From d5e4746cf84a8da1b6465058ec7c7cc19c3c32c0 Mon Sep 17 00:00:00 2001
From: Aaron Durbin <adurbin@chromium.org>
Date: Tue, 17 Apr 2018 14:35:48 -0600
Subject: cpu/x86: expose and add paging helper functions
Add the following functions for use outside of the paging module:
void paging_enable_pae_cr3(uintptr_t cr3);
void paging_enable_pae(void);
void paging_disable_pae(void);
The functions just enable and/or disable paging along with PAE.
Disassembly shows equivalent output for both versions.
BUG=b:72728953
Change-Id: I9665e7ec4795a5f52889791f73cf98a8f4def827
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/25714
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Justin TerAvest <teravest@chromium.org>
---
src/cpu/x86/pae/pgtbl.c | 70 +++++++++++++++++++++++++----------------------
src/include/cpu/x86/pae.h | 8 ++++++
2 files changed, 45 insertions(+), 33 deletions(-)
(limited to 'src')
diff --git a/src/cpu/x86/pae/pgtbl.c b/src/cpu/x86/pae/pgtbl.c
index 063c9aba38..fe7705f4d0 100644
--- a/src/cpu/x86/pae/pgtbl.c
+++ b/src/cpu/x86/pae/pgtbl.c
@@ -17,48 +17,52 @@
#include <console/console.h>
#include <cpu/cpu.h>
#include <arch/cpu.h>
+#include <cpu/x86/cr.h>
#include <cpu/x86/msr.h>
#include <cpu/x86/pae.h>
#include <rules.h>
#include <string.h>
-#if ENV_RAMSTAGE
-static void paging_off(void)
+void paging_enable_pae_cr3(uintptr_t cr3)
{
- __asm__ __volatile__ (
- /* Disable paging */
- "movl %%cr0, %%eax\n\t"
- "andl $0x7FFFFFFF, %%eax\n\t"
- "movl %%eax, %%cr0\n\t"
- /* Disable pae */
- "movl %%cr4, %%eax\n\t"
- "andl $0xFFFFFFDF, %%eax\n\t"
- "movl %%eax, %%cr4\n\t"
- :
- :
- : "eax"
- );
+ /* Load the page table address */
+ write_cr3(cr3);
+ paging_enable_pae();
}
-static void paging_on(void *pdp)
+void paging_enable_pae(void)
{
- __asm__ __volatile__(
- /* Load the page table address */
- "movl %0, %%cr3\n\t"
- /* Enable pae */
- "movl %%cr4, %%eax\n\t"
- "orl $0x00000020, %%eax\n\t"
- "movl %%eax, %%cr4\n\t"
- /* Enable paging */
- "movl %%cr0, %%eax\n\t"
- "orl $0x80000000, %%eax\n\t"
- "movl %%eax, %%cr0\n\t"
- :
- : "r" (pdp)
- : "eax"
- );
+ CRx_TYPE cr0;
+ CRx_TYPE cr4;
+
+ /* Enable PAE */
+ cr4 = read_cr4();
+ cr4 |= CR4_PAE;
+ write_cr4(cr4);
+
+ /* Enable Paging */
+ cr0 = read_cr0();
+ cr0 |= CR0_PG;
+ write_cr0(cr0);
}
+void paging_disable_pae(void)
+{
+ CRx_TYPE cr0;
+ CRx_TYPE cr4;
+
+ /* Disable Paging */
+ cr0 = read_cr0();
+ cr0 &= ~(CRx_TYPE)CR0_PG;
+ write_cr0(cr0);
+
+ /* Disable PAE */
+ cr4 = read_cr4();
+ cr4 &= ~(CRx_TYPE)CR4_PAE;
+ write_cr4(cr4);
+}
+
+#if ENV_RAMSTAGE
void *map_2M_page(unsigned long page)
{
struct pde {
@@ -82,7 +86,7 @@ void *map_2M_page(unsigned long page)
return MAPPING_ERROR;
window = page >> 10;
if (window != mapped_window[index]) {
- paging_off();
+ paging_disable_pae();
if (window > 1) {
struct pde *pd, *pdp;
/* Point the page directory pointers at the page
@@ -109,7 +113,7 @@ void *map_2M_page(unsigned long page)
| ((i & 0x3ff) << 21) | 0xE3;
pd[i].addr_hi = (window >> 1);
}
- paging_on(pdp);
+ paging_enable_pae_cr3((uintptr_t)pdp);
}
mapped_window[index] = window;
}
diff --git a/src/include/cpu/x86/pae.h b/src/include/cpu/x86/pae.h
index 9b9f27b688..5bbfdf3aca 100644
--- a/src/include/cpu/x86/pae.h
+++ b/src/include/cpu/x86/pae.h
@@ -3,6 +3,14 @@
#include <stdint.h>
+/* Enable paging with cr3 value for page directory pointer table as well as PAE
+ option in cr4. */
+void paging_enable_pae_cr3(uintptr_t cr3);
+/* Enable paging as well as PAE option in cr4. */
+void paging_enable_pae(void);
+/* Disable paging as well as PAE option in cr4. */
+void paging_disable_pae(void);
+
/* Set/Clear NXE bit in IA32_EFER MSR */
void paging_set_nxe(int enable);
--
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