[PATCH iwl] ice: acquire NVM lock around each flash read
From: Robert Malz <hidden>
Date: 2026-07-03 10:33:45
Also in:
intel-wired-lan, lkml
Subsystem:
intel ethernet drivers, networking drivers, the rest · Maintainers:
Tony Nguyen, Przemek Kitszel, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
FW caps the NVM read lock at a maximum of 3000ms regardless of the timeout
requested via ice_acquire_nvm(). ice_read_flat_nvm() splits a read into
multiple ice_aq_read_nvm() commands, one per 4KB sector, all issued under a
single lock taken by the caller. Reading a large region can exceed 3000ms,
so FW reclaims the lock mid-read and the remaining commands might fail.
Move the lock acquire/release into ice_read_flat_nvm() so it brackets each
individual ice_aq_read_nvm() command, ensuring the lock is never held
across more than one FW read. ice_release_nvm() issues its own AQ command
and would overwrite sq_last_status, so the read's AQ error is preserved
across the release for callers such as ice_discover_flash_size() that
inspect it.
Callers that previously took the lock around ice_read_flat_nvm(),
ice_read_sr_word() or ice_read_flash_module() now call them without it.
The per-block locking in ice_devlink_nvm_snapshot() is now redundant
and dropped.
Fixes: e94509906d6b ("ice: create function to read a section of the NVM and Shadow RAM")
Signed-off-by: Robert Malz <redacted>
---
.../net/ethernet/intel/ice/devlink/devlink.c | 21 -------
drivers/net/ethernet/intel/ice/ice_ethtool.c | 11 +---
drivers/net/ethernet/intel/ice/ice_nvm.c | 58 ++++++++++---------
3 files changed, 32 insertions(+), 58 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/devlink/devlink.c b/drivers/net/ethernet/intel/ice/devlink/devlink.c
index 22b7d8e6bd9e..7c7fe3d2e9d9 100644
--- a/drivers/net/ethernet/intel/ice/devlink/devlink.c
+++ b/drivers/net/ethernet/intel/ice/devlink/devlink.c@@ -1891,26 +1891,15 @@ static int ice_devlink_nvm_snapshot(struct devlink *devlink, for (i = 0; i < num_blks; i++) { u32 read_sz = min_t(u32, ICE_DEVLINK_READ_BLK_SIZE, left); - status = ice_acquire_nvm(hw, ICE_RES_READ); - if (status) { - dev_dbg(dev, "ice_acquire_nvm failed, err %d aq_err %d\n", - status, hw->adminq.sq_last_status); - NL_SET_ERR_MSG_MOD(extack, "Failed to acquire NVM semaphore"); - vfree(nvm_data); - return -EIO; - } - status = ice_read_flat_nvm(hw, i * ICE_DEVLINK_READ_BLK_SIZE, &read_sz, tmp, read_shadow_ram); if (status) { dev_dbg(dev, "ice_read_flat_nvm failed after reading %u bytes, err %d aq_err %d\n", read_sz, status, hw->adminq.sq_last_status); NL_SET_ERR_MSG_MOD(extack, "Failed to read NVM contents"); - ice_release_nvm(hw); vfree(nvm_data); return -EIO; } - ice_release_nvm(hw); tmp += read_sz; left -= read_sz;
@@ -1966,24 +1955,14 @@ static int ice_devlink_nvm_read(struct devlink *devlink, return -ERANGE; } - status = ice_acquire_nvm(hw, ICE_RES_READ); - if (status) { - dev_dbg(dev, "ice_acquire_nvm failed, err %d aq_err %d\n", - status, hw->adminq.sq_last_status); - NL_SET_ERR_MSG_MOD(extack, "Failed to acquire NVM semaphore"); - return -EIO; - } - status = ice_read_flat_nvm(hw, (u32)offset, &size, data, read_shadow_ram); if (status) { dev_dbg(dev, "ice_read_flat_nvm failed after reading %u bytes, err %d aq_err %d\n", size, status, hw->adminq.sq_last_status); NL_SET_ERR_MSG_MOD(extack, "Failed to read NVM contents"); - ice_release_nvm(hw); return -EIO; } - ice_release_nvm(hw); return 0; }
diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
index 49371b065845..ddeca39d822b 100644
--- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
+++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c@@ -869,24 +869,15 @@ ice_get_eeprom(struct net_device *netdev, struct ethtool_eeprom *eeprom, if (!buf) return -ENOMEM; - ret = ice_acquire_nvm(hw, ICE_RES_READ); - if (ret) { - dev_err(dev, "ice_acquire_nvm failed, err %d aq_err %s\n", - ret, libie_aq_str(hw->adminq.sq_last_status)); - goto out; - } - ret = ice_read_flat_nvm(hw, eeprom->offset, &eeprom->len, buf, false); if (ret) { dev_err(dev, "ice_read_flat_nvm failed, err %d aq_err %s\n", ret, libie_aq_str(hw->adminq.sq_last_status)); - goto release; + goto out; } memcpy(bytes, buf, eeprom->len); -release: - ice_release_nvm(hw); out: kfree(buf); return ret;
