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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-13 20:25:54 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-13 20:25:54 +0100
commitac53b2e053fffc74372da94e734b92f37e70d32c (patch)
treecda82af0fcded5d230e9f56104d3988b7a75c8aa /Documentation
parentMerge tag 'for-linus-4.5' of git://git.code.sf.net/p/openipmi/linux-ipmi (diff)
parentmtd: jz4780_nand: replace if/else blocks with switch/case (diff)
downloadlinux-ac53b2e053fffc74372da94e734b92f37e70d32c.tar.xz
linux-ac53b2e053fffc74372da94e734b92f37e70d32c.zip
Merge tag 'for-linus-20160112' of git://git.infradead.org/linux-mtd
Pull MTD updates from Brian Norris: "Generic MTD: - populate the MTD device 'of_node' field (and get a proper 'of_node' symlink in sysfs) This yielded some new helper functions, and changes across a variety of drivers - partitioning cleanups, to prepare for better device-tree based partitioning in the future Eliminate a lot of boilerplate for drivers that want to use OF-based partition parsing The DT bindings for this didn't settle yet, so most non-cleanup portions are deferred for a future release NAND: - embed a struct mtd_info inside struct nand_chip This is really long overdue; too many drivers have to do the same silly boilerplate to allocate and link up two "independent" structs, when in fact, everyone is assuming there is an exact 1:1 relationship between a NAND chips struct and its underlying MTD. This aids improved helpers and should make certain abstractions easier in the future. Also causes a lot of churn, helped along by some automated code transformations - add more core support for detecting (and "correcting") bitflips in erased pages; requires opt-in by drivers, but at least we kill a few bad implementations and hopefully stave off future ones - pxa3xx_nand: cleanups, a few fixes, and PM improvements - new JZ4780 NAND driver SPI NOR: - provide default erase function, for controllers that just want to send the SECTOR_ERASE command directly - fix some module auto-loading issues with device tree ("jedec,spi-nor") - error handling fixes - new Mediatek QSPI flash driver Other: - cfi: force valid geometry Kconfig (finally!) This one used to trip up randconfigs occasionally, since bots aren't deterred by big scary "advanced configuration" menus More? Probably. See the commit logs" * tag 'for-linus-20160112' of git://git.infradead.org/linux-mtd: (168 commits) mtd: jz4780_nand: replace if/else blocks with switch/case mtd: nand: jz4780: Update ecc correction error codes mtd: nandsim: use nand_get_controller_data() mtd: jz4780_nand: remove useless mtd->priv = chip assignment staging: mt29f_spinand: make use of nand_set/get_controller_data() helpers mtd: nand: make use of nand_set/get_controller_data() helpers ARM: make use of nand_set/get_controller_data() helpers mtd: nand: add helpers to access ->priv mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs mtd: nand: jz4740: remove custom 'erased check' implementation mtd: nand: diskonchip: remove custom 'erased check' implementation mtd: nand: davinci: remove custom 'erased check' implementation mtd: nand: use nand_check_erased_ecc_chunk in default ECC read functions mtd: nand: return consistent error codes in ecc.correct() implementations doc: dt: mtd: new binding for jz4780-{nand,bch} mtd: cfi_cmdset_0001: fixing memory leak and handling failed kmalloc mtd: spi-nor: wait until lock/unlock operations are ready mtd: tests: consolidate kmalloc/memset 0 call to kzalloc jffs2: use to_delayed_work mtd: nand: assign reasonable default name for NAND drivers ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DocBook/mtdnand.tmpl35
-rw-r--r--Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt32
-rw-r--r--Documentation/devicetree/bindings/mtd/ingenic,jz4780-nand.txt86
-rw-r--r--Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt56
-rw-r--r--Documentation/devicetree/bindings/mtd/mtk-quadspi.txt41
-rw-r--r--Documentation/devicetree/bindings/mtd/partition.txt2
-rw-r--r--Documentation/mtd/nand_ecc.txt58
7 files changed, 258 insertions, 52 deletions
diff --git a/Documentation/DocBook/mtdnand.tmpl b/Documentation/DocBook/mtdnand.tmpl
index 7da8f0402af5..b442921bca54 100644
--- a/Documentation/DocBook/mtdnand.tmpl
+++ b/Documentation/DocBook/mtdnand.tmpl
@@ -162,12 +162,15 @@
<sect1 id="Basic_defines">
<title>Basic defines</title>
<para>
- At least you have to provide a mtd structure and
- a storage for the ioremap'ed chip address.
