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Violators will be prosecuted for from ; Thu, 11 May 2017 03:49:40 -0400 From: Stewart Smith To: Anju T Sudhakar , mpe@ellerman.id.au Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, ego@linux.vnet.ibm.com, bsingharora@gmail.com, anton@samba.org, sukadev@linux.vnet.ibm.com, mikey@neuling.org, dja@axtens.net, eranian@google.com, hemant@linux.vnet.ibm.com, maddy@linux.vnet.ibm.com, anju@linux.vnet.ibm.com Subject: Re: [PATCH v8 02/10] powerpc/powernv: Autoload IMC device driver module In-Reply-To: <1493907596-11425-3-git-send-email-anju@linux.vnet.ibm.com> References: <1493907596-11425-1-git-send-email-anju@linux.vnet.ibm.com> <1493907596-11425-3-git-send-email-anju@linux.vnet.ibm.com> Date: Thu, 11 May 2017 17:49:21 +1000 MIME-Version: 1.0 Content-Type: text/plain Message-Id: <87wp9nj0ji.fsf@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Anju T Sudhakar writes: > This patch does three things : > - Enables "opal.c" to create a platform device for the IMC interface > according to the appropriate compatibility string. > - Find the reserved-memory region details from the system device tree > and get the base address of HOMER (Reserved memory) region address for each chip. > - We also get the Nest PMU counter data offsets (in the HOMER region) > and their sizes. The offsets for the counters' data are fixed and > won't change from chip to chip. > > The device tree parsing logic is separated from the PMU creation > functions (which is done in subsequent patches). > > Patch also adds a CONFIG_HV_PERF_IMC_CTRS for the IMC driver. > > Signed-off-by: Anju T Sudhakar > Signed-off-by: Hemant Kumar > Signed-off-by: Madhavan Srinivasan > --- > arch/powerpc/platforms/powernv/Kconfig | 10 +++ > arch/powerpc/platforms/powernv/Makefile | 1 + > arch/powerpc/platforms/powernv/opal-imc.c | 140 ++++++++++++++++++++++++++++++ > arch/powerpc/platforms/powernv/opal.c | 18 ++++ > 4 files changed, 169 insertions(+) > create mode 100644 arch/powerpc/platforms/powernv/opal-imc.c > > diff --git a/arch/powerpc/platforms/powernv/Kconfig b/arch/powerpc/platforms/powernv/Kconfig > index 3a07e4d..1b90a98 100644 > --- a/arch/powerpc/platforms/powernv/Kconfig > +++ b/arch/powerpc/platforms/powernv/Kconfig > @@ -27,3 +27,13 @@ config OPAL_PRD > help > This enables the opal-prd driver, a facility to run processor > recovery diagnostics on OpenPower machines > + > +config HV_PERF_IMC_CTRS > + bool "Hypervisor supplied In Memory Collection PMU events (Nest & Core)" > + default y > + depends on PERF_EVENTS && PPC_POWERNV > + help > + Enable access to hypervisor supplied in-memory collection counters > + in perf. IMC counters are available from Power9 systems. > + > + If unsure, select Y. > diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile > index b5d98cb..715e531 100644 > --- a/arch/powerpc/platforms/powernv/Makefile > +++ b/arch/powerpc/platforms/powernv/Makefile > @@ -12,3 +12,4 @@ obj-$(CONFIG_PPC_SCOM) += opal-xscom.o > obj-$(CONFIG_MEMORY_FAILURE) += opal-memory-errors.o > obj-$(CONFIG_TRACEPOINTS) += opal-tracepoints.o > obj-$(CONFIG_OPAL_PRD) += opal-prd.o > +obj-$(CONFIG_HV_PERF_IMC_CTRS) += opal-imc.o > diff --git a/arch/powerpc/platforms/powernv/opal-imc.c b/arch/powerpc/platforms/powernv/opal-imc.c > new file mode 100644 > index 0000000..3a87000 > --- /dev/null > +++ b/arch/powerpc/platforms/powernv/opal-imc.c > @@ -0,0 +1,140 @@ > +/* > + * OPAL IMC interface detection driver > + * Supported on POWERNV platform > + * > + * Copyright (C) 2017 Madhavan Srinivasan, IBM Corporation. > + * (C) 2017 Anju T Sudhakar, IBM Corporation. > + * (C) 2017 Hemant K Shaw, IBM Corporation. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +struct perchip_nest_info nest_perchip_info[IMC_MAX_CHIPS]; > + > +/* > + * imc_pmu_setup : Setup the IMC PMUs (children of "parent"). > + */ > +static void __init imc_pmu_setup(struct device_node *parent) > +{ > + if (!parent) > + return; > +} > + > +static int opal_imc_counters_probe(struct platform_device *pdev) > +{ > + struct device_node *imc_dev, *dn, *rm_node = NULL; > + struct perchip_nest_info *pcni; > + u32 pages, nest_offset, nest_size, chip_id; > + int i = 0; > + const __be32 *addrp; > + u64 reg_addr, reg_size; > + > + if (!pdev || !pdev->dev.of_node) > + return -ENODEV; > + > + /* > + * Check whether this is kdump kernel. If yes, just return. > + */ > + if (is_kdump_kernel()) > + return -ENODEV; > + > + imc_dev = pdev->dev.of_node; > + > + /* > + * Nest counter data are saved in a reserved memory called HOMER. > + * "imc-nest-offset" identifies the counter data location within HOMER. > + * size : size of the entire nest-counters region > + */ > + if (of_property_read_u32(imc_dev, "imc-nest-offset", &nest_offset)) > + goto err; > + > + if (of_property_read_u32(imc_dev, "imc-nest-size", &nest_size)) > + goto err; > + > + /* Sanity check */ > + if ((nest_size/PAGE_SIZE) > IMC_NEST_MAX_PAGES) > + goto err; > + > + /* Find the "HOMER region" for each chip */ > + rm_node = of_find_node_by_path("/reserved-memory"); > + if (!rm_node) > + goto err; > + > + /* > + * We need to look for the "ibm,homer-image" node in the > + * "/reserved-memory" node. > + */ > + for (dn = of_find_node_by_name(rm_node, "ibm,homer-image"); dn; > + dn = of_find_node_by_name(dn, "ibm,homer-image")) { > + > + /* Get the chip id to which the above homer region belongs to */ > + if (of_property_read_u32(dn, "ibm,chip-id", &chip_id)) > + goto err; So, I was thinking on this (and should probably comment on the firmware side as well). I'd prefer an OPAL interface where instead of looking up where ibm,homer-image is, we provide the kernel with a base address and then have offsets into it. That way, we don't tie the kernel code to counters that are only in the HOMER region. -- Stewart Smith OPAL Architect, IBM.