| Message ID | 20240828085223.42177-2-maddy@linux.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v3,1/3] powerpc/pseries: Macros and wrapper functions for H_HTM call | expand |
Madhavan Srinivasan <maddy@linux.ibm.com> writes: > This patch adds debugfs interface to export Hardware Trace Macro (HTM) > function data in a LPAR. New hypervisor call "H_HTM" has been > defined to setup, configure, control and dump the HTM data. > This patch supports only dumping of HTM data in a LPAR. > New debugfs folder called "htmdump" has been added under > /sys/kernel/debug/arch path which contains files need to > pass required parameters for the H_HTM dump function. New Kconfig > option called "CONFIG_HTMDUMP" has been in platform/pseries for the same. > > With this module loaded, list of files in debugfs path > > /sys/kernel/debug/powerpc/htmdump > coreindexonchip htmtype nodalchipindex nodeindex trace > > Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> > --- > Changelog v2: > - Made driver as modules based on review comments > Changelog v1: > - Changed from tristate to bool with dependency flags > - Trimmed the include headers > > arch/powerpc/platforms/pseries/Kconfig | 9 ++ > arch/powerpc/platforms/pseries/Makefile | 1 + > arch/powerpc/platforms/pseries/htmdump.c | 130 +++++++++++++++++++++++ > 3 files changed, 140 insertions(+) > create mode 100644 arch/powerpc/platforms/pseries/htmdump.c > > diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig > index afc0f6a61337..a66be66d690e 100644 > --- a/arch/powerpc/platforms/pseries/Kconfig > +++ b/arch/powerpc/platforms/pseries/Kconfig > @@ -128,6 +128,15 @@ config CMM > will be reused for other LPARs. The interface allows firmware to > balance memory across many LPARs. > > +config HTMDUMP > + tristate "PHYP HTM data dumper" > + depends on PPC_PSERIES && DEBUG_FS > + default m > + help > + Select this option, if you want to enable the kernel debugfs > + interface to dump the Hardware Trace Macro (HTM) function data > + in the LPAR. > + > config HV_PERF_CTRS > bool "Hypervisor supplied PMU events (24x7 & GPCI)" > default y > diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile > index 7bf506f6b8c8..3f3e3492e436 100644 > --- a/arch/powerpc/platforms/pseries/Makefile > +++ b/arch/powerpc/platforms/pseries/Makefile > @@ -19,6 +19,7 @@ obj-$(CONFIG_HVC_CONSOLE) += hvconsole.o > obj-$(CONFIG_HVCS) += hvcserver.o > obj-$(CONFIG_HCALL_STATS) += hvCall_inst.o > obj-$(CONFIG_CMM) += cmm.o > +obj-$(CONFIG_HTMDUMP) += htmdump.o > obj-$(CONFIG_IO_EVENT_IRQ) += io_event_irq.o > obj-$(CONFIG_LPARCFG) += lparcfg.o > obj-$(CONFIG_IBMVIO) += vio.o > diff --git a/arch/powerpc/platforms/pseries/htmdump.c b/arch/powerpc/platforms/pseries/htmdump.c > new file mode 100644 > index 000000000000..54c28525c4a7 > --- /dev/null > +++ b/arch/powerpc/platforms/pseries/htmdump.c > @@ -0,0 +1,130 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (C) IBM Corporation, 2024 > + */ > + > +#define pr_fmt(fmt) "htmdump: " fmt > + > +#include <linux/debugfs.h> > + > +#include <asm/machdep.h> > +#include <asm/plpar_wrappers.h> > + > +/* This enables us to keep track of the memory removed from each node. */ > +struct htmdump_entry { > + void *buf; > + struct dentry *dir; > + char name[16]; > +}; > How does dir and name gets used? It isn't that obvious, so maybe a comment will be gr8. > +static u32 nodeindex; > +static u32 nodalchipindex; > +static u32 coreindexonchip; > +static u32 htmtype; > +static struct dentry *htmdump_debugfs_dir; > +static struct htmdump_entry *ent; > + > +#define BUFFER_SIZE PAGE_SIZE > + > +static ssize_t htmdump_read(struct file *filp, char __user *ubuf, > + size_t count, loff_t *ppos) > +{ > + struct htmdump_entry *ent = filp->private_data; > + unsigned long page, read_size, available; > + loff_t offset; > + long rc; > + > + page = ALIGN_DOWN(*ppos, BUFFER_SIZE); > + offset = (*ppos) % BUFFER_SIZE; > + > + rc = htm_get_dump_hardware(nodeindex, nodalchipindex, coreindexonchip, > + htmtype, virt_to_phys(ent->buf), BUFFER_SIZE, page); > + > + switch (rc) { > + case H_SUCCESS: > + case H_PARTIAL: > + break; > + case H_NOT_AVAILABLE: > + return 0; Minor nits for error returns here... Is returning 0 correct here? Maybe it is (since 0 means no data read), but wanted to