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// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/* Copyright (c) 2019 Mellanox Technologies */
#include <linux/pci.h>
#include "mlx5_core.h"
#include "pci_vsc.h"
#define MLX5_EXTRACT_C(source, offset, size) \
((((u32)(source)) >> (offset)) & MLX5_ONES32(size))
#define MLX5_EXTRACT(src, start, len) \
(((len) == 32) ? (src) : MLX5_EXTRACT_C(src, start, len))
#define MLX5_ONES32(size) \
((size) ? (0xffffffff >> (32 - (size))) : 0)
#define MLX5_MASK32(offset, size) \
(MLX5_ONES32(size) << (offset))
#define MLX5_MERGE_C(rsrc1, rsrc2, start, len) \
((((rsrc2) << (start)) & (MLX5_MASK32((start), (len)))) | \
((rsrc1) & (~MLX5_MASK32((start), (len)))))
#define MLX5_MERGE(rsrc1, rsrc2, start, len) \
(((len) == 32) ? (rsrc2) : MLX5_MERGE_C(rsrc1, rsrc2, start, len))
#define vsc_read(dev, offset, val) \
pci_read_config_dword((dev)->pdev, (dev)->vsc_addr + (offset), (val))
#define vsc_write(dev, offset, val) \
pci_write_config_dword((dev)->pdev, (dev)->vsc_addr + (offset), (val))
#define VSC_MAX_RETRIES 2048
enum {
VSC_CTRL_OFFSET = 0x4,
VSC_COUNTER_OFFSET = 0x8,
VSC_SEMAPHORE_OFFSET = 0xc,
VSC_ADDR_OFFSET = 0x10,
VSC_DATA_OFFSET = 0x14,
VSC_FLAG_BIT_OFFS = 31,
VSC_FLAG_BIT_LEN = 1,
VSC_SYND_BIT_OFFS = 30,
VSC_SYND_BIT_LEN = 1,
VSC_ADDR_BIT_OFFS = 0,
VSC_ADDR_BIT_LEN = 30,
VSC_SPACE_BIT_OFFS = 0,
VSC_SPACE_BIT_LEN = 16,
VSC_SIZE_VLD_BIT_OFFS = 28,
VSC_SIZE_VLD_BIT_LEN = 1,
VSC_STATUS_BIT_OFFS = 29,
VSC_STATUS_BIT_LEN = 3,
};
void mlx5_pci_vsc_init(struct mlx5_core_dev *dev)
{
if (!mlx5_core_is_pf(dev))
return;
dev->vsc_addr = pci_find_capability(dev->pdev,
PCI_CAP_ID_VNDR);
if (!dev->vsc_addr)
mlx5_core_warn(dev, "Failed to get valid vendor specific ID\n");
}
int mlx5_vsc_gw_lock(struct mlx5_core_dev *dev)
{
u32 counter = 0;
int retries = 0;
u32 lock_val;
int ret;
pci_cfg_access_lock(dev->pdev);
do {
if (retries > VSC_MAX_RETRIES) {
ret = -EBUSY;
goto pci_unlock;
}
/* Check if semaphore is already locked */
ret = vsc_read(dev, VSC_SEMAPHORE_OFFSET, &lock_val);
if (ret)
goto pci_unlock;
if (lock_val) {
retries++;
usleep_range(1000, 2000);
continue;
}
/* Read and write counter value, if written value is
* the same, semaphore was acquired successfully.
*/
ret = vsc_read(dev, VSC_COUNTER_OFFSET, &counter);
if (ret)
goto pci_unlock;
ret = vsc_write(dev, VSC_SEMAPHORE_OFFSET, counter);
if (ret)
goto pci_unlock;
ret = vsc_read(dev, VSC_SEMAPHORE_OFFSET, &lock_val);
if (ret)
goto pci_unlock;
retries++;
} while (counter != lock_val);
return 0;
pci_unlock:
pci_cfg_access_unlock(dev->pdev);
return ret;
}
int mlx5_vsc_gw_unlock(struct mlx5_core_dev *dev)
{
int ret;
ret = vsc_write(dev, VSC_SEMAPHORE_OFFSET, MLX5_VSC_UNLOCK);
pci_cfg_access_unlock(dev->pdev);
return ret;
}
int mlx5_vsc_gw_set_space(struct mlx5_core_dev *dev, u16 space,
u32 *ret_space_size)
{
int ret;
u32 val = 0;
if (!mlx5_vsc_accessible(dev))
return -EINVAL;
if (ret_space_size)
*ret_space_size = 0;
/* Get a unique val */
ret = vsc_read(dev, VSC_CTRL_OFFSET, &val);
if (ret)
goto out;
/* Try to modify the lock */
val = MLX5_MERGE(val, space, VSC_SPACE_BIT_OFFS, VSC_SPACE_BIT_LEN);
ret = vsc_write(dev, VSC_CTRL_OFFSET, val);
if (ret)
goto out;
/* Verify lock was modified */
