* Re: [PATCH 1/2] dt-bindings: remoteproc: add AMD MicroBlaze binding
From: Michal Simek @ 2026-04-15 6:16 UTC (permalink / raw)
To: Krzysztof Kozlowski, Ben Levinsky, andersson, mathieu.poirier
Cc: robh, krzk+dt, conor+dt, linux-remoteproc, devicetree,
linux-kernel, tanmay.shah
In-Reply-To: <774a8e9f-cfd9-4584-aaf0-2fd1189f65e8@kernel.org>
On 4/14/26 19:53, Krzysztof Kozlowski wrote:
> On 14/04/2026 18:15, Ben Levinsky wrote:
>
> A nit, subject: drop second/last, redundant "binding". The "dt-bindings"
> prefix is already stating that these are bindings.
> See also:
> https://elixir.bootlin.com/linux/v6.17-rc3/source/Documentation/devicetree/bindings/submitting-patches.rst#L18
>
>> +---
>> +$id: http://devicetree.org/schemas/remoteproc/amd,microblaze.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: AMD MicroBlaze remote processor
>> +
>> +maintainers:
>> + - Ben Levinsky <ben.levinsky@amd.com>
>> +
>> +description:
>> + MicroBlaze remote processor controlled by Linux through the remoteproc
>> + framework.
>
> Describe hardware, not Linux frameworks. IOW, Linux framework is here
> irrelevant.
>
>> +
>> + The executable firmware memory window is described in the
>> + MicroBlaze-local address space by the node's reg property and translated
>> + to the system physical address space with standard devicetree address
>> + translation provided by the parent bus node's ranges property.
>> +
>> +properties:
>> + $nodename:
>> + pattern: "^remoteproc@[0-9a-f]+$"
>> +
>> + compatible:
>> + const: amd,microblaze
>
> microblaze is architecture, so this feels way too generic. You need SoC
> specific compatibles and I suggest do not reference architecture, but
> name or the function of the processor, if there are such.
I have been arguing internally that I think when you look at driver itself it
can be pretty much generic loader for any firmware and doesn't really matter if
target subsystem is Microblaze/Risc-V/whatever based. And I was suggesting them
to use more generic name.
Because at the end of day reg property is pointing to location where firmware
should be loaded and gpio is a way how to start that subsystem and there is
nothing Microblaze specific.
I can also imagine that the same driver could be extended with optional power
domain, power regulator and clock properties if there is a need to drive them
before subsystem gets out of reset.
Does it make sense?
Thanks,
Michal
^ permalink raw reply
* [PATCH v29 4/4] i2c: ast2600: Add target mode support
From: Ryan Chen @ 2026-04-15 5:14 UTC (permalink / raw)
To: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-aspeed,
linux-kernel, openbmc, Ryan Chen
In-Reply-To: <20260415-upstream_i2c-v29-0-317c1a905ae1@aspeedtech.com>
Add target mode support to the AST2600 I2C driver.
Target mode features implemented include:
- Add target interrupt handling
- Address match and response logic
This complements the existing controller-mode support, enabling
dual-role capability.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v29:
- fix race between unreg_target and IRQ handler.
- move i2cs ier enable from ast2600_i2c_init to probe after master ier enable.
- remove dma/byte transfer, use buffer mode only.
Changes in v28:
- fix typo condication -> condition
- fix compile error, when disable CONFIG_I2C_SLAVE
Changes in v26:
- change int to bool target_operate
- rename target_operate to target_active
- use i2c_bus->target replace require IO
- use WRITE_ONCE replace target_operate write.
---
drivers/i2c/busses/i2c-ast2600.c | 340 +++++++++++++++++++++++++++++++++++++++
1 file changed, 340 insertions(+)
diff --git a/drivers/i2c/busses/i2c-ast2600.c b/drivers/i2c/busses/i2c-ast2600.c
index 787ef6bd6244..137aaf7e26b5 100644
--- a/drivers/i2c/busses/i2c-ast2600.c
+++ b/drivers/i2c/busses/i2c-ast2600.c
@@ -254,6 +254,11 @@ struct ast2600_i2c_bus {
size_t buf_size;
bool multi_master;
void __iomem *buf_base;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /* target structure */
+ bool target_active;
+ struct i2c_client *target;
+#endif
};
static void ast2600_i2c_ac_timing_config(struct ast2600_i2c_bus *i2c_bus)
@@ -337,6 +342,243 @@ static int ast2600_i2c_recover_bus(struct ast2600_i2c_bus *i2c_bus)
return ret;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void ast2600_i2c_target_packet_buff_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ int target_rx_len = 0;
+ u32 cmd = 0;
+ u8 value;
+ int i;
+
+ /* due to controller target is common buffer, need force the master stop not issue */
+ if (readl(i2c_bus->reg_base + AST2600_I2CM_CMD_STS) & GENMASK(15, 0)) {
+ writel(0, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+ i2c_bus->cmd_err = -EBUSY;
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ complete(&i2c_bus->cmd_complete);
+ }
+
+ /* Handle i2c target timeout condition */
+ if (AST2600_I2CS_INACTIVE_TO & sts) {
+ /* Reset timeout counter */
+ u32 ac_timing = readl(i2c_bus->reg_base + AST2600_I2CC_AC_TIMING) &
+ AST2600_I2CC_AC_TIMING_MASK;
+
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ ac_timing |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout);
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ writel(TARGET_TRIGGER_CMD, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ WRITE_ONCE(i2c_bus->target_active, false);
+ return;
+ }
+
+ sts &= ~(AST2600_I2CS_PKT_DONE | AST2600_I2CS_PKT_ERROR);
+
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ WRITE_ONCE(i2c_bus->target_active, true);
+
+ switch (sts) {
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_WAIT_RX_DMA |
+ AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_SLAVE_PENDING |
+ AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_SLAVE_PENDING |
+ AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_STOP:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ fallthrough;
+ case AST2600_I2CS_SLAVE_PENDING |
+ AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ cmd = TARGET_TRIGGER_CMD;
+ if (sts & AST2600_I2CS_RX_DONE) {
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ }
+ if (readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS) & AST2600_I2CS_RX_BUFF_EN)
+ cmd = 0;
+ else
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
+
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ break;
+ case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_RX_DONE:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ cmd |= AST2600_I2CS_RX_BUFF_EN;
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_WAIT_RX_DMA |
+ AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ cmd |= AST2600_I2CS_RX_BUFF_EN;
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ /* workaround for avoid next start with len != 0 */
+ writel(BIT(0), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ /* workaround for avoid next start with len != 0 */
+ writel(BIT(0), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_RX_DONE |
+ AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_STOP:
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &value);
+ writeb(value, i2c_bus->buf_base);
+ break;
+ case AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_SLAVE_MATCH:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &value);
+ writeb(value, i2c_bus->buf_base);
+ writel(AST2600_I2CC_SET_TX_BUF_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_BUFF_EN;
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_STOP |
+ AST2600_I2CS_TX_NAK | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_STOP |
+ AST2600_I2CS_TX_NAK | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_TX_DMA:
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+
+ if (sts & AST2600_I2CS_RX_DONE) {
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &value);
+ } else {
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_PROCESSED, &value);
+ }
+ writeb(value, i2c_bus->buf_base);
+ writel(AST2600_I2CC_SET_TX_BUF_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_BUFF_EN;
+ break;
+ /* workaround : trigger the cmd twice to fix next state keep 1000000 */
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ break;
+ case AST2600_I2CS_TX_NAK | AST2600_I2CS_STOP:
+ case AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled target isr case %x, sts %x\n", sts,
+ readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
+ break;
+ }
+
+ if (cmd)
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+
+ if ((sts & AST2600_I2CS_STOP) && !(sts & AST2600_I2CS_SLAVE_PENDING))
+ WRITE_ONCE(i2c_bus->target_active, false);
+}
+
+static int ast2600_i2c_target_irq(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 ier = readl(i2c_bus->reg_base + AST2600_I2CS_IER);
+ u32 isr = readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+
+ if (!(isr & ier))
+ return 0;
+
+ /*
+ * Target interrupt coming after controller packet done
+ * So need handle controller first.
