Merge tag 'mtd/for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux

Pull MTD updates from Miquel Raynal:
 "Core MTD changes:
   - mtdchar: add MEMREAD ioctl
   - Add ECC error accounting for each read request
   - always initialize 'stats' in struct mtd_oob_ops
   - Track maximum number of bitflips for each read request
   - Fix repeated word in comment
   - Move from strlcpy with unused retval to strscpy
   - Fix a typo in a comment
   - Add binding for U-Boot bootloader partitions

  MTD device drivers changes:
   - FTL: use container_of() rather than cast
   - docg3:
      - Use correct function names in comment blocks
      - Check the return value of devm_ioremap() in the probe
   - physmap-core: Fix NULL pointer dereferencing in
     of_select_probe_type()
   - parsers: add Broadcom's U-Boot parser

  Raw NAND core changes:
   - Replace of_gpio_named_count() by gpiod_count()
   - Remove misguided comment of nand_get_device()
   - bbt: Use the bitmap API to allocate bitmaps

  Raw NAND controller drivers changes:
   - Meson:
      - Stop supporting legacy clocks
      - Refine resource getting in probe
      - Convert bindings to yaml
      - Fix clock handling and update the bindings accordingly
      - Fix bit map use in meson_nfc_ecc_correct()
   - bcm47xx:
      - Fix spelling typo in comment
   - STM32 FMC2:
      - Switch to using devm_fwnode_gpiod_get()
      - Fix dma_map_sg error check
   - Cadence:
      - Remove an unneeded result variable
   - Marvell:
      - Fix error handle regarding dma_map_sg
   - Orion:
      - Use devm_clk_get_optional()
   - Cafe:
      - Use correct function name in comment block
   - Atmel:
      - Unmap streaming DMA mappings
   - Arasan:
      - Stop using 0 as NULL pointer
   - GPMI:
      - Fix typo 'the the' in comment
   - BRCM:
      - Add individual glue driver selection
      - Move Kconfig to driver folder
   - FSL: Fix none ECC mode
   - Intel:
      - Use devm_platform_ioremap_resource_byname()
      - Remove unused clk_rate member from struct ebu_nand
      - Remove unused nand_pa member from ebu_nand_cs
      - Don't re-define NAND_DATA_IFACE_CHECK_ONLY
      - Remove undocumented compatible string
      - Fix compatible string in the bindings
      - Read the chip-select line from the correct OF node
      - Fix maximum chip select value in the bindings"

* tag 'mtd/for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: (43 commits)
  mtd: rawnand: meson: stop supporting legacy clocks
  dt-bindings: nand: meson: convert txt to yaml
  mtd: rawnand: meson: refine resource getting in probe
  mtd: rawnand: meson: fix the clock
  dt-bindings: nand: meson: fix meson nfc clock
  mtd: rawnand: bcm47xx: fix spelling typo in comment
  mtd: rawnand: stm32_fmc2: switch to using devm_fwnode_gpiod_get()
  mtd: rawnand: cadence: Remove an unneeded result variable
  mtd: rawnand: Replace of_gpio_named_count() by gpiod_count()
  mtd: rawnand: marvell: Fix error handle regarding dma_map_sg
  mtd: rawnand: stm32_fmc2: Fix dma_map_sg error check
  mtd: rawnand: remove misguided comment of nand_get_device()
  mtd: rawnand: orion: Use devm_clk_get_optional()
  mtd: rawnand: cafe: Use correct function name in comment block
  mtd: rawnand: atmel: Unmap streaming DMA mappings
  mtd: rawnand: meson: fix bit map use in meson_nfc_ecc_correct()
  mtd: rawnand: arasan: stop using 0 as NULL pointer
  mtd: rawnand: gpmi: Fix typo 'the the' in comment
  mtd: rawnand: brcmnand: Add individual glue driver selection
  mtd: rawnand: brcmnand: Move Kconfig to driver folder
  ...

