On 23/02/17 13:29, Matt Brown wrote:
From: Matt Brown <brownmatt1...@gmail.com>
Did you intend for this to be different from the email you're using to send + sign-off?
The HDAT data area is consumed by skiboot and turned into a device-tree. In some cases we would like to look directly at the HDAT, so this patch adds a sysfs node to allow it to be viewed. This is not possible through /dev/mem as it is reserved memory which is stopped by the /dev/mem filter. Signed-off-by: Matt Brown <matthew.brown....@gmail.com>
Oliver obviously knows more about how HDAT actually works, I won't repeat his comments.
I haven't checked the actual important bit of how HDAT is exposed in device tree but other than that things look fairly good. Boring stylistic comments below!
--- arch/powerpc/include/asm/opal.h | 1 + arch/powerpc/platforms/powernv/opal-msglog.c | 49 ++++++++++++++++++++++++++++ arch/powerpc/platforms/powernv/opal.c | 2 ++ 3 files changed, 52 insertions(+) diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 5c7db0f..b26944e 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -277,6 +277,7 @@ extern int opal_async_comp_init(void); extern int opal_sensor_init(void); extern int opal_hmi_handler_init(void); extern int opal_event_init(void); +extern void opal_hdat_sysfs_init(void); extern int opal_machine_check(struct pt_regs *regs); extern bool opal_mce_check_early_recovery(struct pt_regs *regs); diff --git a/arch/powerpc/platforms/powernv/opal-msglog.c b/arch/powerpc/platforms/powernv/opal-msglog.c index 39d6ff9..a637055 100644 --- a/arch/powerpc/platforms/powernv/opal-msglog.c +++ b/arch/powerpc/platforms/powernv/opal-msglog.c
I think I know why you've put it in opal-msglog.c - the existing code in there does similar things in exposing a chunk of skiboot stuff via a sysfs file - but it's not immediately obvious given that HDAT and msglog are quite different things. Perhaps add a new file, opal-hdat.c?
@@ -31,7 +31,13 @@ struct memcons { __be32 in_cons; }; +struct hdatInfo {
Kernel coding style tends to avoid using camelCase naming, instead preferring all-lowercase separated by underscores. (same applies to a couple of other places)
+ char *base; + u64 size; +}; + static struct memcons *opal_memcons = NULL; +static struct hdatInfo hdat_inf; ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count) { @@ -136,3 +142,46 @@ void __init opal_msglog_sysfs_init(void) if (sysfs_create_bin_file(opal_kobj, &opal_msglog_attr) != 0) pr_warn("OPAL: sysfs file creation failed\n"); } + + + +/* Read function for HDAT attribute in sysfs */ +static ssize_t hdat_read(struct file *file, struct kobject *kobj, + struct bin_attribute *bin_attr, char *to, + loff_t pos, size_t count) +{ + if (!hdat_inf.base) + return -ENODEV; + + return memory_read_from_buffer(to, count, &pos, hdat_inf.base, + hdat_inf.size); +} + + +/* HDAT attribute for sysfs */ +static struct bin_attribute hdat_attr = { + .attr = {.name = "hdat", .mode = 0444}, + .read = hdat_read +}; + +void __init opal_hdat_sysfs_init(void) +{ + u64 hdatAddr[2]; + + /* Check for the hdat-map prop in device-tree */ + if (of_property_read_u64_array(opal_node, "hdat-map", hdatAddr, 2)) { + pr_debug("OPAL: Property hdat-map not found.\n"); + return; + } + + /* Print out hdat-map values. [0]: base, [1]: size */ + pr_debug("HDAT Base address: %#llx\n", hdatAddr[0]); + pr_debug("HDAT Size: %#llx\n", hdatAddr[1]);
Prefix these with "OPAL: " like the other messages?
+ + hdat_inf.base = phys_to_virt(hdatAddr[0]); + hdat_inf.size = hdatAddr[1]; + + if (sysfs_create_bin_file(opal_kobj, &hdat_attr) != 0) + pr_debug("OPAL: sysfs file creation for HDAT failed"); + +} diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index 2822935..cae3745 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -740,6 +740,8 @@ static int __init opal_init(void) opal_sys_param_init(); /* Setup message log sysfs interface. */ opal_msglog_sysfs_init(); + /* Create hdat object under sys/firmware/opal */ + opal_hdat_sysfs_init(); } /* Initialize platform devices: IPMI backend, PRD & flash interface */
-- Andrew Donnellan OzLabs, ADL Canberra andrew.donnel...@au1.ibm.com IBM Australia Limited