[PATCH v2 2/5] misc: fastrpc: Capture kernel and DSP performance counters

From: Ekansh Gupta
Date: Wed Sep 20 2023 - 06:32:07 EST


Add support to capture kernel performance counters for different
kernel level operations. These counters collects the information
for remote call and copies the information to a buffer shared
by user.

Collection of DSP performance counters is also added as part of
this change. DSP updates the performance information in the
metadata which is then copied to a buffer passed by the user.

Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
---
drivers/misc/fastrpc.c | 140 +++++++++++++++++++++++++++++++++++++++++---
include/uapi/misc/fastrpc.h | 14 +++++
2 files changed, 146 insertions(+), 8 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 337ec1f..f8c1c381 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -18,6 +18,7 @@
#include <linux/rpmsg.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
+#include <linux/delay.h>
#include <linux/firmware/qcom/qcom_scm.h>
#include <uapi/misc/fastrpc.h>
#include <linux/of_reserved_mem.h>
@@ -32,6 +33,8 @@
#define FASTRPC_ALIGN 128
#define FASTRPC_MAX_FDLIST 16
#define FASTRPC_MAX_CRCLIST 64
+#define FASTRPC_KERNEL_PERF_LIST (PERF_KEY_MAX)
+#define FASTRPC_DSP_PERF_LIST 12
#define FASTRPC_PHYS(p) ((p) & 0xffffffff)
#define FASTRPC_CTX_MAX (256)
#define FASTRPC_INIT_HANDLE 1
@@ -104,6 +107,27 @@

#define miscdev_to_fdevice(d) container_of(d, struct fastrpc_device, miscdev)

+#define PERF_END ((void)0)
+
+#define PERF(enb, cnt, ff) \
+ {\
+ struct timespec64 startT = {0};\
+ uint64_t *counter = cnt;\
+ if (enb && counter) {\
+ ktime_get_real_ts64(&startT);\
+ } \
+ ff ;\
+ if (enb && counter) {\
+ *counter += getnstimediff(&startT);\
+ } \
+ }
+
+#define GET_COUNTER(perf_ptr, offset) \
+ (perf_ptr != NULL ?\
+ (((offset >= 0) && (offset < PERF_KEY_MAX)) ?\
+ (uint64_t *)(perf_ptr + offset)\
+ : (uint64_t *)NULL) : (uint64_t *)NULL)
+
static const char *domains[FASTRPC_DEV_MAX] = { "adsp", "mdsp",
"sdsp", "cdsp"};
struct fastrpc_phy_page {
@@ -227,6 +251,19 @@ struct fastrpc_map {
struct kref refcount;
};

+struct fastrpc_perf {
+ u64 count;
+ u64 flush;
+ u64 map;
+ u64 copy;
+ u64 link;
+ u64 getargs;
+ u64 putargs;
+ u64 invargs;
+ u64 invoke;
+ u64 tid;
+};
+
struct fastrpc_invoke_ctx {
int nscalars;
int nbufs;
@@ -235,6 +272,8 @@ struct fastrpc_invoke_ctx {
int tgid;
u32 sc;
u32 *crc;
+ u64 *perf_kernel;
+ u64 *perf_dsp;
u64 ctxid;
u64 msg_sz;
struct kref refcount;
@@ -249,6 +288,7 @@ struct fastrpc_invoke_ctx {
struct fastrpc_invoke_args *args;
struct fastrpc_buf_overlap *olaps;
struct fastrpc_channel_ctx *cctx;
+ struct fastrpc_perf *perf;
};

struct fastrpc_session_ctx {
@@ -298,6 +338,7 @@ struct fastrpc_user {
struct fastrpc_session_ctx *sctx;
struct fastrpc_buf *init_mem;

+ u32 profile;
int tgid;
int pd;
bool is_secure_dev;
@@ -307,6 +348,17 @@ struct fastrpc_user {
struct mutex mutex;
};