1 files changed, 59 insertions, 5 deletions

diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h
index 890d9e5b76d7..714d55b49d2a 100644
--- a/include/uapi/mtd/mtd-abi.h
+++ b/include/uapi/mtd/mtd-abi.h
@@ -55,9 +55,9 @@ struct mtd_oob_buf64 {
  * @MTD_OPS_RAW:	data are transferred as-is, with no error correction;
  *			this mode implies %MTD_OPS_PLACE_OOB
  *
- * These modes can be passed to ioctl(MEMWRITE) and are also used internally.
- * See notes on "MTD file modes" for discussion on %MTD_OPS_RAW vs.
- * %MTD_FILE_MODE_RAW.
+ * These modes can be passed to ioctl(MEMWRITE) and ioctl(MEMREAD); they are
+ * also used internally. See notes on "MTD file modes" for discussion on
+ * %MTD_OPS_RAW vs. %MTD_FILE_MODE_RAW.
  */
 enum {
 	MTD_OPS_PLACE_OOB = 0,
@@ -91,6 +91,53 @@ struct mtd_write_req {
 	__u8 padding[7];
 };
 
+/**
+ * struct mtd_read_req_ecc_stats - ECC statistics for a read operation
+ *
+ * @uncorrectable_errors: the number of uncorrectable errors that happened
+ *			  during the read operation
+ * @corrected_bitflips: the number of bitflips corrected during the read
+ *			operation
+ * @max_bitflips: the maximum number of bitflips detected in any single ECC
+ *		  step for the data read during the operation; this information
+ *		  can be used to decide whether the data stored in a specific
+ *		  region of the MTD device should be moved somewhere else to
+ *		  avoid data loss.
+ */
+struct mtd_read_req_ecc_stats {
+	__u32 uncorrectable_errors;
+	__u32 corrected_bitflips;
+	__u32 max_bitflips;
+};
+
+/**
+ * struct mtd_read_req - data structure for requesting a read operation
+ *
+ * @start:	start address
+ * @len:	length of data buffer (only lower 32 bits are used)
+ * @ooblen:	length of OOB buffer (only lower 32 bits are used)
+ * @usr_data:	user-provided data buffer
+ * @usr_oob:	user-provided OOB buffer
+ * @mode:	MTD mode (see "MTD operation modes")
+ * @padding:	reserved, must be set to 0
+ * @ecc_stats:	ECC statistics for the read operation
+ *
+ * This structure supports ioctl(MEMREAD) operations, allowing data and/or OOB
+ * reads in various modes. To read from OOB-only, set @usr_data == NULL, and to
+ * read data-only, set @usr_oob == NULL. However, setting both @usr_data and
+ * @usr_oob to NULL is not allowed.
+ */
+struct mtd_read_req {
+	__u64 start;
+	__u64 len;
+	__u64 ooblen;
+	__u64 usr_data;
+	__u64 usr_oob;
+	__u8 mode;
+	__u8 padding[7];
+	struct mtd_read_req_ecc_stats ecc_stats;
+};
+
 #define MTD_ABSENT		0
 #define MTD_RAM			1
 #define MTD_ROM			2
@@ -207,6 +254,12 @@ struct otp_info {
 #define MEMWRITE		_IOWR('M', 24, struct mtd_write_req)
 /* Erase a given range of user data (must be in mode %MTD_FILE_MODE_OTP_USER) */
 #define OTPERASE		_IOW('M', 25, struct otp_info)
+/*
+ * Most generic read interface; can read in-band and/or out-of-band in various
+ * modes (see "struct mtd_read_req"). This ioctl is not supported for flashes
+ * without OOB, e.g., NOR flash.
+ */
+#define MEMREAD			_IOWR('M', 26, struct mtd_read_req)
 
 /*
  * Obsolete legacy interface. Keep it in order not to break userspace
@@ -270,8 +323,9 @@ struct mtd_ecc_stats {
  * Note: %MTD_FILE_MODE_RAW provides the same functionality as %MTD_OPS_RAW -
  * raw access to the flash, without error correction or autoplacement schemes.
  * Wherever possible, the MTD_OPS_* mode will override the MTD_FILE_MODE_* mode
- * (e.g., when using ioctl(MEMWRITE)), but in some cases, the MTD_FILE_MODE is
- * used out of necessity (e.g., `write()', ioctl(MEMWRITEOOB64)).
+ * (e.g., when using ioctl(MEMWRITE) or ioctl(MEMREAD)), but in some cases, the
+ * MTD_FILE_MODE is used out of necessity (e.g., `write()',
+ * ioctl(MEMWRITEOOB64)).
  */
 enum mtd_file_modes {
 	MTD_FILE_MODE_NORMAL = MTD_OTP_OFF,