On Fri, May 28, 2010 at 7:34 PM, Paul Brook <p...@codesourcery.com> wrote:
>> Use a qemu_irq to request CPU exit.
>
> Needing to request a CPU exit at all is just wrong. See previous discussions
> about how any use of qemu_bh_schedule_idle is fundamentally broken.
I agree for the device case. Is the attached patch then OK?
But what about other uses (with the patch applied):
User emulator signal delivery:
/src/qemu/darwin-user/signal.c:216: cpu_exit(global_env);
/src/qemu/linux-user/signal.c:507: cpu_exit(thread_env);
qemu_notify_event():
/src/qemu/cpus.c:286: cpu_exit(env);
/src/qemu/cpus.c:289: cpu_exit(next_cpu);
Is that broken too and should be removed?
cpu_signal():
/src/qemu/cpus.c:531: cpu_exit(cpu_single_env);
vm_stop():
/src/qemu/cpus.c:733: cpu_exit(cpu_single_env);
KVM IO window exit:
/src/qemu/kvm-all.c:859: cpu_exit(env);
Some exclusive ARM operation:
/src/qemu/linux-user/main.c:152: cpu_exit(other);
ARM/m68k semihosting:
/src/qemu/gdbstub.c:2296: cpu_exit(s->c_cpu);
From 12940e4bf57af4801ffc209095b6adcc0693320f Mon Sep 17 00:00:00 2001
From: Blue Swirl <blauwirbel@gmail.com>
Date: Sat, 29 May 2010 07:59:40 +0000
Subject: [PATCH] dma: remove DMA_schedule and related cpu_request_exit irq
It's wrong for devices to request cpu_exit. Remove DMA_schedule and
cpu_request_exit irq, thus partially reverting
4556bd8b2514a55d48c15b1adb17537f49657744.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
---
hw/dma.c | 19 ++++---------------
hw/fdc.c | 1 -
hw/isa.h | 3 +--
hw/mips_jazz.c | 13 +------------
hw/mips_malta.c | 13 +------------
hw/pc.c | 13 +------------
hw/ppc_prep.c | 13 +------------
hw/sun4m.c | 1 -
hw/sun4u.c | 1 -
9 files changed, 9 insertions(+), 68 deletions(-)
diff --git a/hw/dma.c b/hw/dma.c
index 5b21521..1015b41 100644
--- a/hw/dma.c
+++ b/hw/dma.c
@@ -57,7 +57,6 @@ static struct dma_cont {
uint8_t flip_flop;
int dshift;
struct dma_regs regs[4];
- qemu_irq *cpu_request_exit;
} dma_controllers[2];
enum {
@@ -442,14 +441,6 @@ int DMA_write_memory (int nchan, void *buf, int pos, int len)
return len;
}
-/* request the emulator to transfer a new DMA memory block ASAP */
-void DMA_schedule(int nchan)
-{
- struct dma_cont *d = &dma_controllers[nchan > 3];
-
- qemu_irq_pulse(*d->cpu_request_exit);
-}
-
static void dma_reset(void *opaque)
{
struct dma_cont *d = opaque;
@@ -465,14 +456,12 @@ static int dma_phony_handler (void *opaque, int nchan, int dma_pos, int dma_len)
/* dshift = 0: 8 bit DMA, 1 = 16 bit DMA */
static void dma_init2(struct dma_cont *d, int base, int dshift,
- int page_base, int pageh_base,
- qemu_irq *cpu_request_exit)
+ int page_base, int pageh_base)
{
static const int page_port_list[] = { 0x1, 0x2, 0x3, 0x7 };
int i;
d->dshift = dshift;
- d->cpu_request_exit = cpu_request_exit;
for (i = 0; i < 8; i++) {
register_ioport_write (base + (i << dshift), 1, 1, write_chan, d);
register_ioport_read (base + (i << dshift), 1, 1, read_chan, d);
@@ -542,12 +531,12 @@ static const VMStateDescription vmstate_dma = {
}
};
-void DMA_init(int high_page_enable, qemu_irq *cpu_request_exit)
+void DMA_init(int high_page_enable)
{
dma_init2(&dma_controllers[0], 0x00, 0, 0x80,
- high_page_enable ? 0x480 : -1, cpu_request_exit);
+ high_page_enable ? 0x480 : -1);
dma_init2(&dma_controllers[1], 0xc0, 1, 0x88,
- high_page_enable ? 0x488 : -1, cpu_request_exit);
+ high_page_enable ? 0x488 : -1);
vmstate_register (0, &vmstate_dma, &dma_controllers[0]);
vmstate_register (1, &vmstate_dma, &dma_controllers[1]);
diff --git a/hw/fdc.c b/hw/fdc.c
index 6306496..d4505b4 100644
--- a/hw/fdc.c
+++ b/hw/fdc.c
@@ -1174,7 +1174,6 @@ static void fdctrl_start_transfer(FDCtrl *fdctrl, int direction)
* recall us...
