Samuel Thibault
2008-Feb-11 12:12 UTC
[Xen-devel] [PATCH] ioemu: save 3MB of ioport tables (on 64bit machines)
ioemu: save 3MB of ioport tables (on 64bit machines)
by keeping then initialized to NULL and check for it in the handlers.
Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>
---
This is a bargain between memory usage and CPU usage. Checking for
NULL and setting a default value is just a matter of test;jz;mov, it is
probably worth the saved 3MB.
diff -r 1104e9a108c2 tools/ioemu/vl.c
--- a/tools/ioemu/vl.c Mon Feb 11 11:50:26 2008 +0000
+++ b/tools/ioemu/vl.c Mon Feb 11 12:07:27 2008 +0000
@@ -227,17 +227,29 @@ uint32_t default_ioport_readw(void *opaq
uint32_t default_ioport_readw(void *opaque, uint32_t address)
{
uint32_t data;
- data = ioport_read_table[0][address](ioport_opaque[address], address);
+ IOPortReadFunc *func = ioport_read_table[0][address];
+ if (!func)
+ func = default_ioport_readb;
+ data = func(ioport_opaque[address], address);
address = (address + 1) & (MAX_IOPORTS - 1);
- data |= ioport_read_table[0][address](ioport_opaque[address], address)
<< 8;
+ func = ioport_read_table[0][address];
+ if (!func)
+ func = default_ioport_readb;
+ data |= func(ioport_opaque[address], address) << 8;
return data;
}
void default_ioport_writew(void *opaque, uint32_t address, uint32_t data)
{
- ioport_write_table[0][address](ioport_opaque[address], address, data &
0xff);
+ IOPortWriteFunc *func = ioport_write_table[0][address];
+ if (!func)
+ func = default_ioport_writeb;
+ func(ioport_opaque[address], address, data & 0xff);
address = (address + 1) & (MAX_IOPORTS - 1);
- ioport_write_table[0][address](ioport_opaque[address], address, (data
>> 8) & 0xff);
+ func = ioport_write_table[0][address];
+ if (!func)
+ func = default_ioport_writeb;
+ func(ioport_opaque[address], address, (data >> 8) & 0xff);
}
uint32_t default_ioport_readl(void *opaque, uint32_t address)
@@ -257,16 +269,6 @@ void default_ioport_writel(void *opaque,
void init_ioports(void)
{
- int i;
-
- for(i = 0; i < MAX_IOPORTS; i++) {
- ioport_read_table[0][i] = default_ioport_readb;
- ioport_write_table[0][i] = default_ioport_writeb;
- ioport_read_table[1][i] = default_ioport_readw;
- ioport_write_table[1][i] = default_ioport_writew;
- ioport_read_table[2][i] = default_ioport_readl;
- ioport_write_table[2][i] = default_ioport_writel;
- }
}
/* size is the word size in byte */
@@ -338,11 +340,14 @@ void isa_unassign_ioport(int start, int
void cpu_outb(CPUState *env, int addr, int val)
{
+ IOPortWriteFunc *func = ioport_write_table[0][addr];
+ if (!func)
+ func = default_ioport_writeb;
#ifdef DEBUG_IOPORT
if (loglevel & CPU_LOG_IOPORT)
fprintf(logfile, "outb: %04x %02x\n", addr, val);
#endif
- ioport_write_table[0][addr](ioport_opaque[addr], addr, val);
+ func(ioport_opaque[addr], addr, val);
#ifdef USE_KQEMU
if (env)
env->last_io_time = cpu_get_time_fast();
@@ -351,11 +356,14 @@ void cpu_outb(CPUState *env, int addr, i
void cpu_outw(CPUState *env, int addr, int val)
{
+ IOPortWriteFunc *func = ioport_write_table[1][addr];
+ if (!func)
+ func = default_ioport_writew;
#ifdef DEBUG_IOPORT
if (loglevel & CPU_LOG_IOPORT)
fprintf(logfile, "outw: %04x %04x\n", addr, val);
#endif
- ioport_write_table[1][addr](ioport_opaque[addr], addr, val);
+ func(ioport_opaque[addr], addr, val);
#ifdef USE_KQEMU
if (env)
env->last_io_time = cpu_get_time_fast();
@@ -364,11 +372,14 @@ void cpu_outw(CPUState *env, int addr, i
void cpu_outl(CPUState *env, int addr, int val)
{
+ IOPortWriteFunc *func = ioport_write_table[2][addr];
+ if (!func)
+ func = default_ioport_writel;
#ifdef DEBUG_IOPORT
if (loglevel & CPU_LOG_IOPORT)
fprintf(logfile, "outl: %04x %08x\n", addr, val);
#endif
- ioport_write_table[2][addr](ioport_opaque[addr], addr, val);
+ func(ioport_opaque[addr], addr, val);
#ifdef USE_KQEMU
if (env)
env->last_io_time = cpu_get_time_fast();
@@ -378,7 +389,10 @@ int cpu_inb(CPUState *env, int addr)
int cpu_inb(CPUState *env, int addr)
{
int val;
- val = ioport_read_table[0][addr](ioport_opaque[addr], addr);
+ IOPortReadFunc *func = ioport_read_table[0][addr];
+ if (!func)
+ func = default_ioport_readb;
+ val = func(ioport_opaque[addr], addr);
#ifdef DEBUG_IOPORT
if (loglevel & CPU_LOG_IOPORT)
fprintf(logfile, "inb : %04x %02x\n", addr, val);
@@ -393,7 +407,10 @@ int cpu_inw(CPUState *env, int addr)
int cpu_inw(CPUState *env, int addr)
{
int val;
- val = ioport_read_table[1][addr](ioport_opaque[addr], addr);
+ IOPortReadFunc *func = ioport_read_table[1][addr];
+ if (!func)
+ func = default_ioport_readw;
+ val = func(ioport_opaque[addr], addr);
#ifdef DEBUG_IOPORT
if (loglevel & CPU_LOG_IOPORT)
fprintf(logfile, "inw : %04x %04x\n", addr, val);
@@ -408,7 +425,10 @@ int cpu_inl(CPUState *env, int addr)
int cpu_inl(CPUState *env, int addr)
{
int val;
- val = ioport_read_table[2][addr](ioport_opaque[addr], addr);
+ IOPortReadFunc *func = ioport_read_table[2][addr];
+ if (!func)
+ func = default_ioport_readl;
+ val = func(ioport_opaque[addr], addr);
#ifdef DEBUG_IOPORT
if (loglevel & CPU_LOG_IOPORT)
fprintf(logfile, "inl : %04x %08x\n", addr, val);
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