Messages in this thread | | | Subject | Re: [PATCH v3 13/27] powerpc/powernv/pmem: Read the capability registers & wait for device ready | From | Frederic Barrat <> | Date | Mon, 2 Mar 2020 18:51:07 +0100 |
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Le 21/02/2020 à 04:27, Alastair D'Silva a écrit : > From: Alastair D'Silva <alastair@d-silva.org> > > This patch reads timeouts & firmware version from the controller, and > uses those timeouts to wait for the controller to report that it is ready > before handing the memory over to libnvdimm. > > Signed-off-by: Alastair D'Silva <alastair@d-silva.org> > --- > arch/powerpc/platforms/powernv/pmem/Makefile | 2 +- > arch/powerpc/platforms/powernv/pmem/ocxl.c | 92 +++++++++++++++++++ > .../platforms/powernv/pmem/ocxl_internal.c | 19 ++++ > .../platforms/powernv/pmem/ocxl_internal.h | 24 +++++ > 4 files changed, 136 insertions(+), 1 deletion(-) > create mode 100644 arch/powerpc/platforms/powernv/pmem/ocxl_internal.c > > diff --git a/arch/powerpc/platforms/powernv/pmem/Makefile b/arch/powerpc/platforms/powernv/pmem/Makefile > index 1c55c4193175..4ceda25907d4 100644 > --- a/arch/powerpc/platforms/powernv/pmem/Makefile > +++ b/arch/powerpc/platforms/powernv/pmem/Makefile > @@ -4,4 +4,4 @@ ccflags-$(CONFIG_PPC_WERROR) += -Werror > > obj-$(CONFIG_OCXL_PMEM) += ocxlpmem.o > > -ocxlpmem-y := ocxl.o > +ocxlpmem-y := ocxl.o ocxl_internal.o > diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl.c b/arch/powerpc/platforms/powernv/pmem/ocxl.c > index 3c4eeb5dcc0f..431212c9f0cc 100644 > --- a/arch/powerpc/platforms/powernv/pmem/ocxl.c > +++ b/arch/powerpc/platforms/powernv/pmem/ocxl.c > @@ -8,6 +8,7 @@ > > #include <linux/module.h> > #include <misc/ocxl.h> > +#include <linux/delay.h> > #include <linux/ndctl.h> > #include <linux/mm_types.h> > #include <linux/memory_hotplug.h> > @@ -215,6 +216,36 @@ static int register_lpc_mem(struct ocxlpmem *ocxlpmem) > return 0; > } > > +/** > + * is_usable() - Is a controller usable? > + * @ocxlpmem: the device metadata > + * @verbose: True to log errors > + * Return: true if the controller is usable > + */ > +static bool is_usable(const struct ocxlpmem *ocxlpmem, bool verbose) > +{ > + u64 chi = 0; > + int rc = ocxlpmem_chi(ocxlpmem, &chi); > + > + if (rc < 0) > + return false; > + > + if (!(chi & GLOBAL_MMIO_CHI_CRDY)) { > + if (verbose) > + dev_err(&ocxlpmem->dev, "controller is not ready.\n"); > + return false; > + } > + > + if (!(chi & GLOBAL_MMIO_CHI_MA)) { > + if (verbose) > + dev_err(&ocxlpmem->dev, > + "controller does not have memory available.\n"); > + return false; > + } > + > + return true; > +} > + > /** > * allocate_minor() - Allocate a minor number to use for an OpenCAPI pmem device > * @ocxlpmem: the device metadata > @@ -328,6 +359,48 @@ static void ocxlpmem_remove(struct pci_dev *pdev) > } > } > > +/** > + * read_device_metadata() - Retrieve config information from the AFU and save it for future use > + * @ocxlpmem: the device metadata > + * Return: 0 on success, negative on failure > + */ > +static int read_device_metadata(struct ocxlpmem *ocxlpmem) > +{ > + u64 val; > + int rc; > + > + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_CCAP0, > + OCXL_LITTLE_ENDIAN, &val); > + if (rc) > + return rc; > + > + ocxlpmem->scm_revision = val & 0xFFFF; > + ocxlpmem->read_latency = (val >> 32) & 0xFF; > + ocxlpmem->readiness_timeout = (val >> 48) & 0x0F; > + ocxlpmem->memory_available_timeout = val >> 52; > + > + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_CCAP1, > + OCXL_LITTLE_ENDIAN, &val); > + if (rc) > + return rc; > + > + ocxlpmem->max_controller_dump_size = val & 0xFFFFFFFF; > + > + // Extract