[Skiboot] [PATCH] libflash/file: greatly increase perf of file_erase()

[Stewart Smith]

Do 4096 byte chunks not 8 byte chunks. A ffspart invocation constructing
a 64MB PNOR goes from a couple of seconds to ~0.1seconds with this
patch.

Signed-off-by: Stewart Smith <stewart at linux.ibm.com>
---
 doc/release-notes/skiboot-6.2-rc2.rst | 76 ---------------------------
 libflash/file.c                       |  8 +--
 2 files changed, 5 insertions(+), 79 deletions(-)
 delete mode 100644 doc/release-notes/skiboot-6.2-rc2.rst

diff --git a/doc/release-notes/skiboot-6.2-rc2.rst b/doc/release-notes/skiboot-6.2-rc2.rst
deleted file mode 100644
index 1a3ff63631c7..000000000000
--- a/doc/release-notes/skiboot-6.2-rc2.rst
+++ /dev/null
@@ -1,76 +0,0 @@
-.. _skiboot-6.2-rc2:
-
-skiboot-6.2-rc2
-===============
-
-skiboot v6.2-rc2 was released on Thursday November 29th 2018. It is the second
-release candidate of skiboot 6.2, which will become the new stable release
-of skiboot following the 6.1 release, first released July 11th 2018.
-
-Skiboot 6.2 will mark the basis for op-build v2.2.
-
-skiboot v6.2-rc2 contains all bug fixes as of :ref:`skiboot-6.0.14`,
-and :ref:`skiboot-5.4.10` (the currently maintained
-stable releases).
-
-For how the skiboot stable releases work, see :ref:`stable-rules` for details.
-
-Over :ref:`skiboot-6.2-rc1`, we have the following changes:
-
-- npu2-opencapi: Log extra information on link training failure
-- npu2-opencapi: Detect if link trained in degraded mode
-- platform/firenze: Fix branch-to-null crash
-
-  When the bus alloc and free methods were removed we missed a case in the
-  Firenze platform slot code that relied on the the bus-specific method to
-  the bus pointer in the request structure. This results in a
-  branch-to-null during boot and a crash. This patch fixes it by
-  initialising it manually here.
-- libflash: Don't merge ECC-protected ranges
-
-  Libflash currently merges contiguous ECC-protected ranges, but doesn't
-  check that the ECC bytes at the end of the first and start of the second
-  range actually match sanely. More importantly, if blocklevel_read() is
-  called with a position at the start of a partition that is contained
-  somewhere within a region that has been merged it will update the
-  position assuming ECC wasn't being accounted for. This results in the
-  position being somewhere well after the actual start of the partition
-  which is incorrect.
-
-  For now, remove the code merging ranges. This means more ranges must be
-  held and checked however it prevents incorrectly reading ECC-correct
-  regions like below: ::
-
-    [  174.334119453,7] FLASH: CAPP partition has ECC
-    [  174.437349574,3] ECC: uncorrectable error: ffffffffffffffff ff
-    [  174.437426306,3] FLASH: failed to read the first 0x1000 from CAPP partition, rc 14
-    [  174.439919343,3] CAPP: Error loading ucode lid. index=201d1
-
-- libflash: Restore blocklevel tests
-
-  This fell out in f58be46 "libflash/test: Rewrite Makefile.check to
-  improve scalability". Add it back in as test-blocklevel.
-- Warn on long OPAL calls
-
-  Measure entry/exit time for OPAL calls and warn appropriately if the
-  calls take too long (>100ms gets us a DEBUG log, > 1000ms gets us a
-  warning).
-
-CI, testing, and utilities
---------------------------
-
-- travis: Coverity fixed their SSL cert
-- opal-ci: Use ubuntu:rolling for Ubuntu latest image
-- ffspart: Add test for eraseblock size
-- ffspart: Add toc test
-- hdata/test: workaround dtc bugs
-
-  In dtc v1.4.5 to at least v1.4.7 there have been a few bugs introduced
-  that change the layout of what's produced in the dts. In order to be
-  immune from them, we should use the (provided) dtdiff utility, but we
-  also need to run the dts we're diffing against through a dtb cycle in
-  order to ensure we get the same format as what the hdat_to_dt to dts
-  conversion will.
-
-  This fixes a bunch of unit test failures on the version of dtc shipped
-  with recent Linux distros such as Fedora 29.
diff --git a/libflash/file.c b/libflash/file.c
index 49f61778e946..72765b5777f9 100644
--- a/libflash/file.c
+++ b/libflash/file.c
@@ -117,15 +117,17 @@ static int file_write(struct blocklevel_device *bl, uint64_t dst, const void *sr
  */
 static int file_erase(struct blocklevel_device *bl, uint64_t dst, uint64_t len)
 {
-	unsigned long long int d = ULLONG_MAX;
+	char buf[4096];
 	int i = 0;
 	int rc;
 
+	memset(buf, ~0, sizeof(buf));
+
 	while (len - i > 0) {
-		rc = file_write(bl, dst + i, &d, len - i > sizeof(d) ? sizeof(d) : len - i);
+		rc = file_write(bl, dst + i, buf, len - i > sizeof(buf) ? sizeof(buf) : len - i);
 		if (rc)
 			return rc;
-		i += len - i > sizeof(d) ? sizeof(d) : len - i;
+		i += (len - i > sizeof(buf)) ? sizeof(buf) : len - i;
 	}
 
 	return 0;
-- 
2.19.2