u-boot/arch/arm/lib/cache.c
Patrice Chotard c2a2123e33 cmd: cache: Fix non-cached memory cachability
If dcache is switched OFF to ON state and if non-cached memory is
used, this non-cached memory must be re-declared as uncached to mmu
each time dcache is set ON.

Introduce noncached_set_region() to set this non-cached region's mmu
settings. Let architecture override it by defining it as a weak
function.

For ARM architecture, noncached_set_region() defines all noncached
region as non-cacheable.

Issue found on STM32MP1 platform using dwc_eth_qos ethernet driver,
when going from dcache OFF to dcache ON state, ethernet driver issued
TX timeout errors when performing dhcp or ping.

It can be reproduced with the following sequence:

dhcp
while true ; do
  ping 192.168.1.300 ;
  dcache off ;
  ping 192.168.1.300 ;
  dcache on ;
done

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Cc: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Marek Vasut <marex@denx.de>
2020-05-07 09:01:42 -04:00

160 lines
3.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2002
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*/
/* for now: just dummy functions to satisfy the linker */
#include <common.h>
#include <cpu_func.h>
#include <malloc.h>
DECLARE_GLOBAL_DATA_PTR;
/*
* Flush range from all levels of d-cache/unified-cache.
* Affects the range [start, start + size - 1].
*/
__weak void flush_cache(unsigned long start, unsigned long size)
{
flush_dcache_range(start, start + size);
}
/*
* Default implementation:
* do a range flush for the entire range
*/
__weak void flush_dcache_all(void)
{
flush_cache(0, ~0);
}
/*
* Default implementation of enable_caches()
* Real implementation should be in platform code
*/
__weak void enable_caches(void)
{
puts("WARNING: Caches not enabled\n");
}
__weak void invalidate_dcache_range(unsigned long start, unsigned long stop)
{
/* An empty stub, real implementation should be in platform code */
}
__weak void flush_dcache_range(unsigned long start, unsigned long stop)
{
/* An empty stub, real implementation should be in platform code */
}
int check_cache_range(unsigned long start, unsigned long stop)
{
int ok = 1;
if (start & (CONFIG_SYS_CACHELINE_SIZE - 1))
ok = 0;
if (stop & (CONFIG_SYS_CACHELINE_SIZE - 1))
ok = 0;
if (!ok) {
warn_non_spl("CACHE: Misaligned operation at range [%08lx, %08lx]\n",
start, stop);
}
return ok;
}
#ifdef CONFIG_SYS_NONCACHED_MEMORY
/*
* Reserve one MMU section worth of address space below the malloc() area that
* will be mapped uncached.
*/
static unsigned long noncached_start;
static unsigned long noncached_end;
static unsigned long noncached_next;
void noncached_set_region(void)
{
#if !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
mmu_set_region_dcache_behaviour(noncached_start,
noncached_end - noncached_start,
DCACHE_OFF);
#endif
}
void noncached_init(void)
{
phys_addr_t start, end;
size_t size;
/* If this calculation changes, update board_f.c:reserve_noncached() */
end = ALIGN(mem_malloc_start, MMU_SECTION_SIZE) - MMU_SECTION_SIZE;
size = ALIGN(CONFIG_SYS_NONCACHED_MEMORY, MMU_SECTION_SIZE);
start = end - size;
debug("mapping memory %pa-%pa non-cached\n", &start, &end);
noncached_start = start;
noncached_end = end;
noncached_next = start;
noncached_set_region();
}
phys_addr_t noncached_alloc(size_t size, size_t align)
{
phys_addr_t next = ALIGN(noncached_next, align);
if (next >= noncached_end || (noncached_end - next) < size)
return 0;
debug("allocated %zu bytes of uncached memory @%pa\n", size, &next);
noncached_next = next + size;
return next;
}
#endif /* CONFIG_SYS_NONCACHED_MEMORY */
#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
void invalidate_l2_cache(void)
{
unsigned int val = 0;
asm volatile("mcr p15, 1, %0, c15, c11, 0 @ invl l2 cache"
: : "r" (val) : "cc");
isb();
}
#endif
int arch_reserve_mmu(void)
{
return arm_reserve_mmu();
}
__weak int arm_reserve_mmu(void)
{
#if !(CONFIG_IS_ENABLED(SYS_ICACHE_OFF) && CONFIG_IS_ENABLED(SYS_DCACHE_OFF))
/* reserve TLB table */
gd->arch.tlb_size = PGTABLE_SIZE;
gd->relocaddr -= gd->arch.tlb_size;
/* round down to next 64 kB limit */
gd->relocaddr &= ~(0x10000 - 1);
gd->arch.tlb_addr = gd->relocaddr;
debug("TLB table from %08lx to %08lx\n", gd->arch.tlb_addr,
gd->arch.tlb_addr + gd->arch.tlb_size);
#ifdef CONFIG_SYS_MEM_RESERVE_SECURE
/*
* Record allocated tlb_addr in case gd->tlb_addr to be overwritten
* with location within secure ram.
*/
gd->arch.tlb_allocated = gd->arch.tlb_addr;
#endif
#endif
return 0;
}