confirm if we should return -ENODATA, or -ENODEV (not sure what does H_NOT_AVAILABLE here means) #define ENODATA 61 /* No data available */ > + case H_BUSY: > + case H_LONG_BUSY_ORDER_1_MSEC: > + case H_LONG_BUSY_ORDER_10_MSEC: > + case H_LONG_BUSY_ORDER_100_MSEC: > + case H_LONG_BUSY_ORDER_1_SEC: > + case H_LONG_BUSY_ORDER_10_SEC: > + case H_LONG_BUSY_ORDER_100_SEC: Similarly for above maybe -EBUSY perhaps, instead of -EINVAL #define EBUSY 16 /* Device or resource busy */ > + case H_PARAMETER: > + case H_P2: > + case H_P3: > + case H_P4: > + case H_P5: > + case H_P6: > + case H_STATE: > + case H_AUTHORITY: > + return -EINVAL; > + } > + > + available = BUFFER_SIZE - offset; > + read_size = min(count, available); > + *ppos += read_size; > + return simple_read_from_buffer(ubuf, count, &offset, ent->buf, available); > +} > + > +static const struct file_operations htmdump_fops = { > + .llseek = default_llseek, > + .read = htmdump_read, > + .open = simple_open, > +}; > + > +static int htmdump_init_debugfs(void) > +{ > + ent = kcalloc(1, sizeof(struct htmdump_entry), GFP_KERNEL); > + if (!ent) { > + pr_err("Failed to allocate ent\n"); > + return -EINVAL; return value can be -ENOMEM; > + } > + > + ent->buf = kmalloc(BUFFER_SIZE, GFP_KERNEL); > + if (!ent->buf) { > + pr_err("Failed to allocate htmdump buf\n"); > + return -ENOMEM; kfree(ent)? > + } > + > + pr_debug("%s: ent:%lx buf:%lx\n", > + __func__, (long unsigned int)ent, (long unsigned int)ent->buf); > + maybe %p perhaps? <Documentation/core-api/printk-formats.rst> Plain Pointers -------------- :: %p abcdef12 or 00000000abcdef12 Pointers printed without a specifier extension (i.e unadorned %p) are hashed to prevent leaking information about the kernel memory layout. This has the added benefit of providing a unique identifier. <...> ...the aim of printing the address is to provide more information for debugging, use %p and boot the kernel with the ``no_hash_pointers`` parameter during debugging, which will print all %p addresses unmodified. If you *really* always want the unmodified address, see %px below. > + htmdump_debugfs_dir = debugfs_create_dir("htmdump", > + arch_debugfs_dir); > + > + debugfs_create_u32("nodeindex", 0600, > + htmdump_debugfs_dir, &nodeindex); > + debugfs_create_u32("nodalchipindex", 0600, > + htmdump_debugfs_dir, &nodalchipindex); > + debugfs_create_u32("coreindexonchip", 0600, > + htmdump_debugfs_dir, &coreindexonchip); > + debugfs_create_u32("htmtype", 0600, > + htmdump_debugfs_dir, &htmtype); > + debugfs_create_file("trace", 0400, htmdump_debugfs_dir, ent, &htmdump_fops); > + > + return 0; > +} > + > +static int __init htmdump_init(void) > +{ > + if (htmdump_init_debugfs()) > + return -EINVAL; > + > + return 0; > +} > + > +static void __exit htmdump_exit(void) > +{ > + debugfs_remove_recursive(htmdump_debugfs_dir); > + kfree(ent->buf); > + kfree(ent); > +} > + > +module_init(htmdump_init); > +module_exit(htmdump_exit); > +MODULE_DESCRIPTION("PHYP Hardware Trace Macro (HTM) data dumper"); > +MODULE_LICENSE("GPL"); > -- > 2.45.2
diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index afc0f6a61337..a66be66d690e 100644 --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -128,6 +128,15 @@ config CMM will be reused for other LPARs. The interface allows firmware to balance memory across many LPARs. +config HTMDUMP + tristate "PHYP HTM data dumper" + depends on PPC_PSERIES && DEBUG_FS + default m + help + Select this option, if you want to enable the kernel debugfs + interface to dump the Hardware Trace Macro (HTM) function data + in the LPAR. + config HV_PERF_CTRS bool "Hypervisor supplied PMU events (24x7 & GPCI)" default y diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile index 7bf506f6b8c8..3f3e3492e436 100644 --- a/arch/powerpc/platforms/pseries/Makefile +++ b/arch/powerpc/platforms/pseries/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_HVC_CONSOLE) += hvconsole.o obj-$(CONFIG_HVCS) += hvcserver.o obj-$(CONFIG_HCALL_STATS) += hvCall_inst.o obj-$(CONFIG_CMM) += cmm.o +obj-$(CONFIG_HTMDUMP) += htmdump.o obj-$(CONFIG_IO_EVENT_IRQ) += io_event_irq.o obj-$(CONFIG_LPARCFG) += lparcfg.o obj-$(CONFIG_IBMVIO) += vio.o diff --git a/arch/powerpc/platforms/pseries/htmdump.c b/arch/powerpc/platforms/pseries/htmdump.c new file mode 100644 index 000000000000..54c28525c4a7 --- /dev/null +++ b/arch/powerpc/platforms/pseries/htmdump.