[PATCH 11/12] IB/ehca: Serialize MR alloc and MR free hvCalls
From: Joachim Fenkes <hidden>
Date: 2007-09-11 13:36:24
Also in:
lkml
Subsystem:
infiniband subsystem, the rest · Maintainers:
Jason Gunthorpe, Leon Romanovsky, Linus Torvalds
Some firmware levels exhibit a race condition between H_ALLOC_RESOURCE(MR) and H_FREE_RESOURCE(MR). Work around this problem by locking these hvCalls against each other. Signed-off-by: Joachim Fenkes <redacted> --- drivers/infiniband/hw/ehca/hcp_if.c | 28 +++++++++++++++++++++------- 1 files changed, 21 insertions(+), 7 deletions(-)
diff --git a/drivers/infiniband/hw/ehca/hcp_if.c b/drivers/infiniband/hw/ehca/hcp_if.c
index a70a5ed..d3d1ef2 100644
--- a/drivers/infiniband/hw/ehca/hcp_if.c
+++ b/drivers/infiniband/hw/ehca/hcp_if.c@@ -120,15 +120,28 @@ static long ehca_plpar_hcall_norets(unsigned long opcode, unsigned long arg7) { long ret; - int i, sleep_msecs; + int i, sleep_msecs, do_lock; + unsigned long flags; ehca_gen_dbg("opcode=%lx " HCALL7_REGS_FORMAT, opcode, arg1, arg2, arg3, arg4, arg5, arg6, arg7); + /* lock H_FREE_RESOURCE(MR) against itself and H_ALLOC_RESOURCE(MR) */ + if ((opcode == H_FREE_RESOURCE) && (arg7 == 5)) { + arg7 = 0; /* better not upset firmware */ + do_lock = 1; + } + for (i = 0; i < 5; i++) { + if (do_lock) + spin_lock_irqsave(&hcall_lock, flags); + ret = plpar_hcall_norets(opcode, arg1, arg2, arg3, arg4, arg5, arg6, arg7); + if (do_lock) + spin_unlock_irqrestore(&hcall_lock, flags); + if (H_IS_LONG_BUSY(ret)) { sleep_msecs = get_longbusy_msecs(ret); msleep_interruptible(sleep_msecs);
@@ -161,23 +174,24 @@ static long ehca_plpar_hcall9(unsigned long opcode, unsigned long arg9) { long ret; - int i, sleep_msecs, lock_is_set = 0; + int i, sleep_msecs, do_lock; unsigned long flags = 0; ehca_gen_dbg("INPUT -- opcode=%lx " HCALL9_REGS_FORMAT, opcode, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9); + /* lock H_ALLOC_RESOURCE(MR) against itself and H_FREE_RESOURCE(MR) */ + do_lock = ((opcode == H_ALLOC_RESOURCE) && (arg2 == 5)); + for (i = 0; i < 5; i++) { - if ((opcode == H_ALLOC_RESOURCE) && (arg2 == 5)) { + if (do_lock) spin_lock_irqsave(&hcall_lock, flags); - lock_is_set = 1; - } ret = plpar_hcall9(opcode, outs, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9); - if (lock_is_set) + if (do_lock) spin_unlock_irqrestore(&hcall_lock, flags); if (H_IS_LONG_BUSY(ret)) {
@@ -807,7 +821,7 @@ u64 hipz_h_free_resource_mr(const struct ipz_adapter_handle adapter_handle, return ehca_plpar_hcall_norets(H_FREE_RESOURCE, adapter_handle.handle, /* r4 */ mr->ipz_mr_handle.handle, /* r5 */ - 0, 0, 0, 0, 0); + 0, 0, 0, 0, 5); } u64 hipz_h_reregister_pmr(const struct ipz_adapter_handle adapter_handle,
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1.5.2