--- /dev/null
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2018 Netronome Systems, Inc.
+ * All rights reserved.
+ */
+
+#include <errno.h>
+
+#include <malloc.h>
+#include <time.h>
+#include <sched.h>
+
+#include "nfp_cpp.h"
+#include "nfp6000/nfp6000.h"
+
+#define MUTEX_LOCKED(interface) ((((uint32_t)(interface)) << 16) | 0x000f)
+#define MUTEX_UNLOCK(interface) (0 | 0x0000)
+
+#define MUTEX_IS_LOCKED(value) (((value) & 0xffff) == 0x000f)
+#define MUTEX_IS_UNLOCKED(value) (((value) & 0xffff) == 0x0000)
+#define MUTEX_INTERFACE(value) (((value) >> 16) & 0xffff)
+
+/*
+ * If you need more than 65536 recursive locks, please
+ * rethink your code.
+ */
+#define MUTEX_DEPTH_MAX 0xffff
+
+struct nfp_cpp_mutex {
+ struct nfp_cpp *cpp;
+ uint8_t target;
+ uint16_t depth;
+ unsigned long long address;
+ uint32_t key;
+ unsigned int usage;
+ struct nfp_cpp_mutex *prev, *next;
+};
+
+static int
+_nfp_cpp_mutex_validate(uint32_t model, int *target, unsigned long long address)
+{
+ /* Address must be 64-bit aligned */
+ if (address & 7)
+ return NFP_ERRNO(EINVAL);
+
+ if (NFP_CPP_MODEL_IS_6000(model)) {
+ if (*target != NFP_CPP_TARGET_MU)
+ return NFP_ERRNO(EINVAL);
+ } else {
+ return NFP_ERRNO(EINVAL);
+ }
+
+ return 0;
+}
+
+/*
+ * Initialize a mutex location
+ *
+ * The CPP target:address must point to a 64-bit aligned location, and
+ * will initialize 64 bits of data at the location.
+ *
+ * This creates the initial mutex state, as locked by this
+ * nfp_cpp_interface().
+ *
+ * This function should only be called when setting up
+ * the initial lock state upon boot-up of the system.
+ *
+ * @param mutex NFP CPP Mutex handle
+ * @param target NFP CPP target ID (ie NFP_CPP_TARGET_CLS or
+ * NFP_CPP_TARGET_MU)
+ * @param address Offset into the address space of the NFP CPP target ID
+ * @param key Unique 32-bit value for this mutex
+ *
+ * @return 0 on success, or -1 on failure (and set errno accordingly).
+ */
+int
+nfp_cpp_mutex_init(struct nfp_cpp *cpp, int target, unsigned long long address,
+ uint32_t key)
+{
+ uint32_t model = nfp_cpp_model(cpp);
+ uint32_t muw = NFP_CPP_ID(target, 4, 0); /* atomic_write */
+ int err;
+
+ err = _nfp_cpp_mutex_validate(model, &target, address);
+ if (err < 0)
+ return err;
+
+ err = nfp_cpp_writel(cpp, muw, address + 4, key);
+ if (err < 0)
+ return err;
+
+ err =
+ nfp_cpp_writel(cpp, muw, address + 0,
+ MUTEX_LOCKED(nfp_cpp_interface(cpp)));
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+/*
+ * Create a mutex handle from an address controlled by a MU Atomic engine
+ *
+ * The CPP target:address must point to a 64-bit aligned location, and
+ * reserve 64 bits of data at the location for use by the handle.
+ *
+ * Only target/address pairs that point to entities that support the
+ * MU Atomic Engine are supported.
+ *
+ * @param cpp NFP CPP handle
+ * @param target NFP CPP target ID (ie NFP_CPP_TARGET_CLS or
+ * NFP_CPP_TARGET_MU)
+ * @param address Offset into the address space of the NFP CPP target ID
+ * @param key 32-bit unique key (must match the key at this location)
+ *
+ * @return A non-NULL struct nfp_cpp_mutex * on success, NULL on failure.