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) IBM Corporation, 2024 + */ + +#define pr_fmt(fmt) "htmdump: " fmt + +#include <linux/debugfs.h> + +#include <asm/machdep.h> +#include <asm/plpar_wrappers.h> + +/* This enables us to keep track of the memory removed from each node. */ +struct htmdump_entry { + void *buf; + struct dentry *dir; + char name[16]; +}; + +static u32 nodeindex; +static u32 nodalchipindex; +static u32 coreindexonchip; +static u32 htmtype; +static struct dentry *htmdump_debugfs_dir; +static struct htmdump_entry *ent; + +#define BUFFER_SIZE PAGE_SIZE + +static ssize_t htmdump_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct htmdump_entry *ent = filp->private_data; + unsigned long page, read_size, available; + loff_t offset; + long rc; + + page = ALIGN_DOWN(*ppos, BUFFER_SIZE); + offset = (*ppos) % BUFFER_SIZE; + + rc = htm_get_dump_hardware(nodeindex, nodalchipindex, coreindexonchip, + htmtype, virt_to_phys(ent->buf), BUFFER_SIZE, page); + + switch (rc) { + case H_SUCCESS: + case H_PARTIAL: + break; + case H_NOT_AVAILABLE: + return 0; + case H_BUSY: + case H_LONG_BUSY_ORDER_1_MSEC: + case H_LONG_BUSY_ORDER_10_MSEC: + case H_LONG_BUSY_ORDER_100_MSEC: + case H_LONG_BUSY_ORDER_1_SEC: + case H_LONG_BUSY_ORDER_10_SEC: + case H_LONG_BUSY_ORDER_100_SEC: + case H_PARAMETER: + case H_P2: + case H_P3: + case H_P4: + case H_P5: + case H_P6: + case H_STATE: + case H_AUTHORITY: + return -EINVAL; + } + + available = BUFFER_SIZE - offset; + read_size = min(count, available); + *ppos += read_size; + return simple_read_from_buffer(ubuf, count, &offset, ent->buf, available); +} + +static const struct file_operations htmdump_fops = { + .llseek = default_llseek, + .read = htmdump_read, + .open = simple_open, +}; + +static int htmdump_init_debugfs(void) +{ + ent = kcalloc(1, sizeof(struct htmdump_entry), GFP_KERNEL); + if (!ent) { + pr_err("Failed to allocate ent\n"); + return -EINVAL; + } + + ent->buf = kmalloc(BUFFER_SIZE, GFP_KERNEL); + if (!ent->buf) { + pr_err("Failed to allocate htmdump buf\n"); + return -ENOMEM; + } + + pr_debug("%s: ent:%lx buf:%lx\n", + __func__, (long unsigned int)ent, (long unsigned int)ent->buf); + + htmdump_debugfs_dir = debugfs_create_dir("htmdump", + arch_debugfs_dir); + + debugfs_create_u32("nodeindex", 0600, + htmdump_debugfs_dir, &nodeindex); + debugfs_create_u32("nodalchipindex", 0600, + htmdump_debugfs_dir, &nodalchipindex); + debugfs_create_u32("coreindexonchip", 0600, + htmdump_debugfs_dir, &coreindexonchip); + debugfs_create_u32("htmtype", 0600, + htmdump_debugfs_dir, &htmtype); + debugfs_create_file("trace", 0400, htmdump_debugfs_dir, ent, &htmdump_fops); + + return 0; +} + +static int __init htmdump_init(void) +{ + if (htmdump_init_debugfs()) + return -EINVAL; + + return 0; +} + +static void __exit htmdump_exit(void) +{ + debugfs_remove_recursive(htmdump_debugfs_dir); + kfree(ent->buf); + kfree(ent); +} + +module_init(htmdump_init); +module_exit(htmdump_exit); +MODULE_DESCRIPTION("PHYP Hardware Trace Macro (HTM) data dumper"); +MODULE_LICENSE("GPL");
This patch adds debugfs interface to export Hardware Trace Macro (HTM) function data in a LPAR. New hypervisor call "H_HTM" has been defined to setup, configure, control and dump the HTM data. This patch supports only dumping of HTM data in a LPAR. New debugfs folder called "htmdump" has been added under /sys/kernel/debug/arch path which contains files need to pass required parameters for the H_HTM dump function. New Kconfig option called "CONFIG_HTMDUMP" has been in platform/pseries for the same. With this module loaded, list of files in debugfs path /sys/kernel/debug/powerpc/htmdump coreindexonchip htmtype nodalchipindex nodeindex trace Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> --- Changelog v2: - Made driver as modules based on review comments Changelog v1: - Changed from tristate to bool with dependency flags - Trimmed the include headers arch/powerpc/platforms/pseries/Kconfig | 9 ++ arch/powerpc/platforms/pseries/Makefile | 1 + arch/powerpc/platforms/pseries/htmdump.c | 130 +++++++++++++++++++++++ 3 files changed, 140 insertions(+) create mode 100644 arch/powerpc/platforms/pseries/htmdump.c