[U-Boot] [PATCH v2 26/30] x86: Add LAPIC setup code

Simon Glass sjg at chromium.org
Sat Nov 15 02:18:44 CET 2014


Add code to set up the Local Advanced Peripheral Interrupt Controller.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

Changes in v2:
- Remove use of __PRE_RAM__ define
- Use existing lapic_setup() code instead of duplicating it

 arch/x86/cpu/Makefile        |   1 +
 arch/x86/cpu/lapic.c         |  62 +++++++++++++++++++++
 arch/x86/include/asm/lapic.h | 125 +++++++++++++++++++++++++++++++++++++++++--
 arch/x86/include/asm/post.h  |   1 +
 4 files changed, 186 insertions(+), 3 deletions(-)
 create mode 100644 arch/x86/cpu/lapic.c

diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile
index 1327f08..adfd258 100644
--- a/arch/x86/cpu/Makefile
+++ b/arch/x86/cpu/Makefile
@@ -11,5 +11,6 @@
 extra-y	= start.o
 obj-$(CONFIG_X86_RESET_VECTOR) += resetvec.o start16.o
 obj-y	+= interrupts.o cpu.o call64.o
+obj-y += lapic.o
 obj-$(CONFIG_PCI) += pci.o
 obj-y += turbo.o
diff --git a/arch/x86/cpu/lapic.c b/arch/x86/cpu/lapic.c
new file mode 100644
index 0000000..4d14a8d
--- /dev/null
+++ b/arch/x86/cpu/lapic.c
@@ -0,0 +1,62 @@
+/*
+ * From coreboot file of same name
+ *
+ * Copyright (C) 2008-2009 coresystems GmbH
+ * Copyright (C) 2014 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#include <common.h>
+#include <asm/msr.h>
+#include <asm/io.h>
+#include <asm/lapic.h>
+#include <asm/post.h>
+
+void lapic_setup(void)
+{
+#if NEED_LAPIC == 1
+	/* Only Pentium Pro and later have those MSR stuff */
+	debug("Setting up local apic: ");
+
+	/* Enable the local apic */
+	enable_lapic();
+
+	/*
+	 * Set Task Priority to 'accept all'.
+	 */
+	lapic_write_around(LAPIC_TASKPRI,
+			   lapic_read_around(LAPIC_TASKPRI) & ~LAPIC_TPRI_MASK);
+
+	/* Put the local apic in virtual wire mode */
+	lapic_write_around(LAPIC_SPIV, (lapic_read_around(LAPIC_SPIV) &
+				~(LAPIC_VECTOR_MASK)) | LAPIC_SPIV_ENABLE);
+	lapic_write_around(LAPIC_LVT0, (lapic_read_around(LAPIC_LVT0) &
+			~(LAPIC_LVT_MASKED | LAPIC_LVT_LEVEL_TRIGGER |
+			  LAPIC_LVT_REMOTE_IRR | LAPIC_INPUT_POLARITY |
+			  LAPIC_SEND_PENDING | LAPIC_LVT_RESERVED_1 |
+			  LAPIC_DELIVERY_MODE_MASK)) |
+			(LAPIC_LVT_REMOTE_IRR | LAPIC_SEND_PENDING |
+			 LAPIC_DELIVERY_MODE_EXTINT));
+	lapic_write_around(LAPIC_LVT1, (lapic_read_around(LAPIC_LVT1) &
+			~(LAPIC_LVT_MASKED | LAPIC_LVT_LEVEL_TRIGGER |
+			  LAPIC_LVT_REMOTE_IRR | LAPIC_INPUT_POLARITY |
+			  LAPIC_SEND_PENDING | LAPIC_LVT_RESERVED_1 |
+			  LAPIC_DELIVERY_MODE_MASK)) |
+		(LAPIC_LVT_REMOTE_IRR | LAPIC_SEND_PENDING |
+			LAPIC_DELIVERY_MODE_NMI));
+
+	debug("apic_id: 0x%02lx, ", lapicid());
+#else /* !NEED_LLAPIC */
+	/* Only Pentium Pro and later have those MSR stuff */
+	msr_t msr;
+
+	debug("Disabling local apic:");
+
+	msr = msr_read(LAPIC_BASE_MSR);
+	msr.lo &= ~LAPIC_BASE_MSR_ENABLE;
+	msr_write(LAPIC_BASE_MSR, msr);
+#endif /* !NEED_LAPIC */
+	debug("done.\n");
+	post_code(POST_LAPIC);
+}
diff --git a/arch/x86/include/asm/lapic.h b/arch/x86/include/asm/lapic.h
index 948e643..eaf2a98 100644
--- a/arch/x86/include/asm/lapic.h
+++ b/arch/x86/include/asm/lapic.h
@@ -14,6 +14,13 @@
 #include <asm/msr.h>
 #include <asm/processor.h>
 