+ */
+ if (readl(i2c_bus->reg_base + AST2600_I2CM_ISR) & AST2600_I2CM_PKT_DONE)
+ return 0;
+
+ isr &= ~(AST2600_I2CS_ADDR_INDICATE_MASK);
+
+ if (AST2600_I2CS_ADDR1_NAK & isr)
+ isr &= ~AST2600_I2CS_ADDR1_NAK;
+
+ if (AST2600_I2CS_ADDR2_NAK & isr)
+ isr &= ~AST2600_I2CS_ADDR2_NAK;
+
+ if (AST2600_I2CS_ADDR3_NAK & isr)
+ isr &= ~AST2600_I2CS_ADDR3_NAK;
+
+ if (AST2600_I2CS_ADDR_MASK & isr)
+ isr &= ~AST2600_I2CS_ADDR_MASK;
+
+ if (AST2600_I2CS_PKT_DONE & isr)
+ ast2600_i2c_target_packet_buff_irq(i2c_bus, isr);
+
+ return 1;
+}
+#endif
+
static int ast2600_i2c_setup_buff_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
{
struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
@@ -498,6 +740,20 @@ static void ast2600_i2c_controller_packet_irq(struct ast2600_i2c_bus *i2c_bus, u
}
break;
case AST2600_I2CM_RX_DONE:
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /*
+ * Workaround for controller/target packet mode enable rx done stuck issue
+ * When controller go for first read (RX_DONE), target mode will also effect
+ * Then controller will send nack, not operate anymore.
+ */
+ if (readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS) & AST2600_I2CS_PKT_MODE_EN) {
+ u32 target_cmd = readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(target_cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ }
+ fallthrough;
+#endif
case AST2600_I2CM_RX_DONE | AST2600_I2CM_NORMAL_STOP:
/* do next rx */
xfer_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
@@ -584,6 +840,12 @@ static irqreturn_t ast2600_i2c_bus_irq(int irq, void *dev_id)
{
struct ast2600_i2c_bus *i2c_bus = dev_id;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (i2c_bus->target) {
+ if (ast2600_i2c_target_irq(i2c_bus))
+ return IRQ_HANDLED;
+ }
+#endif
return IRQ_RETVAL(ast2600_i2c_controller_irq(i2c_bus));
}
@@ -600,12 +862,31 @@ static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg
return ret;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (i2c_bus->target_active)
+ return -EBUSY;
+ /*
+ * Controller and target share the same buffer register. A target
+ * transaction can update buffer state asynchronously via IRQ, so block
+ * controller transfers while target is active to avoid buffer corruption.
+ */
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_IER);
+ if (readl(i2c_bus->reg_base + AST2600_I2CS_ISR) || i2c_bus->target_active) {
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_IER);
+ return -EBUSY;
+ }
+#endif
+
i2c_bus->cmd_err = 0;
i2c_bus->msgs = msgs;
i2c_bus->msgs_index = 0;
i2c_bus->msgs_count = num;
reinit_completion(&i2c_bus->cmd_complete);
ret = ast2600_i2c_do_start(i2c_bus);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /* avoid race condition target is wait and controller wait 1st target operate */
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_IER);
+#endif
if (ret)
goto controller_out;
timeout = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
@@ -624,6 +905,9 @@ static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg
* if the bus is still busy.
*/
if (i2c_bus->multi_master &&
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ !i2c_bus->target_active &&
+#endif
(readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) &
AST2600_I2CC_BUS_BUSY_STS))
ast2600_i2c_recover_bus(i2c_bus);
@@ -659,8 +943,54 @@ static int ast2600_i2c_init(struct ast2600_i2c_bus *i2c_bus)
/* Clear Interrupt */
writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CM_ISR);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CS_ISR);
+#endif
+
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static int ast2600_i2c_reg_target(struct i2c_client *client)
+{
+ struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(client->adapter);
+ u32 cmd = TARGET_TRIGGER_CMD;
+
+ if (i2c_bus->target)
+ return -EINVAL;
+
+ dev_dbg(i2c_bus->dev, "target addr %x\n", client->addr);
+
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+ writel(AST2600_I2CC_SLAVE_EN | readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL),
+ i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ i2c_bus->target = client;
+ /* Set target addr. */
+ writel(client->addr | AST2600_I2CS_ADDR1_ENABLE,
+ i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+
+ return 0;
+}
+
+static int ast2600_i2c_unreg_target(struct i2c_client *client)
+{
+ struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(client->adapter);
+ u32 val;
+
+ /* Turn off target mode. */
+ val = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(val & ~AST2600_I2CC_SLAVE_EN, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ val = readl(i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+ writel(val & ~AST2600_I2CS_ADDR1_MASK, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+
+ synchronize_irq(i2c_bus->irq);
+ i2c_bus->target = NULL;
+
return 0;
}
+#endif
static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
{
@@ -670,6 +1000,10 @@ static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
static const struct i2c_algorithm i2c_ast2600_algorithm = {
.xfer = ast2600_i2c_controller_xfer,
.functionality = ast2600_i2c_functionality,
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ .reg_target = ast2600_i2c_reg_target,
+ .unreg_target = ast2600_i2c_unreg_target,
+#endif
};
static int ast2600_i2c_probe(struct platform_device *pdev)
@@ -708,6 +1042,9 @@ static int ast2600_i2c_probe(struct platform_device *pdev)
regmap_write(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, I2CCG_DIV_CTRL);
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ WRITE_ONCE(i2c_bus->target_active, false);
+#endif
i2c_bus->dev = dev;
i2c_bus->multi_master = device_property_read_bool(dev, "multi-master");
@@ -765,6 +1102,9 @@ static int ast2600_i2c_probe(struct platform_device *pdev)
writel(AST2600_I2CM_PKT_DONE | AST2600_I2CM_BUS_RECOVER,
i2c_bus->reg_base + AST2600_I2CM_IER);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_IER);
+#endif
ret = devm_i2c_add_adapter(dev, &i2c_bus->adap);
if (ret)
--
2.34.1
^ permalink raw reply related
* [PATCH v29 3/4] i2c: ast2600: Add controller driver for AST2600 new register set
From: Ryan Chen @ 2026-04-15 5:14 UTC (permalink / raw)
To: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-aspeed,
linux-kernel, openbmc, Ryan Chen
In-Reply-To: <20260415-upstream_i2c-v29-0-317c1a905ae1@aspeedtech.com>
The AST2600 introduces a new I2C controller register layout, selectable
at runtime via global control registers. Compared to the legacy layout
used on AST2400/AST2500, the new layout separates controller (master)
and target (slave) registers and adds support for packet-based transfers
The new register set extends the hardware capabilities with:
- Enhanced clock divider configuration for improved timing precision
- tCKHighMin timing control for SCL high pulse width
- Dual pool buffer mode (separate Tx/Rx buffers)
- Hardware-assisted bus recovery and timeout mechanisms
This patch adds an AST2600-specific I2C controller driver implementing
the new register layout, including support for packet-based transfers.
