MIPS: Add Kconfig variable for CPUs with unaligned load/store instructions
MIPSR6 CPUs do not support unaligned load/store instructions
(LWL, LWR, SWL, SWR and LDL, LDR, SDL, SDR for 64bit).
Currently the MIPS tree has some special cases to avoid these
instructions, and the code is testing for !CONFIG_CPU_MIPSR6.
This patch declares a new Kconfig variable:
CONFIG_CPU_HAS_LOAD_STORE_LR.
This variable indicates that the CPU supports these instructions.
Then, the patch does the following:
- Carefully selects this option on all CPUs except MIPSR6.
- Switches all the special cases to test for the new variable,
and inverts the logic:
'#ifndef CONFIG_CPU_MIPSR6' turns into
'#ifdef CONFIG_CPU_HAS_LOAD_STORE_LR'
and vice-versa.
Also, when this variable is NOT selected (e.g. MIPSR6),
CONFIG_GENERIC_CSUM will default to 'y', to compile generic
C checksum code (instead of special assembly code that uses the
unsupported instructions).
This commit should not affect any existing CPU, and is required
for future Lexra CPU support, that misses these instructions too.
Signed-off-by: Yasha Cherikovsky <yasha.che3@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20808/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index ce55c3c..f065542 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1150,6 +1150,7 @@
config GENERIC_CSUM
bool
+ default y if !CPU_HAS_LOAD_STORE_LR
config GENERIC_ISA_DMA
bool
@@ -1368,6 +1369,7 @@
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
select CPU_SUPPORTS_HUGEPAGES
+ select CPU_HAS_LOAD_STORE_LR
select WEAK_ORDERING
select WEAK_REORDERING_BEYOND_LLSC
select MIPS_PGD_C0_CONTEXT
@@ -1444,6 +1446,7 @@
bool "MIPS32 Release 1"
depends on SYS_HAS_CPU_MIPS32_R1
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
help
@@ -1461,6 +1464,7 @@
bool "MIPS32 Release 2"
depends on SYS_HAS_CPU_MIPS32_R2
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
select CPU_SUPPORTS_MSA
@@ -1479,7 +1483,6 @@
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
select CPU_SUPPORTS_MSA
- select GENERIC_CSUM
select HAVE_KVM
select MIPS_O32_FP64_SUPPORT
help
@@ -1492,6 +1495,7 @@
bool "MIPS64 Release 1"
depends on SYS_HAS_CPU_MIPS64_R1
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
@@ -1511,6 +1515,7 @@
bool "MIPS64 Release 2"
depends on SYS_HAS_CPU_MIPS64_R2
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
@@ -1532,7 +1537,6 @@
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
select CPU_SUPPORTS_MSA
- select GENERIC_CSUM
select MIPS_O32_FP64_SUPPORT if 32BIT || MIPS32_O32
select HAVE_KVM
help
@@ -1545,6 +1549,7 @@
bool "R3000"
depends on SYS_HAS_CPU_R3000
select CPU_HAS_WB
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
help
@@ -1559,12 +1564,14 @@
bool "R39XX"
depends on SYS_HAS_CPU_TX39XX
select CPU_SUPPORTS_32BIT_KERNEL
+ select CPU_HAS_LOAD_STORE_LR
config CPU_VR41XX
bool "R41xx"
depends on SYS_HAS_CPU_VR41XX
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
+ select CPU_HAS_LOAD_STORE_LR
help
The options selects support for the NEC VR4100 series of processors.
Only choose this option if you have one of these processors as a
@@ -1576,6 +1583,7 @@
depends on SYS_HAS_CPU_R4300
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
+ select CPU_HAS_LOAD_STORE_LR
help
MIPS Technologies R4300-series processors.
@@ -1585,6 +1593,7 @@
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HUGEPAGES
+ select CPU_HAS_LOAD_STORE_LR
help
MIPS Technologies R4000-series processors other than 4300, including
the R4000, R4400, R4600, and 4700.
@@ -1593,6 +1602,7 @@
bool "R49XX"
depends on SYS_HAS_CPU_TX49XX
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HUGEPAGES
@@ -1603,6 +1613,7 @@
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HUGEPAGES
+ select CPU_HAS_LOAD_STORE_LR
help
MIPS Technologies R5000-series processors other than the Nevada.
@@ -1612,6 +1623,7 @@
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HUGEPAGES
+ select CPU_HAS_LOAD_STORE_LR
config CPU_R5500
bool "R5500"
@@ -1619,6 +1631,7 @@
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HUGEPAGES
+ select CPU_HAS_LOAD_STORE_LR
help
NEC VR5500 and VR5500A series processors implement 64-bit MIPS IV
instruction set.
@@ -1629,6 +1642,7 @@
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HUGEPAGES
+ select CPU_HAS_LOAD_STORE_LR
help
QED / PMC-Sierra RM52xx-series ("Nevada") processors.
@@ -1636,6 +1650,7 @@
bool "R8000"
depends on SYS_HAS_CPU_R8000
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_64BIT_KERNEL
help
MIPS Technologies R8000 processors. Note these processors are
@@ -1645,6 +1660,7 @@
bool "R10000"
depends on SYS_HAS_CPU_R10000
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
@@ -1656,6 +1672,7 @@
bool "RM7000"
depends on SYS_HAS_CPU_RM7000
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
@@ -1664,6 +1681,7 @@
config CPU_SB1
bool "SB1"
depends on SYS_HAS_CPU_SB1
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
@@ -1674,6 +1692,7 @@
bool "Cavium Octeon processor"
depends on SYS_HAS_CPU_CAVIUM_OCTEON
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_64BIT_KERNEL
select WEAK_ORDERING
select CPU_SUPPORTS_HIGHMEM
@@ -1703,6 +1722,7 @@
select WEAK_ORDERING
select CPU_SUPPORTS_HIGHMEM
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_CPUFREQ
select MIPS_EXTERNAL_TIMER
help
@@ -1711,6 +1731,7 @@
config CPU_XLR
bool "Netlogic XLR SoC"
depends on SYS_HAS_CPU_XLR
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
@@ -1729,6 +1750,7 @@
select WEAK_ORDERING
select WEAK_REORDERING_BEYOND_LLSC
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_MIPSR2
select CPU_SUPPORTS_HUGEPAGES
select MIPS_ASID_BITS_VARIABLE
@@ -1834,12 +1856,14 @@
select CPU_SUPPORTS_HIGHMEM
select CPU_SUPPORTS_HUGEPAGES
select ARCH_HAS_PHYS_TO_DMA
+ select CPU_HAS_LOAD_STORE_LR
config CPU_LOONGSON1
bool
select CPU_MIPS32
select CPU_MIPSR1
select CPU_HAS_PREFETCH
+ select CPU_HAS_LOAD_STORE_LR
select CPU_SUPPORTS_32BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
select CPU_SUPPORTS_CPUFREQ
@@ -2453,6 +2477,13 @@
config CPU_HAS_RIXI
bool
+config CPU_HAS_LOAD_STORE_LR
+ bool
+ help
+ CPU has support for unaligned load and store instructions:
+ LWL, LWR, SWL, SWR (Load/store word left/right).
+ LDL, LDR, SDL, SDR (Load/store doubleword left/right, for 64bit systems).
+
#
# Vectored interrupt mode is an R2 feature
#