[Qemu-devel] [RFC PATCH v2 0/9] resolv device by Flattened Device Tree alias name

[Qemu-devel] [RFC PATCH v2 0/9] resolv device by Flattened Device Tree alias name

[Philippe Mathieu-Daudé]

Hi,

This RFC series is intended to simplify Flattened Device Tree support,
in particular the 'compatible' FDT entry, when Linux names mismatches
QEMU ones, but this is the same device modelled.

So far this is only a 'proof of concept'.

To see how the qtests perform, I only modified the Xilinx ZynqMP machine.

This is only the 6th generic alias compatibility API in QEMU   ¯\_(ツ)_/¯

Since v2:

- Follow Eduardo advice:
"If aliases exist only for compatibility, they should be restricted to
the places where compatibility is really needed."

- Do not modify QOM/qobject, use a specific GHashTable for FDT alias resolv.

- The aliases aren't display in HMP / -device help

If a machine is expected to use FDT, it needs to explicitely resolv any
device name with the type_resolve_fdt_alias() function.

Regards,

Phil.

Philippe Mathieu-Daudé (9):
  hw/sysbus: add helpers to register FDT aliases
  hw/char/cadence_uart: add FDT aliases
  hw/net/cadence_gem: add FDT aliases
  hw/timer/cadence_ttc: add FDT aliases
  hw/dma/axidma: add 'xlnx,eth-dma' FDT alias
  hw/usb/hcd-ehci: add 'xlnx,ps7-usb' FDT aliases
  hw/ssi/xlnx-spips: add 'xlnx.zynq-qspi' FDT alias
  hw/dma/xlnx_dpdma: add 'xlnx,axi-dpdma-1.0' FDT alias
  hw/arm/xlnx-zynqmp: use Linux FDT names

 include/hw/sysbus-fdt.h  | 18 ++++++++++++++++++
 hw/arm/xlnx-zynqmp.c     | 14 ++++++++++----
 hw/char/cadence_uart.c   | 12 ++++++++++++
 hw/core/sysbus-fdt.c     | 30 ++++++++++++++++++++++++++++++
 hw/dma/xilinx_axidma.c   |  2 ++
 hw/dma/xlnx_dpdma.c      |  2 ++
 hw/net/cadence_gem.c     | 10 ++++++++++
 hw/ssi/xilinx_spips.c    |  2 ++
 hw/timer/cadence_ttc.c   |  8 ++++++++
 hw/usb/hcd-ehci-sysbus.c |  8 ++++++++
 hw/core/Makefile.objs    |  1 +
 11 files changed, 103 insertions(+), 4 deletions(-)
 create mode 100644 include/hw/sysbus-fdt.h
 create mode 100644 hw/core/sysbus-fdt.c

-- 
2.15.1

[Qemu-devel] [RFC PATCH v2 1/9] hw/sysbus: add helpers to register FDT aliases

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 include/hw/sysbus-fdt.h | 18 ++++++++++++++++++
 hw/core/sysbus-fdt.c    | 30 ++++++++++++++++++++++++++++++
 hw/core/Makefile.objs   |  1 +
 3 files changed, 49 insertions(+)
 create mode 100644 include/hw/sysbus-fdt.h
 create mode 100644 hw/core/sysbus-fdt.c

diff --git a/include/hw/sysbus-fdt.h b/include/hw/sysbus-fdt.h
new file mode 100644
index 0000000000..21f42dbbad
--- /dev/null
+++ b/include/hw/sysbus-fdt.h
@@ -0,0 +1,18 @@
+/*
+ * Flattened Device Tree alias helpers
+ *
+ * Copyright (C) 2018 Philippe Mathieu-Daudé <f4bug@amsat.org>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version.  See the COPYING file in the
+ * top-level directory.
+ */
+#ifndef HW_SYSBUS_FDT_H
+#define HW_SYSBUS_FDT_H
+
+void type_register_fdt_alias(const char *name, const char *alias);
+void type_register_fdt_aliases(const char *name, const char **aliases);
+
+const char *type_resolve_fdt_alias(const char *alias);
+
+#endif /* HW_SYSBUS_FDT_H */
diff --git a/hw/core/sysbus-fdt.c b/hw/core/sysbus-fdt.c
new file mode 100644
index 0000000000..0d817ba230
--- /dev/null
+++ b/hw/core/sysbus-fdt.c
@@ -0,0 +1,30 @@
+#include "qemu/osdep.h"
+#include "hw/sysbus-fdt.h"
+
+static GHashTable *fdt_aliases(void)
+{
+    static GHashTable *fdt_aliases_singleton;
+
+    if (!fdt_aliases_singleton) {
+        fdt_aliases_singleton = g_hash_table_new(g_str_hash, g_str_equal);
+    }
+    return fdt_aliases_singleton;
+}
+
+void type_register_fdt_alias(const char *name, const char *alias)
+{
+    g_hash_table_insert(fdt_aliases(), (gpointer)name, (gpointer)name);
+    g_hash_table_insert(fdt_aliases(), (gpointer)alias, (gpointer)name);
+}
+
+void type_register_fdt_aliases(const char *name, const char **aliases)
+{
+    for (; *aliases; aliases++) {
+        type_register_fdt_alias(name, *aliases);
+    }
+}
+
+const char *type_resolve_fdt_alias(const char *alias)
+{
+    return g_hash_table_lookup(fdt_aliases(), alias);
+}
diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs
index f8d7a4aaed..f56f0755a5 100644
--- a/hw/core/Makefile.objs
+++ b/hw/core/Makefile.objs
@@ -11,6 +11,7 @@ common-obj-$(CONFIG_EMPTY_SLOT) += empty_slot.o
 common-obj-$(CONFIG_XILINX_AXI) += stream.o
 common-obj-$(CONFIG_PTIMER) += ptimer.o
 common-obj-$(CONFIG_SOFTMMU) += sysbus.o
+common-obj-$(CONFIG_SOFTMMU) += sysbus-fdt.o
 common-obj-$(CONFIG_SOFTMMU) += machine.o
 common-obj-$(CONFIG_SOFTMMU) += loader.o
 common-obj-$(CONFIG_FITLOADER) += loader-fit.o
-- 
2.15.1

[Qemu-devel] [RFC PATCH v2 2/9] hw/char/cadence_uart: add FDT aliases

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/char/cadence_uart.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/hw/char/cadence_uart.c b/hw/char/cadence_uart.c
index 6143494060..f164cee61d 100644
--- a/hw/char/cadence_uart.c
+++ b/hw/char/cadence_uart.c
@@ -23,6 +23,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/sysbus.h"
+#include "hw/sysbus-fdt.h"
 #include "chardev/char-fe.h"
 #include "chardev/char-serial.h"
 #include "qemu/timer.h"
@@ -560,6 +561,17 @@ static const TypeInfo cadence_uart_info = {
 
 static void cadence_uart_register_types(void)
 {
+    static const char *cadence_uart_fdt_aliases[] = {
+        "cdns.uart",
+        "cdns,uart-r1p8",
+        "xlnx,xuartps",     /* Zynq-7xxx SoC */
+        "xlnx.ps7-uart",
+        "cdns,uart-r1p12",
+        "xlnx,zynqmp-uart", /* Zynq Ultrascale+ MPSoC */
+        NULL
+    };
+
+    type_register_fdt_aliases(TYPE_CADENCE_UART, cadence_uart_fdt_aliases);
     type_register_static(&cadence_uart_info);
 }
 
-- 
2.15.1

[Qemu-devel] [RFC PATCH v2 3/9] hw/net/cadence_gem: add FDT aliases

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/net/cadence_gem.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index 3943187572..34ff738bf7 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -25,6 +25,7 @@
 #include "qemu/osdep.h"
 #include <zlib.h> /* For crc32 */
 
+#include "hw/sysbus-fdt.h"
 #include "hw/net/cadence_gem.h"
 #include "qapi/error.h"
 #include "qemu/log.h"
@@ -1552,6 +1553,15 @@ static const TypeInfo gem_info = {
 
 static void gem_register_types(void)
 {
+    static const char *gem_fdt_aliases[] = {
+        "cdns,gem",
+        "cdns,zynq-gem",    /* Zynq-7xxx SoC */
+        "xlnx.ps7-ethernet",
+        "cdns,zynqmp-gem",  /* Zynq Ultrascale+ MPSoC */
+        NULL
+    };
+
+    type_register_fdt_aliases(TYPE_CADENCE_GEM, gem_fdt_aliases);
     type_register_static(&gem_info);
 }
 
-- 
2.15.1

[Qemu-devel] [RFC PATCH v2 4/9] hw/timer/cadence_ttc: add FDT aliases

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/timer/cadence_ttc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/timer/cadence_ttc.c b/hw/timer/cadence_ttc.c
index 5e65fdb5a0..9aff19d3a5 100644
--- a/hw/timer/cadence_ttc.c
+++ b/hw/timer/cadence_ttc.c
@@ -18,6 +18,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/sysbus.h"
+#include "hw/sysbus-fdt.h"
 #include "qemu/timer.h"
 
 #ifdef CADENCE_TTC_ERR_DEBUG
@@ -488,6 +489,13 @@ static const TypeInfo cadence_ttc_info = {
 
 static void cadence_ttc_register_types(void)
 {
+    static const char *cadence_ttc_fdt_aliases[] = {
+        "cdns.ttc",         /* Zynq */
+        "xlnx.ps7-ttc",     /* Zynq-7xxx SoC */
+        NULL
+    };
+
+    type_register_fdt_aliases(TYPE_CADENCE_TTC, cadence_ttc_fdt_aliases);
     type_register_static(&cadence_ttc_info);
 }
 
-- 
2.15.1

[Qemu-devel] [RFC PATCH v2 5/9] hw/dma/axidma: add 'xlnx, eth-dma' FDT alias

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/dma/xilinx_axidma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
index 9b48103574..2359d5c114 100644
--- a/hw/dma/xilinx_axidma.c
+++ b/hw/dma/xilinx_axidma.c
@@ -24,6 +24,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/sysbus.h"
+#include "hw/sysbus-fdt.h"
 #include "qapi/error.h"
 #include "qemu/timer.h"
 #include "hw/ptimer.h"
@@ -648,6 +649,7 @@ static const TypeInfo xilinx_axidma_control_stream_info = {
 
 static void xilinx_axidma_register_types(void)
 {
+    type_register_fdt_alias(TYPE_XILINX_AXI_DMA, "xlnx,eth-dma");
     type_register_static(&axidma_info);
     type_register_static(&xilinx_axidma_data_stream_info);
     type_register_static(&xilinx_axidma_control_stream_info);
-- 
2.15.1

[Qemu-devel] [RFC PATCH v2 6/9] hw/usb/hcd-ehci: add 'xlnx, ps7-usb' FDT aliases

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/usb/hcd-ehci-sysbus.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/usb/hcd-ehci-sysbus.c b/hw/usb/hcd-ehci-sysbus.c
index 3b83beb140..0c1a995c2f 100644
--- a/hw/usb/hcd-ehci-sysbus.c
+++ b/hw/usb/hcd-ehci-sysbus.c
@@ -16,6 +16,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "hw/sysbus-fdt.h"
 #include "hw/usb/hcd-ehci.h"
 
 static const VMStateDescription vmstate_ehci_sysbus = {
@@ -244,6 +245,13 @@ static const TypeInfo ehci_fusbh200_type_info = {
 
 static void ehci_sysbus_register_types(void)
 {
+    static const char *xlnx_ehci_fdt_aliases[] = {
+        "xlnx.zynq-usb",    /* Zynq */
+        "xlnx.ps7-usb",     /* Zynq-7xxx SoC */
+        NULL
+    };
+
+    type_register_fdt_aliases("xlnx,ps7-usb", xlnx_ehci_fdt_aliases);
     type_register_static(&ehci_type_info);
     type_register_static(&ehci_xlnx_type_info);
     type_register_static(&ehci_exynos4210_type_info);
-- 
2.15.1

[Qemu-devel] [RFC PATCH v2 7/9] hw/ssi/xlnx-spips: add 'xlnx.zynq-qspi' FDT alias

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/ssi/xilinx_spips.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/ssi/xilinx_spips.c b/hw/ssi/xilinx_spips.c
index d8187fadd1..9f7edc7a14 100644
--- a/hw/ssi/xilinx_spips.c
+++ b/hw/ssi/xilinx_spips.c
@@ -24,6 +24,7 @@
 
 #include "qemu/osdep.h"
 #include "hw/sysbus.h"
+#include "hw/sysbus-fdt.h"
 #include "sysemu/sysemu.h"
 #include "hw/ptimer.h"
 #include "qemu/log.h"
@@ -1443,6 +1444,7 @@ static const TypeInfo xlnx_zynqmp_qspips_info = {
 
 static void xilinx_spips_register_types(void)
 {
+    type_register_fdt_alias(TYPE_XILINX_QSPIPS, "xlnx.zynq-qspi");
     type_register_static(&xilinx_spips_info);
     type_register_static(&xilinx_qspips_info);
     type_register_static(&xlnx_zynqmp_qspips_info);
-- 
2.15.1

[Qemu-devel] [RFC PATCH v2 8/9] hw/dma/xlnx_dpdma: add 'xlnx, axi-dpdma-1.0' FDT alias

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/dma/xlnx_dpdma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/dma/xlnx_dpdma.c b/hw/dma/xlnx_dpdma.c
index 8ceb21ddb3..d1b508cfe3 100644
--- a/hw/dma/xlnx_dpdma.c
+++ b/hw/dma/xlnx_dpdma.c
@@ -24,6 +24,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/log.h"
+#include "hw/sysbus-fdt.h"
 #include "hw/dma/xlnx_dpdma.h"
 
 #ifndef DEBUG_DPDMA
@@ -607,6 +608,7 @@ static const TypeInfo xlnx_dpdma_info = {
 
 static void xlnx_dpdma_register_types(void)
 {
+    type_register_fdt_alias(TYPE_XLNX_DPDMA, "xlnx,axi-dpdma-1.0"); /* ZynqMP */
     type_register_static(&xlnx_dpdma_info);
 }
 
-- 
2.15.1

[Qemu-devel] [RFC PATCH v2 9/9] hw/arm/xlnx-zynqmp: use Linux FDT names

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/arm/xlnx-zynqmp.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/hw/arm/xlnx-zynqmp.c b/hw/arm/xlnx-zynqmp.c
index 325642058b..fdcd6801b6 100644
--- a/hw/arm/xlnx-zynqmp.c
+++ b/hw/arm/xlnx-zynqmp.c
@@ -24,6 +24,7 @@
 #include "exec/address-spaces.h"
 #include "sysemu/kvm.h"
 #include "kvm_arm.h"
+#include "hw/sysbus-fdt.h"
 
 #define GIC_NUM_SPI_INTR 160
 
@@ -138,6 +139,7 @@ static void xlnx_zynqmp_init(Object *obj)
     XlnxZynqMPState *s = XLNX_ZYNQMP(obj);
     int i;
     int num_apus = MIN(smp_cpus, XLNX_ZYNQMP_NUM_APU_CPUS);
+    const char *type_name;
 
     for (i = 0; i < num_apus; i++) {
         object_initialize(&s->apu_cpu[i], sizeof(s->apu_cpu[i]),
@@ -150,12 +152,14 @@ static void xlnx_zynqmp_init(Object *obj)
     qdev_set_parent_bus(DEVICE(&s->gic), sysbus_get_default());
 
     for (i = 0; i < XLNX_ZYNQMP_NUM_GEMS; i++) {
-        object_initialize(&s->gem[i], sizeof(s->gem[i]), TYPE_CADENCE_GEM);
+        type_name = type_resolve_fdt_alias("cdns,zynqmp-gem");
+        object_initialize(&s->gem[i], sizeof(s->gem[i]), type_name);
         qdev_set_parent_bus(DEVICE(&s->gem[i]), sysbus_get_default());
     }
 
     for (i = 0; i < XLNX_ZYNQMP_NUM_UARTS; i++) {
-        object_initialize(&s->uart[i], sizeof(s->uart[i]), TYPE_CADENCE_UART);
+        type_name = type_resolve_fdt_alias("xlnx,zynqmp-uart");
+        object_initialize(&s->uart[i], sizeof(s->uart[i]), type_name);
         qdev_set_parent_bus(DEVICE(&s->uart[i]), sysbus_get_default());
     }
 
@@ -175,13 +179,15 @@ static void xlnx_zynqmp_init(Object *obj)
         qdev_set_parent_bus(DEVICE(&s->spi[i]), sysbus_get_default());
     }
 
-    object_initialize(&s->qspi, sizeof(s->qspi), TYPE_XLNX_ZYNQMP_QSPIPS);
+    type_name = type_resolve_fdt_alias("xlnx.zynq-qspi");
+    object_initialize(&s->qspi, sizeof(s->qspi), type_name);
     qdev_set_parent_bus(DEVICE(&s->qspi), sysbus_get_default());
 
     object_initialize(&s->dp, sizeof(s->dp), TYPE_XLNX_DP);
     qdev_set_parent_bus(DEVICE(&s->dp), sysbus_get_default());
 
-    object_initialize(&s->dpdma, sizeof(s->dpdma), TYPE_XLNX_DPDMA);
+    type_name = type_resolve_fdt_alias("xlnx,axi-dpdma-1.0");
+    object_initialize(&s->dpdma, sizeof(s->dpdma), type_name);
     qdev_set_parent_bus(DEVICE(&s->dpdma), sysbus_get_default());
 }
 
-- 
2.15.1

Re: [Qemu-devel] [RFC PATCH v2 9/9] hw/arm/xlnx-zynqmp: use Linux FDT names

[Peter Maydell]

On 9 January 2018 at 02:00, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  hw/arm/xlnx-zynqmp.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/hw/arm/xlnx-zynqmp.c b/hw/arm/xlnx-zynqmp.c
> index 325642058b..fdcd6801b6 100644
> --- a/hw/arm/xlnx-zynqmp.c
> +++ b/hw/arm/xlnx-zynqmp.c
> @@ -24,6 +24,7 @@
>  #include "exec/address-spaces.h"
>  #include "sysemu/kvm.h"
>  #include "kvm_arm.h"
> +#include "hw/sysbus-fdt.h"
>
>  #define GIC_NUM_SPI_INTR 160
>
> @@ -138,6 +139,7 @@ static void xlnx_zynqmp_init(Object *obj)
>      XlnxZynqMPState *s = XLNX_ZYNQMP(obj);
>      int i;
>      int num_apus = MIN(smp_cpus, XLNX_ZYNQMP_NUM_APU_CPUS);
> +    const char *type_name;
>
>      for (i = 0; i < num_apus; i++) {
>          object_initialize(&s->apu_cpu[i], sizeof(s->apu_cpu[i]),
> @@ -150,12 +152,14 @@ static void xlnx_zynqmp_init(Object *obj)
>      qdev_set_parent_bus(DEVICE(&s->gic), sysbus_get_default());
>
>      for (i = 0; i < XLNX_ZYNQMP_NUM_GEMS; i++) {
> -        object_initialize(&s->gem[i], sizeof(s->gem[i]), TYPE_CADENCE_GEM);
> +        type_name = type_resolve_fdt_alias("cdns,zynqmp-gem");
> +        object_initialize(&s->gem[i], sizeof(s->gem[i]), type_name);
>          qdev_set_parent_bus(DEVICE(&s->gem[i]), sysbus_get_default());
>      }

I'm having difficulty seeing the benefits of this series. We spend
patches 1-8 adding code to devices to add alias names to them,
and this means that in patch 9 we can replace a single
object_initialize() with ... two lines of code including
a runtime lookup of an alias name. Can you explain why this
is better than what we have currently?

thanks
-- PMM