The legacy and new register layouts represent the same AST2600 I2C
controller IP and therefore share the existing compatible string:
"aspeed,ast2600-i2c-bus"
To preserve DT ABI compatibility, driver selection is performed at probe
time based on DT contents. In particular, the new binding requires the
`aspeed,global-regs` phandle, which is absent from legacy DTBs:
- The new driver only probes successfully when `aspeed,global-regs` is
present.
- The existing i2c-aspeed driver returns -ENODEV for AST2600 nodes that
provide `aspeed,global-regs`, allowing the new driver to bind.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v29:
- update commit message remove transfer mode selection.
- remove dma/byte transfer, use buffer mode only.
- remove sysfs file.
- remove define I2C_TARGET_MSG_BUF_SIZE and AST2600_I2C_DMA_SIZE.
- remove buf_index in struct ast2600_i2c_bus.
Changes in v28:
- Separate xfer_mode_store into distinct parse and availability-check
steps by introducing ast2600_i2c_xfer_mode_check()
- fix tx dma memcpy source point address.
- Use a temporary variable for devm_platform_get_and_ioremap_resource()
to avoid storing an ERR_PTR in i2c_bus->buf_base; drop the redundant
NULL assignment in the error path since i2c_bus is kzalloc()ed
- Add ABI documentation file
Documentation/ABI/testing/sysfs-driver-ast2600-i2c
Changes in v27:
- remove aspeed,transfer-mode selection instead aspeed,dma-mode.
- add sysfs for xfer mode.
Changes in v25:
- Rename AST2600_I2CM_SMBUS_ALT to AST2600_I2CM_SMBUS_ALERT.
- Refactor transfer mode handling using setup_tx/setup_rx helpers.
- Rework DMA handling to use pre-allocated buffers and reduce
mapping overhead in interrupt context.
- Fix IRQ status checks to use consistent (sts & value) style.
- Move device_property_read_bool() to probe().
- Improve probe error handling.
- Handle timeout condition in target_byte_irq().
- Rename "package" to "packet".
- Remove target reset when master wait_for_completion_timeout().
---
drivers/i2c/busses/Makefile | 2 +-
drivers/i2c/busses/i2c-aspeed.c | 5 +
drivers/i2c/busses/i2c-ast2600.c | 808 +++++++++++++++++++++++++++++++++++++++
3 files changed, 814 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 547123ab351f..ece201a67d41 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -37,7 +37,7 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o
obj-$(CONFIG_I2C_ALTERA) += i2c-altera.o
obj-$(CONFIG_I2C_AMD_MP2) += i2c-amd-mp2-pci.o i2c-amd-mp2-plat.o
obj-$(CONFIG_I2C_AMD_ASF) += i2c-amd-asf-plat.o
-obj-$(CONFIG_I2C_ASPEED) += i2c-aspeed.o
+obj-$(CONFIG_I2C_ASPEED) += i2c-aspeed.o i2c-ast2600.o
obj-$(CONFIG_I2C_AT91) += i2c-at91.o
i2c-at91-y := i2c-at91-core.o i2c-at91-master.o
i2c-at91-$(CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL) += i2c-at91-slave.o
diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index a26b74c71206..8286fd2cd130 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -22,6 +22,7 @@
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/property.h>
#include <linux/reset.h>
#include <linux/slab.h>
@@ -1002,6 +1003,10 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
struct clk *parent_clk;
int irq, ret;
+ if (device_is_compatible(&pdev->dev, "aspeed,ast2600-i2c-bus") &&
+ device_property_present(&pdev->dev, "aspeed,global-regs"))
+ return -ENODEV;
+
bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
if (!bus)
return -ENOMEM;
diff --git a/drivers/i2c/busses/i2c-ast2600.c b/drivers/i2c/busses/i2c-ast2600.c
new file mode 100644
index 000000000000..787ef6bd6244
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ast2600.c
@@ -0,0 +1,808 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ASPEED AST2600 new register set I2C controller driver
+ *
+ * Copyright (C) 2026 ASPEED Technology Inc.
+ */
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/minmax.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/unaligned.h>
+
+#define AST2600_I2CG_ISR 0x00
+#define AST2600_I2CG_SLAVE_ISR 0x04
+#define AST2600_I2CG_OWNER 0x08
+#define AST2600_I2CG_CTRL 0x0C
+#define AST2600_I2CG_CLK_DIV_CTRL 0x10
+
+#define AST2600_I2CG_SLAVE_PKT_NAK BIT(4)
+#define AST2600_I2CG_M_S_SEPARATE_INTR BIT(3)
+#define AST2600_I2CG_CTRL_NEW_REG BIT(2)
+#define AST2600_I2CG_CTRL_NEW_CLK_DIV BIT(1)
+#define AST2600_GLOBAL_INIT \
+ (AST2600_I2CG_CTRL_NEW_REG | AST2600_I2CG_CTRL_NEW_CLK_DIV)
+/*
+ * APB clk : 100Mhz
+ * div : scl : baseclk [APB/((div/2) + 1)] : tBuf [1/bclk * 16]
+ * I2CG10[31:24] base clk4 for i2c auto recovery timeout counter (0xC6)
+ * I2CG10[23:16] base clk3 for Standard-mode (100Khz) min tBuf 4.7us
+ * 0x3c : 100.8Khz : 3.225Mhz : 4.96us
+ * 0x3d : 99.2Khz : 3.174Mhz : 5.04us
+ * 0x3e : 97.65Khz : 3.125Mhz : 5.12us
+ * 0x40 : 97.75Khz : 3.03Mhz : 5.28us
+ * 0x41 : 99.5Khz : 2.98Mhz : 5.36us (default)
+ * I2CG10[15:8] base clk2 for Fast-mode (400Khz) min tBuf 1.3us
+ * 0x12 : 400Khz : 10Mhz : 1.6us
+ * I2CG10[7:0] base clk1 for Fast-mode Plus (1Mhz) min tBuf 0.5us
+ * 0x08 : 1Mhz : 20Mhz : 0.8us
+ */
+#define I2CCG_DIV_CTRL 0xC6411208
+
+/* 0x00 : I2CC Controller/Target Function Control Register */
+#define AST2600_I2CC_FUN_CTRL 0x00