*/
DMA_hold_DREQ(fdctrl->dma_chann);
- DMA_schedule(fdctrl->dma_chann);
return;
} else {
FLOPPY_ERROR("dma_mode=%d direction=%d\n", dma_mode, direction);
diff --git a/hw/isa.h b/hw/isa.h
index aaf0272..9681de1 100644
--- a/hw/isa.h
+++ b/hw/isa.h
@@ -40,8 +40,7 @@ int DMA_read_memory (int nchan, void *buf, int pos, int size);
int DMA_write_memory (int nchan, void *buf, int pos, int size);
void DMA_hold_DREQ (int nchan);
void DMA_release_DREQ (int nchan);
-void DMA_schedule(int nchan);
-void DMA_init(int high_page_enable, qemu_irq *cpu_request_exit);
+void DMA_init(int high_page_enable);
void DMA_register_channel (int nchan,
DMA_transfer_handler transfer_handler,
void *opaque);
diff --git a/hw/mips_jazz.c b/hw/mips_jazz.c
index ead3a00..6e0ec8f 100644
--- a/hw/mips_jazz.c
+++ b/hw/mips_jazz.c
@@ -114,15 +114,6 @@ static void audio_init(qemu_irq *pic)
#define MAGNUM_BIOS_SIZE_MAX 0x7e000
#define MAGNUM_BIOS_SIZE (BIOS_SIZE < MAGNUM_BIOS_SIZE_MAX ? BIOS_SIZE : MAGNUM_BIOS_SIZE_MAX)
-static void cpu_request_exit(void *opaque, int irq, int level)
-{
- CPUState *env = cpu_single_env;
-
- if (env && level) {
- cpu_exit(env);
- }
-}
-
static
void mips_jazz_init (ram_addr_t ram_size,
const char *cpu_model,
@@ -139,7 +130,6 @@ void mips_jazz_init (ram_addr_t ram_size,
PITState *pit;
DriveInfo *fds[MAX_FD];
qemu_irq esp_reset;
- qemu_irq *cpu_exit_irq;
ram_addr_t ram_offset;
ram_addr_t bios_offset;
@@ -199,8 +189,7 @@ void mips_jazz_init (ram_addr_t ram_size,
i8259 = i8259_init(env->irq[4]);
isa_bus_new(NULL);
isa_bus_irqs(i8259);
- cpu_exit_irq = qemu_allocate_irqs(cpu_request_exit, NULL, 1);
- DMA_init(0, cpu_exit_irq);
+ DMA_init(0);
pit = pit_init(0x40, i8259[0]);
pcspk_init(pit);
diff --git a/hw/mips_malta.c b/hw/mips_malta.c
index a8f9d15..792709b 100644
--- a/hw/mips_malta.c
+++ b/hw/mips_malta.c
@@ -763,15 +763,6 @@ static void main_cpu_reset(void *opaque)
}
}
-static void cpu_request_exit(void *opaque, int irq, int level)
-{
- CPUState *env = cpu_single_env;
-
- if (env && level) {
- cpu_exit(env);
- }
-}
-
static
void mips_malta_init (ram_addr_t ram_size,
const char *boot_device,
@@ -790,7 +781,6 @@ void mips_malta_init (ram_addr_t ram_size,
FDCtrl *floppy_controller;
MaltaFPGAState *malta_fpga;
qemu_irq *i8259;
- qemu_irq *cpu_exit_irq;
int piix4_devfn;
uint8_t *eeprom_buf;
i2c_bus *smbus;
@@ -953,8 +943,7 @@ void mips_malta_init (ram_addr_t ram_size,
qdev_init_nofail(eeprom);
}
pit = pit_init(0x40, isa_reserve_irq(0));
- cpu_exit_irq = qemu_allocate_irqs(cpu_request_exit, NULL, 1);
- DMA_init(0, cpu_exit_irq);
+ DMA_init(0);
/* Super I/O */
isa_dev = isa_create_simple("i8042");