firmware version text > + rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_FWVER, > + OCXL_HOST_ENDIAN, (u64 *)ocxlpmem->fw_version); > + if (rc) > + return rc; > + > + ocxlpmem->fw_version[8] = '\0'; > + > + dev_info(&ocxlpmem->dev, > + "Firmware version '%s' SCM revision %d:%d\n", ocxlpmem->fw_version, > + ocxlpmem->scm_revision >> 4, ocxlpmem->scm_revision & 0x0F); > + > + return 0; > +} > + > /** > * probe_function0() - Set up function 0 for an OpenCAPI persistent memory device > * This is important as it enables templates higher than 0 across all other functions, > @@ -368,6 +441,7 @@ static int probe(struct pci_dev *pdev, const struct pci_device_id *ent) > { > struct ocxlpmem *ocxlpmem; > int rc; > + u16 elapsed, timeout; > > if (PCI_FUNC(pdev->devfn) == 0) > return probe_function0(pdev); > @@ -422,6 +496,24 @@ static int probe(struct pci_dev *pdev, const struct pci_device_id *ent) > goto err; > } > > + if (read_device_metadata(ocxlpmem)) { > + dev_err(&pdev->dev, "Could not read metadata\n");
Need to set rc
> + goto err; > + } > + > + elapsed = 0; > + timeout = ocxlpmem->readiness_timeout + ocxlpmem->memory_available_timeout; > + while (!is_usable(ocxlpmem, false)) { > + if (elapsed++ > timeout) { > + dev_warn(&ocxlpmem->dev, "OpenCAPI Persistent Memory ready timeout.\n"); > + (void)is_usable(ocxlpmem, true);
I guess that extra call to is_usable() is just to log the cause of the error. However, with some bad luck, the call could now succeed.
Fred
> + rc = -ENXIO; > + goto err; > + } > + > + msleep(1000); > + } > + > rc = register_lpc_mem(ocxlpmem); > if (rc) { > dev_err(&pdev->dev, "Could not register OpenCAPI persistent memory with libnvdimm\n"); > diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c > new file mode 100644 > index 000000000000..617ca943b1b8 > --- /dev/null > +++ b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c > @@ -0,0 +1,19 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +// Copyright 2019 IBM Corp. > + > +#include <misc/ocxl.h> > +#include <linux/delay.h> > +#include "ocxl_internal.h" > + > +int ocxlpmem_chi(const struct ocxlpmem *ocxlpmem, u64 *chi) > +{ > + u64 val; > + int rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_CHI, > + OCXL_LITTLE_ENDIAN, &val); > + if (rc) > + return rc; > + > + *chi = val; > + > + return 0; > +} > diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h > index 9cf3e42750e7..ba0301533d00 100644 > --- a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h > +++ b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h > @@ -97,4 +97,28 @@ struct ocxlpmem { > void *metadata_addr; > struct resource pmem_res; > struct nd_region *nd_region; > + char fw_version[8+1]; > + > + u32 max_controller_dump_size; > + u16 scm_revision; // major/minor > + u8 readiness_timeout; /* The worst case time (in seconds) that the host shall > + * wait for the controller to become operational following a reset (CHI.CRDY). > + */ > + u8 memory_available_timeout; /* The worst case time (in seconds) that the host shall > + * wait for memory to become available following a reset (CHI.MA). > + */ > + > + u16 read_latency; /* The nominal measure of latency (in nanoseconds) > + * associated with an unassisted read of a memory block. > + * This represents the capability of the raw media technology without assistance > + */ > }; > + > +/** > + * ocxlpmem_chi() - Get the value of the CHI register > + * @ocxlpmem: the device metadata > + * @chi: returns the CHI value > + * > + * Returns 0 on success, negative on error > + */ > +int ocxlpmem_chi(const struct ocxlpmem *ocxlpmem, u64 *chi); >
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