diff options
| -rw-r--r-- | arch/arm64/mm/init.c | 5 | ||||
| -rw-r--r-- | drivers/acpi/arm64/iort.c | 55 | ||||
| -rw-r--r-- | include/linux/acpi_iort.h | 4 |
3 files changed, 63 insertions, 1 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index b736890ad3d3..5e534d674c9c 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -29,6 +29,7 @@ #include <linux/kexec.h> #include <linux/crash_dump.h> #include <linux/hugetlb.h> +#include <linux/acpi_iort.h> #include <asm/boot.h> #include <asm/fixmap.h> @@ -193,11 +194,13 @@ static phys_addr_t __init max_zone_phys(unsigned int zone_bits) static void __init zone_sizes_init(unsigned long min, unsigned long max) { unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; + unsigned int __maybe_unused acpi_zone_dma_bits; unsigned int __maybe_unused dt_zone_dma_bits; #ifdef CONFIG_ZONE_DMA + acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address()); dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL)); - zone_dma_bits = min(32U, dt_zone_dma_bits); + zone_dma_bits = min3(32U, dt_zone_dma_bits, acpi_zone_dma_bits); arm64_dma_phys_limit = max_zone_phys(zone_dma_bits); max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit); #endif diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index 9929ff50c0c0..1787406684aa 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -1718,3 +1718,58 @@ void __init acpi_iort_init(void) iort_init_platform_devices(); } + +#ifdef CONFIG_ZONE_DMA +/* + * Extract the highest CPU physical address accessible to all DMA masters in + * the system. PHYS_ADDR_MAX is returned when no constrained device is found. + */ +phys_addr_t __init acpi_iort_dma_get_max_cpu_address(void) +{ + phys_addr_t limit = PHYS_ADDR_MAX; + struct acpi_iort_node *node, *end; + struct acpi_table_iort *iort; + acpi_status status; + int i; + + if (acpi_disabled) + return limit; + + status = acpi_get_table(ACPI_SIG_IORT, 0, + (struct acpi_table_header **)&iort); + if (ACPI_FAILURE(status)) + return limit; + + node = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->node_offset); + end = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->header.length); + + for (i = 0; i < iort->node_count; i++) { + if (node >= end) + break; + + switch (node->type) { + struct acpi_iort_named_component *ncomp; + struct acpi_iort_root_complex *rc; + phys_addr_t local_limit; + + case ACPI_IORT_NODE_NAMED_COMPONENT: + ncomp = (struct acpi_iort_named_component *)node->node_data; + local_limit = DMA_BIT_MASK(ncomp->memory_address_limit); + limit = min_not_zero(limit, local_limit); + break; + + case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: + if (node->revision < 1) + break; + + rc = (struct acpi_iort_root_complex *)node->node_data; + local_limit = DMA_BIT_MASK(rc->memory_address_limit); + limit = min_not_zero(limit, local_limit); + break; + } + node = ACPI_ADD_PTR(struct acpi_iort_node, node, node->length); + } + acpi_put_table(&iort->header); + return limit; +} +#endif diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h index 20a32120bb88..1a12baa58e40 100644 --- a/include/linux/acpi_iort.h +++ b/include/linux/acpi_iort.h @@ -38,6 +38,7 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *size); const struct iommu_ops *iort_iommu_configure_id(struct device *dev, const u32 *id_in); int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head); +phys_addr_t acpi_iort_dma_get_max_cpu_address(void); #else static inline void acpi_iort_init(void) { } static inline u32 iort_msi_map_id(struct device *dev, u32 id) @@ -55,6 +56,9 @@ static inline const struct iommu_ops *iort_iommu_configure_id( static inline int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head) { return 0; } + +static inline phys_addr_t acpi_iort_dma_get_max_cpu_address(void) +{ return PHYS_ADDR_MAX; } #endif #endif /* __ACPI_IORT_H__ */ |