+#define AST2600_I2CC_SLAVE_ADDR_RX_EN BIT(20)
+#define AST2600_I2CC_MASTER_RETRY_MASK GENMASK(19, 18)
+#define AST2600_I2CC_MASTER_RETRY(x) (((x) & GENMASK(1, 0)) << 18)
+#define AST2600_I2CC_BUS_AUTO_RELEASE BIT(17)
+#define AST2600_I2CC_M_SDA_LOCK_EN BIT(16)
+#define AST2600_I2CC_MULTI_MASTER_DIS BIT(15)
+#define AST2600_I2CC_M_SCL_DRIVE_EN BIT(14)
+#define AST2600_I2CC_MSB_STS BIT(9)
+#define AST2600_I2CC_SDA_DRIVE_1T_EN BIT(8)
+#define AST2600_I2CC_M_SDA_DRIVE_1T_EN BIT(7)
+#define AST2600_I2CC_M_HIGH_SPEED_EN BIT(6)
+/* reserver 5 : 2 */
+#define AST2600_I2CC_SLAVE_EN BIT(1)
+#define AST2600_I2CC_MASTER_EN BIT(0)
+
+/* 0x04 : I2CC Controller/Target Clock and AC Timing Control Register #1 */
+#define AST2600_I2CC_AC_TIMING 0x04
+#define AST2600_I2CC_TTIMEOUT(x) (((x) & GENMASK(4, 0)) << 24)
+#define AST2600_I2CC_TCKHIGHMIN(x) (((x) & GENMASK(3, 0)) << 20)
+#define AST2600_I2CC_TCKHIGH(x) (((x) & GENMASK(3, 0)) << 16)
+#define AST2600_I2CC_TCKLOW(x) (((x) & GENMASK(3, 0)) << 12)
+#define AST2600_I2CC_THDDAT(x) (((x) & GENMASK(1, 0)) << 10)
+#define AST2600_I2CC_TOUTBASECLK(x) (((x) & GENMASK(1, 0)) << 8)
+#define AST2600_I2CC_TBASECLK(x) ((x) & GENMASK(3, 0))
+#define AST2600_I2CC_AC_TIMING_MASK GENMASK(23, 0)
+
+/* 0x08 : I2CC Controller/Target Transmit/Receive Byte Buffer Register */
+#define AST2600_I2CC_STS_AND_BUFF 0x08
+#define AST2600_I2CC_TX_DIR_MASK GENMASK(31, 29)
+#define AST2600_I2CC_SDA_OE BIT(28)
+#define AST2600_I2CC_SDA_O BIT(27)
+#define AST2600_I2CC_SCL_OE BIT(26)
+#define AST2600_I2CC_SCL_O BIT(25)
+
+#define AST2600_I2CC_SCL_LINE_STS BIT(18)
+#define AST2600_I2CC_SDA_LINE_STS BIT(17)
+#define AST2600_I2CC_BUS_BUSY_STS BIT(16)
+
+#define AST2600_I2CC_GET_RX_BUFF(x) (((x) >> 8) & GENMASK(7, 0))
+
+/* 0x0C : I2CC Controller/Target Pool Buffer Control Register */
+#define AST2600_I2CC_BUFF_CTRL 0x0C
+#define AST2600_I2CC_GET_RX_BUF_LEN(x) (((x) & GENMASK(29, 24)) >> 24)
+#define AST2600_I2CC_SET_RX_BUF_LEN(x) (((((x) - 1) & GENMASK(4, 0)) << 16) | BIT(0))
+#define AST2600_I2CC_SET_TX_BUF_LEN(x) (((((x) - 1) & GENMASK(4, 0)) << 8) | BIT(0))
+#define AST2600_I2CC_GET_TX_BUF_LEN(x) ((((x) & GENMASK(12, 8)) >> 8) + 1)
+
+/* 0x10 : I2CM Controller Interrupt Control Register */
+#define AST2600_I2CM_IER 0x10
+/* 0x14 : I2CM Controller Interrupt Status Register : WC */
+#define AST2600_I2CM_ISR 0x14
+
+#define AST2600_I2CM_PKT_TIMEOUT BIT(18)
+#define AST2600_I2CM_PKT_ERROR BIT(17)
+#define AST2600_I2CM_PKT_DONE BIT(16)
+
+#define AST2600_I2CM_BUS_RECOVER_FAIL BIT(15)
+#define AST2600_I2CM_SDA_DL_TO BIT(14)
+#define AST2600_I2CM_BUS_RECOVER BIT(13)
+#define AST2600_I2CM_SMBUS_ALERT BIT(12)
+
+#define AST2600_I2CM_SCL_LOW_TO BIT(6)
+#define AST2600_I2CM_ABNORMAL BIT(5)
+#define AST2600_I2CM_NORMAL_STOP BIT(4)
+#define AST2600_I2CM_ARBIT_LOSS BIT(3)
+#define AST2600_I2CM_RX_DONE BIT(2)
+#define AST2600_I2CM_TX_NAK BIT(1)
+#define AST2600_I2CM_TX_ACK BIT(0)
+
+/* 0x18 : I2CM Controller Command/Status Register */
+#define AST2600_I2CM_CMD_STS 0x18
+#define AST2600_I2CM_PKT_ADDR(x) (((x) & GENMASK(6, 0)) << 24)
+#define AST2600_I2CM_PKT_EN BIT(16)
+#define AST2600_I2CM_SDA_OE_OUT_DIR BIT(15)
+#define AST2600_I2CM_SDA_O_OUT_DIR BIT(14)
+#define AST2600_I2CM_SCL_OE_OUT_DIR BIT(13)
+#define AST2600_I2CM_SCL_O_OUT_DIR BIT(12)
+#define AST2600_I2CM_RECOVER_CMD_EN BIT(11)
+
+#define AST2600_I2CM_RX_DMA_EN BIT(9)
+#define AST2600_I2CM_TX_DMA_EN BIT(8)
+/* Command Bit */
+#define AST2600_I2CM_RX_BUFF_EN BIT(7)
+#define AST2600_I2CM_TX_BUFF_EN BIT(6)
+#define AST2600_I2CM_STOP_CMD BIT(5)
+#define AST2600_I2CM_RX_CMD_LAST BIT(4)
+#define AST2600_I2CM_RX_CMD BIT(3)
+
+#define AST2600_I2CM_TX_CMD BIT(1)
+#define AST2600_I2CM_START_CMD BIT(0)
+
+/* 0x1C : I2CM Controller DMA Transfer Length Register */
+#define AST2600_I2CM_DMA_LEN 0x1C
+/* Tx Rx support length 1 ~ 4096 */
+#define AST2600_I2CM_SET_RX_DMA_LEN(x) ((((x) & GENMASK(11, 0)) << 16) | BIT(31))
+#define AST2600_I2CM_SET_TX_DMA_LEN(x) (((x) & GENMASK(11, 0)) | BIT(15))
+
+/* 0x20 : I2CS Target Interrupt Control Register */
+#define AST2600_I2CS_IER 0x20
+/* 0x24 : I2CS Target Interrupt Status Register */
+#define AST2600_I2CS_ISR 0x24
+
+#define AST2600_I2CS_ADDR_INDICATE_MASK GENMASK(31, 30)
+#define AST2600_I2CS_SLAVE_PENDING BIT(29)
+
+#define AST2600_I2CS_WAIT_TX_DMA BIT(25)
+#define AST2600_I2CS_WAIT_RX_DMA BIT(24)
+
+#define AST2600_I2CS_ADDR3_NAK BIT(22)
+#define AST2600_I2CS_ADDR2_NAK BIT(21)
+#define AST2600_I2CS_ADDR1_NAK BIT(20)
+
+#define AST2600_I2CS_ADDR_MASK GENMASK(19, 18)
+#define AST2600_I2CS_PKT_ERROR BIT(17)
+#define AST2600_I2CS_PKT_DONE BIT(16)
+#define AST2600_I2CS_INACTIVE_TO BIT(15)
+
+#define AST2600_I2CS_SLAVE_MATCH BIT(7)
+#define AST2600_I2CS_ABNOR_STOP BIT(5)
+#define AST2600_I2CS_STOP BIT(4)
+#define AST2600_I2CS_RX_DONE_NAK BIT(3)
+#define AST2600_I2CS_RX_DONE BIT(2)
+#define AST2600_I2CS_TX_NAK BIT(1)
+#define AST2600_I2CS_TX_ACK BIT(0)
+
+/* 0x28 : I2CS Target CMD/Status Register */
+#define AST2600_I2CS_CMD_STS 0x28
+#define AST2600_I2CS_ACTIVE_ALL GENMASK(18, 17)
+#define AST2600_I2CS_PKT_MODE_EN BIT(16)
