summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kernel/entry-fpsimd.S
diff options
context:
space:
mode:
authorCatalin Marinas <catalin.marinas@arm.com>2012-03-05 12:49:32 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2012-09-17 14:42:13 +0200
commit53631b54c8704fe5de435582c82ddbc0bfabf06a (patch)
tree3bca49152b4e2eeaf7a96f2405ed963ce17da1e5 /arch/arm64/kernel/entry-fpsimd.S
parentarm64: 32-bit (compat) applications support (diff)
downloadlinux-53631b54c8704fe5de435582c82ddbc0bfabf06a.tar.xz
linux-53631b54c8704fe5de435582c82ddbc0bfabf06a.zip
arm64: Floating point and SIMD
This patch adds support for FP/ASIMD register bank saving and restoring during context switch and FP exception handling to generate SIGFPE. There are 32 128-bit registers and the context switching is currently done non-lazily. Benchmarks on real hardware are required before implementing lazy FP state saving/restoring. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Diffstat (limited to 'arch/arm64/kernel/entry-fpsimd.S')
-rw-r--r--arch/arm64/kernel/entry-fpsimd.S80
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/arm64/kernel/entry-fpsimd.S b/arch/arm64/kernel/entry-fpsimd.S
new file mode 100644
index 000000000000..17988a6e7ea2
--- /dev/null
+++ b/arch/arm64/kernel/entry-fpsimd.S
@@ -0,0 +1,80 @@
+/*
+ * FP/SIMD state saving and restoring
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+
+/*
+ * Save the FP registers.
+ *
+ * x0 - pointer to struct fpsimd_state
+ */
+ENTRY(fpsimd_save_state)
+ stp q0, q1, [x0, #16 * 0]
+ stp q2, q3, [x0, #16 * 2]
+ stp q4, q5, [x0, #16 * 4]
+ stp q6, q7, [x0, #16 * 6]
+ stp q8, q9, [x0, #16 * 8]
+ stp q10, q11, [x0, #16 * 10]
+ stp q12, q13, [x0, #16 * 12]
+ stp q14, q15, [x0, #16 * 14]
+ stp q16, q17, [x0, #16 * 16]
+ stp q18, q19, [x0, #16 * 18]
+ stp q20, q21, [x0, #16 * 20]
+ stp q22, q23, [x0, #16 * 22]
+ stp q24, q25, [x0, #16 * 24]
+ stp q26, q27, [x0, #16 * 26]
+ stp q28, q29, [x0, #16 * 28]
+ stp q30, q31, [x0, #16 * 30]!
+ mrs x8, fpsr
+ str w8, [x0, #16 * 2]
+ mrs x8, fpcr
+ str w8, [x0, #16 * 2 + 4]
+ ret
+ENDPROC(fpsimd_save_state)
+
+/*
+ * Load the FP registers.
+ *
+ * x0 - pointer to struct fpsimd_state
+ */
+ENTRY(fpsimd_load_state)
+ ldp q0, q1, [x0, #16 * 0]
+ ldp q2, q3, [x0, #16 * 2]
+ ldp q4, q5, [x0, #16 * 4]
+ ldp q6, q7, [x0, #16 * 6]
+ ldp q8, q9, [x0, #16 * 8]
+ ldp q10, q11, [x0, #16 * 10]
+ ldp q12, q13, [x0, #16 * 12]
+ ldp q14, q15, [x0, #16 * 14]
+ ldp q16, q17, [x0, #16 * 16]
+ ldp q18, q19, [x0, #16 * 18]
+ ldp q20, q21, [x0, #16 * 20]
+ ldp q22, q23, [x0, #16 * 22]
+ ldp q24, q25, [x0, #16 * 24]
+ ldp q26, q27, [x0, #16 * 26]
+ ldp q28, q29, [x0, #16 * 28]
+ ldp q30, q31, [x0, #16 * 30]!
+ ldr w8, [x0, #16 * 2]
+ ldr w9, [x0, #16 * 2 + 4]
+ msr fpsr, x8
+ msr fpcr, x9
+ ret
+ENDPROC(fpsimd_load_state)