[PATCH] eal/linux: fix HPET symbols export

David Marchand
2026-02-18T10:19:25Z

The .map generation script has no clue about build configuration as it
relies only on the presence of RTE_EXPORT* and RTE_VERSION* markers in
a source file.

As a consequence, Linux eal_exports.map contains references to
HPET symbols regardless of the use_hpet meson option value.

$ meson configure build -Duse_hpet=false
$ ninja -C build
...
$ grep hpet build/lib/eal_exports.map
rte_eal_hpet_init;
rte_get_hpet_cycles;
rte_get_hpet_hz;

As far as I have seen, superfluous exports have no impact on generating
a shared library with the GNU linker, yet it might be different with
other linkers (MSVC linker would complain, for example).

Moving those symbols to a dedicated source file solves this (non?) issue.

Fixes: 57c194d142d9 ("build: use dynamically generated version maps")

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
lib/eal/linux/eal_timer.c | 175 --------------------------------
lib/eal/linux/eal_timer_hpet.c | 179 +++++++++++++++++++++++++++++++++
lib/eal/linux/meson.build | 4 +
3 files changed, 183 insertions(+), 175 deletions(-)
create mode 100644 lib/eal/linux/eal_timer_hpet.c

diff --git a/lib/eal/linux/eal_timer.c b/lib/eal/linux/eal_timer.c
index 0e670a0af6..39f975b6b9 100644
--- a/lib/eal/linux/eal_timer.c
+++ b/lib/eal/linux/eal_timer.c
@@ -6,11 +6,6 @@
#include <stdio.h>
#include <stdint.h>
#include <inttypes.h>
-#ifdef RTE_LIBEAL_USE_HPET
-#include <fcntl.h>
-#include <sys/mman.h>
-#include <unistd.h>
-#endif

#include <rte_common.h>
#include <rte_cycles.h>
@@ -22,176 +17,6 @@
RTE_EXPORT_SYMBOL(eal_timer_source)
enum timer_source eal_timer_source = EAL_TIMER_HPET;

