Commit 51735ae0 authored by Alexander Graf's avatar Alexander Graf Committed by Tom Rini

efi_loader: Add bounce buffer support

Some hardware that is supported by U-Boot can not handle DMA above 32bits.
For these systems, we need to come up with a way to expose the disk interface
in a safe way.

This patch implements EFI specific bounce buffers. For non-EFI cases, this
apparently was no issue so far, since we can just define our environment
variables conveniently.
Signed-off-by: 's avatarAlexander Graf <agraf@suse.de>
parent 851bda81
......@@ -139,6 +139,11 @@ uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
/* Called by board init to initialize the EFI memory map */
int efi_memory_init(void);
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
extern void *efi_bounce_buffer;
#define EFI_LOADER_BOUNCE_BUFFER_SIZE (64 * 1024 * 1024)
#endif
/* Convert strings from normal C strings to uEFI strings */
static inline void ascii2unicode(u16 *unicode, char *ascii)
{
......
......@@ -7,3 +7,12 @@ config EFI_LOADER
on top of U-Boot. If this option is enabled, U-Boot will expose EFI
interfaces to a loaded EFI application, enabling it to reuse U-Boot's
device drivers.
config EFI_LOADER_BOUNCE_BUFFER
bool "EFI Applications use bounce buffers for DMA operations"
depends on EFI_LOADER && ARM64
default n
help
Some hardware does not support DMA to full 64bit addresses. For this
hardware we can create a bounce buffer so that payloads don't have to
worry about platform details.
......@@ -76,9 +76,6 @@ static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
int blocks;
unsigned long n;
EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
buffer_size, buffer);
diskobj = container_of(this, struct efi_disk_obj, ops);
if (!(desc = blk_get_dev(diskobj->ifname, diskobj->dev_index)))
return EFI_EXIT(EFI_DEVICE_ERROR);
......@@ -95,10 +92,11 @@ static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
if (buffer_size & (blksz - 1))
return EFI_EXIT(EFI_DEVICE_ERROR);
if (direction == EFI_DISK_READ)
if (direction == EFI_DISK_READ) {
n = desc->block_read(desc, lba, blocks, buffer);
else
} else {
n = desc->block_write(desc, lba, blocks, buffer);
}
/* We don't do interrupts, so check for timers cooperatively */
efi_timer_check();
......@@ -116,16 +114,70 @@ static efi_status_t efi_disk_read_blocks(struct efi_block_io *this,
u32 media_id, u64 lba, unsigned long buffer_size,
void *buffer)
{
return efi_disk_rw_blocks(this, media_id, lba, buffer_size, buffer,
EFI_DISK_READ);
void *real_buffer = buffer;
efi_status_t r;
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
r = efi_disk_read_blocks(this, media_id, lba,
EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
if (r != EFI_SUCCESS)
return r;
return efi_disk_read_blocks(this, media_id, lba +
EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
}
real_buffer = efi_bounce_buffer;
#endif
EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
buffer_size, buffer);
r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
EFI_DISK_READ);
/* Copy from bounce buffer to real buffer if necessary */
if ((r == EFI_SUCCESS) && (real_buffer != buffer))
memcpy(buffer, real_buffer, buffer_size);
return EFI_EXIT(r);
}
static efi_status_t efi_disk_write_blocks(struct efi_block_io *this,
u32 media_id, u64 lba, unsigned long buffer_size,
void *buffer)
{
return efi_disk_rw_blocks(this, media_id, lba, buffer_size, buffer,
EFI_DISK_WRITE);
void *real_buffer = buffer;
efi_status_t r;
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
r = efi_disk_write_blocks(this, media_id, lba,
EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
if (r != EFI_SUCCESS)
return r;
return efi_disk_write_blocks(this, media_id, lba +
EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
}
real_buffer = efi_bounce_buffer;
#endif
EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
buffer_size, buffer);
/* Populate bounce buffer if necessary */
if (real_buffer != buffer)
memcpy(real_buffer, buffer, buffer_size);
r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
EFI_DISK_WRITE);
return EFI_EXIT(r);
}
static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
......
......@@ -27,6 +27,10 @@ struct efi_mem_list {
/* This list contains all memory map items */
LIST_HEAD(efi_mem);
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
void *efi_bounce_buffer;
#endif
/*
* Sorts the memory list from highest address to lowest address
*
......@@ -349,5 +353,17 @@ int efi_memory_init(void)
efi_add_memory_map(runtime_start, runtime_pages,
EFI_RUNTIME_SERVICES_CODE, false);
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
/* Request a 32bit 64MB bounce buffer region */
uint64_t efi_bounce_buffer_addr = 0xffffffff;
if (efi_allocate_pages(1, EFI_LOADER_DATA,
(64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
&efi_bounce_buffer_addr) != EFI_SUCCESS)
return -1;
efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;
#endif
return 0;
}
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