From: Cédric Le Goater <c...@kaod.org>
The SMC controller on the Aspeed SoC has a set of registers to
configure the mapping of each flash module in the SoC address
space. Writing to these registers triggers a remap of the memory
region and the spec requires a certain number of checks before doing
so.
Signed-off-by: Cédric Le Goater <c...@kaod.org>
Reviewed-by: Andrew Jeffery <and...@aj.id.au>
Message-id: 1474977462-28032-7-git-send-email-...@kaod.org
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
---
hw/ssi/aspeed_smc.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 130 insertions(+), 5 deletions(-)
diff --git a/hw/ssi/aspeed_smc.c b/hw/ssi/aspeed_smc.c
index ecf39cc..6e8403e 100644
--- a/hw/ssi/aspeed_smc.c
+++ b/hw/ssi/aspeed_smc.c
@@ -79,10 +79,10 @@
/* CEx Segment Address Register */
#define R_SEG_ADDR0 (0x30 / 4)
-#define SEG_SIZE_SHIFT 24 /* 8MB units */
-#define SEG_SIZE_MASK 0x7f
+#define SEG_END_SHIFT 24 /* 8MB units */
+#define SEG_END_MASK 0xff
#define SEG_START_SHIFT 16 /* address bit [A29-A23] */
-#define SEG_START_MASK 0x7f
+#define SEG_START_MASK 0xff
#define R_SEG_ADDR1 (0x34 / 4)
#define R_SEG_ADDR2 (0x38 / 4)
#define R_SEG_ADDR3 (0x3C / 4)
@@ -135,8 +135,7 @@
/*
* Default segments mapping addresses and size for each slave per
* controller. These can be changed when board is initialized with the
- * Segment Address Registers but they don't seem do be used on the
- * field.
+ * Segment Address Registers.
*/
static const AspeedSegments aspeed_segments_legacy[] = {
{ 0x10000000, 32 * 1024 * 1024 },
@@ -191,6 +190,118 @@ static const AspeedSMCController controllers[] = {
ASPEED_SOC_SPI2_FLASH_BASE, 0x8000000 },
};
+/*
+ * The Segment Register uses a 8MB unit to encode the start address
+ * and the end address of the mapping window of a flash SPI slave :
+ *
+ * | byte 1 | byte 2 | byte 3 | byte 4 |
+ * +--------+--------+--------+--------+
+ * | end | start | 0 | 0 |
+ *
+ */
+static inline uint32_t aspeed_smc_segment_to_reg(const AspeedSegments *seg)
+{
+ uint32_t reg = 0;
+ reg |= ((seg->addr >> 23) & SEG_START_MASK) << SEG_START_SHIFT;
+ reg |= (((seg->addr + seg->size) >> 23) & SEG_END_MASK) << SEG_END_SHIFT;
+ return reg;
+}
+
+static inline void aspeed_smc_reg_to_segment(uint32_t reg, AspeedSegments *seg)
+{
+ seg->addr = ((reg >> SEG_START_SHIFT) & SEG_START_MASK) << 23;
+ seg->size = (((reg >> SEG_END_SHIFT) & SEG_END_MASK) << 23) - seg->addr;
+}
+
+static bool aspeed_smc_flash_overlap(const AspeedSMCState *s,
+ const AspeedSegments *new,
+ int cs)
+{
+ AspeedSegments seg;
+ int i;
+
+ for (i = 0; i < s->ctrl->max_slaves; i++) {
+ if (i == cs) {
+ continue;
+ }
+
+ aspeed_smc_reg_to_segment(s->regs[R_SEG_ADDR0 + i], &seg);
+
+ if (new->addr + new->size > seg.addr &&
+ new->addr < seg.addr + seg.size) {
+ qemu_log_mask(LOG_GUEST_ERROR, "%s: new segment CS%d [ 0x%"
+ HWADDR_PRIx" - 0x%"HWADDR_PRIx" ] overlaps with "
+ "CS%d [ 0x%"HWADDR_PRIx" - 0x%"HWADDR_PRIx" ]\n",
+ s->ctrl->name, cs, new->addr, new->addr + new->size,
+ i, seg.addr, seg.addr + seg.size);
+ return true;
+ }
+ }
+ return false;
+}
+
+static void aspeed_smc_flash_set_segment(AspeedSMCState *s, int cs,
+ uint64_t new)
+{
+ AspeedSMCFlash *fl = &s->flashes[cs];
+ AspeedSegments seg;
+
+ aspeed_smc_reg_to_segment(new, &seg);
+
+ /* The start address of CS0 is read-only */
+ if (cs == 0 && seg.addr != s->ctrl->flash_window_base) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: Tried to change CS0 start address to 0x%"
+ HWADDR_PRIx "\n", s->ctrl->name, seg.addr);
+ return;
+ }
+
+ /*
+ * The end address of the AST2500 spi controllers is also
+ * read-only.
