io_base and io_size represent physical addresses. So they should use
paddr_t (instead of u64).
However in future, paddr_t may be defined as u32. So when typecasting
values from u64 to paddr_t, one should always check for any possible
truncation. If any truncation is discovered, Xen needs to raise a BUG
for this (as the address is provided either by reading the PCIE registers
or parsing parameters from string, so the error is unrecoverable).
Signed-off-by: Ayan Kumar Halder <ayan.kumar.hal...@amd.com>
---
Changes from -
v1 - NA
v2 - 1. Extracted the patch from "[XEN v2 05/11] xen/arm: Use paddr_t instead
of u64 for address/size"
into a separate patch of its own.
xen/drivers/char/ns16550.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
index 092f6b9c4b..2aee5642f9 100644
--- a/xen/drivers/char/ns16550.c
+++ b/xen/drivers/char/ns16550.c
@@ -42,8 +42,8 @@
static struct ns16550 {
int baud, clock_hz, data_bits, parity, stop_bits, fifo_size, irq;
- u64 io_base; /* I/O port or memory-mapped I/O address. */
- u64 io_size;
+ paddr_t io_base; /* I/O port or memory-mapped I/O address. */
+ paddr_t io_size;
int reg_shift; /* Bits to shift register offset by */
int reg_width; /* Size of access to use, the registers
* themselves are still bytes */
@@ -1166,8 +1166,9 @@ static const struct ns16550_config __initconst
uart_config[] =
static int __init
pci_uart_config(struct ns16550 *uart, bool_t skip_amt, unsigned int idx)
{
- u64 orig_base = uart->io_base;
+ paddr_t orig_base = uart->io_base;
unsigned int b, d, f, nextf, i;
+ u64 pci_uart_io_base;
/* NB. Start at bus 1 to avoid AMT: a plug-in card cannot be on bus 0. */
for ( b = skip_amt ? 1 : 0; b < 0x100; b++ )
@@ -1259,8 +1260,13 @@ pci_uart_config(struct ns16550 *uart, bool_t skip_amt,
unsigned int idx)
else
size = len & PCI_BASE_ADDRESS_MEM_MASK;
- uart->io_base = ((u64)bar_64 << 32) |
- (bar & PCI_BASE_ADDRESS_MEM_MASK);
+ pci_uart_io_base = ((u64)bar_64 << 32) |
+ (bar & PCI_BASE_ADDRESS_MEM_MASK);
+
+ /* Truncation detected while converting to paddr_t */
+ BUG_ON((pci_uart_io_base >> (PADDR_SHIFT - 1)) > 1);
+
+ uart->io_base = pci_uart_io_base;
}
/* IO based */
else if ( !param->mmio && (bar & PCI_BASE_ADDRESS_SPACE_IO) )
@@ -1468,6 +1474,7 @@ static bool __init parse_positional(struct ns16550 *uart,
char **str)
int baud;
const char *conf;
char *name_val_pos;
+ u64 uart_io_base;
conf = *str;
name_val_pos = strchr(conf, '=');
@@ -1532,7 +1539,12 @@ static bool __init parse_positional(struct ns16550
*uart, char **str)
else
#endif
{
- uart->io_base = simple_strtoull(conf, &conf, 0);
+ uart_io_base = simple_strtoull(conf, &conf, 0);
+
+ /* Truncation detected while converting to paddr_t */
+ BUG_ON((uart_io_base >> (PADDR_SHIFT - 1)) > 1);
+
+ uart->io_base = uart_io_base;
}
}
--
2.17.1
