2007-12-10 17:59:54

by Joachim Fenkes

[permalink] [raw]
Subject: [PATCH] IB/ehca: Serialize HCA-related hCalls if necessary

Several pSeries firmware versions share a rare locking issue in the
HCA-related hCalls. Check for a feature flag that indicates the issue being
fixed and serialize all HCA hCalls if not.

Signed-off-by: Joachim Fenkes <[email protected]>
---

This is the revised version of my previous patch, which does not rely on the
processor version any longer.

drivers/infiniband/hw/ehca/ehca_main.c | 13 +++++++++++++
drivers/infiniband/hw/ehca/hcp_if.c | 28 +++++++++++-----------------
drivers/infiniband/hw/ehca/hipz_hw.h | 1 +
3 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/drivers/infiniband/hw/ehca/ehca_main.c b/drivers/infiniband/hw/ehca/ehca_main.c
index 90d4334..c7bff3e 100644
--- a/drivers/infiniband/hw/ehca/ehca_main.c
+++ b/drivers/infiniband/hw/ehca/ehca_main.c
@@ -43,6 +43,7 @@
#ifdef CONFIG_PPC_64K_PAGES
#include <linux/slab.h>
#endif
+
#include "ehca_classes.h"
#include "ehca_iverbs.h"
#include "ehca_mrmw.h"
@@ -66,6 +67,7 @@ int ehca_poll_all_eqs = 1;
int ehca_static_rate = -1;
int ehca_scaling_code = 0;
int ehca_mr_largepage = 1;
+int ehca_lock_hcalls = -1;

module_param_named(open_aqp1, ehca_open_aqp1, int, S_IRUGO);
module_param_named(debug_level, ehca_debug_level, int, S_IRUGO);
@@ -77,6 +79,7 @@ module_param_named(poll_all_eqs, ehca_poll_all_eqs, int, S_IRUGO);
module_param_named(static_rate, ehca_static_rate, int, S_IRUGO);
module_param_named(scaling_code, ehca_scaling_code, int, S_IRUGO);
module_param_named(mr_largepage, ehca_mr_largepage, int, S_IRUGO);
+module_param_named(lock_hcalls, ehca_lock_hcalls, bool, S_IRUGO);

MODULE_PARM_DESC(open_aqp1,
"AQP1 on startup (0: no (default), 1: yes)");
@@ -102,6 +105,9 @@ MODULE_PARM_DESC(scaling_code,
MODULE_PARM_DESC(mr_largepage,
"use large page for MR (0: use PAGE_SIZE (default), "
"1: use large page depending on MR size");
+MODULE_PARM_DESC(lock_hcalls,
+ "serialize all hCalls made by the driver "
+ "(default: autodetect)");

DEFINE_RWLOCK(ehca_qp_idr_lock);
DEFINE_RWLOCK(ehca_cq_idr_lock);
@@ -258,6 +264,7 @@ static struct cap_descr {
{ HCA_CAP_UD_LL_QP, "HCA_CAP_UD_LL_QP" },
{ HCA_CAP_RESIZE_MR, "HCA_CAP_RESIZE_MR" },
{ HCA_CAP_MINI_QP, "HCA_CAP_MINI_QP" },
+ { HCA_CAP_H_ALLOC_RES_SYNC, "HCA_CAP_H_ALLOC_RES_SYNC" },
};

static int ehca_sense_attributes(struct ehca_shca *shca)
@@ -333,6 +340,12 @@ static int ehca_sense_attributes(struct ehca_shca *shca)
if (EHCA_BMASK_GET(hca_cap_descr[i].mask, shca->hca_cap))
ehca_gen_dbg(" %s", hca_cap_descr[i].descr);

