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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
Merge tag 'riscv/for-v5.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Paul Walmsley:
- Ensure that exclusive-load reservations are terminated after system
call or exception handling. This primarily affects QEMU, which does
not expire load reservations.
- Fix an issue primarily affecting RV32 platforms that can cause the DT
header to be corrupted, causing boot failures.
* tag 'riscv/for-v5.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Fix memblock reservation for device tree blob
RISC-V: Clear load reservations while restoring hart contexts
+32
-2
+1
arch/riscv/include/asm/asm.h
+1
arch/riscv/include/asm/asm.h
+20
-1
arch/riscv/kernel/entry.S
+20
-1
arch/riscv/kernel/entry.S
···
98
98
*/
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99
.macro RESTORE_ALL
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REG_L a0, PT_SSTATUS(sp)
101
-
REG_L a2, PT_SEPC(sp)
101
+
/*
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+
* The current load reservation is effectively part of the processor's
103
+
* state, in the sense that load reservations cannot be shared between
104
+
* different hart contexts. We can't actually save and restore a load
105
+
* reservation, so instead here we clear any existing reservation --
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+
* it's always legal for implementations to clear load reservations at
107
+
* any point (as long as the forward progress guarantee is kept, but
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+
* we'll ignore that here).
109
+
*
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+
* Dangling load reservations can be the result of taking a trap in the
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+
* middle of an LR/SC sequence, but can also be the result of a taken
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+
* forward branch around an SC -- which is how we implement CAS. As a
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+
* result we need to clear reservations between the last CAS and the
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+
* jump back to the new context. While it is unlikely the store
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+
* completes, implementations are allowed to expand reservations to be
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+
* arbitrarily large.
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+
*/
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+
REG_L a2, PT_SEPC(sp)
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+
REG_SC x0, a2, PT_SEPC(sp)
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+
102
121
csrw CSR_SSTATUS, a0
103
122
csrw CSR_SEPC, a2
104
123
+11
-1
arch/riscv/mm/init.c
+11
-1
arch/riscv/mm/init.c
···
11
11
#include <linux/swap.h>
12
12
#include <linux/sizes.h>
13
13
#include <linux/of_fdt.h>
14
+
#include <linux/libfdt.h>
14
15
15
16
#include <asm/fixmap.h>
16
17
#include <asm/tlbflush.h>
···
83
82
}
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83
#endif /* CONFIG_BLK_DEV_INITRD */
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+
static phys_addr_t dtb_early_pa __initdata;
86
+
86
87
void __init setup_bootmem(void)
87
88
{
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89
struct memblock_region *reg;
···
120
117
setup_initrd();
121
118
#endif /* CONFIG_BLK_DEV_INITRD */
122
119
123
-
early_init_fdt_reserve_self();
120
+
/*
121
+
* Avoid using early_init_fdt_reserve_self() since __pa() does
122
+
* not work for DTB pointers that are fixmap addresses
123
+
*/
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+
memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
125
+
124
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early_init_fdt_scan_reserved_mem();
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memblock_allow_resize();
126
128
memblock_dump_all();
···
401
393
402
394
/* Save pointer to DTB for early FDT parsing */
403
395
dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
396
+
/* Save physical address for memblock reservation */
397
+
dtb_early_pa = dtb_pa;
404
398
}
405
399
406
400
static void __init setup_vm_final(void)