+ */
+ if ((s->ctrl->segments == aspeed_segments_ast2500_spi1 ||
+ s->ctrl->segments == aspeed_segments_ast2500_spi2) &&
+ cs == s->ctrl->max_slaves &&
+ seg.addr + seg.size != s->ctrl->segments[cs].addr +
+ s->ctrl->segments[cs].size) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: Tried to change CS%d end address to 0x%"
+ HWADDR_PRIx "\n", s->ctrl->name, cs, seg.addr);
+ return;
+ }
+
+ /* Keep the segment in the overall flash window */
+ if (seg.addr + seg.size <= s->ctrl->flash_window_base ||
+ seg.addr > s->ctrl->flash_window_base + s->ctrl->flash_window_size) {
+ qemu_log_mask(LOG_GUEST_ERROR, "%s: new segment for CS%d is invalid : "
+ "[ 0x%"HWADDR_PRIx" - 0x%"HWADDR_PRIx" ]\n",
+ s->ctrl->name, cs, seg.addr, seg.addr + seg.size);
+ return;
+ }
+
+ /* Check start address vs. alignment */
+ if (seg.addr % seg.size) {
+ qemu_log_mask(LOG_GUEST_ERROR, "%s: new segment for CS%d is not "
+ "aligned : [ 0x%"HWADDR_PRIx" - 0x%"HWADDR_PRIx" ]\n",
+ s->ctrl->name, cs, seg.addr, seg.addr + seg.size);
+ }
+
+ /* And segments should not overlap */
+ if (aspeed_smc_flash_overlap(s, &seg, cs)) {
+ return;
+ }
+
+ /* All should be fine now to move the region */
+ memory_region_transaction_begin();
+ memory_region_set_size(&fl->mmio, seg.size);
+ memory_region_set_address(&fl->mmio, seg.addr -
s->ctrl->flash_window_base);
+ memory_region_set_enabled(&fl->mmio, true);
+ memory_region_transaction_commit();
+
+ s->regs[R_SEG_ADDR0 + cs] = new;
+}
+
static uint64_t aspeed_smc_flash_default_read(void *opaque, hwaddr addr,
unsigned size)
{
@@ -314,6 +425,12 @@ static void aspeed_smc_reset(DeviceState *d)
s->regs[s->r_ctrl0 + i] |= CTRL_CE_STOP_ACTIVE;
}
+ /* setup default segment register values for all */
+ for (i = 0; i < s->ctrl->max_slaves; ++i) {
+ s->regs[R_SEG_ADDR0 + i] =
+ aspeed_smc_segment_to_reg(&s->ctrl->segments[i]);
+ }
+
aspeed_smc_update_cs(s);
}
@@ -334,6 +451,7 @@ static uint64_t aspeed_smc_read(void *opaque, hwaddr addr,
unsigned int size)
addr == s->r_timings ||
addr == s->r_ce_ctrl ||
addr == R_INTR_CTRL ||
+ (addr >= R_SEG_ADDR0 && addr < R_SEG_ADDR0 + s->ctrl->max_slaves) ||
(addr >= s->r_ctrl0 && addr < s->r_ctrl0 + s->num_cs)) {
return s->regs[addr];
} else {
@@ -365,6 +483,13 @@ static void aspeed_smc_write(void *opaque, hwaddr addr,
uint64_t data,
} else if (addr >= s->r_ctrl0 && addr < s->r_ctrl0 + s->num_cs) {
s->regs[addr] = value;
aspeed_smc_update_cs(s);
+ } else if (addr >= R_SEG_ADDR0 &&
+ addr < R_SEG_ADDR0 + s->ctrl->max_slaves) {
+ int cs = addr - R_SEG_ADDR0;
+
+ if (value != s->regs[R_SEG_ADDR0 + cs]) {
+ aspeed_smc_flash_set_segment(s, cs, value);
+ }
} else {
qemu_log_mask(LOG_UNIMP, "%s: not implemented: 0x%" HWADDR_PRIx "\n",
__func__, addr);
--
2.7.4