- You can allocate the mtd structure using kmalloc
- or you can allocate it statically.
- In case of static allocation you have to allocate
- a nand_chip structure too.
+ At least you have to provide a nand_chip structure
+ and a storage for the ioremap'ed chip address.
+ You can allocate the nand_chip structure using
+ kmalloc or you can allocate it statically.
+ The NAND chip structure embeds an mtd structure
+ which will be registered to the MTD subsystem.
+ You can extract a pointer to the mtd structure
+ from a nand_chip pointer using the nand_to_mtd()
+ helper.
</para>
<para>
Kmalloc based example
@@ -180,7 +183,6 @@ static void __iomem *baseaddr;
Static example
</para>
<programlisting>
-static struct mtd_info board_mtd;
static struct nand_chip board_chip;
static void __iomem *baseaddr;
</programlisting>
@@ -235,7 +237,7 @@ static void board_hwcontrol(struct mtd_info *mtd, int cmd)
<programlisting>
static void board_hwcontrol(struct mtd_info *mtd, int cmd)
{
- struct nand_chip *this = (struct nand_chip *) mtd->priv;
+ struct nand_chip *this = mtd_to_nand(mtd);
switch(cmd){
case NAND_CTL_SETCLE: this->IO_ADDR_W |= CLE_ADRR_BIT; break;
case NAND_CTL_CLRCLE: this->IO_ADDR_W &amp;= ~CLE_ADRR_BIT; break;
@@ -274,13 +276,15 @@ static int __init board_init (void)
int err = 0;
/* Allocate memory for MTD device structure and private data */
- board_mtd = kzalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip), GFP_KERNEL);
- if (!board_mtd) {
+ this = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
+ if (!this) {
printk ("Unable to allocate NAND MTD device structure.\n");
err = -ENOMEM;
goto out;
}
+ board_mtd = nand_to_mtd(this);
+
/* map physical address */
baseaddr = ioremap(CHIP_PHYSICAL_ADDRESS, 1024);
if (!baseaddr) {
@@ -289,11 +293,6 @@ static int __init board_init (void)
goto out_mtd;
}
- /* Get pointer to private data */
- this = (struct nand_chip *) ();
- /* Link the private data with the MTD structure */
- board_mtd->priv = this;
-
/* Set address of NAND IO lines */
this->IO_ADDR_R = baseaddr;
this->IO_ADDR_W = baseaddr;
@@ -317,7 +316,7 @@ static int __init board_init (void)
out_ior:
iounmap(baseaddr);
out_mtd:
- kfree (board_mtd);
+ kfree (this);
out:
return err;
}
@@ -343,7 +342,7 @@ static void __exit board_cleanup (void)
iounmap(baseaddr);
/* Free the MTD device structure */
- kfree (board_mtd);
+ kfree (mtd_to_nand(board_mtd));
}
module_exit(board_cleanup);
#endif
@@ -399,7 +398,7 @@ static void board_select_chip (struct mtd_info *mtd, int chip)
<programlisting>
static void board_select_chip (struct mtd_info *mtd, int chip)
{
- struct nand_chip *this = (struct nand_chip *) mtd->priv;
+ struct nand_chip *this = mtd_to_nand(mtd);
/* Deselect all chips */
this->IO_ADDR_R &amp;= ~BOARD_NAND_ADDR_MASK;
diff --git a/Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt b/Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt
index 4ff7128ee3b2..c2546ced9c02 100644
--- a/Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt
+++ b/Documentation/devicetree/bindings/mtd/brcm,brcmnand.txt
@@ -45,6 +45,8 @@ Required properties:
- #size-cells : <0>
Optional properties:
+- clock : reference to the clock for the NAND controller
+- clock-names : "nand" (required for the above clock)
- brcm,nand-has-wp : Some versions of this IP include a write-protect
(WP) control bit. It is always available on >=
v7.0. Use this property to describe the rare
@@ -72,6 +74,12 @@ we define additional 'compatible' properties and associated register resources w
and enable registers
- reg-names: (required) "nand-int-base"
+ * "brcm,nand-bcm6368"
