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RISC-V: ACPI: Enhance acpi_os_ioremap with MMIO remapping

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Enhance the acpi_os_ioremap() to support opregions in MMIO space. Also,
have strict checks using EFI memory map to allow remapping the RAM similar
to arm64.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231018124007.1306159-2-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Sunil V L 2023-10-18 18:10:04 +05:30 committed by Palmer Dabbelt
parent 0bb80ecc33
commit e8065df5b0
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
2 changed files with 87 additions and 3 deletions
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1
arch/riscv/Kconfig
View File

@ -39,6 +39,7 @@ config RISCV
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAS_VDSO_DATA
select ARCH_KEEP_MEMBLOCK if ACPI
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
select ARCH_STACKWALK

89
arch/riscv/kernel/acpi.c
View File

@ -14,9 +14,10 @@
*/
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/pci.h>
#include <linux/efi.h>
#include <linux/io.h>
#include <linux/memblock.h>
#include <linux/pci.h>
int acpi_noirq = 1; /* skip ACPI IRQ initialization */
int acpi_disabled = 1;
@ -217,7 +218,89 @@ void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
{
return (void __iomem *)memremap(phys, size, MEMREMAP_WB);
efi_memory_desc_t *md, *region = NULL;
pgprot_t prot;
if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP)))
return NULL;
for_each_efi_memory_desc(md) {
u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
if (phys < md->phys_addr || phys >= end)
continue;
if (phys + size > end) {
pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n");
return NULL;
}
region = md;
break;
}
/*
* It is fine for AML to remap regions that are not represented in the
* EFI memory map at all, as it only describes normal memory, and MMIO
* regions that require a virtual mapping to make them accessible to
* the EFI runtime services.
*/
prot = PAGE_KERNEL_IO;
if (region) {
switch (region->type) {
case EFI_LOADER_CODE:
case EFI_LOADER_DATA:
case EFI_BOOT_SERVICES_CODE:
case EFI_BOOT_SERVICES_DATA:
case EFI_CONVENTIONAL_MEMORY:
case EFI_PERSISTENT_MEMORY:
if (memblock_is_map_memory(phys) ||
!memblock_is_region_memory(phys, size)) {
pr_warn(FW_BUG "requested region covers kernel memory\n");
return NULL;
}
/*
* Mapping kernel memory is permitted if the region in
* question is covered by a single memblock with the
* NOMAP attribute set: this enables the use of ACPI
* table overrides passed via initramfs.
* This particular use case only requires read access.
*/
fallthrough;
case EFI_RUNTIME_SERVICES_CODE:
/*
* This would be unusual, but not problematic per se,
* as long as we take care not to create a writable
* mapping for executable code.
*/
prot = PAGE_KERNEL_RO;
break;
case EFI_ACPI_RECLAIM_MEMORY:
/*
* ACPI reclaim memory is used to pass firmware tables
* and other data that is intended for consumption by
* the OS only, which may decide it wants to reclaim
* that memory and use it for something else. We never
* do that, but we usually add it to the linear map
* anyway, in which case we should use the existing
* mapping.
*/
if (memblock_is_map_memory(phys))
return (void __iomem *)__va(phys);
fallthrough;
default:
if (region->attribute & EFI_MEMORY_WB)
prot = PAGE_KERNEL;
else if ((region->attribute & EFI_MEMORY_WC) ||
(region->attribute & EFI_MEMORY_WT))
prot = pgprot_writecombine(PAGE_KERNEL);
}
}
return ioremap_prot(phys, size, pgprot_val(prot));
}
#ifdef CONFIG_PCI