| From ca15b67dc746c13a8231d11a3e2925f128982a7d Mon Sep 17 00:00:00 2001 |
| From: Robin Murphy <robin.murphy@arm.com> |
| Date: Fri, 3 Dec 2021 11:44:54 +0000 |
| Subject: [PATCH 19/40] perf/arm-cmn: Streamline node iteration |
| |
| Refactor the places where we scan through the set of nodes to switch |
| from explicit array indexing to pointer-based iteration. This leads to |
| slightly simpler object code, but also makes the source less dense and |
| more pleasant for further development. It also unearths an almost-bug |
| in arm_cmn_event_init() where we've been depending on the "array index" |
| of NULL relative to cmn->dns being a sufficiently large number, yuck. |
| |
| Signed-off-by: Robin Murphy <robin.murphy@arm.com> |
| Link: https://lore.kernel.org/r/ee0c9eda9a643f46001ac43aadf3f0b1fd5660dd.1638530442.git.robin.murphy@arm.com |
| Signed-off-by: Will Deacon <will@kernel.org> |
| |
| Upstream-Status: Backport [https://lore.kernel.org/r/ee0c9eda9a643f46001ac43aadf3f0b1fd5660dd.1638530442.git.robin.murphy@arm.com] |
| Signed-off-by: Rupinderjit Singh <rupinderjit.singh@arm.com> |
| --- |
| drivers/perf/arm-cmn.c | 33 ++++++++++++++++++++------------- |
| 1 file changed, 20 insertions(+), 13 deletions(-) |
| |
| diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c |
| index adf50d613734..da7bf779fec2 100644 |
| --- a/drivers/perf/arm-cmn.c |
| +++ b/drivers/perf/arm-cmn.c |
| @@ -299,11 +299,11 @@ static struct arm_cmn_node *arm_cmn_node_to_xp(struct arm_cmn_node *dn) |
| static struct arm_cmn_node *arm_cmn_node(const struct arm_cmn *cmn, |
| enum cmn_node_type type) |
| { |
| - int i; |
| + struct arm_cmn_node *dn; |
| |
| - for (i = 0; i < cmn->num_dns; i++) |
| - if (cmn->dns[i].type == type) |
| - return &cmn->dns[i]; |
| + for (dn = cmn->dns; dn->type; dn++) |
| + if (dn->type == type) |
| + return dn; |
| return NULL; |
| } |
| |
| @@ -941,8 +941,8 @@ static int arm_cmn_event_init(struct perf_event *event) |
| { |
| struct arm_cmn *cmn = to_cmn(event->pmu); |
| struct arm_cmn_hw_event *hw = to_cmn_hw(event); |
| + struct arm_cmn_node *dn; |
| enum cmn_node_type type; |
| - unsigned int i; |
| bool bynodeid; |
| u16 nodeid, eventid; |
| |
| @@ -974,10 +974,12 @@ static int arm_cmn_event_init(struct perf_event *event) |
| nodeid = CMN_EVENT_NODEID(event); |
| |
| hw->dn = arm_cmn_node(cmn, type); |
| - for (i = hw->dn - cmn->dns; i < cmn->num_dns && cmn->dns[i].type == type; i++) { |
| + if (!hw->dn) |
| + return -EINVAL; |
| + for (dn = hw->dn; dn->type == type; dn++) { |
| if (!bynodeid) { |
| hw->num_dns++; |
| - } else if (cmn->dns[i].id != nodeid) { |
| + } else if (dn->id != nodeid) { |
| hw->dn++; |
| } else { |
| hw->num_dns = 1; |
| @@ -1332,7 +1334,7 @@ static int arm_cmn_init_dtcs(struct arm_cmn *cmn) |
| |
| cmn->xps = arm_cmn_node(cmn, CMN_TYPE_XP); |
| |
| - for (dn = cmn->dns; dn < cmn->dns + cmn->num_dns; dn++) { |
| + for (dn = cmn->dns; dn->type; dn++) { |
| if (dn->type != CMN_TYPE_XP) |
| arm_cmn_init_node_to_xp(cmn, dn); |
| else if (cmn->num_dtcs == 1) |
| @@ -1382,6 +1384,7 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) |
| u32 xp_offset[CMN_MAX_XPS]; |
| u64 reg; |
| int i, j; |
| + size_t sz; |
| |
| cfg_region = cmn->base + rgn_offset; |
| reg = readl_relaxed(cfg_region + CMN_CFGM_PERIPH_ID_2); |
| @@ -1408,14 +1411,13 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) |
| cmn->num_dns += FIELD_GET(CMN_CI_CHILD_COUNT, reg); |
| } |
| |
| - /* Cheeky +1 to help terminate pointer-based iteration */ |
| - cmn->dns = devm_kcalloc(cmn->dev, cmn->num_dns + 1, |
| - sizeof(*cmn->dns), GFP_KERNEL); |
| - if (!cmn->dns) |
| + /* Cheeky +1 to help terminate pointer-based iteration later */ |
| + dn = devm_kcalloc(cmn->dev, cmn->num_dns + 1, sizeof(*dn), GFP_KERNEL); |
| + if (!dn) |
| return -ENOMEM; |
| |
| /* Pass 2: now we can actually populate the nodes */ |
| - dn = cmn->dns; |
| + cmn->dns = dn; |
| for (i = 0; i < cmn->num_xps; i++) { |
| void __iomem *xp_region = cmn->base + xp_offset[i]; |
| struct arm_cmn_node *xp = dn++; |
| @@ -1484,6 +1486,11 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) |
| /* Correct for any nodes we skipped */ |
| cmn->num_dns = dn - cmn->dns; |
| |
| + sz = (void *)(dn + 1) - (void *)cmn->dns; |
| + dn = devm_krealloc(cmn->dev, cmn->dns, sz, GFP_KERNEL); |
| + if (dn) |
| + cmn->dns = dn; |
| + |
| /* |
| * If mesh_x wasn't set during discovery then we never saw |
| * an XP at (0,1), thus we must have an Nx1 configuration. |
| -- |
| 2.34.1 |
| |