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authorNathan Lynch <nathanl@linux.ibm.com>2020-12-07 15:51:47 -0600
committerMichael Ellerman <mpe@ellerman.id.au>2020-12-08 21:40:59 +1100
commit4d756894ba75f1afe7945ccafe9afebff50484b6 (patch)
tree1e4dcd82593b2ace225e0e12055ab079058c9c44
parentpowerpc/pseries/mobility: retry partition suspend after error (diff)
downloadlinux-dev-4d756894ba75f1afe7945ccafe9afebff50484b6.tar.xz
linux-dev-4d756894ba75f1afe7945ccafe9afebff50484b6.zip
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 <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-16-nathanl@linux.ibm.com
-rw-r--r--arch/powerpc/include/asm/rtas.h5
-rw-r--r--arch/powerpc/kernel/rtas.c2
-rw-r--r--arch/powerpc/platforms/pseries/mobility.c5
3 files changed, 11 insertions, 1 deletions
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)