-#ifdef RTE_LIBEAL_USE_HPET
-
-#define DEV_HPET "/dev/hpet"
-
-/* Maximum number of counters. */
-#define HPET_TIMER_NUM 3
-
-/* General capabilities register */
-#define CLK_PERIOD_SHIFT 32 /* Clock period shift. */
-#define CLK_PERIOD_MASK 0xffffffff00000000ULL /* Clock period mask. */
-
-/**
- * HPET timer registers. From the Intel IA-PC HPET (High Precision Event
- * Timers) Specification.
- */
-struct eal_hpet_regs {
- /* Memory-mapped, software visible registers */
- uint64_t capabilities; /**< RO General Capabilities Register. */
- uint64_t reserved0; /**< Reserved for future use. */
- uint64_t config; /**< RW General Configuration Register. */
- uint64_t reserved1; /**< Reserved for future use. */
- uint64_t isr; /**< RW Clear General Interrupt Status. */
- uint64_t reserved2[25]; /**< Reserved for future use. */
- union {
- uint64_t counter; /**< RW Main Counter Value Register. */
- struct {
- uint32_t counter_l; /**< RW Main Counter Low. */
- uint32_t counter_h; /**< RW Main Counter High. */
- };
- };
- uint64_t reserved3; /**< Reserved for future use. */
- struct {
- uint64_t config; /**< RW Timer Config and Capability Reg. */
- uint64_t comp; /**< RW Timer Comparator Value Register. */
- uint64_t fsb; /**< RW FSB Interrupt Route Register. */
- uint64_t reserved4; /**< Reserved for future use. */
- } timers[HPET_TIMER_NUM]; /**< Set of HPET timers. */
-};
-
-/* Mmap'd hpet registers */
-static volatile struct eal_hpet_regs *eal_hpet = NULL;
-
-/* Period at which the HPET counter increments in
- * femtoseconds (10^-15 seconds). */
-static uint32_t eal_hpet_resolution_fs = 0;
-
-/* Frequency of the HPET counter in Hz */
-static uint64_t eal_hpet_resolution_hz = 0;
-
-/* Incremented 4 times during one 32bits hpet full count */
-static uint32_t eal_hpet_msb;
-
-static rte_thread_t msb_inc_thread_id;
-
-/*
- * This function runs on a specific thread to update a global variable
- * containing used to process MSB of the HPET (unfortunately, we need
- * this because hpet is 32 bits by default under linux).
- */
-static uint32_t
-hpet_msb_inc(__rte_unused void *arg)
-{
- uint32_t t;
-
- while (1) {
- t = (eal_hpet->counter_l >> 30);
- if (t != (eal_hpet_msb & 3))
- eal_hpet_msb ++;
- sleep(10);
- }
- return 0;
-}
-
-RTE_EXPORT_SYMBOL(rte_get_hpet_hz)
-uint64_t
-rte_get_hpet_hz(void)
-{
- const struct internal_config *internal_conf =
- eal_get_internal_configuration();
-
- if (internal_conf->no_hpet)
- rte_panic("Error, HPET called, but no HPET present\n");
-
- return eal_hpet_resolution_hz;
-}
-
-RTE_EXPORT_SYMBOL(rte_get_hpet_cycles)
-uint64_t
-rte_get_hpet_cycles(void)
-{
- uint32_t t, msb;
- uint64_t ret;
- const struct internal_config *internal_conf =
- eal_get_internal_configuration();
-
- if (internal_conf->no_hpet)
- rte_panic("Error, HPET called, but no HPET present\n");
-
- t = eal_hpet->counter_l;
- msb = eal_hpet_msb;
- ret = (msb + 2 - (t >> 30)) / 4;
- ret <<= 32;
- ret += t;
- return ret;
-}
-
-#endif
-
-#ifdef RTE_LIBEAL_USE_HPET
-/*
- * Open and mmap /dev/hpet (high precision event timer) that will
- * provide our time reference.
- */
-RTE_EXPORT_SYMBOL(rte_eal_hpet_init)
-int
-rte_eal_hpet_init(int make_default)
-{
- int fd, ret;
- struct internal_config *internal_conf =
- eal_get_internal_configuration();
-
- if (internal_conf->no_hpet) {
- EAL_LOG(NOTICE, "HPET is disabled");
- return -1;
- }
-
- fd = open(DEV_HPET, O_RDONLY);
- if (fd < 0) {
- EAL_LOG(ERR, "ERROR: Cannot open "DEV_HPET": %s!",
- strerror(errno));
- internal_conf->no_hpet = 1;
- return -1;
- }
- eal_hpet = mmap(NULL, 1024, PROT_READ, MAP_SHARED, fd, 0);
- if (eal_hpet == MAP_FAILED) {
- EAL_LOG(ERR, "ERROR: Cannot mmap "DEV_HPET"!");
- close(fd);
- internal_conf->no_hpet = 1;
- return -1;
- }
- close(fd);
-
- eal_hpet_resolution_fs = (uint32_t)((eal_hpet->capabilities &
- CLK_PERIOD_MASK) >>
- CLK_PERIOD_SHIFT);
-
- eal_hpet_resolution_hz = (1000ULL*1000ULL*1000ULL*1000ULL*1000ULL) /
- (uint64_t)eal_hpet_resolution_fs;
-
- EAL_LOG(INFO, "HPET frequency is ~%"PRIu64" kHz",
- eal_hpet_resolution_hz/1000);
-
- eal_hpet_msb = (eal_hpet->counter_l >> 30);
-
- /* create a thread that will increment a global variable for
- * msb (hpet is 32 bits by default under linux) */
- ret = rte_thread_create_internal_control(&msb_inc_thread_id, "hpet-msb",
- hpet_msb_inc, NULL);
- if (ret != 0) {
- EAL_LOG(ERR, "ERROR: Cannot create HPET timer thread!");
- internal_conf->no_hpet = 1;
- return -1;
- }
-
- if (make_default)
- eal_timer_source = EAL_TIMER_HPET;
- return 0;
-}
-#endif
-
/* Check if the kernel deems the arch provided TSC frequency trustworthy. */