ret = vsc_read(dev, VSC_CTRL_OFFSET, &val);
if (ret)
goto out;
if (MLX5_EXTRACT(val, VSC_STATUS_BIT_OFFS, VSC_STATUS_BIT_LEN) == 0)
return -EINVAL;
/* Get space max address if indicated by size valid bit */
if (ret_space_size &&
MLX5_EXTRACT(val, VSC_SIZE_VLD_BIT_OFFS, VSC_SIZE_VLD_BIT_LEN)) {
ret = vsc_read(dev, VSC_ADDR_OFFSET, &val);
if (ret) {
mlx5_core_warn(dev, "Failed to get max space size\n");
goto out;
}
*ret_space_size = MLX5_EXTRACT(val, VSC_ADDR_BIT_OFFS,
VSC_ADDR_BIT_LEN);
}
return 0;
out:
return ret;
}
static int mlx5_vsc_wait_on_flag(struct mlx5_core_dev *dev, u8 expected_val)
{
int retries = 0;
u32 flag;
int ret;
do {
if (retries > VSC_MAX_RETRIES)
return -EBUSY;
ret = vsc_read(dev, VSC_ADDR_OFFSET, &flag);
if (ret)
return ret;
flag = MLX5_EXTRACT(flag, VSC_FLAG_BIT_OFFS, VSC_FLAG_BIT_LEN);
retries++;
if ((retries & 0xf) == 0)
usleep_range(1000, 2000);
} while (flag != expected_val);
return 0;
}
static int mlx5_vsc_gw_write(struct mlx5_core_dev *dev, unsigned int address,
u32 data)
{
int ret;
if (MLX5_EXTRACT(address, VSC_SYND_BIT_OFFS,
VSC_FLAG_BIT_LEN + VSC_SYND_BIT_LEN))
return -EINVAL;
/* Set flag to 0x1 */
address = MLX5_MERGE(address, 1, VSC_FLAG_BIT_OFFS, 1);
ret = vsc_write(dev, VSC_DATA_OFFSET, data);
if (ret)
goto out;
ret = vsc_write(dev, VSC_ADDR_OFFSET, address);
if (ret)
goto out;
/* Wait for the flag to be cleared */
ret = mlx5_vsc_wait_on_flag(dev, 0);
out:
return ret;
}
static int mlx5_vsc_gw_read(struct mlx5_core_dev *dev, unsigned int address,
u32 *data)
{
int ret;
if (MLX5_EXTRACT(address, VSC_SYND_BIT_OFFS,
VSC_FLAG_BIT_LEN + VSC_SYND_BIT_LEN))
return -EINVAL;
ret = vsc_write(dev, VSC_ADDR_OFFSET, address);
if (ret)
goto out;
ret = mlx5_vsc_wait_on_flag(dev, 1);
if (ret)
goto out;
ret = vsc_read(dev, VSC_DATA_OFFSET, data);
out:
return ret;
}
static int mlx5_vsc_gw_read_fast(struct mlx5_core_dev *dev,
unsigned int read_addr,
unsigned int *next_read_addr,
u32 *data)
{
int ret;
ret = mlx5_vsc_gw_read(dev, read_addr, data);
if (ret)
goto out;
ret = vsc_read(dev, VSC_ADDR_OFFSET, next_read_addr);
if (ret)
goto out;
*next_read_addr = MLX5_EXTRACT(*next_read_addr, VSC_ADDR_BIT_OFFS,
VSC_ADDR_BIT_LEN);
if (*next_read_addr <= read_addr)
ret = -EINVAL;
out:
return ret;
}
int mlx5_vsc_gw_read_block_fast(struct mlx5_core_dev *dev, u32 *data,
int length)
{
unsigned int next_read_addr = 0;
unsigned int read_addr = 0;
while (read_addr < length) {
if (mlx5_vsc_gw_read_fast(dev, read_addr, &next_read_addr,
&data[(read_addr >> 2)]))
return read_addr;
read_addr = next_read_addr;
}
return length;
}
int mlx5_vsc_sem_set_space(struct mlx5_core_dev *dev, u16 space,
enum mlx5_vsc_state state)
{
u32 data, id = 0;
int ret;
ret = mlx5_vsc_gw_set_space(dev, MLX5_SEMAPHORE_SPACE_DOMAIN, NULL);
if (ret) {
mlx5_core_warn(dev, "Failed to set gw space %d\n", ret);
return ret;
}
if (state == MLX5_VSC_LOCK) {
/* Get a unique ID based on the counter */
ret = vsc_read(dev, VSC_COUNTER_OFFSET, &id);
if (ret)
return ret;
}
/* Try to modify lock */
ret = mlx5_vsc_gw_write(dev, space, id);
if (ret)
return ret;
/* Verify lock was modified */
ret = mlx5_vsc_gw_read(dev, space, &data);
if (ret)
return -EINVAL;
if (data != id)
return -EBUSY;
return 0;
}
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