[S] Change in flashrom[master]: programmer: Add rget_io_perms programmer req framework

[Edward O'Callaghan (Code Review)]

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/68662 )

Change subject: programmer: Add rget_io_perms programmer req framework
......................................................................

programmer: Add rget_io_perms programmer req framework

Some programmers require special i/o port access permissions.
Add a flag in the programmer entry to allow the programmer to
flag this requirement to the flashrom core logic rather than
each bespoke programmer init() calling rget_io_perms() in their
own ways.

This allows for flashrom core logic to assume and drop privileges
exactly where they are needed rather than for the entire life-time
of the program. It also deduplicates the assuming privilege code in
each driver.

Change-Id: I2be81995f8fe7e212a01008a5e7bdb49b1592ca2
Signed-off-by: Edward O'Callaghan 
---
M flashrom.c
M include/programmer.h
2 files changed, 30 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/62/68662/1

diff --git a/flashrom.c b/flashrom.c
index 624c463..908f46e 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -32,6 +32,7 @@
 #include "flashchips.h"
 #include "programmer.h"
 #include "hwaccess_physmap.h"
+#include "hwaccess_x86_io.h" /* required for rget_io_perms() */
 #include "chipdrivers.h"

const char flashrom_version[] = FLASHROM_VERSION;
@@ -149,6 +150,13 @@
    /* Default to allowing writes. Broken programmers set this to 0. */
    programmer_may_write = true;

+	if (prog->rget_io_perms) {
+#if defined(__i386__) || defined(__x86_64__)
+		if (rget_io_perms())
+			return -2;
+#endif
+	}
+
    struct programmer_cfg cfg;

if (param) {
diff --git a/include/programmer.h b/include/programmer.h
index 9603443..6da1be9 100644
--- a/include/programmer.h
+++ b/include/programmer.h
@@ -43,6 +43,7 @@
 struct programmer_entry {
    const char *name;
    const enum programmer_type type;
+	const bool rget_io_perms_req;
    union {
    	const struct dev_entry *const dev;
    	const char *const note;