+/* See if I need to initialize the local apic */
+#if CONFIG_SMP || CONFIG_IOAPIC
+#  define NEED_LAPIC 1
+#else
+#  define NEED_LAPIC 0
+#endif
+
 static inline __attribute__((always_inline))
 		unsigned long lapic_read(unsigned long reg)
 {
@@ -36,9 +43,9 @@ static inline void enable_lapic(void)
 	msr_t msr;
 
 	msr = msr_read(LAPIC_BASE_MSR);
-	msr.hi &= 0xffffff00;
-	msr.lo &= 0x000007ff;
-	msr.lo |= LAPIC_DEFAULT_BASE | (1 << 11);
+	msr.lo |= LAPIC_BASE_MSR_ENABLE;
+	msr.lo &= ~LAPIC_BASE_MSR_ADDR_MASK;
+	msr.lo |= LAPIC_DEFAULT_BASE;
 	msr_write(LAPIC_BASE_MSR, msr);
 }
 
@@ -56,4 +63,116 @@ static inline __attribute__((always_inline)) unsigned long lapicid(void)
 	return lapic_read(LAPIC_ID) >> 24;
 }
 
+#if !CONFIG_AP_IN_SIPI_WAIT
+/* If we need to go back to sipi wait, we use the long non-inlined version of
+ * this function in lapic_cpu_init.c
+ */
+static inline __attribute__((always_inline)) void stop_this_cpu(void)
+{
+	/* Called by an AP when it is ready to halt and wait for a new task */
+	for (;;)
+		cpu_hlt();
+}
+#else
+void stop_this_cpu(void);
+#endif
+
+#define xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), (ptr), \
+							sizeof(*(ptr))))
+
+struct __xchg_dummy { unsigned long a[100]; };
+#define __xg(x) ((struct __xchg_dummy *)(x))
+
+/*
+ * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
+ * Note 2: xchg has side effect, so that attribute volatile is necessary,
+ *	  but generally the primitive is invalid, *ptr is output argument. --ANK
+ */
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
+				   int size)
+{
+	switch (size) {
+	case 1:
+		__asm__ __volatile__("xchgb %b0,%1"
+			: "=q" (x)
+			: "m" (*__xg(ptr)), "0" (x)
+			: "memory");
+		break;
+	case 2:
+		__asm__ __volatile__("xchgw %w0,%1"
+			: "=r" (x)
+			: "m" (*__xg(ptr)), "0" (x)
+			: "memory");
+		break;
+	case 4:
+		__asm__ __volatile__("xchgl %0,%1"
+			: "=r" (x)
+			: "m" (*__xg(ptr)), "0" (x)
+			: "memory");
+		break;
+	}
+
+	return x;
+}
+
+static inline void lapic_write_atomic(unsigned long reg, unsigned long v)
+{
+	(void)xchg((volatile unsigned long *)(LAPIC_DEFAULT_BASE + reg), v);
+}
+
+
+#ifdef X86_GOOD_APIC
+# define FORCE_READ_AROUND_WRITE 0
+# define lapic_read_around(x) lapic_read(x)
+# define lapic_write_around(x, y) lapic_write((x), (y))
+#else
+# define FORCE_READ_AROUND_WRITE 1
+# define lapic_read_around(x) lapic_read(x)
+# define lapic_write_around(x, y) lapic_write_atomic((x), (y))
+#endif
+
+static inline int lapic_remote_read(int apicid, int reg, unsigned long *pvalue)
+{
+	int timeout;
+	unsigned long status;
+	int result;
+	lapic_wait_icr_idle();
+	lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
+	lapic_write_around(LAPIC_ICR, LAPIC_DM_REMRD | (reg >> 4));
+	timeout = 0;
+	do {
+		status = lapic_read(LAPIC_ICR) & LAPIC_ICR_RR_MASK;
+	} while (status == LAPIC_ICR_RR_INPROG && timeout++ < 1000);
+
+	result = -1;
+	if (status == LAPIC_ICR_RR_VALID) {
+		*pvalue = lapic_read(LAPIC_RRR);
+		result = 0;
+	}
+	return result;
+}
+
+
+void lapic_setup(void);
+
+#if CONFIG_SMP
+struct device;
+int start_cpu(struct device *cpu);
+#endif /* CONFIG_SMP */
+
+int boot_cpu(void);
+
+/**
+ * struct x86_cpu_priv - Information about a single CPU
+ *
+ * @apic_id: Advanced Programmable Interrupt Controller Identifier, which is
+ * just a number representing the CPU core
+ *
+ * TODO: Move this to driver model once lifecycle is understood
+ */
+struct x86_cpu_priv {
+	int apic_id;
+	int start_err;
+};
+
 #endif
diff --git a/arch/x86/include/asm/post.h b/arch/x86/include/asm/post.h
index ce68839..6d2ae5d 100644
--- a/arch/x86/include/asm/post.h
+++ b/arch/x86/include/asm/post.h
@@ -30,6 +30,7 @@
 #define POST_PRE_MRC		0x2e
 #define POST_MRC		0x2f
 #define POST_DRAM		0x2f
+#define POST_LAPIC		0x30
 
 #define POST_RAM_FAILURE	0xea
 
-- 
2.1.0.rc2.206.gedb03e5



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