/**
* imr_is_enabled - true if an IMR is enabled false otherwise.
*
* Determines if an IMR is enabled based on address range and read/write
* mask. An IMR set with an address range set to zero and a read/write
* access mask set to all is considered to be disabled. An IMR in any
* other state - for example set to zero but without read/write access
* all is considered to be enabled. This definition of disabled is how
* firmware switches off an IMR and is maintained in kernel for
* consistency.
*
* @imr: pointer to IMR descriptor.
* @return: true if IMR enabled false if disabled.
*/
static inline int imr_is_enabled(struct imr_regs *imr)
{
return !(imr->rmask == IMR_READ_ACCESS_ALL &&
imr->wmask == IMR_WRITE_ACCESS_ALL &&
imr_to_phys(imr->addr_lo) == 0 &&
imr_to_phys(imr->addr_hi) == 0);
}
/**
* imr_write - write an IMR at a given index.
*
* Requires caller to hold imr mutex.
* Note lock bits need to be written independently of address bits.
*
* @idev: pointer to imr_device structure.
* @imr_id: IMR entry to write.
* @imr: IMR structure representing address and access masks.
* @lock: indicates if the IMR lock bit should be applied.
* @return: 0 on success or error code passed from mbi_iosf on failure.
*/
static int imr_write(struct imr_device *idev, u32 imr_id,
struct imr_regs *imr, bool lock)
{
unsigned long flags;
u32 reg = imr_id * IMR_NUM_REGS + idev->reg_base;
int ret;
local_irq_save(flags);
ret = iosf_mbi_write(QRK_MBI_UNIT_MM, MBI_REG_WRITE, reg++, imr->addr_lo);
if (ret)
goto failed;
ret = iosf_mbi_write(QRK_MBI_UNIT_MM, MBI_REG_WRITE, reg++, imr->addr_hi);
if (ret)
goto failed;
ret = iosf_mbi_write(QRK_MBI_UNIT_MM, MBI_REG_WRITE, reg++, imr->rmask);
if (ret)
goto failed;
ret = iosf_mbi_write(QRK_MBI_UNIT_MM, MBI_REG_WRITE, reg++, imr->wmask);
if (ret)
goto failed;
/* Lock bit must be set separately to addr_lo address bits. */
if (lock) {
imr->addr_lo |= IMR_LOCK;
ret = iosf_mbi_write(QRK_MBI_UNIT_MM, MBI_REG_WRITE,
reg - IMR_NUM_REGS, imr->addr_lo);
if (ret)
goto failed;
}
local_irq_restore(flags);
return 0;
failed:
/*
* If writing to the IOSF failed then we're in an unknown state,
* likely a very bad state. An IMR in an invalid state will almost
* certainly lead to a memory access violation.
*/
local_irq_restore(flags);
WARN(ret, "IOSF-MBI write fail range 0x%08x-0x%08x unreliable\n",
imr_to_phys(imr->addr_lo), imr_to_phys(imr->addr_hi) + IMR_MASK);
return ret;
}
/**
* imr_dbgfs_state_show - print state of IMR registers.
*
* @s: pointer to seq_file for output.
* @unused: unused parameter.
* @return: 0 on success or error code passed from mbi_iosf on failure.
*/
static int imr_dbgfs_state_show(struct seq_file *s, void *unused)
{
phys_addr_t base;
phys_addr_t end;
int i;
struct imr_device *idev = s->private;
struct imr_regs imr;
size_t size;
int ret = -ENODEV;
mutex_lock(&idev->lock);
for (i = 0; i < idev->max_imr; i++) {
ret = imr_read(idev, i, &imr);
if (ret)
break;
/*
* Remember to add IMR_ALIGN bytes to size to indicate the
* inherent IMR_ALIGN size bytes contained in the masked away
* lower ten bits.
*/
if (imr_is_enabled(&imr)) {
base = imr_to_phys(imr.addr_lo);
end = imr_to_phys(imr.addr_hi) + IMR_MASK;
size = end - base + 1;
} else {
base = 0;
end = 0;
size = 0;
}
seq_printf(s, "imr%02i: base=%pa, end=%pa, size=0x%08zx "
"rmask=0x%08x, wmask=0x%08x, %s, %s\n", i,
&base, &end, size, imr.rmask, imr.wmask,
imr_is_enabled(&imr) ? "enabled " : "disabled",
imr.addr_lo & IMR_LOCK ? "locked" : "unlocked");
}
mutex_unlock(&idev->lock);
return ret;
}
/**
* __imr_remove_range - delete an Isolated Memory Region.
*
* This function allows you to delete an IMR by its index specified by reg or
* by address range specified by base and size respectively. If you specify an
* index on its own the base and size parameters are ignored.
* imr_remove_range(0, base, size); delete IMR at index 0 base/size ignored.
* imr_remove_range(-1, base, size); delete IMR from base to base+size.
*
* @reg: imr index to remove.
* @base: physical base address of region aligned to 1 KiB.
* @size: physical size of region in bytes aligned to 1 KiB.
* @return: -EINVAL on invalid range or out or range id
* -ENODEV if reg is valid but no IMR exists or is locked
* 0 on success.
*/
static int __imr_remove_range(int reg, phys_addr_t base, size_t size)
{
phys_addr_t end;
bool found = false;
unsigned int i;
struct imr_device *idev = &imr_dev;
struct imr_regs imr;
size_t raw_size;
int ret = 0;
if (WARN_ONCE(idev->init == false, "driver not initialized"))
return -ENODEV;
/*
* Validate address range if deleting by address, else we are
* deleting by index where base and size will be ignored.
*/
if (reg == -1) {
ret = imr_check_params(base, size);
if (ret)
return ret;
}
/* Tweak the size value. */
raw_size = imr_raw_size(size);
end = base + raw_size;
mutex_lock(&idev->lock);
if (reg >= 0) {
/* If a specific IMR is given try to use it. */
ret = imr_read(idev, reg, &imr);
if (ret)
goto failed;
if (!imr_is_enabled(&imr) || imr.addr_lo & IMR_LOCK) {
ret = -ENODEV;
goto failed;
}
found = true;
} else {
/* Search for match based on address range. */
for (i = 0; i < idev->max_imr; i++) {
ret = imr_read(idev, i, &imr);
if (ret)
goto failed;
if (!imr_is_enabled(&imr) || imr.addr_lo & IMR_LOCK)
continue;
if ((imr_to_phys(imr.addr_lo) == base) &&
(imr_to_phys(imr.addr_hi) == end)) {
found = true;
reg = i;
break;
}
}
}
if (!found) {
ret = -ENODEV;
goto failed;
}
pr_debug("remove %d phys %pa-%pa size %zx\n", reg, &base, &end, raw_size);
/* Tear down the IMR. */
imr.addr_lo = 0;
imr.addr_hi = 0;
imr.rmask = IMR_READ_ACCESS_ALL;
imr.wmask = IMR_WRITE_ACCESS_ALL;
ret = imr_write(idev, reg, &imr);
failed:
mutex_unlock(&idev->lock);
return ret;
}
/**
* imr_address_overlap - detects an address overlap.
*
* @addr: address to check against an existing IMR.
* @imr: imr being checked.
* @return: true for overlap false for no overlap.
*/
static inline int imr_address_overlap(phys_addr_t addr, struct imr_regs *imr)
{
return addr >= imr_to_phys(imr->addr_lo) && addr <= imr_to_phys(imr->addr_hi);
}