pflash: fix erase command when using mtd backend

The libflash mtd backend lacked support for full-chip erase so it did
not work.  This patch adds that support to libflash. Patch is on it's
way upstream[1].

Note: the old MMIO access method could perform a wole-chip
erase on SPI NOR parts that supported it. This was sometimes a fraction
faster than erasing each page one-by-one when re-flashing the entire
chip.

The mtd API does not (yet) provide a userspace API for that, so libflash
always erases the flash one page at a time. This means you are better
off using the -e command over -E.

Fixes: openbmc/openbmc#747

[1] http://patchwork.ozlabs.org/patch/691765/

Change-Id: I20cf50e70a8487edc8cd77d41e73832913237b1b
Signed-off-by: Joel Stanley <joel@jms.id.au>

2 files changed, 51 insertions, 0 deletions

diff --git a/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot.inc b/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot.inc
index 248e13f7f..fa30f091e 100644
--- a/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot.inc
+++ b/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot.inc
@@ -3,6 +3,7 @@ LICENSE = "Apache-2.0"
 
 SRC_URI += "git://github.com/open-power/skiboot.git;nobranch=1"
 SRC_URI += "file://0001-external-Use-more-standard-PREFIX-vs-prefix.patch"
+SRC_URI += "file://0002-external-common-Teach-ARM-code-to-erase-mtd-chips.patch"
 
 FILESEXTRAPATHS_append := "${THISDIR}/skiboot:"
 
diff --git a/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot/0002-external-common-Teach-ARM-code-to-erase-mtd-chips.patch b/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot/0002-external-common-Teach-ARM-code-to-erase-mtd-chips.patch
new file mode 100644
index 000000000..3ed951993
--- /dev/null
+++ b/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot/0002-external-common-Teach-ARM-code-to-erase-mtd-chips.patch
@@ -0,0 +1,50 @@
+From patchwork Mon Nov  7 06:28:49 2016
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [1/3] external/common: Teach ARM code to erase 'mtd chips'
+From: Cyril Bur <cyril.bur@au1.ibm.com>
+X-Patchwork-Id: 691765
+Message-Id: <20161107062851.1016-1-cyril.bur@au1.ibm.com>
+To: skiboot@lists.ozlabs.org
+Date: Mon,  7 Nov 2016 17:28:49 +1100
+
+Currently the arch flash code for all architectures can only perform
+chip erases if there is a real flash driver attached.
+
+With increasing use of MTD on both host and BMC this code needs to know
+how to behave of the backend of blocklevel is MTD.
+
+This patch teaches the ARM specific code to pass an erase for the full
+size of the chip down the stack. This can be optimised into a chip erase
+within the kernel.
+
+Signed-off-by: Cyril Bur <cyril.bur@au1.ibm.com>
+---
+ external/common/arch_flash_arm.c | 13 +++++++++++--
+ 1 file changed, 11 insertions(+), 2 deletions(-)
+
+diff --git a/external/common/arch_flash_arm.c b/external/common/arch_flash_arm.c
+index 697609d..bb8800f 100644
+--- a/external/common/arch_flash_arm.c
++++ b/external/common/arch_flash_arm.c
+@@ -300,8 +300,17 @@ int arch_flash_erase_chip(struct blocklevel_device *bl)
+ 	if (!arch_data.init_bl || arch_data.init_bl != bl)
+ 		return -1;
+ 
+-	if (!arch_data.flash_chip)
+-		return -1;
++	if (!arch_data.flash_chip) {
++		/* Just assume its a regular erase */
++		int rc;
++		uint64_t total_size;
++
++		rc = blocklevel_get_info(bl, NULL, &total_size, NULL);
++		if (rc)
++			return rc;
++
++		return blocklevel_erase(bl, 0, total_size);
++	}
+ 
+ 	return flash_erase_chip(arch_data.flash_chip);
+ }