+#define AST2600_I2CS_AUTO_NAK_NOADDR BIT(15)
+#define AST2600_I2CS_AUTO_NAK_EN BIT(14)
+
+#define AST2600_I2CS_ALT_EN BIT(10)
+#define AST2600_I2CS_RX_DMA_EN BIT(9)
+#define AST2600_I2CS_TX_DMA_EN BIT(8)
+#define AST2600_I2CS_RX_BUFF_EN BIT(7)
+#define AST2600_I2CS_TX_BUFF_EN BIT(6)
+#define AST2600_I2CS_RX_CMD_LAST BIT(4)
+
+#define AST2600_I2CS_TX_CMD BIT(2)
+
+#define AST2600_I2CS_DMA_LEN 0x2C
+#define AST2600_I2CS_SET_RX_DMA_LEN(x) (((((x) - 1) & GENMASK(11, 0)) << 16) | BIT(31))
+#define AST2600_I2CS_SET_TX_DMA_LEN(x) ((((x) - 1) & GENMASK(11, 0)) | BIT(15))
+
+/* I2CM Controller DMA Tx Buffer Register */
+#define AST2600_I2CM_TX_DMA 0x30
+/* I2CM Controller DMA Rx Buffer Register */
+#define AST2600_I2CM_RX_DMA 0x34
+/* I2CS Target DMA Tx Buffer Register */
+#define AST2600_I2CS_TX_DMA 0x38
+/* I2CS Target DMA Rx Buffer Register */
+#define AST2600_I2CS_RX_DMA 0x3C
+
+#define AST2600_I2CS_ADDR_CTRL 0x40
+
+#define AST2600_I2CS_ADDR3_MASK GENMASK(22, 16)
+#define AST2600_I2CS_ADDR2_MASK GENMASK(14, 8)
+#define AST2600_I2CS_ADDR1_MASK GENMASK(6, 0)
+
+#define AST2600_I2CM_DMA_LEN_STS 0x48
+#define AST2600_I2CS_DMA_LEN_STS 0x4C
+
+#define AST2600_I2C_GET_TX_DMA_LEN(x) ((x) & GENMASK(12, 0))
+#define AST2600_I2C_GET_RX_DMA_LEN(x) (((x) & GENMASK(28, 16)) >> 16)
+
+/* 0x40 : Target Device Address Register */
+#define AST2600_I2CS_ADDR3_ENABLE BIT(23)
+#define AST2600_I2CS_ADDR3(x) ((x) << 16)
+#define AST2600_I2CS_ADDR2_ENABLE BIT(15)
+#define AST2600_I2CS_ADDR2(x) ((x) << 8)
+#define AST2600_I2CS_ADDR1_ENABLE BIT(7)
+#define AST2600_I2CS_ADDR1(x) (x)
+
+#define CONTROLLER_TRIGGER_LAST_STOP (AST2600_I2CM_RX_CMD_LAST | AST2600_I2CM_STOP_CMD)
+#define TARGET_TRIGGER_CMD (AST2600_I2CS_ACTIVE_ALL | AST2600_I2CS_PKT_MODE_EN)
+
+#define AST_I2C_TIMEOUT_CLK 0x1
+
+struct ast2600_i2c_bus {
+ struct i2c_adapter adap;
+ struct device *dev;
+ void __iomem *reg_base;
+ struct regmap *global_regs;
+ struct clk *clk;
+ struct i2c_timings timing_info;
+ struct completion cmd_complete;
+ struct i2c_msg *msgs;
+ u32 apb_clk;
+ u32 timeout;
+ int irq;
+ int cmd_err;
+ int msgs_index;
+ int msgs_count;
+ int controller_xfer_cnt;
+ size_t buf_size;
+ bool multi_master;
+ void __iomem *buf_base;
+};
+
+static void ast2600_i2c_ac_timing_config(struct ast2600_i2c_bus *i2c_bus)
+{
+ unsigned long base_clk[16];
+ int baseclk_idx = 0;
+ int divisor = 0;
+ u32 clk_div_reg;
+ u32 scl_low;
+ u32 scl_high;
+ u32 data;
+
+ regmap_read(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, &clk_div_reg);
+
+ for (int i = 0; i < ARRAY_SIZE(base_clk); i++) {
+ if (i == 0)
+ base_clk[i] = i2c_bus->apb_clk;
+ else if (i < 5)
+ base_clk[i] = (i2c_bus->apb_clk * 2) /
+ (((clk_div_reg >> ((i - 1) * 8)) & GENMASK(7, 0)) + 2);
+ else
+ base_clk[i] = base_clk[4] >> (i - 4);
+
+ if ((base_clk[i] / i2c_bus->timing_info.bus_freq_hz) <= 32) {
+ baseclk_idx = i;
+ divisor = DIV_ROUND_UP(base_clk[i], i2c_bus->timing_info.bus_freq_hz);
+ break;
+ }
+ }
+ baseclk_idx = min(baseclk_idx, 15);
+ divisor = min(divisor, 32);
+ scl_low = min(divisor * 9 / 16 - 1, 15);
+ scl_high = (divisor - scl_low - 2) & GENMASK(3, 0);
+ data = (scl_high - 1) << 20 | scl_high << 16 | scl_low << 12 | baseclk_idx;
+ if (i2c_bus->timeout) {
+ data |= AST2600_I2CC_TOUTBASECLK(AST_I2C_TIMEOUT_CLK);
+ data |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout);
+ }
+
+ writel(data, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+}
+
+static int ast2600_i2c_recover_bus(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ int ret = 0;
+ u32 ctrl;
+ int r;
+
+ dev_dbg(i2c_bus->dev, "%d-bus recovery bus [%x]\n", i2c_bus->adap.nr, state);
+
+ /* reset controller */
+ ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl & ~AST2600_I2CC_MASTER_EN, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ reinit_completion(&i2c_bus->cmd_complete);
+ i2c_bus->cmd_err = 0;
+
+ /* Check SDA/SCL status in the status register. */
+ state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ if (!(state & AST2600_I2CC_SDA_LINE_STS) && (state & AST2600_I2CC_SCL_LINE_STS)) {
+ writel(AST2600_I2CM_RECOVER_CMD_EN, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+ r = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
+ if (r == 0) {
+ dev_dbg(i2c_bus->dev, "recovery timed out\n");
+ return -ETIMEDOUT;
+ } else if (i2c_bus->cmd_err) {
+ dev_dbg(i2c_bus->dev, "recovery error\n");
+ ret = -EPROTO;
+ }
+ }
+
+ /* Recovery done */
+ state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ if (state & AST2600_I2CC_BUS_BUSY_STS) {
+ dev_dbg(i2c_bus->dev, "Can't recover bus [%x]\n", state);
+ ret = -EPROTO;
+ }
+
+ return ret;
+}
+
+static int ast2600_i2c_setup_buff_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+ u32 wbuf_dword;
+ int i;
+
+ cmd |= AST2600_I2CM_PKT_EN;
+
+ if (xfer_len > i2c_bus->buf_size)
+ xfer_len = i2c_bus->buf_size;
+ else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
+ cmd |= AST2600_I2CM_STOP_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if (xfer_len) {
+ cmd |= AST2600_I2CM_TX_BUFF_EN | AST2600_I2CM_TX_CMD;
+ /*
+ * The controller's buffer register supports dword writes only.
