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From: "Alastair D'Silva" <alastair@au1.ibm.com>
To: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Cc: "Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
	"Paul Mackerras" <paulus@samba.org>,
	"Michael Ellerman" <mpe@ellerman.id.au>,
	"Frederic Barrat" <fbarrat@linux.ibm.com>,
	"Andrew Donnellan" <ajd@linux.ibm.com>,
	"Arnd Bergmann" <arnd@arndb.de>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Mauro Carvalho Chehab" <mchehab+samsung@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	"Rob Herring" <robh@kernel.org>,
	"Anton Blanchard" <anton@ozlabs.org>,
	"Krzysztof Kozlowski" <krzk@kernel.org>,
	"Mahesh Salgaonkar" <mahesh@linux.vnet.ibm.com>,
	"Madhavan Srinivasan" <maddy@linux.vnet.ibm.com>,
	"Cédric Le Goater" <clg@kaod.org>,
	"Anju T Sudhakar" <anju@linux.vnet.ibm.com>,
	"Hari Bathini" <hbathini@linux.ibm.com>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Greg Kurz" <groug@kaod.org>,
	"Nicholas Piggin" <npiggin@gmail.com>,
	"Masahiro Yamada" <yamada.masahiro@socionext.com>,
	"Alexey Kardashevskiy" <aik@ozlabs.ru>,
	linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-nvdimm@lists.01.org, linux-mm@kvack.org
Subject: RE: [PATCH v2 12/27] nvdimm/ocxl: Read the capability registers & wait for device ready
Date: Wed, 19 Feb 2020 15:46:58 +1100
Message-ID: <6c7e944c0370663a00aca33538957248f29e027d.camel@au1.ibm.com> (raw)
In-Reply-To: <20200203132351.00005281@Huawei.com>

On Mon, 2020-02-03 at 13:23 +0000, Jonathan Cameron wrote:
> On Tue, 3 Dec 2019 14:46:40 +1100
> Alastair D'Silva <alastair@au1.ibm.com> wrote:
> 
> > 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>
> > ---
> >  drivers/nvdimm/ocxl/Makefile       |  2 +-
> >  drivers/nvdimm/ocxl/scm.c          | 84
> > ++++++++++++++++++++++++++++++
> >  drivers/nvdimm/ocxl/scm_internal.c | 19 +++++++
> >  drivers/nvdimm/ocxl/scm_internal.h | 24 +++++++++
> >  4 files changed, 128 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/nvdimm/ocxl/scm_internal.c
> > 
> > diff --git a/drivers/nvdimm/ocxl/Makefile
> > b/drivers/nvdimm/ocxl/Makefile
> > index 74a1bd98848e..9b6e31f0eb3e 100644
> > --- a/drivers/nvdimm/ocxl/Makefile
> > +++ b/drivers/nvdimm/ocxl/Makefile
> > @@ -4,4 +4,4 @@ ccflags-$(CONFIG_PPC_WERROR)	+= -Werror
> >  
> >  obj-$(CONFIG_OCXL_SCM) += ocxlscm.o
> >  
> > -ocxlscm-y := scm.o
> > +ocxlscm-y := scm.o scm_internal.o
> > diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c
> > index 571058a9e7b8..8088f65c289e 100644
> > --- a/drivers/nvdimm/ocxl/scm.c
> > +++ b/drivers/nvdimm/ocxl/scm.c
> > @@ -7,6 +7,7 @@
> >  
> >  #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>
> > @@ -266,6 +267,30 @@ static int scm_register_lpc_mem(struct
> > scm_data *scm_data)
> >  	return 0;
> >  }
> >  
> > +/**
> > + * scm_is_usable() - Is a controller usable?
> > + * @scm_data: a pointer to the SCM device data
> > + * Return: true if the controller is usable
> > + */
> > +static bool scm_is_usable(const struct scm_data *scm_data)
> > +{
> > +	u64 chi = 0;
> > +	int rc = scm_chi(scm_data, &chi);
> > +
> > +	if (!(chi & GLOBAL_MMIO_CHI_CRDY)) {
> > +		dev_err(&scm_data->dev, "SCM controller is not
> > ready.\n");
> > +		return false;
> > +	}
> > +
> > +	if (!(chi & GLOBAL_MMIO_CHI_MA)) {
> > +		dev_err(&scm_data->dev,
> > +			"SCM controller does not have memory
> > available.\n");
> > +		return false;
> > +	}
> > +
> > +	return true;
> > +}
> > +
> >  /**
> >   * allocate_scm_minor() - Allocate a minor number to use for an
> > SCM device
> >   * @scm_data: The SCM device to associate the minor with
> > @@ -380,6 +405,48 @@ static void scm_remove(struct pci_dev *pdev)
> >  	}
> >  }
> >  
> > +/**
> > + * read_device_metadata() - Retrieve config information from the
> > AFU and save it for future use
> > + * @scm_data: the SCM metadata
> > + * Return: 0 on success, negative on failure
> > + */
> > +static int read_device_metadata(struct scm_data *scm_data)
> > +{
> > +	u64 val;
> > +	int rc;
> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CCAP0,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	scm_data->scm_revision = val & 0xFFFF;
> > +	scm_data->read_latency = (val >> 32) & 0xFF;
> > +	scm_data->readiness_timeout = (val >> 48) & 0xff;
> > +	scm_data->memory_available_timeout = val >> 52;
> 
> This overlaps with the masked region for readiness_timeout.  I'll
> guess the maks
> on that should be 0xF.
