[PATCH 0/3] OpenRISC updates for user space FPU

From: Stafford Horne <shorne@gmail.com>
To: QEMU Development <qemu-devel@nongnu.org>
Cc: Linux OpenRISC <linux-openrisc@vger.kernel.org>,
	Stafford Horne <shorne@gmail.com>
Subject: [PATCH 0/3] OpenRISC updates for user space FPU
Date: Tue,  2 May 2023 19:57:28 +0100	[thread overview]
Message-ID: <20230502185731.3543420-1-shorne@gmail.com> (raw)

This series adds support for the FPU related architecture changes defined in
architecture spec revision v1.4.

 - https://openrisc.io/revisions/r1.4

In summary the architecture changes are:

 - Change FPCSR SPR permissions to allow for reading and writing from user
   space.
 - Clarify that FPU underflow detection is done by detecting tininess before
   rounding.

Previous to this series FPCSR reads and writes from user-mode in QEMU would
throw an illegal argument exception.  The proper behavior should have been to
treat these operations as no-ops as the cpu implementations do.  As mentioned
series changes FPCSR read/write to follow the spec.

The series has been tested with the FPU support added in glibc test suite and
all math tests are passing.

Stafford Horne (3):
  target/openrisc: Allow fpcsr access in user mode
  target/openrisc: Set PC to cpu state on FPU exception
  target/openrisc: Setup FPU for detecting tininess before rounding

 target/openrisc/cpu.c        |  5 +++
 target/openrisc/fpu_helper.c |  4 ++
 target/openrisc/sys_helper.c | 45 +++++++++++++++++-----
 target/openrisc/translate.c  | 72 ++++++++++++++++--------------------
 4 files changed, 76 insertions(+), 50 deletions(-)

-- 
2.39.1