+ - compatible: should contain "brcm,nand-bcm<soc>", "brcm,nand-bcm6368"
+ - reg: (required) the 'NAND_INTR_BASE' register range, with combined status
+ and enable registers, and boot address registers
+ - reg-names: (required) "nand-int-base"
+
* "brcm,nand-iproc"
- reg: (required) the "IDM" register range, for interrupt enable and APB
bus access endianness configuration, and the "EXT" register range,
@@ -148,3 +156,27 @@ nand@f0442800 {
};
};
};
+
+nand@10000200 {
+ compatible = "brcm,nand-bcm63168", "brcm,nand-bcm6368",
+ "brcm,brcmnand-v4.0", "brcm,brcmnand";
+ reg = <0x10000200 0x180>,
+ <0x10000600 0x200>,
+ <0x100000b0 0x10>;
+ reg-names = "nand", "nand-cache", "nand-int-base";
+ interrupt-parent = <&periph_intc>;
+ interrupts = <50>;
+ clocks = <&periph_clk 20>;
+ clock-names = "nand";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ nand0: nandcs@0 {
+ compatible = "brcm,nandcs";
+ reg = <0>;
+ nand-on-flash-bbt;
+ nand-ecc-strength = <1>;
+ nand-ecc-step-size = <512>;
+ };
+};
diff --git a/Documentation/devicetree/bindings/mtd/ingenic,jz4780-nand.txt b/Documentation/devicetree/bindings/mtd/ingenic,jz4780-nand.txt
new file mode 100644
index 000000000000..29ea5853ca91
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/ingenic,jz4780-nand.txt
@@ -0,0 +1,86 @@
+* Ingenic JZ4780 NAND/BCH
+
+This file documents the device tree bindings for NAND flash devices on the
+JZ4780. NAND devices are connected to the NEMC controller (described in
+memory-controllers/ingenic,jz4780-nemc.txt), and thus NAND device nodes must
+be children of the NEMC node.
+
+Required NAND controller device properties:
+- compatible: Should be set to "ingenic,jz4780-nand".
+- reg: For each bank with a NAND chip attached, should specify a bank number,
+ an offset of 0 and a size of 0x1000000 (i.e. the whole NEMC bank).
+
+Optional NAND controller device properties:
+- ingenic,bch-controller: To make use of the hardware BCH controller, this
+ property must contain a phandle for the BCH controller node. The required
+ properties for this node are described below. If this is not specified,
+ software BCH will be used instead.
+
+Optional children nodes:
+- Individual NAND chips are children of the NAND controller node.
+
+Required children node properties:
+- reg: An integer ranging from 1 to 6 representing the CS line to use.
+
+Optional children node properties:
+- nand-ecc-step-size: ECC block size in bytes.
+- nand-ecc-strength: ECC strength (max number of correctable bits).
+- nand-ecc-mode: String, operation mode of the NAND ecc mode. "hw" by default
+- nand-on-flash-bbt: boolean to enable on flash bbt option, if not present false
+- rb-gpios: GPIO specifier for the busy pin.
+- wp-gpios: GPIO specifier for the write protect pin.
+
+Optional child node of NAND chip nodes:
+- partitions: see Documentation/devicetree/bindings/mtd/partition.txt
+
+Example:
+
+nemc: nemc@13410000 {
+ ...
+
+ nandc: nand-controller@1 {
+ compatible = "ingenic,jz4780-nand";
+ reg = <1 0 0x1000000>; /* Bank 1 */
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ingenic,bch-controller = <&bch>;
+
+ nand@1 {
+ reg = <1>;
+
+ nand-ecc-step-size = <1024>;
+ nand-ecc-strength = <24>;
+ nand-ecc-mode = "hw";
+ nand-on-flash-bbt;
+
+ rb-gpios = <&gpa 20 GPIO_ACTIVE_LOW>;
+ wp-gpios = <&gpf 22 GPIO_ACTIVE_LOW>;
+
+ partitions {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ ...
+ }
+ };
+ };
+};
+
+The BCH controller is a separate SoC component used for error correction on
+NAND devices. The following is a description of the device properties for a
+BCH controller.