+ * Therefore, write dwords to the buffer register in a 4-byte aligned,
+ * and write the remaining unaligned data at the end.
+ */
+ for (i = 0; i < xfer_len; i += 4) {
+ int xfer_cnt = i2c_bus->controller_xfer_cnt + i;
+
+ switch (min(xfer_len - i, 4) % 4) {
+ case 1:
+ wbuf_dword = msg->buf[xfer_cnt];
+ break;
+ case 2:
+ wbuf_dword = get_unaligned_le16(&msg->buf[xfer_cnt]);
+ break;
+ case 3:
+ wbuf_dword = get_unaligned_le24(&msg->buf[xfer_cnt]);
+ break;
+ default:
+ wbuf_dword = get_unaligned_le32(&msg->buf[xfer_cnt]);
+ break;
+ }
+ writel(wbuf_dword, i2c_bus->buf_base + i);
+ }
+ writel(AST2600_I2CC_SET_TX_BUF_LEN(xfer_len),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_buff_rx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+
+ cmd |= AST2600_I2CM_PKT_EN | AST2600_I2CM_RX_BUFF_EN | AST2600_I2CM_RX_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if (msg->flags & I2C_M_RECV_LEN) {
+ dev_dbg(i2c_bus->dev, "smbus read\n");
+ xfer_len = 1;
+ } else if (xfer_len > i2c_bus->buf_size) {
+ xfer_len = i2c_bus->buf_size;
+ } else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) {
+ cmd |= CONTROLLER_TRIGGER_LAST_STOP;
+ }
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(xfer_len), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_do_start(struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+
+ /* send start */
+ dev_dbg(i2c_bus->dev, "[%d] %s %d byte%s %s 0x%02x\n",
+ i2c_bus->msgs_index, str_read_write(msg->flags & I2C_M_RD),
+ msg->len, str_plural(msg->len),
+ msg->flags & I2C_M_RD ? "from" : "to", msg->addr);
+
+ i2c_bus->controller_xfer_cnt = 0;
+
+ if (msg->flags & I2C_M_RD)
+ return ast2600_i2c_setup_buff_rx(AST2600_I2CM_START_CMD, i2c_bus);
+
+ return ast2600_i2c_setup_buff_tx(AST2600_I2CM_START_CMD, i2c_bus);
+}
+
+static int ast2600_i2c_irq_err_to_errno(u32 irq_status)
+{
+ if (irq_status & AST2600_I2CM_ARBIT_LOSS)
+ return -EAGAIN;
+ if (irq_status & (AST2600_I2CM_SDA_DL_TO | AST2600_I2CM_SCL_LOW_TO))
+ return -ETIMEDOUT;
+ if (irq_status & (AST2600_I2CM_ABNORMAL))
+ return -EPROTO;
+
+ return 0;
+}
+
+static void ast2600_i2c_controller_packet_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len;
+ int i;
+
+ sts &= ~AST2600_I2CM_PKT_DONE;
+ writel(AST2600_I2CM_PKT_DONE, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ switch (sts) {
+ case AST2600_I2CM_PKT_ERROR:
+ i2c_bus->cmd_err = -EAGAIN;
+ complete(&i2c_bus->cmd_complete);
+ break;
+ case AST2600_I2CM_PKT_ERROR | AST2600_I2CM_TX_NAK: /* a0 fix for issue */
+ fallthrough;
+ case AST2600_I2CM_PKT_ERROR | AST2600_I2CM_TX_NAK | AST2600_I2CM_NORMAL_STOP:
+ i2c_bus->cmd_err = -ENXIO;
+ complete(&i2c_bus->cmd_complete);
+ break;
+ case AST2600_I2CM_NORMAL_STOP:
+ /* write 0 byte only have stop isr */
+ i2c_bus->msgs_index++;
+ if (i2c_bus->msgs_index < i2c_bus->msgs_count) {
+ if (ast2600_i2c_do_start(i2c_bus)) {
+ i2c_bus->cmd_err = -ENOMEM;
+ complete(&i2c_bus->cmd_complete);
+ }
+ } else {
+ i2c_bus->cmd_err = i2c_bus->msgs_index;
+ complete(&i2c_bus->cmd_complete);
+ }
+ break;
+ case AST2600_I2CM_TX_ACK:
+ case AST2600_I2CM_TX_ACK | AST2600_I2CM_NORMAL_STOP:
+ xfer_len = AST2600_I2CC_GET_TX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ i2c_bus->controller_xfer_cnt += xfer_len;
+
+ if (i2c_bus->controller_xfer_cnt == msg->len) {
+ i2c_bus->msgs_index++;
+ if (i2c_bus->msgs_index == i2c_bus->msgs_count) {
+ i2c_bus->cmd_err = i2c_bus->msgs_index;
+ complete(&i2c_bus->cmd_complete);
+ } else {
+ if (ast2600_i2c_do_start(i2c_bus)) {
+ i2c_bus->cmd_err = -ENOMEM;
+ complete(&i2c_bus->cmd_complete);
+ }
+ }
+ } else {
+ ast2600_i2c_setup_buff_tx(0, i2c_bus);
+ }
+ break;
+ case AST2600_I2CM_RX_DONE:
+ case AST2600_I2CM_RX_DONE | AST2600_I2CM_NORMAL_STOP:
+ /* do next rx */
+ xfer_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < xfer_len; i++)
+ msg->buf[i2c_bus->controller_xfer_cnt + i] =
+ readb(i2c_bus->buf_base + 0x10 + i);
+
+ if (msg->flags & I2C_M_RECV_LEN) {
+ u8 recv_len = AST2600_I2CC_GET_RX_BUFF(readl(i2c_bus->reg_base
+ + AST2600_I2CC_STS_AND_BUFF));
+ msg->len = min_t(unsigned int, recv_len, I2C_SMBUS_BLOCK_MAX);
+ msg->len += ((msg->flags & I2C_CLIENT_PEC) ? 2 : 1);
+ msg->flags &= ~I2C_M_RECV_LEN;
+ if (!recv_len)
+ i2c_bus->controller_xfer_cnt = 0;
+ else
+ i2c_bus->controller_xfer_cnt = 1;
+ } else {
+ i2c_bus->controller_xfer_cnt += xfer_len;
+ }
+
+ if (i2c_bus->controller_xfer_cnt == msg->len) {
+ i2c_bus->msgs_index++;
+ if (i2c_bus->msgs_index == i2c_bus->msgs_count) {
+ i2c_bus->cmd_err = i2c_bus->msgs_index;
+ complete(&i2c_bus->cmd_complete);
+ } else {
+ if (ast2600_i2c_do_start(i2c_bus)) {
+ i2c_bus->cmd_err = -ENOMEM;
+ complete(&i2c_bus->cmd_complete);
+ }
+ }
+ } else {
+ ast2600_i2c_setup_buff_rx(0, i2c_bus);
+ }
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled sts %x\n", sts);
+ break;
+ }
+}
+
+static int ast2600_i2c_controller_irq(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 sts = readl(i2c_bus->reg_base + AST2600_I2CM_ISR);
+ u32 ctrl;
+
+ sts &= ~AST2600_I2CM_SMBUS_ALERT;
+
+ if (sts & AST2600_I2CM_BUS_RECOVER_FAIL) {
+ writel(AST2600_I2CM_BUS_RECOVER_FAIL, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ i2c_bus->cmd_err = -EPROTO;
+ complete(&i2c_bus->cmd_complete);
+ return 1;
+ }
+
+ if (sts & AST2600_I2CM_BUS_RECOVER) {
+ writel(AST2600_I2CM_BUS_RECOVER, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ i2c_bus->cmd_err = 0;