+static inline int64_t getnstimediff(struct timespec64 *start)
+{
+ int64_t ns;
+ struct timespec64 ts, b;
+
+ ktime_get_real_ts64(&ts);
+ b = timespec64_sub(ts, *start);
+ ns = timespec64_to_ns(&b);
+ return ns;
+}
+
static void fastrpc_free_map(struct kref *ref)
{
struct fastrpc_map *map;
@@ -492,6 +544,9 @@ static void fastrpc_context_free(struct kref *ref)
if (ctx->buf)
fastrpc_buf_free(ctx->buf);

+ if (ctx->fl->profile)
+ kfree(ctx->perf);
+
spin_lock_irqsave(&cctx->lock, flags);
idr_remove(&cctx->ctx_idr, ctx->ctxid >> 4);
spin_unlock_irqrestore(&cctx->lock, flags);
@@ -611,6 +666,14 @@ static struct fastrpc_invoke_ctx *fastrpc_context_alloc(
fastrpc_channel_ctx_get(cctx);

ctx->crc = (u32 *)(uintptr_t)invoke->crc;
+ ctx->perf_dsp = (u64 *)(uintptr_t)invoke->perf_dsp;
+ ctx->perf_kernel = (u64 *)(uintptr_t)invoke->perf_kernel;
+ if (ctx->fl->profile) {
+ ctx->perf = kzalloc(sizeof(*(ctx->perf)), GFP_KERNEL);
+ if (!ctx->perf)
+ return ERR_PTR(-ENOMEM);
+ ctx->perf->tid = ctx->fl->tgid;
+ }
ctx->sc = sc;
ctx->retval = -1;
ctx->pid = current->pid;
@@ -872,7 +935,8 @@ static int fastrpc_get_meta_size(struct fastrpc_invoke_ctx *ctx)
sizeof(struct fastrpc_invoke_buf) +
sizeof(struct fastrpc_phy_page)) * ctx->nscalars +
sizeof(u64) * FASTRPC_MAX_FDLIST +
- sizeof(u32) * FASTRPC_MAX_CRCLIST;
+ sizeof(u32) * FASTRPC_MAX_CRCLIST +
+ sizeof(u32) + sizeof(u64) * FASTRPC_DSP_PERF_LIST;

return size;
}
@@ -939,16 +1003,22 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx)
int inbufs, i, oix, err = 0;
u64 len, rlen, pkt_size;
u64 pg_start, pg_end;
+ u64 *perf_counter = NULL;
uintptr_t args;
int metalen;

+ if (ctx->fl->profile)
+ perf_counter = (u64 *)ctx->perf + PERF_COUNT;
+
inbufs = REMOTE_SCALARS_INBUFS(ctx->sc);
metalen = fastrpc_get_meta_size(ctx);
pkt_size = fastrpc_get_payload_size(ctx, metalen);

+ PERF(ctx->fl->profile, GET_COUNTER(perf_counter, PERF_MAP),
err = fastrpc_create_maps(ctx);
if (err)
return err;
+ PERF_END);

ctx->msg_sz = pkt_size;

@@ -980,6 +1050,7 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx)
if (ctx->maps[i]) {
struct vm_area_struct *vma = NULL;

+ PERF(ctx->fl->profile, GET_COUNTER(perf_counter, PERF_MAP),
rpra[i].buf.pv = (u64) ctx->args[i].ptr;
pages[i].addr = ctx->maps[i]->phys;

@@ -994,9 +1065,9 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx)
pg_end = ((ctx->args[i].ptr + len - 1) & PAGE_MASK) >>
PAGE_SHIFT;
pages[i].size = (pg_end - pg_start + 1) * PAGE_SIZE;
-
+ PERF_END);
} else {
-
+ PERF(ctx->fl->profile, GET_COUNTER(perf_counter, PERF_COPY),
if (ctx->olaps[oix].offset == 0) {
rlen -= ALIGN(args, FASTRPC_ALIGN) - args;
args = ALIGN(args, FASTRPC_ALIGN);
@@ -1018,12 +1089,14 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx)
pages[i].size = (pg_end - pg_start + 1) * PAGE_SIZE;
args = args + mlen;
rlen -= mlen;
+ PERF_END);
}

if (i < inbufs && !ctx->maps[i]) {
void *dst = (void *)(uintptr_t)rpra[i].buf.pv;
void *src = (void *)(uintptr_t)ctx->args[i].ptr;

