mtd: maps: remove AMD Élan specific drivers

From: Arnd Bergmann <[email protected]>

Rather than using platform data or DT properties, the configuration for this mtd map driver used to be passed through the global uclinux_ram_map structure, but the last instance was removed in commit 4ba66a976072 ("arch: remove blackfin port") in 2018.

After commit 251f26c9e828 ("mtd: maps: Make uclinux_ram_map static"), it became impossible to configure it at all, even with out-of-tree platform code.

Clearly nobody is using it, so remove it.

Signed-off-by Arnd Bergmann <[email protected]>

---
  drivers/mtd/maps/Kconfig   |   6 --
  drivers/mtd/maps/Makefile  |   1 -
  drivers/mtd/maps/uclinux.c | 118 -------------------------------------
  3 files changed, 125 deletions(-)

delete mode 100644 drivers/mtd/maps/uclinux.c

drivers/mtd/maps/Kconfig +0 -6

index 784dba14e908..1e8f2b518ddd 100644
@@ -284,12 +284,6 @@ config MTD_PCMCIA_ANONYMOUS
 
  	  If unsure, say N.
 
-config MTD_UCLINUX
-	bool "Generic uClinux RAM/ROM filesystem support"
-	depends on (MTD_RAM=y || MTD_ROM=y) && (!MMU || COLDFIRE)
-	help
-	  Map driver to support image based filesystems for uClinux.
-
  config MTD_PLATRAM
  	tristate "Map driver for platform device RAM (mtd-ram)"
  	select MTD_RAM

drivers/mtd/maps/Makefile +0 -1

index 157f911f86d8..eff28fc0b60e 100644
@@ -31,7 +31,6 @@ obj-$(CONFIG_MTD_SCx200_DOCFLASH)+= scx200_docflash.o
  obj-$(CONFIG_MTD_SOLUTIONENGINE)+= solutionengine.o
  obj-$(CONFIG_MTD_PCI)		+= pci.o
  obj-$(CONFIG_MTD_IMPA7)		+= impa7.o
-obj-$(CONFIG_MTD_UCLINUX)	+= uclinux.o
  obj-$(CONFIG_MTD_SCB2_FLASH)	+= scb2_flash.o
  obj-$(CONFIG_MTD_PLATRAM)	+= plat-ram.o
  obj-$(CONFIG_MTD_VMU)		+= vmu-flash.o

drivers/mtd/maps/uclinux.c deleted +0 -108

deleted file mode 100644
index de4c46318abb..000000000000
@@ -1,118 +0,0 @@
-/****************************************************************************/
-
-/*
- *	uclinux.c -- generic memory mapped MTD driver for uclinux
- *
- *	(C) Copyright 2002, Greg Ungerer ([email protected])
- *
- *      License: GPL
- */
-
-/****************************************************************************/
-
-#include <linux/moduleparam.h>
-#include <linux/types.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/major.h>
-#include <linux/mtd/mtd.h>
-#include <linux/mtd/map.h>
-#include <linux/mtd/partitions.h>
-#include <asm/io.h>
-#include <asm/sections.h>
-
-/****************************************************************************/
-
-#ifdef CONFIG_MTD_ROM
-#define MAP_NAME "rom"
-#else
-#define MAP_NAME "ram"
-#endif
-
-static struct map_info uclinux_ram_map = {
-	.name = MAP_NAME,
-	.size = 0,
-};
-
-static unsigned long physaddr = -1;
-module_param(physaddr, ulong, S_IRUGO);
-
-static struct mtd_info *uclinux_ram_mtdinfo;
-
-/****************************************************************************/
-
-static const struct mtd_partition uclinux_romfs[] = {
-	{ .name = "ROMfs" }
-};
-
-#define	NUM_PARTITIONS	ARRAY_SIZE(uclinux_romfs)
-
-/****************************************************************************/
-
-static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
-	size_t *retlen, void **virt, resource_size_t *phys)
-{
-	struct map_info *map = mtd->priv;
-	*virt = map->virt + from;
-	if (phys)
-		*phys = map->phys + from;
-	*retlen = len;
-	return(0);
-}
-
-/****************************************************************************/
-
-static int __init uclinux_mtd_init(void)
-{
-	struct mtd_info *mtd;
-	struct map_info *mapp;
-
-	mapp = &uclinux_ram_map;
-
-	if (physaddr == -1)
-		mapp->phys = (resource_size_t)__bss_stop;
-	else
-		mapp->phys = physaddr;
-
-	if (!mapp->size)
-		mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
-	mapp->bankwidth = 4;
-
-	printk("uclinux[mtd]: probe address=0x%x size=0x%x\n",
-	       	(int) mapp->phys, (int) mapp->size);
-
-	/*
-	 * The filesystem is guaranteed to be in direct mapped memory. It is
-	 * directly following the kernels own bss region. Following the same
-	 * mechanism used by architectures setting up traditional initrds we
-	 * use phys_to_virt to get the virtual address of its start.
-	 */
-	mapp->virt = phys_to_virt(mapp->phys);
-
-	if (mapp->virt == 0) {
-		printk("uclinux[mtd]: no virtual mapping?\n");
-		return(-EIO);
-	}
-
-	simple_map_init(mapp);
-
-	mtd = do_map_probe("map_" MAP_NAME, mapp);
-	if (!mtd) {
-		printk("uclinux[mtd]: failed to find a mapping?\n");
-		return(-ENXIO);
-	}
-
-	mtd->owner = THIS_MODULE;
-	mtd->_point = uclinux_point;

On 26/5/26 20:32, Arnd Bergmann wrote:

It is used on some ColdFire platforms, and was working all the way up to being removed in the current merge window.