+
+Required BCH properties:
+- compatible: Should be set to "ingenic,jz4780-bch".
+- reg: Should specify the BCH controller registers location and length.
+- clocks: Clock for the BCH controller.
+
+Example:
+
+bch: bch@134d0000 {
+ compatible = "ingenic,jz4780-bch";
+ reg = <0x134d0000 0x10000>;
+
+ clocks = <&cgu JZ4780_CLK_BCH>;
+};
diff --git a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt
index 2bee68103b01..2c91c03e7eb0 100644
--- a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt
+++ b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt
@@ -1,15 +1,61 @@
-* MTD SPI driver for ST M25Pxx (and similar) serial flash chips
+* SPI NOR flash: ST M25Pxx (and similar) serial flash chips
Required properties:
- #address-cells, #size-cells : Must be present if the device has sub-nodes
representing partitions.
- compatible : May include a device-specific string consisting of the
- manufacturer and name of the chip. Bear in mind the DT binding
- is not Linux-only, but in case of Linux, see the "m25p_ids"
- table in drivers/mtd/devices/m25p80.c for the list of supported
- chips.
+ manufacturer and name of the chip. A list of supported chip
+ names follows.
Must also include "jedec,spi-nor" for any SPI NOR flash that can
be identified by the JEDEC READ ID opcode (0x9F).
+
+ Supported chip names:
+ at25df321a
+ at25df641
+ at26df081a
+ mr25h256
+ mx25l4005a
+ mx25l1606e
+ mx25l6405d
+ mx25l12805d
+ mx25l25635e
+ n25q064
+ n25q128a11
+ n25q128a13
+ n25q512a
+ s25fl256s1
+ s25fl512s
+ s25sl12801
+ s25fl008k
+ s25fl064k
+ sst25vf040b
+ m25p40
+ m25p80
+ m25p16
+ m25p32
+ m25p64
+ m25p128
+ w25x80
+ w25x32
+ w25q32
+ w25q32dw
+ w25q80bl
+ w25q128
+ w25q256
+
+ The following chip names have been used historically to
+ designate quirky versions of flash chips that do not support the
+ JEDEC READ ID opcode (0x9F):
+ m25p05-nonjedec
+ m25p10-nonjedec
+ m25p20-nonjedec
+ m25p40-nonjedec
+ m25p80-nonjedec
+ m25p16-nonjedec
+ m25p32-nonjedec
+ m25p64-nonjedec
+ m25p128-nonjedec
+
- reg : Chip-Select number
- spi-max-frequency : Maximum frequency of the SPI bus the chip can operate at
diff --git a/Documentation/devicetree/bindings/mtd/mtk-quadspi.txt b/Documentation/devicetree/bindings/mtd/mtk-quadspi.txt
new file mode 100644
index 000000000000..fb314f09861b
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/mtk-quadspi.txt
@@ -0,0 +1,41 @@
+* Serial NOR flash controller for MTK MT81xx (and similar)
+
+Required properties:
+- compatible: should be "mediatek,mt8173-nor";
+- reg: physical base address and length of the controller's register
+- clocks: the phandle of the clocks needed by the nor controller
+- clock-names: the names of the clocks
+ the clocks should be named "spi" and "sf". "spi" is used for spi bus,
+ and "sf" is used for controller, these are the clocks witch
+ hardware needs to enabling nor flash and nor flash controller.
+ See Documentation/devicetree/bindings/clock/clock-bindings.txt for details.
+- #address-cells: should be <1>
+- #size-cells: should be <0>
+
+The SPI flash must be a child of the nor_flash node and must have a
+compatible property. Also see jedec,spi-nor.txt.
+
+Required properties:
+- compatible: May include a device-specific string consisting of the manufacturer
+ and name of the chip. Must also include "jedec,spi-nor" for any
+ SPI NOR flash that can be identified by the JEDEC READ ID opcode (0x9F).