+ */
+struct nfp_cpp_mutex *
+nfp_cpp_mutex_alloc(struct nfp_cpp *cpp, int target,
+ unsigned long long address, uint32_t key)
+{
+ uint32_t model = nfp_cpp_model(cpp);
+ struct nfp_cpp_mutex *mutex;
+ uint32_t mur = NFP_CPP_ID(target, 3, 0); /* atomic_read */
+ int err;
+ uint32_t tmp;
+
+ /* Look for cached mutex */
+ for (mutex = cpp->mutex_cache; mutex; mutex = mutex->next) {
+ if (mutex->target == target && mutex->address == address)
+ break;
+ }
+
+ if (mutex) {
+ if (mutex->key == key) {
+ mutex->usage++;
+ return mutex;
+ }
+
+ /* If the key doesn't match... */
+ return NFP_ERRPTR(EEXIST);
+ }
+
+ err = _nfp_cpp_mutex_validate(model, &target, address);
+ if (err < 0)
+ return NULL;
+
+ err = nfp_cpp_readl(cpp, mur, address + 4, &tmp);
+ if (err < 0)
+ return NULL;
+
+ if (tmp != key)
+ return NFP_ERRPTR(EEXIST);
+
+ mutex = calloc(sizeof(*mutex), 1);
+ if (!mutex)
+ return NFP_ERRPTR(ENOMEM);
+
+ mutex->cpp = cpp;
+ mutex->target = target;
+ mutex->address = address;
+ mutex->key = key;
+ mutex->depth = 0;
+ mutex->usage = 1;
+
+ /* Add mutex to the cache */
+ if (cpp->mutex_cache) {
+ cpp->mutex_cache->prev = mutex;
+ mutex->next = cpp->mutex_cache;
+ cpp->mutex_cache = mutex;
+ } else {
+ cpp->mutex_cache = mutex;
+ }
+
+ return mutex;
+}
+
+struct nfp_cpp *
+nfp_cpp_mutex_cpp(struct nfp_cpp_mutex *mutex)
+{
+ return mutex->cpp;
+}
+
+uint32_t
+nfp_cpp_mutex_key(struct nfp_cpp_mutex *mutex)
+{
+ return mutex->key;
+}
+
+uint16_t
+nfp_cpp_mutex_owner(struct nfp_cpp_mutex *mutex)
+{
+ uint32_t mur = NFP_CPP_ID(mutex->target, 3, 0); /* atomic_read */
+ uint32_t value, key;
+ int err;
+
+ err = nfp_cpp_readl(mutex->cpp, mur, mutex->address, &value);
+ if (err < 0)
+ return err;
+
+ err = nfp_cpp_readl(mutex->cpp, mur, mutex->address + 4, &key);
+ if (err < 0)
+ return err;
+
+ if (key != mutex->key)
+ return NFP_ERRNO(EPERM);
+
+ if (!MUTEX_IS_LOCKED(value))
+ return 0;
+
+ return MUTEX_INTERFACE(value);
+}
+
+int
+nfp_cpp_mutex_target(struct nfp_cpp_mutex *mutex)
+{
+ return mutex->target;
+}
+
+uint64_t
+nfp_cpp_mutex_address(struct nfp_cpp_mutex *mutex)
+{
+ return mutex->address;
+}
+
+/*
+ * Free a mutex handle - does not alter the lock state
+ *
+ * @param mutex NFP CPP Mutex handle
+ */
+void
+nfp_cpp_mutex_free(struct nfp_cpp_mutex *mutex)
+{
+ mutex->usage--;
+ if (mutex->usage > 0)
+ return;
+
+ /* Remove mutex from the cache */
+ if (mutex->next)
+ mutex->next->prev = mutex->prev;
+ if (mutex->prev)
+ mutex->prev->next = mutex->next;
+
+ /* If mutex->cpp == NULL, something broke */
+ if (mutex->cpp && mutex == mutex->cpp->mutex_cache)
+ mutex->cpp->mutex_cache = mutex->next;
+
+ free(mutex);
+}
+
+/*
+ * Lock a mutex handle, using the NFP MU Atomic Engine
+ *
+ * @param mutex NFP CPP Mutex handle
+ *
+ * @return 0 on success, or -1 on failure (and set errno accordingly).
+ */
+int
+nfp_cpp_mutex_lock(struct nfp_cpp_mutex *mutex)
+{
+ int err;
+ time_t warn_at = time(NULL) + 15;
+
+ while ((err = nfp_cpp_mutex_trylock(mutex)) != 0) {
+ /* If errno != EBUSY, then the lock was damaged */
+ if (err < 0 && errno != EBUSY)
+ return err;
+ if (time(NULL) >= warn_at) {
+ printf("Warning: waiting for NFP mutex\n");
+ printf("\tusage:%u\n", mutex->usage);
+ printf("\tdepth:%hd]\n", mutex->depth);
+ printf("\ttarget:%d\n", mutex->target);
+ printf("\taddr:%llx\n", mutex->address);
+ printf("\tkey:%08x]\n", mutex->key);
+ warn_at = time(NULL) + 60;
+ }
+ sched_yield();
+ }
+ return 0;
+}
+
+/*
+ * Unlock a mutex handle, using the NFP MU Atomic Engine
+ *
+ * @param mutex NFP CPP Mutex handle
+ *
+ * @return 0 on success, or -1 on failure (and set errno accordingly).
+ */
+int
+nfp_cpp_mutex_unlock(struct nfp_cpp_mutex *mutex)
+{
+ uint32_t muw = NFP_CPP_ID(mutex->target, 4, 0); /* atomic_write */
+ uint32_t mur = NFP_CPP_ID(mutex->target, 3, 0); /* atomic_read */
+ struct nfp_cpp *cpp = mutex->cpp;
+ uint32_t key, value;
+ uint16_t interface = nfp_cpp_interface(cpp);
+ int err;
+
+ if (mutex->depth > 1) {
+ mutex->depth--;
+ return 0;
+ }
+
+ err = nfp_cpp_readl(mutex->cpp, mur, mutex->address, &value);
+ if (err < 0)
+ goto exit;
+
+ err = nfp_cpp_readl(mutex->cpp, mur, mutex->address + 4, &key);
+ if (err < 0)
+ goto exit;
+
+ if (key != mutex->key) {
+ err = NFP_ERRNO(EPERM);
+ goto exit;
+ }
+
+ if (value != MUTEX_LOCKED(interface)) {
+ err = NFP_ERRNO(EACCES);
+ goto exit;
+ }
+
+ err = nfp_cpp_writel(cpp, muw, mutex->address, MUTEX_UNLOCK(interface));
+ if (err < 0)
+ goto exit;
+
+ mutex->depth = 0;
+
+exit:
+ return err;
+}
+
+/*
+ * Attempt to lock a mutex handle, using the NFP MU Atomic Engine
+ *
+ * Valid lock states:
+ *
+ * 0x....0000 - Unlocked
+ * 0x....000f - Locked
+ *
+ * @param mutex NFP CPP Mutex handle
+ * @return 0 if the lock succeeded, -1 on failure (and errno set
+ * appropriately).
+ */
+int
+nfp_cpp_mutex_trylock(struct nfp_cpp_mutex *mutex)
+{
+ uint32_t mur = NFP_CPP_ID(mutex->target, 3, 0); /* atomic_read */
+ uint32_t muw = NFP_CPP_ID(mutex->target, 4, 0); /* atomic_write */
+ uint32_t mus = NFP_CPP_ID(mutex->target, 5, 3); /* test_set_imm */
+ uint32_t key, value, tmp;
+ struct nfp_cpp *cpp = mutex->cpp;
+ int err;
+
+ if (mutex->depth > 0) {
+ if (mutex->depth == MUTEX_DEPTH_MAX)
+ return NFP_ERRNO(E2BIG);
+
+ mutex->depth++;
+ return 0;
+ }
+
+ /* Verify that the lock marker is not damaged */
+ err = nfp_cpp_readl(cpp, mur, mutex->address + 4, &key);
+ if (err < 0)
+ goto exit;
+
+ if (key != mutex->key) {
+ err = NFP_ERRNO(EPERM);
+ goto exit;
+ }
+
+ /*
+ * Compare against the unlocked state, and if true,
+ * write the interface id into the top 16 bits, and
+ * mark as locked.
+ */
+ value = MUTEX_LOCKED(nfp_cpp_interface(cpp));
+
+ /*
+ * We use test_set_imm here, as it implies a read
+ * of the current state, and sets the bits in the
+ * bytemask of the command to 1s. Since the mutex
+ * is guaranteed to be 64-bit aligned, the bytemask
+ * of this 32-bit command is ensured to be 8'b00001111,
+ * which implies that the lower 4 bits will be set to
+ * ones regardless of the initial state.
+ *
+ * Since this is a 'Readback' operation, with no Pull
+ * data, we can treat this as a normal Push (read)
+ * atomic, which returns the original value.
+ */
+ err = nfp_cpp_readl(cpp, mus, mutex->address, &tmp);
+ if (err < 0)
+ goto exit;
+
+ /* Was it unlocked? */
+ if (MUTEX_IS_UNLOCKED(tmp)) {
+ /*
+ * The read value can only be 0x....0000 in the unlocked state.
+ * If there was another contending for this lock, then
+ * the lock state would be 0x....000f
+ *
+ * Write our owner ID into the lock
+ * While not strictly necessary, this helps with
+ * debug and bookkeeping.
+ */
+ err = nfp_cpp_writel(cpp, muw, mutex->address, value);
+ if (err < 0)
+ goto exit;
+
+ mutex->depth = 1;
+ goto exit;
+ }
+
+ /* Already locked by us? Success! */
+ if (tmp == value) {
+ mutex->depth = 1;
+ goto exit;
+ }
+
+ err = NFP_ERRNO(MUTEX_IS_LOCKED(tmp) ? EBUSY : EINVAL);
+
+exit:
+ return err;
+}
Code Review / deb_dpdk.git / blobdiff