linux-toradex.git/include/linux/mtd/map.h, branch v4.13-rc5 Linux kernel for Apalis and Colibri modules mtd: avoid stack overflow in MTD CFI code 2016-04-03T23:46:24+00:00 Arnd Bergmann arnd@arndb.de 2016-02-29T12:20:28+00:00 fddcca5107051adf9e4481d2a79ae0616577fd2c 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 <arnd@arndb.de> [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 <computersforpeace@gmail.com> 
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 <arnd@arndb.de>
[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 <computersforpeace@gmail.com>
mtd: map: fix .set_vpp() documentation 2016-02-12T19:09:32+00:00 Linus Walleij linus.walleij@linaro.org 2016-02-01T22:02:48+00:00 95a001f22b1c5717eafd500a43832249ddd93662 As of commit 876fe76d793d03077eb61ba3afab4a383f46c554 "mtd: maps: physmap: Add reference counter to set_vpp()" the comment in the header file is incorrect and misleading. Fix it up. Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Parsons <lost.distance@yahoo.com> Fixes: 876fe76d793d ("mtd: maps: physmap: Add reference counter to set_vpp()") Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Brian Norris <computersforpeace@gmail.com> 
As of commit 876fe76d793d03077eb61ba3afab4a383f46c554
"mtd: maps: physmap: Add reference counter to set_vpp()"
the comment in the header file is incorrect and misleading.
Fix it up.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Parsons <lost.distance@yahoo.com>
Fixes: 876fe76d793d ("mtd: maps: physmap: Add reference counter to set_vpp()")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
mtd: cfi: don't warn about broken geometry for !CONFIG_MTD 2015-11-30T20:36:44+00:00 Arnd Bergmann arnd@arndb.de 2015-11-24T22:09:02+00:00 fe7579d6122f2869d00b55842bca9e2a9be51607 The linux/mtd/map.h header file is included by a couple of platform specific files that are built even when CONFIG_MTD is disabled, and we always get warning "No CONFIG_MTD_MAP_BANK_WIDTH_xx selected. No NOR chip support can work" in that case. This adds an #ifdef around the pointless warning, as everything is really fine when we don't build the drivers anyway. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Brian Norris <computersforpeace@gmail.com> 
The linux/mtd/map.h header file is included by a couple of
platform specific files that are built even when CONFIG_MTD
is disabled, and we always get

 warning "No CONFIG_MTD_MAP_BANK_WIDTH_xx selected. No NOR chip support can work"

in that case. This adds an #ifdef around the pointless warning,
as everything is really fine when we don't build the drivers
anyway.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
arch, drivers: don't include <asm/io.h> directly, use <linux/io.h> instead 2015-08-11T03:07:05+00:00 Dan Williams dan.j.williams@intel.com 2015-08-11T03:07:05+00:00 2584cf83578c26db144730ef498f4070f82ee3ea Preparation for uniform definition of ioremap, ioremap_wc, ioremap_wt, and ioremap_cache, tree-wide. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> 
Preparation for uniform definition of ioremap, ioremap_wc, ioremap_wt,
and ioremap_cache, tree-wide.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
mtd: clean up whitespace in linux/mtd/map.h 2015-03-11T22:25:56+00:00 Arnd Bergmann arnd@arndb.de 2015-03-10T16:51:55+00:00 7234bea69de200e2060d099685c4c674b556edc0 As the only comments I got for the "mtd: cfi: reduce stack size" patch were about whitespace changes, it appears necessary to fix up the rest of the file as well, which contains the exact same mistakes. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Brian Norris <computersforpeace@gmail.com> 
As the only comments I got for the "mtd: cfi: reduce stack size"
patch were about whitespace changes, it appears necessary to fix
up the rest of the file as well, which contains the exact same
mistakes.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
mtd: cfi: reduce stack size 2015-03-11T22:25:51+00:00 Arnd Bergmann arnd@arndb.de 2015-03-10T16:48:37+00:00 d09957fbb4d0b059b3176b510540df69048ad170 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 <arnd@arndb.de> Signed-off-by: Brian Norris <computersforpeace@gmail.com> 
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 <arnd@arndb.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
mtd: map: fixed bug in 64-bit systems 2013-11-07T07:32:59+00:00 Wang Haitao wang.haitao1@zte.com.cn 2013-08-22T11:32:38+00:00 a4d62babf988fe5dfde24437fa135ef147bc7aa0 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 <pang.xunlei@zte.com.cn> Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn> Signed-off-by: Lu Zhongjun <lu.zhongjun@zte.com.cn> Cc: <stable@vger.kernel.org> Signed-off-by: Brian Norris <computersforpeace@gmail.com> 
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 <pang.xunlei@zte.com.cn>
Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn>
Signed-off-by: Lu Zhongjun <lu.zhongjun@zte.com.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
mtd: map: BUG() in non handled cases 2013-02-22T07:22:19+00:00 Dmitry Eremin-Solenikov dmitry_eremin@mentor.com 2013-01-31T17:06:34+00:00 24dea0c9feccf699749f860fa2f4ccd84d30390d 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 <dmitry_eremin@mentor.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> 
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 <dmitry_eremin@mentor.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
mtd: cfi_cmdset_0002: Support Persistent Protection Bits (PPB) locking 2013-02-04T07:27:33+00:00 Stefan Roese sr@denx.de 2013-01-18T12:10:05+00:00 1648eaaa1575ea686acb82fb8cb3d8839764ef2c 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 <sr@denx.de> Tested-by: Holger Brunck <holger.brunck@keymile.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> 
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 <sr@denx.de>
Tested-by: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
mtd: uninitialized variable warning in map.h 2012-11-16T08:57:39+00:00 Arnd Bergmann arnd@arndb.de 2012-11-06T21:55:28+00:00 5d27aa5af04f58f3020de1c224dcf8a62151fd58 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 <arnd@arndb.de> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> 
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 <arnd@arndb.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>