+ complete(&i2c_bus->cmd_complete);
+ return 1;
+ }
+
+ i2c_bus->cmd_err = ast2600_i2c_irq_err_to_errno(sts);
+ if (i2c_bus->cmd_err) {
+ writel(AST2600_I2CM_PKT_DONE, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ complete(&i2c_bus->cmd_complete);
+ return 1;
+ }
+
+ if (sts & AST2600_I2CM_PKT_DONE) {
+ ast2600_i2c_controller_packet_irq(i2c_bus, sts);
+ return 1;
+ }
+
+ return 0;
+}
+
+static irqreturn_t ast2600_i2c_bus_irq(int irq, void *dev_id)
+{
+ struct ast2600_i2c_bus *i2c_bus = dev_id;
+
+ return IRQ_RETVAL(ast2600_i2c_controller_irq(i2c_bus));
+}
+
+static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(adap);
+ unsigned long timeout;
+ int ret;
+
+ if (!i2c_bus->multi_master &&
+ (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) & AST2600_I2CC_BUS_BUSY_STS)) {
+ ret = ast2600_i2c_recover_bus(i2c_bus);
+ if (ret)
+ return ret;
+ }
+
+ i2c_bus->cmd_err = 0;
+ i2c_bus->msgs = msgs;
+ i2c_bus->msgs_index = 0;
+ i2c_bus->msgs_count = num;
+ reinit_completion(&i2c_bus->cmd_complete);
+ ret = ast2600_i2c_do_start(i2c_bus);
+ if (ret)
+ goto controller_out;
+ timeout = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
+ if (timeout == 0) {
+ u32 ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ dev_dbg(i2c_bus->dev, "timeout isr[%x], sts[%x]\n",
+ readl(i2c_bus->reg_base + AST2600_I2CM_ISR),
+ readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
+ writel(ctrl & ~AST2600_I2CC_MASTER_EN, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ /*
+ * A slave holding SCL low can stall the transfer and trigger
+ * a master timeout. In multi-master mode, attempt bus recovery
+ * if the bus is still busy.
+ */
+ if (i2c_bus->multi_master &&
+ (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) &
+ AST2600_I2CC_BUS_BUSY_STS))
+ ast2600_i2c_recover_bus(i2c_bus);
+ ret = -ETIMEDOUT;
+ } else {
+ ret = i2c_bus->cmd_err;
+ }
+
+ dev_dbg(i2c_bus->dev, "bus%d-m: %d end\n", i2c_bus->adap.nr, i2c_bus->cmd_err);
+
+controller_out:
+ return ret;
+}
+
+static int ast2600_i2c_init(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 fun_ctrl = AST2600_I2CC_BUS_AUTO_RELEASE | AST2600_I2CC_MASTER_EN;
+
+ /* I2C Reset */
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ if (!i2c_bus->multi_master)
+ fun_ctrl |= AST2600_I2CC_MULTI_MASTER_DIS;
+
+ /* Enable Controller Mode */
+ writel(fun_ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ /* disable target address */
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+
+ /* Set AC Timing */
+ ast2600_i2c_ac_timing_config(i2c_bus);
+
+ /* Clear Interrupt */
+ writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CM_ISR);
+
+ return 0;
+}
+
+static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static const struct i2c_algorithm i2c_ast2600_algorithm = {
+ .xfer = ast2600_i2c_controller_xfer,
+ .functionality = ast2600_i2c_functionality,
+};
+
+static int ast2600_i2c_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ast2600_i2c_bus *i2c_bus;
+ void __iomem *buf_base;
+ struct reset_control *rst;
+ struct resource *res;
+ u32 global_ctrl;
+ int ret;
+
+ if (!device_property_present(dev, "aspeed,global-regs"))
+ return -ENODEV;
+
+ i2c_bus = devm_kzalloc(dev, sizeof(*i2c_bus), GFP_KERNEL);
+ if (!i2c_bus)
+ return -ENOMEM;
+
+ i2c_bus->reg_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(i2c_bus->reg_base))
+ return PTR_ERR(i2c_bus->reg_base);
+
+ rst = devm_reset_control_get_shared_deasserted(dev, NULL);
+ if (IS_ERR(rst))
+ return dev_err_probe(dev, PTR_ERR(rst), "Missing reset ctrl\n");
+
+ i2c_bus->global_regs =
+ syscon_regmap_lookup_by_phandle(dev_of_node(dev), "aspeed,global-regs");
+ if (IS_ERR(i2c_bus->global_regs))
+ return PTR_ERR(i2c_bus->global_regs);
+
+ regmap_read(i2c_bus->global_regs, AST2600_I2CG_CTRL, &global_ctrl);
+ if ((global_ctrl & AST2600_GLOBAL_INIT) != AST2600_GLOBAL_INIT) {
+ regmap_write(i2c_bus->global_regs, AST2600_I2CG_CTRL, AST2600_GLOBAL_INIT);
+ regmap_write(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, I2CCG_DIV_CTRL);
+ }
+
+ i2c_bus->dev = dev;
+ i2c_bus->multi_master = device_property_read_bool(dev, "multi-master");
+
+ buf_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
+ if (IS_ERR(buf_base))
+ return dev_err_probe(dev, PTR_ERR(buf_base), "Missing buffer resource\n");
+ i2c_bus->buf_base = buf_base;
+ i2c_bus->buf_size = resource_size(res) / 2;
+
+ /*
+ * i2c timeout counter: use base clk4 1Mhz,
+ * per unit: 1/(1000/1024) = 1024us
+ */
+ ret = device_property_read_u32(dev, "i2c-scl-clk-low-timeout-us", &i2c_bus->timeout);
+ if (!ret)
+ i2c_bus->timeout = DIV_ROUND_UP(i2c_bus->timeout, 1024);
+
+ init_completion(&i2c_bus->cmd_complete);
+
+ i2c_bus->irq = platform_get_irq(pdev, 0);
+ if (i2c_bus->irq < 0)
+ return i2c_bus->irq;
+
+ platform_set_drvdata(pdev, i2c_bus);
+
+ i2c_bus->clk = devm_clk_get(i2c_bus->dev, NULL);
+ if (IS_ERR(i2c_bus->clk))
+ return dev_err_probe(i2c_bus->dev, PTR_ERR(i2c_bus->clk), "Can't get clock\n");
+
+ i2c_bus->apb_clk = clk_get_rate(i2c_bus->clk);
+
+ i2c_parse_fw_timings(i2c_bus->dev, &i2c_bus->timing_info, true);
+
+ /* Initialize the I2C adapter */
+ i2c_bus->adap.owner = THIS_MODULE;
+ i2c_bus->adap.algo = &i2c_ast2600_algorithm;
+ i2c_bus->adap.retries = 0;
+ i2c_bus->adap.dev.parent = i2c_bus->dev;
+ device_set_node(&i2c_bus->adap.dev, dev_fwnode(dev));
+ i2c_bus->adap.algo_data = i2c_bus;
