Madhavan Srinivasan <ma...@linux.vnet.ibm.com> writes:
> From: Hemant Kumar <hem...@linux.vnet.ibm.com>
>
> 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).
>
> Signed-off-by: Anju T Sudhakar <a...@linux.vnet.ibm.com>
> Signed-off-by: Hemant Kumar <hem...@linux.vnet.ibm.com>
> Signed-off-by: Madhavan Srinivasan <ma...@linux.vnet.ibm.com>
> ---
> arch/powerpc/platforms/powernv/Makefile | 2 +-
> arch/powerpc/platforms/powernv/opal-imc.c | 126
> ++++++++++++++++++++++++++++++
> arch/powerpc/platforms/powernv/opal.c | 14 ++++
> 3 files changed, 141 insertions(+), 1 deletion(-)
> create mode 100644 arch/powerpc/platforms/powernv/opal-imc.c
>
> diff --git a/arch/powerpc/platforms/powernv/Makefile
> b/arch/powerpc/platforms/powernv/Makefile
> index b5d98cb3f482..44909fec1121 100644
> --- a/arch/powerpc/platforms/powernv/Makefile
> +++ b/arch/powerpc/platforms/powernv/Makefile
> @@ -2,7 +2,7 @@ obj-y += setup.o opal-wrappers.o opal.o
> opal-async.o idle.o
> obj-y += opal-rtc.o opal-nvram.o opal-lpc.o
> opal-flash.o
> obj-y += rng.o opal-elog.o opal-dump.o
> opal-sysparam.o opal-sensor.o
> obj-y += opal-msglog.o opal-hmi.o opal-power.o
> opal-irqchip.o
> -obj-y += opal-kmsg.o
> +obj-y += opal-kmsg.o opal-imc.o
>
> obj-$(CONFIG_SMP) += smp.o subcore.o subcore-asm.o
> obj-$(CONFIG_PCI) += pci.o pci-ioda.o npu-dma.o
> diff --git a/arch/powerpc/platforms/powernv/opal-imc.c
> b/arch/powerpc/platforms/powernv/opal-imc.c
> new file mode 100644
> index 000000000000..c476d596c6a8
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/opal-imc.c
> @@ -0,0 +1,126 @@
> +/*
> + * OPAL IMC interface detection driver
> + * Supported on POWERNV platform
> + *
> + * Copyright (C) 2016 Madhavan Srinivasan, IBM Corporation.
> + * (C) 2016 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 <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/miscdevice.h>
> +#include <linux/fs.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +#include <linux/poll.h>
> +#include <linux/mm.h>
> +#include <linux/slab.h>
> +#include <linux/crash_dump.h>
> +#include <asm/opal.h>
> +#include <asm/io.h>
> +#include <asm/uaccess.h>
> +#include <asm/cputable.h>
> +#include <asm/imc-pmu.h>
> +
> +struct perchip_nest_info nest_perchip_info[IMC_MAX_CHIPS];
> +
> +static int opal_imc_counters_probe(struct platform_device *pdev)
> +{
> + struct device_node *child, *imc_dev, *rm_node = NULL;
> + struct perchip_nest_info *pcni;
> + u32 pages, nest_offset, nest_size, idx;
> + int i = 0;
> + const char *node_name;
> + const __be32 *addrp;
> + u64 reg_addr, reg_size;
> +
> + if (!pdev || !pdev->dev.of_node)
> + return -ENODEV;
> +
> + /*
> + * Check whether this kdump kernel. If yes, just return.
> + */
> + if (is_kdump_kernel())
> + return -ENODEV;
> +
> + imc_dev = pdev->dev.of_node;
> +
> + /*
> + * nest_offset : where the nest-counters' data start.
> + * 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;
> +
> + /* Find the "homer region" for each chip */
> + rm_node = of_find_node_by_path("/reserved-memory");
> + if (!rm_node)
> + goto err;
> +
> + for_each_child_of_node(rm_node, child) {
> + if (of_property_read_string_index(child, "name", 0,
> + &node_name))
> + continue;
> + if (strncmp("ibm,homer-image", node_name,
> + strlen("ibm,homer-image")))
> + continue;
A better way to do this would be to reference the memory region, like
what's shown in
Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
just reference the phandle of the memory region.
seeing as these are per chip, why not just have something linking
together chip-id and the IMC layout node?
--
Stewart Smith
OPAL Architect, IBM.
