[U-Boot] [PATCH v2 10/50] x86: Add a way to reinit the cpu
Simon Glass
sjg at chromium.org
Fri Apr 26 03:58:42 UTC 2019
We cannot init the CPU fully both than once during a boot. Add a new
function which can be called to figure out the CPU identity, but which
does not change anything. For x86_64, this is empty for now.
Signed-off-by: Simon Glass <sjg at chromium.org>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---
Changes in v2: None
arch/x86/cpu/i386/cpu.c | 113 ++++++++++++++++++------------
arch/x86/cpu/x86_64/cpu.c | 5 ++
arch/x86/include/asm/u-boot-x86.h | 20 ++++++
3 files changed, 94 insertions(+), 44 deletions(-)
diff --git a/arch/x86/cpu/i386/cpu.c b/arch/x86/cpu/i386/cpu.c
index 3bde44ebf53..90b546e7410 100644
--- a/arch/x86/cpu/i386/cpu.c
+++ b/arch/x86/cpu/i386/cpu.c
@@ -309,21 +309,22 @@ u32 cpu_get_stepping(void)
return gd->arch.x86_mask;
}
-int x86_cpu_init_f(void)
+/* initialise FPU, reset EM, set MP and NE */
+static void setup_cpu_features(void)
{
const u32 em_rst = ~X86_CR0_EM;
const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
- if (ll_boot_init()) {
- /* initialize FPU, reset EM, set MP and NE */
- asm ("fninit\n" \
- "movl %%cr0, %%eax\n" \
- "andl %0, %%eax\n" \
- "orl %1, %%eax\n" \
- "movl %%eax, %%cr0\n" \
- : : "i" (em_rst), "i" (mp_ne_set) : "eax");
- }
+ asm ("fninit\n" \
+ "movl %%cr0, %%eax\n" \
+ "andl %0, %%eax\n" \
+ "orl %1, %%eax\n" \
+ "movl %%eax, %%cr0\n" \
+ : : "i" (em_rst), "i" (mp_ne_set) : "eax");
+}
+static void setup_identity(void)
+{
/* identify CPU via cpuid and store the decoded info into gd->arch */
if (has_cpuid()) {
struct cpu_device_id cpu;
@@ -339,46 +340,70 @@ int x86_cpu_init_f(void)
gd->arch.has_mtrr = has_mtrr();
}
- /* Don't allow PCI region 3 to use memory in the 2-4GB memory hole */
+}
+
+/* Don't allow PCI region 3 to use memory in the 2-4GB memory hole */
+static void setup_pci_ram_top(void)
+{
gd->pci_ram_top = 0x80000000U;
+}
+
+static void setup_mtrr(void)
+{
+ u64 mtrr_cap;
/* Configure fixed range MTRRs for some legacy regions */
- if (gd->arch.has_mtrr) {
- u64 mtrr_cap;
-
- mtrr_cap = native_read_msr(MTRR_CAP_MSR);
- if (mtrr_cap & MTRR_CAP_FIX) {
- /* Mark the VGA RAM area as uncacheable */
- native_write_msr(MTRR_FIX_16K_A0000_MSR,
- MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE),
- MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE));
-
- /*
- * Mark the PCI ROM area as cacheable to improve ROM
- * execution performance.
- */
- native_write_msr(MTRR_FIX_4K_C0000_MSR,
- MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
- MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
- native_write_msr(MTRR_FIX_4K_C8000_MSR,
- MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
- MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
- native_write_msr(MTRR_FIX_4K_D0000_MSR,
- MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
- MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
- native_write_msr(MTRR_FIX_4K_D8000_MSR,
- MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
- MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
-
- /* Enable the fixed range MTRRs */
- msr_setbits_64(MTRR_DEF_TYPE_MSR, MTRR_DEF_TYPE_FIX_EN);
- }
+ if (!gd->arch.has_mtrr)
+ return;
+
+ mtrr_cap = native_read_msr(MTRR_CAP_MSR);
+ if (mtrr_cap & MTRR_CAP_FIX) {
+ /* Mark the VGA RAM area as uncacheable */
+ native_write_msr(MTRR_FIX_16K_A0000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE),
+ MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE));
+
+ /*
+ * Mark the PCI ROM area as cacheable to improve ROM
+ * execution performance.
+ */
+ native_write_msr(MTRR_FIX_4K_C0000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
+ native_write_msr(MTRR_FIX_4K_C8000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
+ native_write_msr(MTRR_FIX_4K_D0000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
+ native_write_msr(MTRR_FIX_4K_D8000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
+
+ /* Enable the fixed range MTRRs */
+ msr_setbits_64(MTRR_DEF_TYPE_MSR, MTRR_DEF_TYPE_FIX_EN);
}
+}
+
+int x86_cpu_init_f(void)
+{
+ if (ll_boot_init())
+ setup_cpu_features();
+ setup_identity();
+ setup_mtrr();
+ setup_pci_ram_top();
-#ifdef CONFIG_I8254_TIMER
/* Set up the i8254 timer if required */
- i8254_init();
-#endif
+ if (IS_ENABLED(CONFIG_I8254_TIMER))
+ i8254_init();
+
+ return 0;
+}
+
+int x86_cpu_reinit_f(void)
+{
+ setup_identity();
+ setup_pci_ram_top();
return 0;
}
diff --git a/arch/x86/cpu/x86_64/cpu.c b/arch/x86/cpu/x86_64/cpu.c
index 6c063e82009..42abb23a9ed 100644
--- a/arch/x86/cpu/x86_64/cpu.c
+++ b/arch/x86/cpu/x86_64/cpu.c
@@ -61,3 +61,8 @@ int print_cpuinfo(void)
{
return 0;
}
+
+int x86_cpu_reinit_f(void)
+{
+ return 0;
+}
diff --git a/arch/x86/include/asm/u-boot-x86.h b/arch/x86/include/asm/u-boot-x86.h
index 670fcdc0093..c252192bf41 100644
--- a/arch/x86/include/asm/u-boot-x86.h
+++ b/arch/x86/include/asm/u-boot-x86.h
@@ -13,7 +13,27 @@ extern char gdt_rom[];
/* cpu/.../cpu.c */
int arch_cpu_init(void);
+
+/**
+ * x86_cpu_init_f() - Set up basic features of the x86 CPU
+ *
+ * 0 on success, -ve on error
+ */
int x86_cpu_init_f(void);
+
+/**
+ * x86_cpu_reinit_f() - Set up the CPU a second time
+ *
+ * Once cpu_init_f() has been called (e.g. in SPL) we should not call it
+ * again (e.g. in U-Boot proper) since it sets up the state from scratch.
+ * Call this function in later phases of U-Boot instead. It reads the CPU
+ * identify so that CPU functions can be used correctly, but does not change
+ * anything.
+ *
+ * @return 0 (indicating success, to mimic cpu_init_f())
+ */
+int x86_cpu_reinit_f(void);
+
int cpu_init_f(void);
void setup_gdt(struct global_data *id, u64 *gdt_addr);
/*
--
2.21.0.593.g511ec345e18-goog
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