u-boot/arch/arm/lib/cache-cp15.c
Alexander Graf d990f5c834 arm: Add support for HYP mode and LPAE page tables
We currently always modify the SVC versions of registers and only support
the short descriptor PTE format.

Some boards however (like the RPi2) run in HYP mode. There, we need to modify
the HYP version of system registers and HYP mode only supports the long
descriptor PTE format.

So this patch introduces support for both long descriptor PTEs and HYP mode
registers.

Signed-off-by: Alexander Graf <agraf@suse.de>
2016-03-27 09:12:17 -04:00

285 lines
6 KiB
C

/*
* (C) Copyright 2002
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/system.h>
#include <asm/cache.h>
#include <linux/compiler.h>
#if !(defined(CONFIG_SYS_ICACHE_OFF) && defined(CONFIG_SYS_DCACHE_OFF))
DECLARE_GLOBAL_DATA_PTR;
__weak void arm_init_before_mmu(void)
{
}
__weak void arm_init_domains(void)
{
}
static void cp_delay (void)
{
volatile int i;
/* copro seems to need some delay between reading and writing */
for (i = 0; i < 100; i++)
nop();
asm volatile("" : : : "memory");
}
void set_section_dcache(int section, enum dcache_option option)
{
#ifdef CONFIG_ARMV7_LPAE
u64 *page_table = (u64 *)gd->arch.tlb_addr;
/* Need to set the access flag to not fault */
u64 value = TTB_SECT_AP | TTB_SECT_AF;
#else
u32 *page_table = (u32 *)gd->arch.tlb_addr;
u32 value = TTB_SECT_AP;
#endif
/* Add the page offset */
value |= ((u32)section << MMU_SECTION_SHIFT);
/* Add caching bits */
value |= option;
/* Set PTE */
page_table[section] = value;
}
__weak void mmu_page_table_flush(unsigned long start, unsigned long stop)
{
debug("%s: Warning: not implemented\n", __func__);
}
void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size,
enum dcache_option option)
{
u32 *page_table = (u32 *)gd->arch.tlb_addr;
unsigned long upto, end;
end = ALIGN(start + size, MMU_SECTION_SIZE) >> MMU_SECTION_SHIFT;
start = start >> MMU_SECTION_SHIFT;
debug("%s: start=%pa, size=%zu, option=%d\n", __func__, &start, size,
option);
for (upto = start; upto < end; upto++)
set_section_dcache(upto, option);
mmu_page_table_flush((u32)&page_table[start], (u32)&page_table[end]);
}
__weak void dram_bank_mmu_setup(int bank)
{
bd_t *bd = gd->bd;
int i;
debug("%s: bank: %d\n", __func__, bank);
for (i = bd->bi_dram[bank].start >> MMU_SECTION_SHIFT;
i < (bd->bi_dram[bank].start >> MMU_SECTION_SHIFT) +
(bd->bi_dram[bank].size >> MMU_SECTION_SHIFT);
i++) {
#if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
set_section_dcache(i, DCACHE_WRITETHROUGH);
#elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
set_section_dcache(i, DCACHE_WRITEALLOC);
#else
set_section_dcache(i, DCACHE_WRITEBACK);
#endif
}
}
/* to activate the MMU we need to set up virtual memory: use 1M areas */
static inline void mmu_setup(void)
{
int i;
u32 reg;
arm_init_before_mmu();
/* Set up an identity-mapping for all 4GB, rw for everyone */
for (i = 0; i < ((4096ULL * 1024 * 1024) >> MMU_SECTION_SHIFT); i++)
set_section_dcache(i, DCACHE_OFF);
for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
dram_bank_mmu_setup(i);
}
#ifdef CONFIG_ARMV7_LPAE
/* Set up 4 PTE entries pointing to our 4 1GB page tables */
for (i = 0; i < 4; i++) {
u64 *page_table = (u64 *)(gd->arch.tlb_addr + (4096 * 4));
