blob: e9b017ad570b8d8089859ac43c348f6fcfd77d01 [file] [log] [blame]
// SPDX-License-Identifier: MIT
/*
* The sart code is copied from m1n1 (https://github.com/AsahiLinux/m1n1) and
* licensed as MIT.
*
* (C) Copyright 2022 The Asahi Linux Contributors
*/
#include <asm/io.h>
#include <asm/arch/sart.h>
#include <linux/bitfield.h>
#include <linux/types.h>
#include <malloc.h>
#define APPLE_SART_MAX_ENTRIES 16
/* This is probably a bitfield but the exact meaning of each bit is unknown. */
#define APPLE_SART_FLAGS_ALLOW 0xff
/* SARTv2 registers */
#define APPLE_SART2_CONFIG(idx) (0x00 + 4 * (idx))
#define APPLE_SART2_CONFIG_FLAGS GENMASK(31, 24)
#define APPLE_SART2_CONFIG_SIZE GENMASK(23, 0)
#define APPLE_SART2_CONFIG_SIZE_SHIFT 12
#define APPLE_SART2_CONFIG_SIZE_MAX GENMASK(23, 0)
#define APPLE_SART2_PADDR(idx) (0x40 + 4 * (idx))
#define APPLE_SART2_PADDR_SHIFT 12
/* SARTv3 registers */
#define APPLE_SART3_CONFIG(idx) (0x00 + 4 * (idx))
#define APPLE_SART3_PADDR(idx) (0x40 + 4 * (idx))
#define APPLE_SART3_PADDR_SHIFT 12
#define APPLE_SART3_SIZE(idx) (0x80 + 4 * (idx))
#define APPLE_SART3_SIZE_SHIFT 12
#define APPLE_SART3_SIZE_MAX GENMASK(29, 0)
struct apple_sart {
uintptr_t base;
u32 protected_entries;
void (*get_entry)(struct apple_sart *sart, int index, u8 *flags, void **paddr,
size_t *size);
bool (*set_entry)(struct apple_sart *sart, int index, u8 flags, void *paddr,
size_t size);
};
static void sart2_get_entry(struct apple_sart *sart, int index, u8 *flags, void **paddr,
size_t *size)
{
u32 cfg = readl(sart->base + APPLE_SART2_CONFIG(index));
*flags = FIELD_GET(APPLE_SART2_CONFIG_FLAGS, cfg);
*size = (size_t)FIELD_GET(APPLE_SART2_CONFIG_SIZE, cfg) << APPLE_SART2_CONFIG_SIZE_SHIFT;
*paddr = (void *)
((u64)readl(sart->base + APPLE_SART2_PADDR(index)) << APPLE_SART2_PADDR_SHIFT);
}
static bool sart2_set_entry(struct apple_sart *sart, int index, u8 flags, void *paddr_,
size_t size)
{
u32 cfg;
u64 paddr = (u64)paddr_;
if (size & ((1 << APPLE_SART2_CONFIG_SIZE_SHIFT) - 1))
return false;
if (paddr & ((1 << APPLE_SART2_PADDR_SHIFT) - 1))
return false;
size >>= APPLE_SART2_CONFIG_SIZE_SHIFT;
paddr >>= APPLE_SART2_PADDR_SHIFT;
if (size > APPLE_SART2_CONFIG_SIZE_MAX)
return false;
cfg = FIELD_PREP(APPLE_SART2_CONFIG_FLAGS, flags);
cfg |= FIELD_PREP(APPLE_SART2_CONFIG_SIZE, size);
writel(paddr, sart->base + APPLE_SART2_PADDR(index));
writel(cfg, sart->base + APPLE_SART2_CONFIG(index));
return true;
}
static void sart3_get_entry(struct apple_sart *sart, int index, u8 *flags, void **paddr,
size_t *size)
{
*flags = readl(sart->base + APPLE_SART3_CONFIG(index));
*size = (size_t)readl(sart->base + APPLE_SART3_SIZE(index)) << APPLE_SART3_SIZE_SHIFT;
*paddr = (void *)
((u64)readl(sart->base + APPLE_SART3_PADDR(index)) << APPLE_SART3_PADDR_SHIFT);
}
static bool sart3_set_entry(struct apple_sart *sart, int index, u8 flags, void *paddr_,
size_t size)
{
u64 paddr = (u64)paddr_;
if (size & ((1 << APPLE_SART3_SIZE_SHIFT) - 1))
return false;
if (paddr & ((1 << APPLE_SART3_PADDR_SHIFT) - 1))
return false;
paddr >>= APPLE_SART3_PADDR_SHIFT;
size >>= APPLE_SART3_SIZE_SHIFT;
if (size > APPLE_SART3_SIZE_MAX)
return false;
writel(paddr, sart->base + APPLE_SART3_PADDR(index));
writel(size, sart->base + APPLE_SART3_SIZE(index));
writel(flags, sart->base + APPLE_SART3_CONFIG(index));
return true;
}
struct apple_sart *sart_init(ofnode node)
{
phys_addr_t base;
u32 sart_version;
struct apple_sart *sart;
base = ofnode_get_addr(node);
if (base == FDT_ADDR_T_NONE)
return NULL;
if (ofnode_device_is_compatible(node, "apple,t8103-sart")) {
sart_version = 2;
} else if (ofnode_device_is_compatible(node, "apple,t6000-sart")) {
sart_version = 3;
} else {
printf("sart: unknown SART compatible: %sd\n",
ofnode_read_string(node, "compatible"));
return NULL;
}
sart = calloc(sizeof(*sart), 1);
if (!sart)
return NULL;
sart->base = base;
switch (sart_version) {
case 2:
sart->get_entry = sart2_get_entry;
sart->set_entry = sart2_set_entry;
break;
case 3:
sart->get_entry = sart3_get_entry;
sart->set_entry = sart3_set_entry;
break;
default:
printf("sart: SART has unknown version %d\n", sart_version);
free(sart);
return NULL;
}
sart->protected_entries = 0;
for (unsigned int i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) {
void *paddr;
u8 flags;
size_t sz;
sart->get_entry(sart, i, &flags, &paddr, &sz);
if (flags)
sart->protected_entries |= 1 << i;
}
return sart;
}
void sart_free(struct apple_sart *sart)
{
for (unsigned int i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) {
if (sart->protected_entries & (1 << i))
continue;
sart->set_entry(sart, i, 0, NULL, 0);
}
free(sart);
}
bool sart_add_allowed_region(struct apple_sart *sart, void *paddr, size_t sz)
{
for (unsigned int i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) {
void *e_paddr;
u8 e_flags;
size_t e_sz;
if (sart->protected_entries & (1 << i))
continue;
sart->get_entry(sart, i, &e_flags, &e_paddr, &e_sz);
if (e_flags)
continue;
return sart->set_entry(sart, i, APPLE_SART_FLAGS_ALLOW, paddr, sz);
}
printf("sart: no more free entries\n");
return false;
}
bool sart_remove_allowed_region(struct apple_sart *sart, void *paddr, size_t sz)
{
for (unsigned int i = 0; i < APPLE_SART_MAX_ENTRIES; ++i) {
void *e_paddr;
u8 e_flags;
size_t e_sz;
if (sart->protected_entries & (1 << i))
continue;
sart->get_entry(sart, i, &e_flags, &e_paddr, &e_sz);
if (!e_flags)
continue;
if (e_paddr != paddr)
continue;
if (e_sz != sz)
continue;
return sart->set_entry(sart, i, 0, NULL, 0);
}
printf("sart: could not find entry to be removed\n");
return false;
}