[PATCH v7 8/9] powerpc/pseries: Enable hvpipe with ibm,set-system-parameter RTAS
From: Haren Myneni <haren@linux.ibm.com>
Date: 2025-09-09 08:45:23
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
The partition uses “Hypervisor Pipe OS Enablement Notification” system parameter token (value = 64) to enable / disable hvpipe in the hypervisor. Once hvpipe is enabled, the hypervisor notifies OS if the payload is pending for that partition from any source. This system parameter token takes 1 byte length of data with 1 = Enable and 0 = Disable. Enable hvpipe in the hypervisor with ibm,set-system-parameter RTAS after registering hvpipe event source interrupt. Signed-off-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Tested-by: Shashank MS <redacted> --- arch/powerpc/include/asm/papr-sysparm.h | 1 + arch/powerpc/platforms/pseries/papr-hvpipe.c | 34 ++++++++++++++++++-- 2 files changed, 33 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/papr-sysparm.h b/arch/powerpc/include/asm/papr-sysparm.h
index c3cd5b131033..a3b5a0d05db6 100644
--- a/arch/powerpc/include/asm/papr-sysparm.h
+++ b/arch/powerpc/include/asm/papr-sysparm.h@@ -21,6 +21,7 @@ typedef struct { #define PAPR_SYSPARM_COOP_MEM_OVERCOMMIT_ATTRS mk_papr_sysparm(44) #define PAPR_SYSPARM_TLB_BLOCK_INVALIDATE_ATTRS mk_papr_sysparm(50) #define PAPR_SYSPARM_LPAR_NAME mk_papr_sysparm(55) +#define PAPR_SYSPARM_HVPIPE_ENABLE mk_papr_sysparm(64) /** * struct papr_sysparm_buf - RTAS work area layout for system parameter functions.
diff --git a/arch/powerpc/platforms/pseries/papr-hvpipe.c b/arch/powerpc/platforms/pseries/papr-hvpipe.c
index eb312594b1f0..65368dbb134b 100644
--- a/arch/powerpc/platforms/pseries/papr-hvpipe.c
+++ b/arch/powerpc/platforms/pseries/papr-hvpipe.c@@ -15,6 +15,7 @@ #include <asm/machdep.h> #include <asm/rtas.h> #include <asm/rtas-work-area.h> +#include <asm/papr-sysparm.h> #include <uapi/asm/papr-hvpipe.h> #include "pseries.h" #include "papr-hvpipe.h"
@@ -648,6 +649,32 @@ static irqreturn_t hvpipe_event_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } +/* + * Enable hvpipe by system parameter set with parameter + * token = 64 and with 1 byte buffer data: + * 0 = hvpipe not in use/disable + * 1 = hvpipe in use/enable + */ +static int set_hvpipe_sys_param(u8 val) +{ + struct papr_sysparm_buf *buf; + int ret; + + buf = papr_sysparm_buf_alloc(); + if (!buf) + return -ENOMEM; + + buf->len = cpu_to_be16(1); + buf->val[0] = val; + ret = papr_sysparm_set(PAPR_SYSPARM_HVPIPE_ENABLE, buf); + if (ret) + pr_err("Can not enable hvpipe %d\n", ret); + + papr_sysparm_buf_free(buf); + + return ret; +} + static int __init enable_hvpipe_IRQ(void) { struct device_node *np;
@@ -705,8 +732,11 @@ static int __init papr_hvpipe_init(void) } ret = enable_hvpipe_IRQ(); - if (!ret) - ret = misc_register(&papr_hvpipe_dev); + if (!ret) { + ret = set_hvpipe_sys_param(1); + if (!ret) + ret = misc_register(&papr_hvpipe_dev); + } if (!ret) { pr_info("hvpipe feature is enabled\n");
--
2.50.1