From 4d756894ba75f1afe7945ccafe9afebff50484b6 Mon Sep 17 00:00:00 2001 From: Nathan Lynch Date: Mon, 7 Dec 2020 15:51:47 -0600 Subject: powerpc/rtas: dispatch partition migration requests to pseries sys_rtas() cannot call ibm,suspend-me directly in the same way it handles other inputs. Instead it must dispatch the request to code that can first perform the H_JOIN sequence before any call to ibm,suspend-me can succeed. Over time kernel/rtas.c has accreted a fair amount of platform-specific code to implement this. Since a different, more robust implementation of the suspend sequence is now in the pseries platform code, we want to dispatch the request there. Note that invoking ibm,suspend-me via the RTAS syscall is all but deprecated; this change preserves ABI compatibility for old programs while providing to them the benefit of the new partition suspend implementation. This is a behavior change in that the kernel performs the device tree update and firmware activation before returning, but experimentation indicates this is tolerated fine by legacy user space. Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201207215200.1785968-16-nathanl@linux.ibm.com --- arch/powerpc/include/asm/rtas.h | 5 +++++ arch/powerpc/kernel/rtas.c | 2 +- arch/powerpc/platforms/pseries/mobility.c | 5 +++++ 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h index fdefe6a974eb..3b52d8574fcc 100644 --- a/arch/powerpc/include/asm/rtas.h +++ b/arch/powerpc/include/asm/rtas.h @@ -279,8 +279,13 @@ extern time64_t last_rtas_event; extern int clobbering_unread_rtas_event(void); extern int pseries_devicetree_update(s32 scope); extern void post_mobility_fixup(void); +int rtas_syscall_dispatch_ibm_suspend_me(u64 handle); #else static inline int clobbering_unread_rtas_event(void) { return 0; } +static inline int rtas_syscall_dispatch_ibm_suspend_me(u64 handle) +{ + return -EINVAL; +} #endif #ifdef CONFIG_PPC_RTAS_DAEMON diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index 3a740ae933f8..d4b048571728 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -1272,7 +1272,7 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) int rc = 0; u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32) | be32_to_cpu(args.args[1]); - rc = rtas_ibm_suspend_me_unsafe(handle); + rc = rtas_syscall_dispatch_ibm_suspend_me(handle); if (rc == -EAGAIN) args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE); else if (rc == -EIO) diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c index fe7e35cdc9d5..e670180f311d 100644 --- a/arch/powerpc/platforms/pseries/mobility.c +++ b/arch/powerpc/platforms/pseries/mobility.c @@ -615,6 +615,11 @@ static int pseries_migrate_partition(u64 handle) return ret; } +int rtas_syscall_dispatch_ibm_suspend_me(u64 handle) +{ + return pseries_migrate_partition(handle); +} + static ssize_t migration_store(struct class *class, struct class_attribute *attr, const char *buf, size_t count) -- cgit v1.2.3