static bool
diff --git a/lib/eal/linux/eal_timer_hpet.c b/lib/eal/linux/eal_timer_hpet.c
new file mode 100644
index 0000000000..63e38bd53e
--- /dev/null
+++ b/lib/eal/linux/eal_timer_hpet.c
@@ -0,0 +1,179 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2014 Intel Corporation.
+ * Copyright(c) 2012-2013 6WIND S.A.
+ */
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <rte_cycles.h>
+#include <rte_thread.h>
+
+#include <eal_export.h>
+#include "eal_private.h"
+
+#define DEV_HPET "/dev/hpet"
+
+/* Maximum number of counters. */
+#define HPET_TIMER_NUM 3
+
+/* General capabilities register */
+#define CLK_PERIOD_SHIFT 32 /* Clock period shift. */
+#define CLK_PERIOD_MASK 0xffffffff00000000ULL /* Clock period mask. */
+
+/**
+ * HPET timer registers. From the Intel IA-PC HPET (High Precision Event
+ * Timers) Specification.
+ */
+struct eal_hpet_regs {
+ /* Memory-mapped, software visible registers */
+ uint64_t capabilities; /**< RO General Capabilities Register. */
+ uint64_t reserved0; /**< Reserved for future use. */
+ uint64_t config; /**< RW General Configuration Register. */
+ uint64_t reserved1; /**< Reserved for future use. */
+ uint64_t isr; /**< RW Clear General Interrupt Status. */
+ uint64_t reserved2[25]; /**< Reserved for future use. */
+ union {
+ uint64_t counter; /**< RW Main Counter Value Register. */
+ struct {
+ uint32_t counter_l; /**< RW Main Counter Low. */
+ uint32_t counter_h; /**< RW Main Counter High. */
+ };
+ };
+ uint64_t reserved3; /**< Reserved for future use. */
+ struct {
+ uint64_t config; /**< RW Timer Config and Capability Reg. */
+ uint64_t comp; /**< RW Timer Comparator Value Register. */
+ uint64_t fsb; /**< RW FSB Interrupt Route Register. */
+ uint64_t reserved4; /**< Reserved for future use. */
+ } timers[HPET_TIMER_NUM]; /**< Set of HPET timers. */
+};
+
+/* Mmap'd hpet registers */
+static volatile struct eal_hpet_regs *eal_hpet;
+
+/* Period at which the HPET counter increments in femtoseconds (10^-15 seconds). */
+static uint32_t eal_hpet_resolution_fs;
+
+/* Frequency of the HPET counter in Hz */
+static uint64_t eal_hpet_resolution_hz;
+
+/* Incremented 4 times during one 32bits hpet full count */
+static uint32_t eal_hpet_msb;
+
+static rte_thread_t msb_inc_thread_id;
+
+/*
+ * This function runs on a specific thread to update a global variable
+ * containing used to process MSB of the HPET (unfortunately, we need
+ * this because hpet is 32 bits by default under linux).
+ */
+static uint32_t
+hpet_msb_inc(__rte_unused void *arg)
+{
+ uint32_t t;
+
+ while (1) {
+ t = (eal_hpet->counter_l >> 30);
+ if (t != (eal_hpet_msb & 3))
+ eal_hpet_msb++;
+ sleep(10);
+ }
+ return 0;