diff --git a/hw/pc.c b/hw/pc.c
index e7f31d3..d2fb9be 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -914,15 +914,6 @@ void pc_vga_init(PCIBus *pci_bus)
}
}
-static void cpu_request_exit(void *opaque, int irq, int level)
-{
- CPUState *env = cpu_single_env;
-
- if (env && level) {
- cpu_exit(env);
- }
-}
-
void pc_basic_device_init(qemu_irq *isa_irq,
FDCtrl **floppy_controller,
ISADevice **rtc_state)
@@ -932,7 +923,6 @@ void pc_basic_device_init(qemu_irq *isa_irq,
PITState *pit;
qemu_irq *a20_line;
ISADevice *i8042;
- qemu_irq *cpu_exit_irq;
register_ioport_write(0x80, 1, 1, ioport80_write, NULL);
@@ -965,8 +955,7 @@ void pc_basic_device_init(qemu_irq *isa_irq,
i8042_setup_a20_line(i8042, a20_line);
vmmouse_init(i8042);
- cpu_exit_irq = qemu_allocate_irqs(cpu_request_exit, NULL, 1);
- DMA_init(0, cpu_exit_irq);
+ DMA_init(0);
for(i = 0; i < MAX_FD; i++) {
fd[i] = drive_get(IF_FLOPPY, 0, i);
diff --git a/hw/ppc_prep.c b/hw/ppc_prep.c
index 16c9950..e9c7370 100644
--- a/hw/ppc_prep.c
+++ b/hw/ppc_prep.c
@@ -547,15 +547,6 @@ static CPUReadMemoryFunc * const PPC_prep_io_read[] = {
#define NVRAM_SIZE 0x2000
-static void cpu_request_exit(void *opaque, int irq, int level)
-{
- CPUState *env = cpu_single_env;
-
- if (env && level) {
- cpu_exit(env);
- }
-}
-
/* PowerPC PREP hardware initialisation */
static void ppc_prep_init (ram_addr_t ram_size,
const char *boot_device,
@@ -574,7 +565,6 @@ static void ppc_prep_init (ram_addr_t ram_size,
uint32_t kernel_base, kernel_size, initrd_base, initrd_size;
PCIBus *pci_bus;
qemu_irq *i8259;
- qemu_irq *cpu_exit_irq;
int ppc_boot_device;
DriveInfo *hd[MAX_IDE_BUS * MAX_IDE_DEVS];
DriveInfo *fd[MAX_FD];
@@ -730,8 +720,7 @@ static void ppc_prep_init (ram_addr_t ram_size,
}
isa_create_simple("i8042");
- cpu_exit_irq = qemu_allocate_irqs(cpu_request_exit, NULL, 1);
- DMA_init(1, cpu_exit_irq);
+ DMA_init(1);
// SB16_init();
diff --git a/hw/sun4m.c b/hw/sun4m.c
index 7ba0f76..8e040b8 100644
--- a/hw/sun4m.c
+++ b/hw/sun4m.c
@@ -151,7 +151,6 @@ int DMA_write_memory (int nchan, void *buf, int pos, int size)
}
void DMA_hold_DREQ (int nchan) {}
void DMA_release_DREQ (int nchan) {}
-void DMA_schedule(int nchan) {}
void DMA_init(int high_page_enable, qemu_irq *cpu_request_exit)
{
diff --git a/hw/sun4u.c b/hw/sun4u.c
index 40b5f1f..ee81f56 100644
--- a/hw/sun4u.c
+++ b/hw/sun4u.c
@@ -104,7 +104,6 @@ int DMA_write_memory (int nchan, void *buf, int pos, int size)
}
void DMA_hold_DREQ (int nchan) {}
void DMA_release_DREQ (int nchan) {}
-void DMA_schedule(int nchan) {}
void DMA_init(int high_page_enable, qemu_irq *cpu_request_exit)
{
--
1.5.6.5
