Change in flashrom[master]: dummyflasher.c: Get rid of get_data_from_context()

[Edward O'Callaghan (Code Review)]

Edward O'Callaghan has submitted this change. ( https://review.coreboot.org/c/flashrom/+/54907 )

Change subject: dummyflasher.c: Get rid of get_data_from_context()
......................................................................

dummyflasher.c: Get rid of get_data_from_context()

Relying on the global state 'dummy_buses_supported' to
determine the member master struct [mst.par or mst.spi]
is both buggy and ultimately unnecessary. It became
apparent after commit 4eef651ff503f81b77 just how fragile
this really was as the 'defaults' simultaneously selected
both buses causing get_data_from_context() to fall-though
however memory happened to workout by chance due to the
union. With the member master structs now being struct
fields the subtle bug is more apparent.

BUG=none
BRANCH=none
TEST=`./flashrom -r /tmp/fwupdater.apnSQQ -p dummy:emulate=VARIABLE_SIZE,image=test_update.sh.tmp.emu,size=8388608`

Change-Id: I07a34faf50ff0679cb3d6bc683142f82160010b1
Signed-off-by: Edward O'Callaghan 
Reviewed-on: https://review.coreboot.org/c/flashrom/+/54907
Reviewed-by: Anastasia Klimchuk 
Reviewed-by: Sam McNally 
Tested-by: build bot (Jenkins) 
---
M dummyflasher.c
1 file changed, 2 insertions(+), 14 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Sam McNally: Looks good to me, approved
  Anastasia Klimchuk: Looks good to me, but someone else must approve

diff --git a/dummyflasher.c b/dummyflasher.c
index 587fc61..b7cfab8 100644
--- a/dummyflasher.c
+++ b/dummyflasher.c
@@ -103,18 +103,6 @@
 #endif
 #endif

-static enum chipbustype dummy_buses_supported = BUS_NONE;
-
-static struct emu_data* get_data_from_context(const struct flashctx *flash)
-{
-	if (dummy_buses_supported & BUS_NONSPI)
-		return (struct emu_data *)flash->mst->par.data;
-	else if (dummy_buses_supported & BUS_SPI)
-		return (struct emu_data *)flash->mst->spi.data;
-
-	return NULL;	/* buses was set to BUS_NONE. */
-}
-
 void *dummy_map(const char *descr, uintptr_t phys_addr, size_t len)
 {
    msg_pspew("%s: Mapping %s, 0x%zx bytes at 0x%0*" PRIxPTR "\n",
@@ -688,7 +676,7 @@
    /* Convert the parameters to lowercase. */
    tolower_string(bustext);

-	dummy_buses_supported = BUS_NONE;
+	enum chipbustype dummy_buses_supported = BUS_NONE;
    if (strstr(bustext, "parallel")) {
    	dummy_buses_supported |= BUS_PARALLEL;
    	msg_pdbg("Enabling support for %s flash.\n", "parallel");
@@ -1041,7 +1029,7 @@
 int probe_variable_size(struct flashctx *flash)
 {
    unsigned int i;
-	const struct emu_data *emu_data = get_data_from_context(flash);
+	const struct emu_data *emu_data = flash->mst->spi.data;

/* Skip the probing if we don't emulate this chip. */
    if (!emu_data || emu_data->emu_chip != EMULATE_VARIABLE_SIZE)