+}
+
+RTE_EXPORT_SYMBOL(rte_get_hpet_hz)
+uint64_t
+rte_get_hpet_hz(void)
+{
+ const struct internal_config *internal_conf =
+ eal_get_internal_configuration();
+
+ if (internal_conf->no_hpet)
+ rte_panic("Error, HPET called, but no HPET present\n");
+
+ return eal_hpet_resolution_hz;
+}
+
+RTE_EXPORT_SYMBOL(rte_get_hpet_cycles)
+uint64_t
+rte_get_hpet_cycles(void)
+{
+ uint32_t t, msb;
+ uint64_t ret;
+ const struct internal_config *internal_conf =
+ eal_get_internal_configuration();
+
+ if (internal_conf->no_hpet)
+ rte_panic("Error, HPET called, but no HPET present\n");
+
+ t = eal_hpet->counter_l;
+ msb = eal_hpet_msb;
+ ret = (msb + 2 - (t >> 30)) / 4;
+ ret <<= 32;
+ ret += t;
+ return ret;
+}
+
+/*
+ * Open and mmap /dev/hpet (high precision event timer) that will
+ * provide our time reference.
+ */
+RTE_EXPORT_SYMBOL(rte_eal_hpet_init)
+int
+rte_eal_hpet_init(int make_default)
+{
+ int fd, ret;
+ struct internal_config *internal_conf =
+ eal_get_internal_configuration();
+
+ if (internal_conf->no_hpet) {
+ EAL_LOG(NOTICE, "HPET is disabled");
+ return -1;
+ }
+
+ fd = open(DEV_HPET, O_RDONLY);
+ if (fd < 0) {
+ EAL_LOG(ERR, "ERROR: Cannot open "DEV_HPET": %s!",
+ strerror(errno));
+ internal_conf->no_hpet = 1;
+ return -1;
+ }
+ eal_hpet = mmap(NULL, 1024, PROT_READ, MAP_SHARED, fd, 0);
+ if (eal_hpet == MAP_FAILED) {
+ EAL_LOG(ERR, "ERROR: Cannot mmap "DEV_HPET"!");
+ close(fd);
+ internal_conf->no_hpet = 1;
+ return -1;
+ }
+ close(fd);
+
+ eal_hpet_resolution_fs = (uint32_t)((eal_hpet->capabilities &
+ CLK_PERIOD_MASK) >>
+ CLK_PERIOD_SHIFT);
+
+ eal_hpet_resolution_hz = (1000ULL*1000ULL*1000ULL*1000ULL*1000ULL) /
+ (uint64_t)eal_hpet_resolution_fs;
+
+ EAL_LOG(INFO, "HPET frequency is ~%"PRIu64" kHz",
+ eal_hpet_resolution_hz/1000);
+
+ eal_hpet_msb = (eal_hpet->counter_l >> 30);
+
+ /* create a thread that will increment a global variable for
+ * msb (hpet is 32 bits by default under linux)
+ */
+ ret = rte_thread_create_internal_control(&msb_inc_thread_id, "hpet-msb",
+ hpet_msb_inc, NULL);
+ if (ret != 0) {
+ EAL_LOG(ERR, "ERROR: Cannot create HPET timer thread!");
+ internal_conf->no_hpet = 1;
+ return -1;
+ }
+
+ if (make_default)
+ eal_timer_source = EAL_TIMER_HPET;
+ return 0;
+}
diff --git a/lib/eal/linux/meson.build b/lib/eal/linux/meson.build
index e99ebed256..29ba313218 100644
--- a/lib/eal/linux/meson.build
+++ b/lib/eal/linux/meson.build
@@ -19,6 +19,10 @@ sources += files(
'eal_vfio_mp_sync.c',
)

+if dpdk_conf.get('RTE_LIBEAL_USE_HPET')
+ sources += files('eal_timer_hpet.c')
+endif
+
deps += ['kvargs', 'telemetry']
if has_libnuma
dpdk_conf.set10('RTE_EAL_NUMA_AWARE_HUGEPAGES', true)
--
2.53.0