summaryrefslogtreecommitdiffstats
path: root/drivers/firmware/efi/memmap.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/firmware/efi/memmap.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/firmware/efi/memmap.c')
-rw-r--r--drivers/firmware/efi/memmap.c148
1 files changed, 148 insertions, 0 deletions
diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
new file mode 100644
index 000000000..f1c04d7cf
--- /dev/null
+++ b/drivers/firmware/efi/memmap.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common EFI memory map functions.
+ */
+
+#define pr_fmt(fmt) "efi: " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/efi.h>
+#include <linux/io.h>
+#include <linux/memblock.h>
+#include <linux/slab.h>
+
+#include <asm/early_ioremap.h>
+#include <asm/efi.h>
+
+/**
+ * __efi_memmap_init - Common code for mapping the EFI memory map
+ * @data: EFI memory map data
+ *
+ * This function takes care of figuring out which function to use to
+ * map the EFI memory map in efi.memmap based on how far into the boot
+ * we are.
+ *
+ * During bootup EFI_MEMMAP_LATE in data->flags should be clear since we
+ * only have access to the early_memremap*() functions as the vmalloc
+ * space isn't setup. Once the kernel is fully booted we can fallback
+ * to the more robust memremap*() API.
+ *
+ * Returns: zero on success, a negative error code on failure.
+ */
+int __init __efi_memmap_init(struct efi_memory_map_data *data)
+{
+ struct efi_memory_map map;
+ phys_addr_t phys_map;
+
+ phys_map = data->phys_map;
+
+ if (data->flags & EFI_MEMMAP_LATE)
+ map.map = memremap(phys_map, data->size, MEMREMAP_WB);
+ else
+ map.map = early_memremap(phys_map, data->size);
+
+ if (!map.map) {
+ pr_err("Could not map the memory map! phys_map=%pa, size=0x%lx\n",
+ &phys_map, data->size);
+ return -ENOMEM;
+ }
+
+ map.phys_map = data->phys_map;
+ map.nr_map = data->size / data->desc_size;
+ map.map_end = map.map + data->size;
+
+ map.desc_version = data->desc_version;
+ map.desc_size = data->desc_size;
+ map.flags = data->flags;
+
+ set_bit(EFI_MEMMAP, &efi.flags);
+
+ efi.memmap = map;
+
+ return 0;
+}
+
+/**
+ * efi_memmap_init_early - Map the EFI memory map data structure
+ * @data: EFI memory map data
+ *
+ * Use early_memremap() to map the passed in EFI memory map and assign
+ * it to efi.memmap.
+ *
+ * Returns: zero on success, a negative error code on failure.
+ */
+int __init efi_memmap_init_early(struct efi_memory_map_data *data)
+{
+ /* Cannot go backwards */
+ WARN_ON(efi.memmap.flags & EFI_MEMMAP_LATE);
+
+ data->flags = 0;
+ return __efi_memmap_init(data);
+}
+
+void __init efi_memmap_unmap(void)
+{
+ if (!efi_enabled(EFI_MEMMAP))
+ return;
+
+ if (!(efi.memmap.flags & EFI_MEMMAP_LATE)) {
+ unsigned long size;
+
+ size = efi.memmap.desc_size * efi.memmap.nr_map;
+ early_memunmap(efi.memmap.map, size);
+ } else {
+ memunmap(efi.memmap.map);
+ }
+
+ efi.memmap.map = NULL;
+ clear_bit(EFI_MEMMAP, &efi.flags);
+}
+
+/**
+ * efi_memmap_init_late - Map efi.memmap with memremap()
+ * @addr: Physical address of the new EFI memory map
+ * @size: Size in bytes of the new EFI memory map
+ *
+ * Setup a mapping of the EFI memory map using ioremap_cache(). This
+ * function should only be called once the vmalloc space has been
+ * setup and is therefore not suitable for calling during early EFI
+ * initialise, e.g. in efi_init(). Additionally, it expects
+ * efi_memmap_init_early() to have already been called.
+ *
+ * The reason there are two EFI memmap initialisation
+ * (efi_memmap_init_early() and this late version) is because the
+ * early EFI memmap should be explicitly unmapped once EFI
+ * initialisation is complete as the fixmap space used to map the EFI
+ * memmap (via early_memremap()) is a scarce resource.
+ *
+ * This late mapping is intended to persist for the duration of
+ * runtime so that things like efi_mem_desc_lookup() and
+ * efi_mem_attributes() always work.
+ *
+ * Returns: zero on success, a negative error code on failure.
+ */
+int __init efi_memmap_init_late(phys_addr_t addr, unsigned long size)
+{
+ struct efi_memory_map_data data = {
+ .phys_map = addr,
+ .size = size,
+ .flags = EFI_MEMMAP_LATE,
+ };
+
+ /* Did we forget to unmap the early EFI memmap? */
+ WARN_ON(efi.memmap.map);
+
+ /* Were we already called? */
+ WARN_ON(efi.memmap.flags & EFI_MEMMAP_LATE);
+
+ /*
+ * It makes no sense to allow callers to register different
+ * values for the following fields. Copy them out of the
+ * existing early EFI memmap.
+ */
+ data.desc_version = efi.memmap.desc_version;
+ data.desc_size = efi.memmap.desc_size;
+
+ return __efi_memmap_init(&data);
+}