u64 tpt = gd->arch.tlb_addr + (4096 * i);
page_table[i] = tpt | TTB_PAGETABLE;
}
reg = TTBCR_EAE;
#if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
reg |= TTBCR_ORGN0_WT | TTBCR_IRGN0_WT;
#elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
reg |= TTBCR_ORGN0_WBWA | TTBCR_IRGN0_WBWA;
#else
reg |= TTBCR_ORGN0_WBNWA | TTBCR_IRGN0_WBNWA;
#endif
if (is_hyp()) {
/* Set HCTR to enable LPAE */
asm volatile("mcr p15, 4, %0, c2, c0, 2"
: : "r" (reg) : "memory");
/* Set HTTBR0 */
asm volatile("mcrr p15, 4, %0, %1, c2"
:
: "r"(gd->arch.tlb_addr + (4096 * 4)), "r"(0)
: "memory");
/* Set HMAIR */
asm volatile("mcr p15, 4, %0, c10, c2, 0"
: : "r" (MEMORY_ATTRIBUTES) : "memory");
} else {
/* Set TTBCR to enable LPAE */
asm volatile("mcr p15, 0, %0, c2, c0, 2"
: : "r" (reg) : "memory");
/* Set 64-bit TTBR0 */
asm volatile("mcrr p15, 0, %0, %1, c2"
:
: "r"(gd->arch.tlb_addr + (4096 * 4)), "r"(0)
: "memory");
/* Set MAIR */
asm volatile("mcr p15, 0, %0, c10, c2, 0"
: : "r" (MEMORY_ATTRIBUTES) : "memory");
}
#elif defined(CONFIG_CPU_V7)
/* Set TTBR0 */
reg = gd->arch.tlb_addr & TTBR0_BASE_ADDR_MASK;
#if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
reg |= TTBR0_RGN_WT | TTBR0_IRGN_WT;
#elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
reg |= TTBR0_RGN_WBWA | TTBR0_IRGN_WBWA;
#else
reg |= TTBR0_RGN_WB | TTBR0_IRGN_WB;
#endif
asm volatile("mcr p15, 0, %0, c2, c0, 0"
: : "r" (reg) : "memory");
#else
/* Copy the page table address to cp15 */
asm volatile("mcr p15, 0, %0, c2, c0, 0"
: : "r" (gd->arch.tlb_addr) : "memory");
#endif
/* Set the access control to all-supervisor */
asm volatile("mcr p15, 0, %0, c3, c0, 0"
: : "r" (~0));
arm_init_domains();
/* and enable the mmu */
reg = get_cr(); /* get control reg. */
cp_delay();
set_cr(reg | CR_M);
}
static int mmu_enabled(void)
{
return get_cr() & CR_M;
}
/* cache_bit must be either CR_I or CR_C */
static void cache_enable(uint32_t cache_bit)
{
uint32_t reg;
/* The data cache is not active unless the mmu is enabled too */
if ((cache_bit == CR_C) && !mmu_enabled())
mmu_setup();
reg = get_cr(); /* get control reg. */
cp_delay();
set_cr(reg | cache_bit);
}
/* cache_bit must be either CR_I or CR_C */
static void cache_disable(uint32_t cache_bit)
{
uint32_t reg;
reg = get_cr();
cp_delay();
if (cache_bit == CR_C) {
/* if cache isn;t enabled no need to disable */
if ((reg & CR_C) != CR_C)
return;
/* if disabling data cache, disable mmu too */
cache_bit |= CR_M;
}
reg = get_cr();
cp_delay();
if (cache_bit == (CR_C | CR_M))
flush_dcache_all();
set_cr(reg & ~cache_bit);
}
#endif
#ifdef CONFIG_SYS_ICACHE_OFF
void icache_enable (void)
{
return;
}
void icache_disable (void)
{
return;
}
int icache_status (void)
{
return 0; /* always off */
}
#else
void icache_enable(void)
{
cache_enable(CR_I);
}
void icache_disable(void)
{
cache_disable(CR_I);
}
int icache_status(void)
{
return (get_cr() & CR_I) != 0;
}
#endif
#ifdef CONFIG_SYS_DCACHE_OFF
void dcache_enable (void)
{
return;
}
void dcache_disable (void)
{
return;
}
int dcache_status (void)
{
return 0; /* always off */
}
#else
void dcache_enable(void)
{
cache_enable(CR_C);
}
void dcache_disable(void)
{
cache_disable(CR_C);
}
int dcache_status(void)
{
return (get_cr() & CR_C) != 0;
}
#endif