+- reg : Chip-Select number
+
+Example:
+
+nor_flash: spi@1100d000 {
+ compatible = "mediatek,mt8173-nor";
+ reg = <0 0x1100d000 0 0xe0>;
+ clocks = <&pericfg CLK_PERI_SPI>,
+ <&topckgen CLK_TOP_SPINFI_IFR_SEL>;
+ clock-names = "spi", "sf";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ status = "disabled";
+
+ flash@0 {
+ compatible = "jedec,spi-nor";
+ reg = <0>;
+ };
+};
+
diff --git a/Documentation/devicetree/bindings/mtd/partition.txt b/Documentation/devicetree/bindings/mtd/partition.txt
index 1c63e40659fc..81a224da63be 100644
--- a/Documentation/devicetree/bindings/mtd/partition.txt
+++ b/Documentation/devicetree/bindings/mtd/partition.txt
@@ -32,6 +32,8 @@ Optional properties:
partition should only be mounted read-only. This is usually used for flash
partitions containing early-boot firmware images or data which should not be
clobbered.
+- lock : Do not unlock the partition at initialization time (not supported on
+ all devices)
Examples:
diff --git a/Documentation/mtd/nand_ecc.txt b/Documentation/mtd/nand_ecc.txt
index e129b2479ea8..f8c3284bf6a7 100644
--- a/Documentation/mtd/nand_ecc.txt
+++ b/Documentation/mtd/nand_ecc.txt
@@ -107,7 +107,7 @@ for (i = 0; i < 256; i++)
if (i & 0x01)
rp1 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp1;
else
- rp0 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp1;
+ rp0 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp0;
if (i & 0x02)
rp3 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp3;
else
@@ -127,7 +127,7 @@ for (i = 0; i < 256; i++)
if (i & 0x20)
rp11 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp11;
else
- rp10 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp10;
+ rp10 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp10;
if (i & 0x40)
rp13 = bit7 ^ bit6 ^ bit5 ^ bit4 ^ bit3 ^ bit2 ^ bit1 ^ bit0 ^ rp13;
else
@@ -158,7 +158,7 @@ the values in any order. So instead of calculating all the bits
individually, let us try to rearrange things.
For the column parity this is easy. We can just xor the bytes and in the
end filter out the relevant bits. This is pretty nice as it will bring
-all cp calculation out of the if loop.
+all cp calculation out of the for loop.
Similarly we can first xor the bytes for the various rows.
This leads to:
@@ -271,11 +271,11 @@ to write our code in such a way that we process data in 32 bit chunks.
Of course this means some modification as the row parity is byte by
byte. A quick analysis:
for the column parity we use the par variable. When extending to 32 bits
-we can in the end easily calculate p0 and p1 from it.
+we can in the end easily calculate rp0 and rp1 from it.
(because par now consists of 4 bytes, contributing to rp1, rp0, rp1, rp0
-respectively)
+respectively, from MSB to LSB)
also rp2 and rp3 can be easily retrieved from par as rp3 covers the
-first two bytes and rp2 the last two bytes.
+first two MSBs and rp2 covers the last two LSBs.
Note that of course now the loop is executed only 64 times (256/4).
And note that care must taken wrt byte ordering. The way bytes are
@@ -387,11 +387,11 @@ Analysis 2
The code (of course) works, and hurray: we are a little bit faster than
the linux driver code (about 15%). But wait, don't cheer too quickly.
-THere is more to be gained.
+There is more to be gained.
If we look at e.g. rp14 and rp15 we see that we either xor our data with
rp14 or with rp15. However we also have par which goes over all data.
This means there is no need to calculate rp14 as it can be calculated from
-rp15 through rp14 = par ^ rp15;
+rp15 through rp14 = par ^ rp15, because par = rp14 ^ rp15;
(or if desired we can avoid calculating rp15 and calculate it from
rp14). That is why some places refer to inverse parity.
Of course the same thing holds for rp4/5, rp6/7, rp8/9, rp10/11 and rp12/13.
@@ -419,12 +419,12 @@ with
if (i & 0x20) rp15 ^= cur;
and outside the loop added:
- rp4 = par ^ rp5;
- rp6 = par ^ rp7;
- rp8 = par ^ rp9;
- rp10 = par ^ rp11;
- rp12 = par ^ rp13;
- rp14 = par ^ rp15;
+ rp4 = par ^ rp5;
+ rp6 = par ^ rp7;
+ rp8 = par ^ rp9;
+ rp10 = par ^ rp11;
+ rp12 = par ^ rp13;
+ rp14 = par ^ rp15;
And after that the code takes about 30% more time, although the number of
statements is reduced. This is also reflected in the assembly code.