The ColdFire platform startup code (arch/m68k/coldfire/head.S) has a somewhat unusual setup that can copy an attached filesystem blob to _bss_stop, and this is one of the places the uclinux.c map driver can use as the filesystem memory address. From uclinux.c

     static int __init uclinux_mtd_init(void)
     {
         struct mtd_info *mtd;
         struct map_info *mapp;

         mapp = &uclinux_ram_map;

         if (physaddr == -1)
                 mapp->phys = (resource_size_t)__bss_stop;
         else
                 mapp->phys = physaddr;

No out of tree code is required. Most of the ColdFire defconfigs have CONFIG_MTD_UCLINUX enabled, since it is commonly used.

Can we get this reverted?

Quoted 22 lines · Greg Ungerer

On 26/5/26 20:32, Arnd Bergmann wrote:

It is used on some ColdFire platforms, and was working all the way up to being removed in the current merge window.

The ColdFire platform startup code (arch/m68k/coldfire/head.S) has a somewhat unusual setup that can copy an attached filesystem blob to _bss_stop, and this is one of the places the uclinux.c map driver can use as the filesystem memory address. From uclinux.c

      static int __init uclinux_mtd_init(void)
      {
          struct mtd_info *mtd;
          struct map_info *mapp;

          mapp = &uclinux_ram_map;

          if (physaddr == -1)
                  mapp->phys = (resource_size_t)__bss_stop;
          else
                  mapp->phys = physaddr;

Quoted 2 lines

No out of tree code is required. Most of the ColdFire defconfigs have CONFIG_MTD_UCLINUX enabled, since it is commonly used.

I see, this is surprising from reading the source and git history, but I can see exactly how it got there.

So this is not actually a device but rather a replacement for CONFIG_BLK_DEV_INITRD that does can work with CONFIG_BLOCK=y, right?

Quoted 1 line

Can we get this reverted?

Yes, of course. Miquel/Richard/Vignesh, should I send a revert or can you just apply one with Greg's explanation and my Ack?

Quoted 2 lines · Arnd Bergmann

Quoted 1 line · Greg Ungerer

On 26/5/26 20:32, Arnd Bergmann wrote:

Quoted 5 lines

Quoted 2 lines

No out of tree code is required. Most of the ColdFire defconfigs have CONFIG_MTD_UCLINUX enabled, since it is commonly used.

I see, this is surprising from reading the source and git history, but I can see exactly how it got there.

The early, and probably more interesting history, predates git. It has always "just worked" on ColdFire platforms, so it really hasn't needed alot of change over the years for this use case.

Quoted 2 lines

No out of tree code is required. Most of the ColdFire defconfigs have CONFIG_MTD_UCLINUX enabled, since it is commonly used.

I see, this is surprising from reading the source and git history, but I can see exactly how it got there.

So this is not actually a device but rather a replacement for CONFIG_BLK_DEV_INITRD that does can work with CONFIG_BLOCK=y, right?

Quoted 1 line

Can we get this reverted?

Yes, of course. Miquel/Richard/Vignesh, should I send a revert or can you just apply one with Greg's explanation and my Ack?

Quoted 1 line

Can we get this reverted?

Yes, of course. Miquel/Richard/Vignesh, should I send a revert or can you just apply one with Greg's explanation and my Ack?

Arnd

Hello,

Quoted 5 lines

Quoted 1 line

Can we get this reverted?

Yes, of course. Miquel/Richard/Vignesh, should I send a revert or can you just apply one with Greg's explanation and my Ack?

Quoted 1 line

Arnd

Just sent a revert, I hope I got it all right.

Link:
https://lore.kernel.org/linux-mtd/[email protected]/T/#u

From: Arnd Bergmann <[email protected]>

There are four MTD maps drivers that are used with AMD Élan SoCs. Since 486-class CPU support was removed in commit 8b793a92d862 ("x86/cpu:
Remove M486/M486SX/ELAN support"), it is no longer possible to actually use these, so just remove the drivers entirely.

On 26/05/2026 at 12:32:04 +02, Arnd Bergmann <[email protected]> wrote:

     3 files changed, 469 deletions(-)

Is it okay for you?

Quoted 5 lines · Miquel Raynal

On 26/05/2026 at 12:32:04 +02, Arnd Bergmann <[email protected]> wrote:

     3 files changed, 469 deletions(-)

Is it okay for you?

Looks good to me, thanks a lot for rebasing the patch.