user/sven/linux.git/include/linux/mtd/map.h, branch v3.18.104

mtd: cfi: reduce stack size

2017-05-15T07:19:03Z

commit d09957fbb4d0b059b3176b510540df69048ad170 upstream. The cfi_staa_write_buffers function uses a large amount of kernel stack whenever CONFIG_MTD_MAP_BANK_WIDTH_32 is set, and that results in a warning on ARM allmodconfig builds: drivers/mtd/chips/cfi_cmdset_0020.c: In function 'cfi_staa_write_buffers': drivers/mtd/chips/cfi_cmdset_0020.c:651:1: warning: the frame size of 1208 bytes is larger than 1024 bytes [-Wframe-larger-than=] It turns out that this is largely a result of a suboptimal implementation of map_word_andequal(). Replacing this function with a straightforward one reduces the stack size in this function by exactly 200 bytes, shrinks the .text segment for this file from 27648 bytes to 26608 bytes, and makes the warning go away. Signed-off-by: Arnd Bergmann Signed-off-by: Brian Norris Signed-off-by: Greg Kroah-Hartman

mtd: avoid stack overflow in MTD CFI code

2017-05-08T05:44:09Z

commit fddcca5107051adf9e4481d2a79ae0616577fd2c upstream. When map_word gets too large, we use a lot of kernel stack, and for MTD_MAP_BANK_WIDTH_32, this means we use more than the recommended 1024 bytes in a number of functions: drivers/mtd/chips/cfi_cmdset_0020.c: In function 'cfi_staa_write_buffers': drivers/mtd/chips/cfi_cmdset_0020.c:651:1: warning: the frame size of 1336 bytes is larger than 1024 bytes [-Wframe-larger-than=] drivers/mtd/chips/cfi_cmdset_0020.c: In function 'cfi_staa_erase_varsize': drivers/mtd/chips/cfi_cmdset_0020.c:972:1: warning: the frame size of 1208 bytes is larger than 1024 bytes [-Wframe-larger-than=] drivers/mtd/chips/cfi_cmdset_0001.c: In function 'do_write_buffer': drivers/mtd/chips/cfi_cmdset_0001.c:1835:1: warning: the frame size of 1240 bytes is larger than 1024 bytes [-Wframe-larger-than=] This can be avoided if all operations on the map word are done indirectly and the stack gets reused between the calls. We can mostly achieve this by selecting MTD_COMPLEX_MAPPINGS whenever MTD_MAP_BANK_WIDTH_32 is set, but for the case that no other bank width is enabled, we also need to use a non-constant map_bankwidth() to convince the compiler to use less stack. Signed-off-by: Arnd Bergmann [Brian: this patch mostly achieves its goal by forcing MTD_COMPLEX_MAPPINGS (and the accompanying indirection) for 256-bit mappings; the rest of the change is mostly a wash, though it helps reduce stack size slightly. If we really care about supporting 256-bit mappings though, we should consider rewriting some of this code to avoid keeping and assigning so many 256-bit objects on the stack.] Signed-off-by: Brian Norris Signed-off-by: Greg Kroah-Hartman

mtd: map: fixed bug in 64-bit systems

2013-11-07T07:32:59Z

Hardware: CPU: XLP832,the 64-bit OS NOR Flash:S29GL128S 128M Software: Kernel:2.6.32.41 Filesystem:JFFS2 When writing files, errors appear: Write len 182 but return retlen 180 Write of 182 bytes at 0x072c815c failed. returned -5, retlen 180 Write len 186 but return retlen 184 Write of 186 bytes at 0x072caff4 failed. returned -5, retlen 184 These errors exist only in 64-bit systems,not in 32-bit systems. After analysis, we found that the left shift operation is wrong in map_word_load_partial. For instance: unsigned char buf[3] ={0x9e,0x3a,0xea}; map_bankwidth(map) is 4; for (i=0; i < 3; i++) { int bitpos; bitpos = (map_bankwidth(map)-1-i)*8; orig.x[0] &= ~(0xff << bitpos); orig.x[0] |= buf[i] << bitpos; } The value of orig.x[0] is expected to be 0x9e3aeaff, but in this situation(64-bit System) we'll get the wrong value of 0xffffffff9e3aeaff due to the 64-bit sign extension: buf[i] is defined as "unsigned char" and the left-shift operation will convert it to the type of "signed int", so when left-shift buf[i] by 24 bits, the final result will get the wrong value: 0xffffffff9e3aeaff. If the left-shift bits are less than 24, then sign extension will not occur. Whereas the bankwidth of the nor flash we used is 4, therefore this BUG emerges. Signed-off-by: Pang Xunlei Signed-off-by: Zhang Yi Signed-off-by: Lu Zhongjun Cc: Signed-off-by: Brian Norris

