/**
* nfp_cpp_mutex_reclaim() - Unlock mutex if held by local endpoint
* @cpp: NFP CPP handle
* @target: NFP CPP target ID (ie NFP_CPP_TARGET_CLS or NFP_CPP_TARGET_MU)
* @address: Offset into the address space of the NFP CPP target ID
*
* Release lock if held by local system. Extreme care is advised, call only
* when no local lock users can exist.
*
* Return: 0 if the lock was OK, 1 if locked by us, -errno on invalid mutex
*/
int nfp_cpp_mutex_reclaim(struct nfp_cpp *cpp, int target,
unsigned long long address)
{
const u32 mur = NFP_CPP_ID(target, 3, 0); /* atomic_read */
const u32 muw = NFP_CPP_ID(target, 4, 0); /* atomic_write */
u16 interface = nfp_cpp_interface(cpp);
int err;
u32 tmp;
err = nfp_cpp_mutex_validate(interface, &target, address);
if (err)
return err;
/* Check lock */
err = nfp_cpp_readl(cpp, mur, address, &tmp);
if (err < 0)
return err;
if (nfp_mutex_is_unlocked(tmp) || nfp_mutex_owner(tmp) != interface)
return 0;
/* Bust the lock */
err = nfp_cpp_writel(cpp, muw, address, nfp_mutex_unlocked(interface));
if (err < 0)
return err;
return 1;
}
/**
* nfp_cpp_mutex_alloc() - Create a mutex handle
* @cpp: NFP CPP handle
* @target: NFP CPP target ID (ie NFP_CPP_TARGET_CLS or NFP_CPP_TARGET_MU)
* @address: Offset into the address space of the NFP CPP target ID
* @key: 32-bit unique key (must match the key at this location)
*
* 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's CmpAndSwap32 command are supported.
*
* 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, u32 key)
{
const u32 mur = NFP_CPP_ID(target, 3, 0); /* atomic_read */
u16 interface = nfp_cpp_interface(cpp);
struct nfp_cpp_mutex *mutex;
int err;
u32 tmp;
err = nfp_cpp_mutex_validate(interface, &target, address);
if (err)
return NULL;
err = nfp_cpp_readl(cpp, mur, address + 4, &tmp);
if (err < 0)
return NULL;
if (tmp != key)
return NULL;
mutex = kzalloc(sizeof(*mutex), GFP_KERNEL);
if (!mutex)
return NULL;
mutex->cpp = cpp;
mutex->target = target;
mutex->address = address;
mutex->key = key;
mutex->depth = 0;
return mutex;
}
/**
* nfp_cpp_mutex_init() - Initialize a mutex location
* @cpp: NFP CPP handle
* @target: NFP CPP target ID (ie NFP_CPP_TARGET_CLS or NFP_CPP_TARGET_MU)
* @address: Offset into the address space of the NFP CPP target ID
* @key: Unique 32-bit value for this mutex
*
* 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.
*
* Return: 0 on success, or -errno on failure
*/
int nfp_cpp_mutex_init(struct nfp_cpp *cpp,
int target, unsigned long long address, u32 key)
{
const u32 muw = NFP_CPP_ID(target, 4, 0); /* atomic_write */
u16 interface = nfp_cpp_interface(cpp);
int err;
err = nfp_cpp_mutex_validate(interface, &target, address);
if (err)
return err;
err = nfp_cpp_writel(cpp, muw, address + 4, key);
if (err)
return err;
err = nfp_cpp_writel(cpp, muw, address, nfp_mutex_locked(interface));
if (err)
return err;
return 0;
}
/**
* nfp_net_fw_load() - Load the firmware image
* @pdev: PCI Device structure
* @pf: NFP PF Device structure
* @nsp: NFP SP handle
*
* Return: -ERRNO, 0 for no firmware loaded, 1 for firmware loaded
*/
static int
nfp_fw_load(struct pci_dev *pdev, struct nfp_pf *pf, struct nfp_nsp *nsp)
{
const struct firmware *fw;
u16 interface;
int err;
interface = nfp_cpp_interface(pf->cpp);
if (NFP_CPP_INTERFACE_UNIT_of(interface) != 0) {
/* Only Unit 0 should reset or load firmware */
dev_info(&pdev->dev, "Firmware will be loaded by partner\n");
return 0;
}
fw = nfp_net_fw_find(pdev, pf);
if (!fw)
return 0;
dev_info(&pdev->dev, "Soft-reset, loading FW image\n");
err = nfp_nsp_device_soft_reset(nsp);
if (err < 0) {
dev_err(&pdev->dev, "Failed to soft reset the NFP: %d\n",
err);
goto exit_release_fw;
}
err = nfp_nsp_load_fw(nsp, fw);
if (err < 0) {
dev_err(&pdev->dev, "FW loading failed: %d\n", err);
goto exit_release_fw;
}
dev_info(&pdev->dev, "Finished loading FW image\n");
exit_release_fw:
release_firmware(fw);
return err < 0 ? err : 1;
}
/**
* nfp_cpp_mutex_unlock() - Unlock a mutex handle, using the MU Atomic Engine
* @mutex: NFP CPP Mutex handle
*
* Return: 0 on success, or -errno on failure
*/
int nfp_cpp_mutex_unlock(struct nfp_cpp_mutex *mutex)
{
const u32 muw = NFP_CPP_ID(mutex->target, 4, 0); /* atomic_write */
const u32 mur = NFP_CPP_ID(mutex->target, 3, 0); /* atomic_read */
struct nfp_cpp *cpp = mutex->cpp;
u32 key, value;
u16 interface;
int err;
interface = nfp_cpp_interface(cpp);
if (mutex->depth > 1) {
mutex->depth--;
return 0;
}
err = nfp_cpp_readl(mutex->cpp, mur, mutex->address + 4, &key);
if (err < 0)
return err;
if (key != mutex->key)
return -EPERM;
err = nfp_cpp_readl(mutex->cpp, mur, mutex->address, &value);
if (err < 0)
return err;
if (value != nfp_mutex_locked(interface))
return -EACCES;
err = nfp_cpp_writel(cpp, muw, mutex->address,
nfp_mutex_unlocked(interface));
if (err < 0)
return err;
mutex->depth = 0;
return 0;
}
/**
* nfp_cpp_mutex_trylock() - Attempt to lock a mutex handle
* @mutex: NFP CPP Mutex handle
*
* Return: 0 if the lock succeeded, -errno on failure
*/
int nfp_cpp_mutex_trylock(struct nfp_cpp_mutex *mutex)
{
const u32 muw = NFP_CPP_ID(mutex->target, 4, 0); /* atomic_write */
const u32 mus = NFP_CPP_ID(mutex->target, 5, 3); /* test_set_imm */
const u32 mur = NFP_CPP_ID(mutex->target, 3, 0); /* atomic_read */
struct nfp_cpp *cpp = mutex->cpp;
u32 key, value, tmp;
int err;
if (mutex->depth > 0) {
if (mutex->depth == NFP_MUTEX_DEPTH_MAX)
return -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)
return err;
if (key != mutex->key)
return -EPERM;
/* Compare against the unlocked state, and if true,
* write the interface id into the top 16 bits, and
* mark as locked.
*/
value = nfp_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)
return err;
/* Was it unlocked? */
if (nfp_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)
return err;
mutex->depth = 1;
return 0;
}
return nfp_mutex_is_locked(tmp) ? -EBUSY : -EINVAL;
}
