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csky: Fixup cpu speculative execution to IO area
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For the memory size ( > 512MB, < 1GB), the MSA setting is:

 - SSEG0: PHY_START        , PHY_START + 512MB
 - SSEG1: PHY_START + 512MB, PHY_START + 1GB

But the real memory is no more than 1GB, there is a gap between the
end size of memory and border of 1GB. CPU could speculatively
execute to that gap and if the gap of the bus couldn't respond to
the CPU request, then the crash will happen.

Now make the setting with:

 - SSEG0: PHY_START        , PHY_START + 512MB (no change)
 - SSEG1: Disabled (We use highmem to use the memory of 512MB~1GB)

We also deprecated zhole_szie[] settings, it's only used by arm
style CPUs. All memory gap should use Reserved setting of dts in
csky system.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
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Guo Ren committed Apr 3, 2020
1 parent 8f6bb79 commit aefd946
Showing 5 changed files with 25 additions and 58 deletions.
5 changes: 1 addition & 4 deletions arch/csky/abiv1/inc/abi/entry.h
Original file line number Diff line number Diff line change
@@ -172,10 +172,7 @@
addi r6, 0xe
cpwcr r6, cpcr30

lsri r6, 28
addi r6, 2
lsli r6, 28
addi r6, 0xe
movi r6, 0
cpwcr r6, cpcr31
.endm

7 changes: 2 additions & 5 deletions arch/csky/abiv2/inc/abi/entry.h
Original file line number Diff line number Diff line change
@@ -290,11 +290,8 @@
addi r6, 0x1ce
mtcr r6, cr<30, 15> /* Set MSA0 */

lsri r6, 28
addi r6, 2
lsli r6, 28
addi r6, 0x1ce
mtcr r6, cr<31, 15> /* Set MSA1 */
movi r6, 0
mtcr r6, cr<31, 15> /* Clr MSA1 */

/* enable MMU */
mfcr r6, cr18
5 changes: 5 additions & 0 deletions arch/csky/kernel/head.S
Original file line number Diff line number Diff line change
@@ -21,6 +21,11 @@ END(_start)
ENTRY(_start_smp_secondary)
SETUP_MMU

/* copy msa1 from CPU0 */
lrw r6, secondary_msa1
ld.w r6, (r6, 0)
mtcr r6, cr<31, 15>

/* set stack point */
lrw r6, secondary_stack
ld.w r6, (r6, 0)
63 changes: 14 additions & 49 deletions arch/csky/kernel/setup.c
Original file line number Diff line number Diff line change
@@ -24,26 +24,9 @@ struct screen_info screen_info = {
};
#endif

phys_addr_t __init_memblock memblock_end_of_REG0(void)
{
return (memblock.memory.regions[0].base +
memblock.memory.regions[0].size);
}

phys_addr_t __init_memblock memblock_start_of_REG1(void)
{
return memblock.memory.regions[1].base;
}

size_t __init_memblock memblock_size_of_REG1(void)
{
return memblock.memory.regions[1].size;
}

static void __init csky_memblock_init(void)
{
unsigned long zone_size[MAX_NR_ZONES];
unsigned long zhole_size[MAX_NR_ZONES];
signed long size;

memblock_reserve(__pa(_stext), _end - _stext);
@@ -54,54 +37,36 @@ static void __init csky_memblock_init(void)
memblock_dump_all();

memset(zone_size, 0, sizeof(zone_size));
memset(zhole_size, 0, sizeof(zhole_size));

min_low_pfn = PFN_UP(memblock_start_of_DRAM());
max_pfn = PFN_DOWN(memblock_end_of_DRAM());

max_low_pfn = PFN_UP(memblock_end_of_REG0());
if (max_low_pfn == 0)
max_low_pfn = max_pfn;
max_low_pfn = max_pfn = PFN_DOWN(memblock_end_of_DRAM());

size = max_pfn - min_low_pfn;

if (memblock.memory.cnt > 1) {
zone_size[ZONE_NORMAL] =
PFN_DOWN(memblock_start_of_REG1()) - min_low_pfn;
zhole_size[ZONE_NORMAL] =
PFN_DOWN(memblock_start_of_REG1()) - max_low_pfn;
if (size <= PFN_DOWN(SSEG_SIZE - PHYS_OFFSET_OFFSET))
zone_size[ZONE_NORMAL] = size;
else if (size < PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET)) {
zone_size[ZONE_NORMAL] =
PFN_DOWN(SSEG_SIZE - PHYS_OFFSET_OFFSET);
max_low_pfn = min_low_pfn + zone_size[ZONE_NORMAL];
} else {
if (size <= PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET))
zone_size[ZONE_NORMAL] = max_pfn - min_low_pfn;
else {
zone_size[ZONE_NORMAL] =
zone_size[ZONE_NORMAL] =
PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
max_low_pfn = min_low_pfn + zone_size[ZONE_NORMAL];
}
max_low_pfn = min_low_pfn + zone_size[ZONE_NORMAL];
write_mmu_msa1(read_mmu_msa0() + SSEG_SIZE);
}

#ifdef CONFIG_HIGHMEM
size = 0;
if (memblock.memory.cnt > 1) {
size = PFN_DOWN(memblock_size_of_REG1());
highstart_pfn = PFN_DOWN(memblock_start_of_REG1());
} else {
size = max_pfn - min_low_pfn -
PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
highstart_pfn = min_low_pfn +
PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
}

if (size > 0)
zone_size[ZONE_HIGHMEM] = size;
zone_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;

highend_pfn = max_pfn;
highstart_pfn = max_low_pfn;
highend_pfn = max_pfn;
#endif
memblock_set_current_limit(PFN_PHYS(max_low_pfn));

dma_contiguous_reserve(0);

free_area_init_node(0, zone_size, min_low_pfn, zhole_size);
free_area_init_node(0, zone_size, min_low_pfn, NULL);
}

void __init setup_arch(char **cmdline_p)
3 changes: 3 additions & 0 deletions arch/csky/kernel/smp.c
Original file line number Diff line number Diff line change
@@ -159,6 +159,8 @@ volatile unsigned int secondary_hint;
volatile unsigned int secondary_ccr;
volatile unsigned int secondary_stack;

unsigned long secondary_msa1;

int __cpu_up(unsigned int cpu, struct task_struct *tidle)
{
unsigned long mask = 1 << cpu;
@@ -167,6 +169,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle)
(unsigned int) task_stack_page(tidle) + THREAD_SIZE - 8;
secondary_hint = mfcr("cr31");
secondary_ccr = mfcr("cr18");
secondary_msa1 = read_mmu_msa1();

/*
* Because other CPUs are in reset status, we must flush data

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