MIPS: Add arch CDMM definitions and probing
Add architectural definitions and probing for the MIPS Common Device
Memory Map (CDMM) region. When supported and enabled at a particular
physical address, this region allows some number of per-CPU devices to
be discovered and controlled via MMIO.
A bit exists in Config3 to determine whether the feature is present, and
a CDMMBase CP0 register allows the region to be enabled at a particular
physical address.
[ralf@linux-mips.org: Sort conflict with other patches.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9178/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 0d8208d..ea68a38 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -366,4 +366,8 @@
# define cpu_has_fre (cpu_data[0].options & MIPS_CPU_FRE)
#endif
+#ifndef cpu_has_cdmm
+# define cpu_has_cdmm (cpu_data[0].options & MIPS_CPU_CDMM)
+#endif
+
#endif /* __ASM_CPU_FEATURES_H */
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index 1568723..15903ca 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -377,6 +377,7 @@
#define MIPS_CPU_MAAR 0x400000000ull /* MAAR(I) registers are present */
#define MIPS_CPU_FRE 0x800000000ull /* FRE & UFE bits implemented */
#define MIPS_CPU_RW_LLB 0x1000000000ull /* LLADDR/LLB writes are allowed */
+#define MIPS_CPU_CDMM 0x2000000000ull /* CPU has Common Device Memory Map */
/*
* CPU ASE encodings
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index fef0044..9e28922 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -751,6 +751,14 @@
#define MIPS_PWCTL_PSN_SHIFT 0
#define MIPS_PWCTL_PSN_MASK 0x0000003f
+/* CDMMBase register bit definitions */
+#define MIPS_CDMMBASE_SIZE_SHIFT 0
+#define MIPS_CDMMBASE_SIZE (_ULCAST_(511) << MIPS_CDMMBASE_SIZE_SHIFT)
+#define MIPS_CDMMBASE_CI (_ULCAST_(1) << 9)
+#define MIPS_CDMMBASE_EN (_ULCAST_(1) << 10)
+#define MIPS_CDMMBASE_ADDR_SHIFT 11
+#define MIPS_CDMMBASE_ADDR_START 15
+
#ifndef __ASSEMBLY__
/*
@@ -1282,6 +1290,9 @@
#define read_c0_ebase() __read_32bit_c0_register($15, 1)
#define write_c0_ebase(val) __write_32bit_c0_register($15, 1, val)
+#define read_c0_cdmmbase() __read_ulong_c0_register($15, 2)
+#define write_c0_cdmmbase(val) __write_ulong_c0_register($15, 2, val)
+
/* MIPSR3 */
#define read_c0_segctl0() __read_32bit_c0_register($5, 2)
#define write_c0_segctl0(val) __write_32bit_c0_register($5, 2, val)
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 48dfb9d..1bae006 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -441,6 +441,8 @@
c->htw_seq = 0;
c->options |= MIPS_CPU_HTW;
}
+ if (config3 & MIPS_CONF3_CDMM)
+ c->options |= MIPS_CPU_CDMM;
return config3 & MIPS_CONF_M;
}