diff --git a/drivers/net/ethernet/intel/ice/ice_nvm.c b/drivers/net/ethernet/intel/ice/ice_nvm.c
index 7e187a804dfa..cb1541844242 100644
--- a/drivers/net/ethernet/intel/ice/ice_nvm.c
+++ b/drivers/net/ethernet/intel/ice/ice_nvm.c@@ -58,6 +58,11 @@ int ice_aq_read_nvm(struct ice_hw *hw, u16 module_typeid, u32 offset, * breaks read requests across Shadow RAM sectors and ensures that no single * read request exceeds the maximum 4KB read for a single AdminQ command. * + * FW caps the read lock at a maximum of 3000ms, so a read spanning multiple + * 4KB sectors cannot be done under a single lock without FW reclaiming it + * mid-read. The NVM lock is therefore acquired and released around each AQ + * read, so this function must be called without the lock held. + * * Returns a status code on failure. Note that the data pointer may be * partially updated if some reads succeed before a failure. */
@@ -65,6 +70,7 @@ int ice_read_flat_nvm(struct ice_hw *hw, u32 offset, u32 *length, u8 *data, bool read_shadow_ram) { + enum libie_aq_err aq_err; u32 inlen = *length; u32 bytes_read = 0; bool last_cmd;
@@ -92,12 +98,28 @@ ice_read_flat_nvm(struct ice_hw *hw, u32 offset, u32 *length, u8 *data, last_cmd = !(bytes_read + read_size < inlen); + status = ice_acquire_nvm(hw, ICE_RES_READ); + if (status) + break; + status = ice_aq_read_nvm(hw, ICE_AQC_NVM_START_POINT, offset, read_size, data + bytes_read, last_cmd, read_shadow_ram, NULL); - if (status) + if (status) { + /* ice_release_nvm() issues an AQ command that would + * overwrite sq_last_status, which some callers + * inspect after a failed read. Preserve the read's + * AQ error across the release. + */ + aq_err = hw->adminq.sq_last_status; + + ice_release_nvm(hw); + hw->adminq.sq_last_status = aq_err; break; + } + + ice_release_nvm(hw); bytes_read += read_size; offset += read_size;
@@ -330,14 +352,8 @@ ice_read_flash_module(struct ice_hw *hw, enum ice_bank_select bank, u16 module, return -EINVAL; } - status = ice_acquire_nvm(hw, ICE_RES_READ); - if (status) - return status; - status = ice_read_flat_nvm(hw, start + offset, &length, data, false); - ice_release_nvm(hw); - return status; }
@@ -419,24 +435,19 @@ ice_read_netlist_module(struct ice_hw *hw, enum ice_bank_select bank, u32 offset } /** - * ice_read_sr_word - Reads Shadow RAM word and acquire NVM if necessary + * ice_read_sr_word - Reads Shadow RAM word * @hw: pointer to the HW structure * @offset: offset of the Shadow RAM word to read (0x000000 - 0x001FFF) * @data: word read from the Shadow RAM * - * Reads one 16 bit word from the Shadow RAM using the ice_read_sr_word_aq. + * Reads one 16 bit word from the Shadow RAM using ice_read_sr_word_aq. + * + * The NVM lock is acquired and released internally by ice_read_flat_nvm() + * around the FW read, so this function must be called without the lock held. */ int ice_read_sr_word(struct ice_hw *hw, u16 offset, u16 *data) { - int status; - - status = ice_acquire_nvm(hw, ICE_RES_READ); - if (!status) { - status = ice_read_sr_word_aq(hw, offset, data); - ice_release_nvm(hw); - } - - return status; + return ice_read_sr_word_aq(hw, offset, data); } /**
@@ -856,11 +867,7 @@ int ice_get_inactive_netlist_ver(struct ice_hw *hw, struct ice_netlist_info *net static int ice_discover_flash_size(struct ice_hw *hw) { u32 min_size = 0, max_size = ICE_AQC_NVM_MAX_OFFSET + 1; - int status; - - status = ice_acquire_nvm(hw, ICE_RES_READ); - if (status) - return status; + int status = 0; while ((max_size - min_size) > 1) { u32 offset = (max_size + min_size) / 2;
@@ -880,7 +887,7 @@ static int ice_discover_flash_size(struct ice_hw *hw) min_size = offset; } else { /* an unexpected error occurred */ - goto err_read_flat_nvm; + return status; } }
@@ -888,9 +895,6 @@ static int ice_discover_flash_size(struct ice_hw *hw) hw->flash.flash_size = max_size; -err_read_flat_nvm: - ice_release_nvm(hw); - return status; }
--
2.34.1