+ PERF(ctx->fl->profile, GET_COUNTER(perf_counter, PERF_COPY),
if (!kernel) {
if (copy_from_user(dst, (void __user *)src,
len)) {
@@ -1033,6 +1106,7 @@ static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx)
} else {
memcpy(dst, src, len);
}
+ PERF_END);
}
}

@@ -1063,9 +1137,9 @@ static int fastrpc_put_args(struct fastrpc_invoke_ctx *ctx,
struct fastrpc_map *mmap = NULL;
struct fastrpc_invoke_buf *list;
struct fastrpc_phy_page *pages;
- u64 *fdlist;
- u32 *crclist;
- int i, inbufs, outbufs, handles;
+ u64 *fdlist, *perf_dsp_list;
+ u32 *crclist, *poll;
+ int i, inbufs, outbufs, handles, perferr;

inbufs = REMOTE_SCALARS_INBUFS(ctx->sc);
outbufs = REMOTE_SCALARS_OUTBUFS(ctx->sc);
@@ -1074,6 +1148,8 @@ static int fastrpc_put_args(struct fastrpc_invoke_ctx *ctx,
pages = fastrpc_phy_page_start(list, ctx->nscalars);
fdlist = (u64 *)(pages + inbufs + outbufs + handles);
crclist = (u32 *)(fdlist + FASTRPC_MAX_FDLIST);
+ poll = (u32 *)(crclist + FASTRPC_MAX_CRCLIST);
+ perf_dsp_list = (u64 *)(poll + 1);

for (i = inbufs; i < ctx->nbufs; ++i) {
if (!ctx->maps[i]) {
@@ -1098,8 +1174,16 @@ static int fastrpc_put_args(struct fastrpc_invoke_ctx *ctx,
}

if (ctx->crc && crclist && rpra) {
- if (copy_to_user((void __user *)ctx->crc, crclist, FASTRPC_MAX_CRCLIST * sizeof(u32)))
+ if (copy_to_user((void __user *)ctx->crc, crclist,
+ FASTRPC_MAX_CRCLIST * sizeof(u32))) {
return -EFAULT;
+ }
+ }
+ if (ctx->perf_dsp && perf_dsp_list) {
+ perferr = copy_to_user((void __user *)ctx->perf_dsp,
+ perf_dsp_list, FASTRPC_DSP_PERF_LIST * sizeof(u64));
+ if (perferr)
+ dev_info(fl->sctx->dev, "Warning: failed to copy perf data %d\n", perferr);
}
return 0;
}
@@ -1136,6 +1220,20 @@ static int fastrpc_invoke_send(struct fastrpc_session_ctx *sctx,

}

+static void fastrpc_update_invoke_count(u32 handle, u64 *perf_counter,
+ struct timespec64 *invoket)
+{
+ u64 *invcount, *count;
+
+ invcount = GET_COUNTER(perf_counter, PERF_INVOKE);
+ if (invcount)
+ *invcount += getnstimediff(invoket);
+
+ count = GET_COUNTER(perf_counter, PERF_COUNT);
+ if (count)
+ *count += 1;
+}
+
static int fastrpc_internal_invoke(struct fastrpc_user *fl, u32 kernel,
struct fastrpc_enhanced_invoke *invoke)
{
@@ -1143,7 +1241,12 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl, u32 kernel,
struct fastrpc_buf *buf, *b;
struct fastrpc_invoke *inv = &invoke->inv;
u32 handle, sc;
- int err = 0;
+ u64 *perf_counter = NULL;
+ int err = 0, perferr = 0;
+ struct timespec64 invoket = {0};
+
+ if (fl->profile)
+ ktime_get_real_ts64(&invoket);

if (!fl->sctx)
return -EINVAL;
@@ -1162,18 +1265,24 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl, u32 kernel,
if (IS_ERR(ctx))
return PTR_ERR(ctx);