> 
Good catch, you're correct.

> > +
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CCAP1,
> > +				     OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	scm_data->max_controller_dump_size = val & 0xFFFFFFFF;
> > +
> > +	// Extract firmware version text
> > +	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_FWVER,
> > +				     OCXL_HOST_ENDIAN, (u64 *)scm_data-
> > >fw_version);
> > +	if (rc)
> > +		return rc;
> > +
> > +	scm_data->fw_version[8] = '\0';
> > +
> > +	dev_info(&scm_data->dev,
> > +		 "Firmware version '%s' SCM revision %d:%d\n",
> > scm_data->fw_version,
> > +		 scm_data->scm_revision >> 4, scm_data->scm_revision &
> > 0x0F);
> > +
> > +	return 0;
> > +}
> > +
> >  /**
> >   * scm_probe_function_0 - Set up function 0 for an OpenCAPI
> > Storage Class Memory device
> >   * This is important as it enables templates higher than 0 across
> > all other functions,
> > @@ -420,6 +487,8 @@ static int scm_probe_function_0(struct pci_dev
> > *pdev)
> >  static int scm_probe(struct pci_dev *pdev, const struct
> > pci_device_id *ent)
> >  {
> >  	struct scm_data *scm_data = NULL;
> > +	int elapsed;
> > +	u16 timeout;
> >  
> >  	if (PCI_FUNC(pdev->devfn) == 0)
> >  		return scm_probe_function_0(pdev);
> > @@ -469,6 +538,21 @@ static int scm_probe(struct pci_dev *pdev,
> > const struct pci_device_id *ent)
> >  		goto err;
> >  	}
> >  
> > +	if (read_device_metadata(scm_data)) {
> > +		dev_err(&pdev->dev, "Could not read SCM device
> > metadata\n");
> > +		goto err;
> > +	}
> > +
> > +	elapsed = 0;
> > +	timeout = scm_data->readiness_timeout + scm_data-
> > >memory_available_timeout;
> > +	while (!scm_is_usable(scm_data)) {
> > +		if (elapsed++ > timeout) {
> > +			dev_warn(&scm_data->dev, "SCM ready
> > timeout.\n");
> > +			goto err;
> > +		}
> > +
> > +		msleep(1000);
> > +	}
> >  	if (scm_register_lpc_mem(scm_data)) {
> >  		dev_err(&pdev->dev, "Could not register OCXL SCM memory
> > with libnvdimm\n");
> >  		goto err;
> > diff --git a/drivers/nvdimm/ocxl/scm_internal.c
> > b/drivers/nvdimm/ocxl/scm_internal.c
> > new file mode 100644
> > index 000000000000..72d3c0e7d846
> > --- /dev/null
> > +++ b/drivers/nvdimm/ocxl/scm_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 "scm_internal.h"
> > +
> > +int scm_chi(const struct scm_data *scm_data, u64 *chi)
> > +{
> > +	u64 val;
> > +	int rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CHI,
> > +					 OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	*chi = val;
> > +
> > +	return 0;
> > +}
> > diff --git a/drivers/nvdimm/ocxl/scm_internal.h
> > b/drivers/nvdimm/ocxl/scm_internal.h
> > index d6ab361f5de9..584450f55e30 100644
> > --- a/drivers/nvdimm/ocxl/scm_internal.h
> > +++ b/drivers/nvdimm/ocxl/scm_internal.h
> > @@ -97,4 +97,28 @@ struct scm_data {
> >  	void *metadata_addr;
> >  	struct resource scm_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
> > +			   */
> >  };
> > +
> > +/**
> > + * scm_chi() - Get the value of the CHI register
> > + * @scm_data: The SCM metadata
> > + * @chi: returns the CHI value
> > + *
> > + * Returns 0 on success, negative on error
> > + */
> > +int scm_chi(const struct scm_data *scm_data, u64 *chi);
-- 
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819
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  reply index

Thread overview: 67+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-03  3:46 [PATCH v2 00/27] Add support for OpenCAPI SCM devices Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 01/27] memory_hotplug: Add a bounds check to __add_pages Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 02/27] nvdimm: remove prototypes for nonexistent functions Alastair D'Silva
2019-12-03  4:47   ` Andrew Donnellan
2019-12-04  0:10   ` Dan Williams
2020-01-23 21:49     ` Dan Williams
2019-12-03  3:46 ` [PATCH v2 03/27] powerpc: Add OPAL calls for LPC memory alloc/release Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 04/27] mm/memory_hotplug: Allow check_hotplug_memory_addressable to be called from drivers Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 05/27] powerpc: Map & release OpenCAPI LPC memory Alastair D'Silva