+ /* Autodetect hCall locking -- the "H_ALLOC_RESOURCE synced" flag is
+ * a firmware property, so it's valid across all adapters
+ */
+ if (ehca_lock_hcalls == -1)
+ ehca_lock_hcalls = !(shca->hca_cap & HCA_CAP_H_ALLOC_RES_SYNC);
+
/* translate supported MR page sizes; always support 4K */
shca->hca_cap_mr_pgsize = EHCA_PAGESIZE;
if (ehca_mr_largepage) { /* support extra sizes only if enabled */
diff --git a/drivers/infiniband/hw/ehca/hcp_if.c b/drivers/infiniband/hw/ehca/hcp_if.c
index c16a213..331b5e8 100644
--- a/drivers/infiniband/hw/ehca/hcp_if.c
+++ b/drivers/infiniband/hw/ehca/hcp_if.c
@@ -89,6 +89,7 @@
#define HCALL9_REGS_FORMAT HCALL7_REGS_FORMAT " r11=%lx r12=%lx"

static DEFINE_SPINLOCK(hcall_lock);
+extern int ehca_lock_hcalls;

static u32 get_longbusy_msecs(int longbusy_rc)
{
@@ -120,26 +121,21 @@ static long ehca_plpar_hcall_norets(unsigned long opcode,
unsigned long arg7)
{
long ret;
- int i, sleep_msecs, do_lock;
- unsigned long flags;
+ int i, sleep_msecs;
+ unsigned long flags = 0;

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)
+ /* serialize hCalls to work around firmware issue */
+ if (ehca_lock_hcalls)
spin_lock_irqsave(&hcall_lock, flags);

ret = plpar_hcall_norets(opcode, arg1, arg2, arg3, arg4,
arg5, arg6, arg7);

- if (do_lock)
+ if (ehca_lock_hcalls)
spin_unlock_irqrestore(&hcall_lock, flags);

if (H_IS_LONG_BUSY(ret)) {
@@ -174,24 +170,22 @@ static long ehca_plpar_hcall9(unsigned long opcode,
unsigned long arg9)
{
long ret;
- int i, sleep_msecs, do_lock;
+ int i, sleep_msecs;
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 (do_lock)
+ /* serialize hCalls to work around firmware issue */
+ if (ehca_lock_hcalls)
spin_lock_irqsave(&hcall_lock, flags);

ret = plpar_hcall9(opcode, outs,
arg1, arg2, arg3, arg4, arg5,
arg6, arg7, arg8, arg9);

- if (do_lock)
+ if (ehca_lock_hcalls)
spin_unlock_irqrestore(&hcall_lock, flags);

if (H_IS_LONG_BUSY(ret)) {
@@ -821,7 +815,7 @@ 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, 5);
+ 0, 0, 0, 0, 0);
}

u64 hipz_h_reregister_pmr(const struct ipz_adapter_handle adapter_handle,
diff --git a/drivers/infiniband/hw/ehca/hipz_hw.h b/drivers/infiniband/hw/ehca/hipz_hw.h
index 485b840..bf996c7 100644
--- a/drivers/infiniband/hw/ehca/hipz_hw.h
+++ b/drivers/infiniband/hw/ehca/hipz_hw.h
@@ -378,6 +378,7 @@ struct hipz_query_hca {
#define HCA_CAP_UD_LL_QP EHCA_BMASK_IBM(16, 16)
#define HCA_CAP_RESIZE_MR EHCA_BMASK_IBM(17, 17)
#define HCA_CAP_MINI_QP EHCA_BMASK_IBM(18, 18)
+#define HCA_CAP_H_ALLOC_RES_SYNC EHCA_BMASK_IBM(19, 19)

/* query port response block */
struct hipz_query_port {
--
1.5.2


2007-12-12 20:29:25

by Roland Dreier

[permalink] [raw]
Subject: Re: [PATCH] IB/ehca: Serialize HCA-related hCalls if necessary

thanks, applied.

With your next batch of patches for 2.6.25, could you clean up:

> --- a/drivers/infiniband/hw/ehca/hcp_if.c
> +++ b/drivers/infiniband/hw/ehca/hcp_if.c
> @@ -89,6 +89,7 @@
> #define HCALL9_REGS_FORMAT HCALL7_REGS_FORMAT " r11=%lx r12=%lx"
>
> static DEFINE_SPINLOCK(hcall_lock);
> +extern int ehca_lock_hcalls;

and move that extern declaration into an appropriate header file?

Thanks...