+ if (fl->profile)
+ perf_counter = (u64 *)ctx->perf + PERF_COUNT;
+ PERF(fl->profile, GET_COUNTER(perf_counter, PERF_GETARGS),
if (ctx->nscalars) {
err = fastrpc_get_args(kernel, ctx);
if (err)
goto bail;
}
+ PERF_END);

/* make sure that all CPU memory writes are seen by DSP */
dma_wmb();
+ PERF(fl->profile, GET_COUNTER(perf_counter, PERF_LINK),
/* Send invoke buffer to remote dsp */
err = fastrpc_invoke_send(fl->sctx, ctx, kernel, handle);
if (err)
goto bail;
+ PERF_END);

if (kernel) {
if (!wait_for_completion_timeout(&ctx->work, 10 * HZ))
@@ -1193,10 +1302,12 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl, u32 kernel,
if (ctx->nscalars) {
/* make sure that all memory writes by DSP are seen by CPU */
dma_rmb();
+ PERF(fl->profile, GET_COUNTER(perf_counter, PERF_PUTARGS),
/* populate all the output buffers with results */
err = fastrpc_put_args(ctx, kernel);
if (err)
goto bail;
+ PERF_END);
}

bail:
@@ -1213,6 +1324,15 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl, u32 kernel,
list_del(&buf->node);
list_add_tail(&buf->node, &fl->cctx->invoke_interrupted_mmaps);
}
+ } else if (ctx) {
+ if (fl->profile && !err)
+ fastrpc_update_invoke_count(handle, perf_counter, &invoket);
+ if (fl->profile && ctx->perf && ctx->perf_kernel) {
+ perferr = copy_to_user((void __user *)ctx->perf_kernel,
+ ctx->perf, FASTRPC_KERNEL_PERF_LIST * sizeof(u64));
+ if (perferr)
+ dev_info(fl->sctx->dev, "Warning: failed to copy perf data %d\n", perferr);
+ }
}

if (err)
@@ -1706,6 +1826,7 @@ static int fastrpc_multimode_invoke(struct fastrpc_user *fl, char __user *argp)
struct fastrpc_invoke_args *args = NULL;
struct fastrpc_ioctl_multimode_invoke invoke;
u32 nscalars;
+ u64 *perf_kernel;
int err;

if (copy_from_user(&invoke, argp, sizeof(invoke)))
@@ -1729,6 +1850,9 @@ static int fastrpc_multimode_invoke(struct fastrpc_user *fl, char __user *argp)
return -EFAULT;
}
}
+ perf_kernel = (u64 *)(uintptr_t)einv.perf_kernel;
+ if (perf_kernel)
+ fl->profile = true;
einv.inv.args = (__u64)args;
err = fastrpc_internal_invoke(fl, false, &einv);
kfree(args);
diff --git a/include/uapi/misc/fastrpc.h b/include/uapi/misc/fastrpc.h
index 36694fb..c64cf6a 100644
--- a/include/uapi/misc/fastrpc.h
+++ b/include/uapi/misc/fastrpc.h
@@ -165,4 +165,18 @@ struct fastrpc_ioctl_capability {
__u32 reserved[4];
};

+enum fastrpc_perfkeys {
+ PERF_COUNT = 0,
+ PERF_RESERVED1 = 1,
+ PERF_MAP = 2,
+ PERF_COPY = 3,
+ PERF_LINK = 4,
+ PERF_GETARGS = 5,
+ PERF_PUTARGS = 6,
+ PERF_RESERVED2 = 7,
+ PERF_INVOKE = 8,
+ PERF_RESERVED3 = 9,
+ PERF_KEY_MAX = 10,
+};
+
#endif /* __QCOM_FASTRPC_H__ */
--
2.7.4