2020-01-09 14:41   ` Frederic Barrat
2020-01-21  6:46   ` Andrew Donnellan
2020-01-21  7:11     ` Greg Kurz
2020-02-14 11:09   ` Frederic Barrat
2020-02-18 23:44     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 06/27] ocxl: Tally up the LPC memory on a link & allow it to be mapped Alastair D'Silva
2020-01-09 14:48   ` Frederic Barrat
2020-02-03 12:37   ` Jonathan Cameron
2020-02-19  0:01     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 07/27] ocxl: Add functions to map/unmap LPC memory Alastair D'Silva
2020-01-09 14:49   ` Frederic Barrat
2020-02-03 12:49   ` Jonathan Cameron
2020-02-19  2:39     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 08/27] ocxl: Save the device serial number in ocxl_fn Alastair D'Silva
2020-02-03 12:53   ` Jonathan Cameron
2020-02-19  4:03     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 09/27] ocxl: Free detached contexts in ocxl_context_detach_all() Alastair D'Silva
2020-01-09 14:54   ` Frederic Barrat
2019-12-03  3:46 ` [PATCH v2 10/27] nvdimm: Add driver for OpenCAPI Storage Class Memory Alastair D'Silva
2019-12-03  5:05   ` Alastair D'Silva
2020-02-03 13:20   ` Jonathan Cameron
2020-02-19  4:40     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 11/27] nvdimm/ocxl: Add register addresses & status values to header Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 12/27] nvdimm/ocxl: Read the capability registers & wait for device ready Alastair D'Silva
2020-02-03 13:23   ` Jonathan Cameron
2020-02-19  4:46     ` Alastair D'Silva [this message]
2019-12-03  3:46 ` [PATCH v2 13/27] nvdimm/ocxl: Add support for Admin commands Alastair D'Silva
2020-02-03 14:18   ` Jonathan Cameron
2020-02-19  5:00     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 14/27] nvdimm/ocxl: Add support for near storage commands Alastair D'Silva
2020-02-03 14:22   ` Jonathan Cameron
2020-02-19  4:54     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 15/27] nvdimm/ocxl: Register a character device for userspace to interact with Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 16/27] nvdimm/ocxl: Implement the Read Error Log command Alastair D'Silva
2019-12-05  3:42   ` Alastair D'Silva
2019-12-05 19:34   ` kbuild test robot
2019-12-03  3:46 ` [PATCH v2 17/27] nvdimm/ocxl: Add controller dump IOCTLs Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 18/27] nvdimm/ocxl: Add an IOCTL to report controller statistics Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 19/27] nvdimm/ocxl: Forward events to userspace Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 20/27] nvdimm/ocxl: Add an IOCTL to request controller health & perf data Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 21/27] nvdimm/ocxl: Support firmware update via sysfs Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 22/27] nvdimm/ocxl: Implement the heartbeat command Alastair D'Silva
2020-02-03 15:11   ` Jonathan Cameron
2020-02-19  5:02     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 23/27] nvdimm/ocxl: Add debug IOCTLs Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 24/27] nvdimm/ocxl: Implement Overwrite Alastair D'Silva
2020-02-03 15:10   ` Jonathan Cameron
2020-02-19  5:13     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 25/27] nvdimm/ocxl: Expose SMART data via ndctl Alastair D'Silva
2019-12-16  0:15   ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 26/27] powerpc: Enable OpenCAPI Storage Class Memory driver on bare metal Alastair D'Silva
2019-12-03  4:54   ` Andrew Donnellan
2019-12-03  4:57     ` Alastair D'Silva
2019-12-03  3:46 ` [PATCH v2 27/27] MAINTAINERS: Add myself & nvdimm/ocxl to ocxl Alastair D'Silva
2019-12-03  3:50 ` [PATCH v2 00/27] Add support for OpenCAPI SCM devices Matthew Wilcox
2019-12-03  4:01   ` Alastair D'Silva
2019-12-03 12:42     ` Matthew Wilcox
2019-12-04  0:15       ` Dan Williams

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