = IORESOURCE_MEM; + + rc = papr_scm_nvdimm_init(p); + if (rc) + goto err2; + + platform_set_drvdata(pdev, p); + + return 0; + +err2: drc_pmem_unbind(p); +err: kfree(p); + return rc; +} + +static int papr_scm_remove(struct platform_device *pdev) +{ + struct papr_scm_priv *p = platform_get_drvdata(pdev); + + nvdimm_bus_unregister(p->bus); + drc_pmem_unbind(p); + kfree(p); + + return 0; +} + +static const struct of_device_id papr_scm_match[] = { + { .compatible = "ibm,pmemory" }, + { }, +}; + +static struct platform_driver papr_scm_driver = { + .probe = papr_scm_probe, + .remove = papr_scm_remove, + .driver = { + .name = "papr_scm", + .owner = THIS_MODULE, + .of_match_table = papr_scm_match, + }, +}; + +module_platform_driver(papr_scm_driver); +MODULE_DEVICE_TABLE(of, papr_scm_match); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("IBM Corporation"); -- 2.30.2