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armv7: mmu: Use 'tlbimva' to invalidate TLB entries 

The tlbimvaa operation (invalidate unified TLB by MVA, all address
space identifiers) is only available on armv7 processors that support
Multiprocessing Extensions. When used on processors that do not support
the extensions it causes an "undefined instruction" exception.

This patch changes the MMU table entry filling code to use the tlbimva
(invalidate unified TLB entry by MVA and address space identifier)
operation for invalidating TLB entries, which is supported on all armv7
processors.

As address space identifiers are not used in TLB entries in coreboot
(all entries are set as global), these two operations can safely be
used interchangeably. The ASID value supplied to the operation is not
checked for global TLB entries.

More information as well as the data formats for the tlbimvaa and
tlbimva operations are detailed in the "ARM Architecture Reference
Manual ARMv7-A" edition, issue "C.c" page B4-1747.

TEST: Booted Beaglebone Black (my current in progress port)

Change-Id: Ie7dfb4adab20dc7eecb1b20aa2ee6355215a1521
Signed-off-by: Sam Lewis <sam.vr.lewis@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43137
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
This commit is contained in:
Sam Lewis 2020-07-05 19:52:18 +10:00 committed by Julius Werner
parent 93d7bcbc67
commit e69b1af925
2 changed files with 5 additions and 5 deletions
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4
src/arch/arm/armv7/mmu.c
View File

@ -118,7 +118,7 @@ static void mmu_fill_table(pte_t *table, u32 start_idx, u32 end_idx,
/* Invalidate the TLB entries. */
for (i = start_idx; i < end_idx; i++)
tlbimvaa(offset + (i << shift));
tlbimva(offset + (i << shift));
dsb();
isb();
}
@ -152,7 +152,7 @@ static pte_t *mmu_create_subtable(pte_t *pgd_entry)
*pgd_entry = (pte_t)(uintptr_t)table | ATTR_NEXTLEVEL;
dccmvac((uintptr_t)pgd_entry);
dsb();
tlbimvaa(start_addr);
tlbimva(start_addr);
dsb();
isb();

6
src/arch/arm/include/armv7/arch/cache.h
View File

@ -73,10 +73,10 @@ static inline void tlbiall(void)
asm volatile ("mcr p15, 0, %0, c8, c7, 0" : : "r" (0) : "memory");
}
/* invalidate unified TLB by MVA, all ASID */
static inline void tlbimvaa(unsigned long mva)
/* invalidate unified TLB by MVA and ASID */
static inline void tlbimva(unsigned long mva)
{
asm volatile ("mcr p15, 0, %0, c8, c7, 3" : : "r" (mva) : "memory");
asm volatile ("mcr p15, 0, %0, c8, c7, 1" : : "r" (mva) : "memory");
}
/* write data access control register (DACR) */