UEFI uses early IO or memory mappings for runtime services before
normal ioremap() is usable. Add the necessary fixmap bindings and
pmd mappings for generic ioremap support to work.
Signed-off-by: Atish Patra <atish.patra@xxxxxxx>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/Kbuild | 1 +
arch/riscv/include/asm/fixmap.h | 13 +++++++++++++
arch/riscv/include/asm/io.h | 1 +
arch/riscv/kernel/setup.c | 1 +
arch/riscv/mm/init.c | 33 +++++++++++++++++++++++++++++++++
6 files changed, 50 insertions(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 7b5905529146..15597f5f504f 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -37,6 +37,7 @@ config RISCV
select GENERIC_ARCH_TOPOLOGY if SMP
select GENERIC_ATOMIC64 if !64BIT
select GENERIC_CLOCKEVENTS
+ select GENERIC_EARLY_IOREMAP
select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
select GENERIC_IOREMAP
select GENERIC_IRQ_MULTI_HANDLER
diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index 3d9410bb4de0..59dd7be55005 100644
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
+generic-y += early_ioremap.h
generic-y += extable.h
generic-y += flat.h
generic-y += kvm_para.h
diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h
index 11613f38228a..54cbf07fb4e9 100644
--- a/arch/riscv/include/asm/fixmap.h
+++ b/arch/riscv/include/asm/fixmap.h
@@ -27,6 +27,19 @@ enum fixed_addresses {
FIX_TEXT_POKE1,
FIX_TEXT_POKE0,
FIX_EARLYCON_MEM_BASE,
+
+ __end_of_permanent_fixed_addresses,
+ /*
+ * Temporary boot-time mappings, used by early_ioremap(),
+ * before ioremap() is functional.
+ */
+#define NR_FIX_BTMAPS (SZ_256K / PAGE_SIZE)
+#define FIX_BTMAPS_SLOTS 7
+#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
+
+ FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
+ FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
+
__end_of_fixed_addresses
};
diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h
index 3835c3295dc5..c025a746a148 100644
--- a/arch/riscv/include/asm/io.h
+++ b/arch/riscv/include/asm/io.h
@@ -14,6 +14,7 @@
#include <linux/types.h>
#include <linux/pgtable.h>
#include <asm/mmiowb.h>
+#include <asm/early_ioremap.h>
/*
* MMIO access functions are separated out to break dependency cycles
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 6a0ee2405813..c71788e6aff4 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -72,6 +72,7 @@ void __init setup_arch(char **cmdline_p)
*cmdline_p = boot_command_line;
+ early_ioremap_setup();
parse_early_param();
setup_bootmem();
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 2b651f63f5c4..b75ebe8e7a92 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -403,6 +403,9 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
uintptr_t load_pa = (uintptr_t)(&_start);
uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
+#ifndef __PAGETABLE_PMD_FOLDED
+ pmd_t fix_bmap_spmd, fix_bmap_epmd;
+#endif
va_pa_offset = PAGE_OFFSET - load_pa;
pfn_base = PFN_DOWN(load_pa);
@@ -456,6 +459,36 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL);
dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1));
dtb_early_pa = dtb_pa;
+
+ /*
+ * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
+ * range can not span multiple pmds.
+ */
+ BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
+ != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
+
+#ifndef __PAGETABLE_PMD_FOLDED
+ /*
+ * Early ioremap fixmap is already created as it lies within first 2MB
+ * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
+ * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
+ * the user if not.
+ */
+ fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
+ fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
+ if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
+ WARN_ON(1);
+ pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
+ pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
+ pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
+ fix_to_virt(FIX_BTMAP_BEGIN));
+ pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
+ fix_to_virt(FIX_BTMAP_END));
+
+ pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
+ pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN);
+ }
+#endif
}
static void __init setup_vm_final(void)
--
2.24.0