@@ -524,12 +524,12 @@ THe code within the for loop was changed to:
cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp6 ^= cur;
cur = *bp++; tmppar ^= cur; rp6 ^= cur;
- cur = *bp++; tmppar ^= cur; rp4 ^= cur;
- cur = *bp++; tmppar ^= cur; rp10 ^= tmppar;
+ cur = *bp++; tmppar ^= cur; rp4 ^= cur;
+ cur = *bp++; tmppar ^= cur; rp10 ^= tmppar;
- cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp6 ^= cur; rp8 ^= cur;
+ cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp6 ^= cur; rp8 ^= cur;
cur = *bp++; tmppar ^= cur; rp6 ^= cur; rp8 ^= cur;
- cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp8 ^= cur;
+ cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp8 ^= cur;
cur = *bp++; tmppar ^= cur; rp8 ^= cur;
cur = *bp++; tmppar ^= cur; rp4 ^= cur; rp6 ^= cur;
@@ -537,7 +537,7 @@ THe code within the for loop was changed to:
cur = *bp++; tmppar ^= cur; rp4 ^= cur;
cur = *bp++; tmppar ^= cur;
- par ^= tmppar;
+ par ^= tmppar;
if ((i & 0x1) == 0) rp12 ^= tmppar;
if ((i & 0x2) == 0) rp14 ^= tmppar;
}
@@ -548,8 +548,8 @@ to rp12 and rp14.
While making the changes I also found that I could exploit that tmppar
contains the running parity for this iteration. So instead of having:
-rp4 ^= cur; rp6 = cur;
-I removed the rp6 = cur; statement and did rp6 ^= tmppar; on next
+rp4 ^= cur; rp6 ^= cur;
+I removed the rp6 ^= cur; statement and did rp6 ^= tmppar; on next
statement. A similar change was done for rp8 and rp10
@@ -593,22 +593,22 @@ The new code now looks like:
cur = *bp++; tmppar ^= cur; rp4_6 ^= cur;
cur = *bp++; tmppar ^= cur; rp6 ^= cur;
- cur = *bp++; tmppar ^= cur; rp4 ^= cur;
- cur = *bp++; tmppar ^= cur; rp10 ^= tmppar;
+ cur = *bp++; tmppar ^= cur; rp4 ^= cur;
+ cur = *bp++; tmppar ^= cur; rp10 ^= tmppar;
- notrp8 = tmppar;
- cur = *bp++; tmppar ^= cur; rp4_6 ^= cur;
+ notrp8 = tmppar;
+ cur = *bp++; tmppar ^= cur; rp4_6 ^= cur;
cur = *bp++; tmppar ^= cur; rp6 ^= cur;
- cur = *bp++; tmppar ^= cur; rp4 ^= cur;
+ cur = *bp++; tmppar ^= cur; rp4 ^= cur;
cur = *bp++; tmppar ^= cur;
- rp8 = rp8 ^ tmppar ^ notrp8;
+ rp8 = rp8 ^ tmppar ^ notrp8;
cur = *bp++; tmppar ^= cur; rp4_6 ^= cur;
cur = *bp++; tmppar ^= cur; rp6 ^= cur;
cur = *bp++; tmppar ^= cur; rp4 ^= cur;
cur = *bp++; tmppar ^= cur;
- par ^= tmppar;
+ par ^= tmppar;
if ((i & 0x1) == 0) rp12 ^= tmppar;
if ((i & 0x2) == 0) rp14 ^= tmppar;
}
@@ -700,7 +700,7 @@ Conclusion
The gain when calculating the ecc is tremendous. Om my development hardware
a speedup of a factor of 18 for ecc calculation was achieved. On a test on an
embedded system with a MIPS core a factor 7 was obtained.
-On a test with a Linksys NSLU2 (ARMv5TE processor) the speedup was a factor
+On a test with a Linksys NSLU2 (ARMv5TE processor) the speedup was a factor
5 (big endian mode, gcc 4.1.2, -O3)
For correction not much gain could be obtained (as bitflips are rare). Then
again there are also much less cycles spent there.