The parameters to the 24x7 HCALL have variable number of elements in them.
Set the minimum number of such elements to 1 rather than 0 and eliminate
the temporary structures.
This would enable us to submit multiple counter requests and process
multiple results from a single HCALL (in a follow on patch).
Signed-off-by: Sukadev Bhattiprolu <sukadev at linux.vnet.ibm.com>
---
arch/powerpc/perf/hv-24x7.c | 77 ++++++++++++++++++++++-----------------------
arch/powerpc/perf/hv-24x7.h | 8 ++---
2 files changed, 41 insertions(+), 44 deletions(-)
diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
index 9445a82..408e6e9 100644
--- a/arch/powerpc/perf/hv-24x7.c
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -142,6 +142,15 @@ static struct attribute_group event_long_desc_group = {
static struct kmem_cache *hv_page_cache;
+/*
+ * request_buffer and result_buffer are not required to be 4k aligned,
+ * but are not allowed to cross any 4k boundary. Aligning them to 4k is
+ * the simplest way to ensure that.
+ */
+#define H24x7_DATA_BUFFER_SIZE 4096
+DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
+DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
+
static char *event_name(struct hv_24x7_event_data *ev, int *len)
{
*len = be16_to_cpu(ev->event_name_len) - 2;
@@ -976,31 +985,16 @@ static const struct attribute_group *attr_groups[] = {
NULL,
};
-DEFINE_PER_CPU(char, hv_24x7_reqb[4096]) __aligned(4096);
-DEFINE_PER_CPU(char, hv_24x7_resb[4096]) __aligned(4096);
-
static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix,
- u16 lpar, u64 *res,
+ u16 lpar, u64 *count,
bool success_expected)
{
unsigned long ret;
- /*
- * request_buffer and result_buffer are not required to be 4k aligned,
- * but are not allowed to cross any 4k boundary. Aligning them to 4k is
- * the simplest way to ensure that.
- */
- struct reqb {
- struct hv_24x7_request_buffer buf;
- struct hv_24x7_request req;
- } __packed *request_buffer;
-
- struct {
- struct hv_24x7_data_result_buffer buf;
- struct hv_24x7_result res;
- struct hv_24x7_result_element elem;
- __be64 result;
- } __packed *result_buffer;
+ struct hv_24x7_request_buffer *request_buffer;
+ struct hv_24x7_data_result_buffer *result_buffer;
+ struct hv_24x7_result *resb;
+ struct hv_24x7_request *req;
BUILD_BUG_ON(sizeof(*request_buffer) > 4096);
BUILD_BUG_ON(sizeof(*result_buffer) > 4096);
@@ -1011,38 +1005,41 @@ static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix,
memset(request_buffer, 0, 4096);
memset(result_buffer, 0, 4096);
- *request_buffer = (struct reqb) {
- .buf = {
- .interface_version = HV_24X7_IF_VERSION_CURRENT,
- .num_requests = 1,
- },
- .req = {
- .performance_domain = domain,
- .data_size = cpu_to_be16(8),
- .data_offset = cpu_to_be32(offset),
- .starting_lpar_ix = cpu_to_be16(lpar),
- .max_num_lpars = cpu_to_be16(1),
- .starting_ix = cpu_to_be16(ix),
- .max_ix = cpu_to_be16(1),
- }
- };
+ request_buffer->interface_version = HV_24X7_IF_VERSION_CURRENT;
+ request_buffer->num_requests = 1;
+
+ req = &request_buffer->requests[0];
+ req->performance_domain = domain;
+ req->data_size = cpu_to_be16(8);
+ req->data_offset = cpu_to_be32(offset);
+ req->starting_lpar_ix = cpu_to_be16(lpar),
+ req->max_num_lpars = cpu_to_be16(1);
+ req->starting_ix = cpu_to_be16(ix);
+ req->max_ix = cpu_to_be16(1);
+
+ /*
+ * NOTE: Due to variable number of array elements in request and
+ * result buffer(s), sizeof() is not reliable. Use the actual
+ * allocated buffer size, H24x7_DATA_BUFFER_SIZE.
+ */
ret = plpar_hcall_norets(H_GET_24X7_DATA,
- virt_to_phys(request_buffer), sizeof(*request_buffer),
- virt_to_phys(result_buffer), sizeof(*result_buffer));
+ virt_to_phys(request_buffer), H24x7_DATA_BUFFER_SIZE,
+ virt_to_phys(result_buffer), H24x7_DATA_BUFFER_SIZE);
if (ret) {
if (success_expected)
pr_err_ratelimited("hcall failed: %d %#x %#x %d => "
"0x%lx (%ld) detail=0x%x failing ix=%x\n",
domain, offset, ix, lpar, ret, ret,
- result_buffer->buf.detailed_rc,
- result_buffer->buf.failing_request_ix);
+ result_buffer->detailed_rc,
+ result_buffer->failing_request_ix);
goto out;
}
- *res = be64_to_cpu(result_buffer->result);
+ resb = &result_buffer->results[0];
+ *count = be64_to_cpu(resb->elements[0].element_data[0]);
out:
return ret;
}
diff --git a/arch/powerpc/perf/hv-24x7.h b/arch/powerpc/perf/hv-24x7.h
index 69cd4e6..0f9fa21 100644
--- a/arch/powerpc/perf/hv-24x7.h
+++ b/arch/powerpc/perf/hv-24x7.h
@@ -50,7 +50,7 @@ struct hv_24x7_request_buffer {
__u8 interface_version;
__u8 num_requests;
__u8 reserved[0xE];
- struct hv_24x7_request requests[];
+ struct hv_24x7_request requests[1];
} __packed;
struct hv_24x7_result_element {
@@ -66,7 +66,7 @@ struct hv_24x7_result_element {
__be32 lpar_cfg_instance_id;
/* size = @result_element_data_size of cointaining result. */
- __u8 element_data[];
+ __u64 element_data[1];
} __packed;
struct hv_24x7_result {
@@ -87,7 +87,7 @@ struct hv_24x7_result {
/* WARNING: only valid for first result element due to variable sizes
* of result elements */
/* struct hv_24x7_result_element[@num_elements_returned] */
- struct hv_24x7_result_element elements[];
+ struct hv_24x7_result_element elements[1];
} __packed;
struct hv_24x7_data_result_buffer {
@@ -103,7 +103,7 @@ struct hv_24x7_data_result_buffer {
__u8 reserved2[0x8];
/* WARNING: only valid for the first result due to variable sizes of
* results */
- struct hv_24x7_result results[]; /* [@num_results] */
+ struct hv_24x7_result results[1]; /* [@num_results] */
} __packed;
#endif
--
1.8.3.1