mtd: map: BUG() in non handled cases

2013-02-22T07:22:19Z

Several map-related functions look like a serie of ifs, checking widths of map. Those functions do not have any handling for default case. Instead of fiddling with uninitialized_var in those functions, let's just add a (correct) BUG() to the default case on those maps. This will also allow us to catch potential errors in maps setup in future. Signed-off-by: Dmitry Eremin-Solenikov Signed-off-by: Artem Bityutskiy

mtd: cfi_cmdset_0002: Support Persistent Protection Bits (PPB) locking

2013-02-04T07:27:33Z

Currently cfi_cmdset_0002.c does not support PPB locking of sectors. This patch adds support for this locking/unlocking mechanism. It is needed on some platforms, since newer U-Boot versions do support this PPB locking and protect for example their environment sector(s) this way. This PPB locking/unlocking will be enabled for all devices supported by cfi_cmdset_0002 reporting 8 in the CFI word 0x49 (Sector Protect/Unprotect scheme). Please note that PPB locking does support sector-by-sector locking. But the whole chip can only be unlocked together. So unlocking one sector will automatically unlock all sectors of this device. Because of this chip limitation, the PPB unlocking function saves the current locking status of all sectors before unlocking the whole device. After unlocking the saved locking status is re-configured. This way only the addressed sectors will be unlocked. To selectively enable this advanced sector protection mechanism, the device-tree property "use-advanced-sector-protection" has been created. To enable support for this locking this property needs to be present in the flash DT node. E.g.: nor_flash@0,0 { compatible = "amd,s29gl256n", "cfi-flash"; bank-width = <2>; use-advanced-sector-protection; ... Tested with Spansion S29GL512S10THI and Micron JS28F512M29EWx flash devices. Signed-off-by: Stefan Roese Tested-by: Holger Brunck Signed-off-by: Artem Bityutskiy

mtd: uninitialized variable warning in map.h

2012-11-16T08:57:39Z

The map_word_load() function initializes exactly as many words in the buffer as required, but gcc cannot figure this out and gives a misleading warning. Marking the local variable as uninitialized_var shuts up that warning. Without this patch, building acs5k_defconfig results in: drivers/mtd/chips/cfi_cmdset_0002.c: In function 'cfi_amdstd_panic_write': include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wuninitialized] drivers/mtd/chips/cfi_cmdset_0002.c: In function 'cfi_amdstd_write_words': include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wuninitialized] drivers/mtd/chips/cfi_cmdset_0001.c: In function 'cfi_intelext_write_words': include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wuninitialized] Signed-off-by: Arnd Bergmann Signed-off-by: Artem Bityutskiy

mtd: map: Fix compilation warning

2012-11-15T17:50:30Z

This patch is an attempt to fix following compilation warning. In file included from drivers/mtd/chips/cfi_cmdset_0001.c:35:0: drivers/mtd/chips/cfi_cmdset_0001.c: In function 'cfi_intelext_write_words': include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wmaybe-uninitialized] I could have used uninitialized_var() too, but didn't used it as the final else part of map_word_load() is missing. So there is a chance that it might be passed uninitialized. Better initialize to zero. Signed-off-by: Viresh Kumar Signed-off-by: Artem Bityutskiy

Remove all #inclusions of asm/system.h

2012-03-28T17:30:03Z

Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*.*\n!!' `grep -Irl '^#\s*include\s*' *` Signed-off-by: David Howells

Add #includes needed to permit the removal of asm/system.h

2012-03-28T17:30:03Z

asm/system.h is a cause of circular dependency problems because it contains commonly used primitive stuff like barrier definitions and uncommonly used stuff like switch_to() that might require MMU definitions. asm/system.h has been disintegrated by this point on all arches into the following common segments: (1) asm/barrier.h Moved memory barrier definitions here. (2) asm/cmpxchg.h Moved xchg() and cmpxchg() here. #included in asm/atomic.h. (3) asm/bug.h Moved die() and similar here. (4) asm/exec.h Moved arch_align_stack() here. (5) asm/elf.h Moved AT_VECTOR_SIZE_ARCH here. (6) asm/switch_to.h Moved switch_to() here. Signed-off-by: David Howells

mtd: map.h: fix arm cross-build failure

2012-01-09T18:24:34Z

This patch fixes the following build failure: In file included from include/linux/mtd/qinfo.h:4:0, from include/linux/mtd/pfow.h:7, from drivers/mtd/lpddr/lpddr_cmds.c:27: include/linux/mtd/map.h: In function 'inline_map_read': include/linux/mtd/map.h:409:3: error: implicit declaration of function 'BUILD_BUG_ON' [-Werror=implicit-function-declaration] Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse