Re: [PATCH 01/11] powerpc: Add Microwatt platform

2021-06-16 Thread Paul Mackerras 
On Wed, Jun 16, 2021 at 01:40:07PM -0500, Segher Boessenkool wrote:
> Hi Paul,
> 
> On Tue, Jun 15, 2021 at 08:57:43AM +1000, Paul Mackerras wrote:
> > --- a/arch/powerpc/Kconfig
> > +++ b/arch/powerpc/Kconfig
> > @@ -422,7 +422,7 @@ config HUGETLB_PAGE_SIZE_VARIABLE
> >  
> >  config MATH_EMULATION
> > bool "Math emulation"
> > -   depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE
> > +   depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE || PPC_MICROWATT
> > select PPC_FPU_REGS
> 
> Why do you need this / want this, since you have FP hardware?

The FPU is optional, and doesn't fit in the smaller (-35T) version of
the Artix-7 that is readily available.

I should mention this in the commit message.

Paul.

Re: [PATCH 01/11] powerpc: Add Microwatt platform

2021-06-16 Thread Segher Boessenkool 
Hi Paul,

On Tue, Jun 15, 2021 at 08:57:43AM +1000, Paul Mackerras wrote:
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -422,7 +422,7 @@ config HUGETLB_PAGE_SIZE_VARIABLE
>  
>  config MATH_EMULATION
>   bool "Math emulation"
> - depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE
> + depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE || PPC_MICROWATT
>   select PPC_FPU_REGS

Why do you need this / want this, since you have FP hardware?


Segher

[PATCH 01/11] powerpc: Add Microwatt platform

2021-06-14 Thread Paul Mackerras 
Microwatt is a FPGA-based implementation of the Power ISA.  It
currently only implements little-endian 64-bit mode, and does
not (yet) support SMP, VMX, VSX or transactional memory.

This adds a new machine type to support FPGA-based SoCs with a
Microwatt core.

Signed-off-by: Paul Mackerras 
---
 arch/powerpc/Kconfig  |  2 +-
 arch/powerpc/platforms/Kconfig|  1 +
 arch/powerpc/platforms/Makefile   |  1 +
 arch/powerpc/platforms/microwatt/Kconfig  |  9 +
 arch/powerpc/platforms/microwatt/Makefile |  1 +
 arch/powerpc/platforms/microwatt/setup.c  | 23 +++
 6 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/platforms/microwatt/Kconfig
 create mode 100644 arch/powerpc/platforms/microwatt/Makefile
 create mode 100644 arch/powerpc/platforms/microwatt/setup.c

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 386ae12d8523..5ce51c38a346 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -422,7 +422,7 @@ config HUGETLB_PAGE_SIZE_VARIABLE
 
 config MATH_EMULATION
bool "Math emulation"
-   depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE
+   depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE || PPC_MICROWATT
select PPC_FPU_REGS
help
  Some PowerPC chips designed for embedded applications do not have
diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 7a5e8f4541e3..74be4d06afbf 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -20,6 +20,7 @@ source "arch/powerpc/platforms/embedded6xx/Kconfig"
 source "arch/powerpc/platforms/44x/Kconfig"
 source "arch/powerpc/platforms/40x/Kconfig"
 source "arch/powerpc/platforms/amigaone/Kconfig"
+source "arch/powerpc/platforms/microwatt/Kconfig"
 
 config KVM_GUEST
bool "KVM Guest support"
diff --git a/arch/powerpc/platforms/Makefile b/arch/powerpc/platforms/Makefile
index 143d4417f6cc..edcb54cdb1a8 100644
--- a/arch/powerpc/platforms/Makefile
+++ b/arch/powerpc/platforms/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_PPC_CELL)+= cell/
 obj-$(CONFIG_PPC_PS3)  += ps3/
 obj-$(CONFIG_EMBEDDED6xx)  += embedded6xx/
 obj-$(CONFIG_AMIGAONE) += amigaone/
+obj-$(CONFIG_PPC_MICROWATT)+= microwatt/
diff --git a/arch/powerpc/platforms/microwatt/Kconfig 
b/arch/powerpc/platforms/microwatt/Kconfig
new file mode 100644
index ..3be01e78ce57
--- /dev/null
+++ b/arch/powerpc/platforms/microwatt/Kconfig
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+config PPC_MICROWATT
+   depends on PPC_BOOK3S_64 && !SMP
+   bool "Microwatt SoC platform"
+   select PPC_XICS
+   select PPC_NATIVE
+   help
+  This option enables support for FPGA-based Microwatt implementations.
+
diff --git a/arch/powerpc/platforms/microwatt/Makefile 
b/arch/powerpc/platforms/microwatt/Makefile
new file mode 100644
index ..e6885b3b2ee7
--- /dev/null
+++ b/arch/powerpc/platforms/microwatt/Makefile
@@ -0,0 +1 @@
+obj-y  += setup.o
diff --git a/arch/powerpc/platforms/microwatt/setup.c 
b/arch/powerpc/platforms/microwatt/setup.c
new file mode 100644
index ..d80d52612672
--- /dev/null
+++ b/arch/powerpc/platforms/microwatt/setup.c
@@ -0,0 +1,23 @@
+/*
+ * Microwatt FPGA-based SoC platform setup code.
+ *
+ * Copyright 2020 Paul Mackerras (pau...@ozlabs.org), IBM Corp.
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+static int __init microwatt_probe(void)
+{
+   return of_machine_is_compatible("microwatt-soc");
+}
+
+define_machine(microwatt) {
+   .name   = "microwatt",
+   .probe  = microwatt_probe,
+   .calibrate_decr = generic_calibrate_decr,
+};
-- 
2.31.1