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fw_cfg: replace ioport data read with generic method

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IOPort read access is limited to one byte at a time by
fw_cfg_comb_valid(). As such, fw_cfg_comb_read() may safely
ignore its size argument (which will always be 1), and simply
call its fw_cfg_read() helper function once, returning 8 bits
via the least significant byte of a 64-bit return value.

This patch replaces fw_cfg_comb_read() with the generic method
fw_cfg_data_read(), and removes the unused fw_cfg_read() helper.

When called with size = 1, fw_cfg_data_read() acts exactly like
fw_cfg_read(), performing the same set of sanity checks, and
executing the while loop at most once (subject to the current
read offset being within range).

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Marc Marí <markmb@redhat.com>
Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
Message-id: 1446733972-1602-7-git-send-email-somlo@cmu.edu
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Gabriel L. Somlo 2015-11-05 09:32:52 -05:00 committed by Gerd Hoffmann
parent 38bf20931a
commit 6c8d56a2e9
1 changed files with 1 additions and 24 deletions
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25
hw/nvram/fw_cfg.c
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@ -304,23 +304,6 @@ static uint64_t fw_cfg_data_read(void *opaque, hwaddr addr, unsigned size)
return value;
}
static uint8_t fw_cfg_read(FWCfgState *s)
{
int arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL);
FWCfgEntry *e = (s->cur_entry == FW_CFG_INVALID) ? NULL :
&s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
uint8_t ret;
if (s->cur_entry == FW_CFG_INVALID || !e->data || s->cur_offset >= e->len)
ret = 0;
else {
ret = e->data[s->cur_offset++];
}
trace_fw_cfg_read(s, ret);
return ret;
}
static void fw_cfg_data_mem_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
@ -470,12 +453,6 @@ static bool fw_cfg_ctl_mem_valid(void *opaque, hwaddr addr,
return is_write && size == 2;
}
static uint64_t fw_cfg_comb_read(void *opaque, hwaddr addr,
unsigned size)
{
return fw_cfg_read(opaque);
}
static void fw_cfg_comb_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
@ -513,7 +490,7 @@ static const MemoryRegionOps fw_cfg_data_mem_ops = {
};
static const MemoryRegionOps fw_cfg_comb_mem_ops = {
.read = fw_cfg_comb_read,
.read = fw_cfg_data_read,
.write = fw_cfg_comb_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid.accepts = fw_cfg_comb_valid,