Merge tag 'nand/for-4.19' of git://git.infradead.org/linux-mtd into mtd/next

Pull NAND updates from Miquel Raynal:

"
 NAND core changes:
 - Add the SPI-NAND framework.
 - Create a helper to find the best ECC configuration.
 - Create NAND controller operations.
 - Allocate dynamically ONFI parameters structure.
 - Add defines for ONFI version bits.
 - Add manufacturer fixup for ONFI parameter page.
 - Add an option to specify NAND chip as a boot device.
 - Add Reed-Solomon error correction algorithm.
 - Better name for the controller structure.
 - Remove unused caller_is_module() definition.
 - Make subop helpers return unsigned values.
 - Expose _notsupp() helpers for raw page accessors.
 - Add default values for dynamic timings.
 - Kill the chip->scan_bbt() hook.
 - Rename nand_default_bbt() into nand_create_bbt().
 - Start to clean the nand_chip structure.
 - Remove stale prototype from rawnand.h.

 Raw NAND controllers drivers changes:
 - Qcom: structuring cleanup.
 - Denali: use core helper to find the best ECC configuration.
 - Possible build of almost all drivers by adding a dependency on
   COMPILE_TEST for almost all of them in Kconfig, implies various
   fixes, Kconfig cleanup, GPIO headers inclusion cleanup, and even
   changes in sparc64 and ia64 architectures.
 - Clean the ->probe() functions error path of a lot of drivers.
 - Migrate all drivers to use nand_scan() instead of
   nand_scan_ident()/nand_scan_tail() pair.
 - Use mtd_device_register() where applicable to simplify the code.
 - Marvell:
   * Handle on-die ECC.
   * Better clocks handling.
   * Remove bogus comment.
   * Add suspend and resume support.
 - Tegra: add NAND controller driver.
 - Atmel:
   * Add module param to avoid using dma.
   * Drop Wenyou Yang from MAINTAINERS.
 - Denali: optimize timings handling.
 - FSMC: Stop using chip->read_buf().
 - FSL:
   * Switch to SPDX license tag identifiers.
   * Fix qualifiers in MXC init functions.

 Raw NAND chip drivers changes:
 - Micron:
   * Add fixup for ONFI revision.
   * Update ecc_stats.corrected.
   * Make ECC activation stateful.
   * Avoid enabling/disabling ECC when it can't be disabled.
   * Get the actual number of bitflips.
   * Allow forced on-die ECC.
   * Support 8/512 on-die ECC.
   * Fix on-die ECC detection logic.
 - Hynix:
   * Fix decoding the OOB size on H27UCG8T2BTR.
   * Use ->exec_op() in hynix_nand_reg_write_op().
"

1 files changed, 16 insertions, 0 deletions

diff --git a/lib/dec_and_lock.c b/lib/dec_and_lock.c
index 347fa7ac2e8a..9555b68bb774 100644
--- a/lib/dec_and_lock.c
+++ b/lib/dec_and_lock.c
@@ -33,3 +33,19 @@ int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
 }
 
 EXPORT_SYMBOL(_atomic_dec_and_lock);
+
+int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock,
+				 unsigned long *flags)
+{
+	/* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
+	if (atomic_add_unless(atomic, -1, 1))
+		return 0;
+
+	/* Otherwise do it the slow way */
+	spin_lock_irqsave(lock, *flags);
+	if (atomic_dec_and_test(atomic))
+		return 1;
+	spin_unlock_irqrestore(lock, *flags);
+	return 0;
+}
+EXPORT_SYMBOL(_atomic_dec_and_lock_irqsave);