+ strscpy(i2c_bus->adap.name, pdev->name);
+ i2c_set_adapdata(&i2c_bus->adap, i2c_bus);
+
+ ret = ast2600_i2c_init(i2c_bus);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Unable to initialize i2c %d\n", ret);
+
+ ret = devm_request_irq(dev, i2c_bus->irq, ast2600_i2c_bus_irq, 0,
+ dev_name(dev), i2c_bus);
+ if (ret < 0) {
+ ret = dev_err_probe(dev, ret, "Unable to request irq %d\n",
+ i2c_bus->irq);
+ goto err;
+ }
+
+ writel(AST2600_I2CM_PKT_DONE | AST2600_I2CM_BUS_RECOVER,
+ i2c_bus->reg_base + AST2600_I2CM_IER);
+
+ ret = devm_i2c_add_adapter(dev, &i2c_bus->adap);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(0, i2c_bus->reg_base + AST2600_I2CM_IER);
+ return ret;
+}
+
+static void ast2600_i2c_remove(struct platform_device *pdev)
+{
+ struct ast2600_i2c_bus *i2c_bus = platform_get_drvdata(pdev);
+
+ /* Disable everything. */
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(0, i2c_bus->reg_base + AST2600_I2CM_IER);
+}
+
+static const struct of_device_id ast2600_i2c_of_match[] = {
+ { .compatible = "aspeed,ast2600-i2c-bus" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ast2600_i2c_of_match);
+
+static struct platform_driver ast2600_i2c_driver = {
+ .probe = ast2600_i2c_probe,
+ .remove = ast2600_i2c_remove,
+ .driver = {
+ .name = "ast2600-i2c",
+ .of_match_table = ast2600_i2c_of_match,
+ },
+};
+module_platform_driver(ast2600_i2c_driver);
+
+MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
+MODULE_DESCRIPTION("ASPEED AST2600 I2C Controller Driver");
+MODULE_LICENSE("GPL");
--
2.34.1
^ permalink raw reply related
* [PATCH v29 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs properties
From: Ryan Chen @ 2026-04-15 5:14 UTC (permalink / raw)
To: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-aspeed,
linux-kernel, openbmc, Ryan Chen
In-Reply-To: <20260415-upstream_i2c-v29-0-317c1a905ae1@aspeedtech.com>
Add the aspeed,global-regs phandle to reference the AST2600 global
registers syscon node, containing the SoC-common I2C register set.
These properties apply only to the AST2600 binding. Legacy DTs remain
unchanged.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v29:
- remove aspeed,enable-dma properties.
Changes in v28:
- update commit message correspond with aspeed,enable-dma.
- remove aspeed,transfer-mode and add aspeed,enable-dma property and
description.
- Fix aspeed,enable-dma description to reflect hardware capability rather
than software behavior
Changes in v27:
- change aspeed,transfer-mode to aspeed,enable-dma.
---
Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
index de2c359037da..0c769efb76a5 100644
--- a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
@@ -37,6 +37,12 @@ properties:
resets:
maxItems: 1
+ aspeed,global-regs:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description:
+ Phandle reference to the i2c global syscon node, containing the
+ SoC-common i2c register set.
+
required:
- reg
- compatible
@@ -59,4 +65,5 @@ examples:
resets = <&syscon ASPEED_RESET_I2C>;
clock-frequency = <100000>;
interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+ aspeed,global-regs = <&i2c_global>;
};
--
2.34.1
^ permalink raw reply related
* [PATCH v29 1/4] dt-bindings: i2c: Split AST2600 binding into a new YAML
From: Ryan Chen @ 2026-04-15 5:14 UTC (permalink / raw)
To: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-aspeed,
linux-kernel, openbmc, Ryan Chen
In-Reply-To: <20260415-upstream_i2c-v29-0-317c1a905ae1@aspeedtech.com>
The AST2600 I2C controller introduces a completely new register layout
with separate controller and target register blocks, unlike the mixed
register layout used by AST2400/AST2500.
Move AST2600 I2C binding from aspeed,i2c.yaml to a dedicated
aspeed,ast2600-i2c.yaml schema.
Besides the split, this also adjusts for AST2600-specific requirements.
- require two reg regions (controller register block + buffer block)
- use clock-frequency for bus speed description
- interrupts are required on AST2600
- use correct DTS coding style in example
No compatible strings are changed.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v26:
- commit message: include details of changes from original binding
- fix example property ordering to follow DTS coding style
- use consistent "AST2600" naming
---
.../bindings/i2c/aspeed,ast2600-i2c.yaml | 62 ++++++++++++++++++++++
.../devicetree/bindings/i2c/aspeed,i2c.yaml | 3 +-
2 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
new file mode 100644
index 000000000000..de2c359037da
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/aspeed,ast2600-i2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASPEED I2C on the AST2600 SoCs
+
+maintainers:
+ - Ryan Chen <ryan_chen@aspeedtech.com>
+
+allOf:
+ - $ref: /schemas/i2c/i2c-controller.yaml#
+
+properties:
+ compatible:
+ enum:
+ - aspeed,ast2600-i2c-bus
+
+ reg:
+ items:
+ - description: controller registers
+ - description: controller buffer space
+
+ interrupts:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ clock-frequency:
+ description: Desired operating frequency of the I2C bus in Hz.
+ minimum: 500
+ maximum: 4000000
+ default: 100000
+
+ resets:
+ maxItems: 1
+
+required:
+ - reg
+ - compatible
+ - clocks
+ - resets
+ - interrupts
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/aspeed-clock.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ i2c@80 {
+ compatible = "aspeed,ast2600-i2c-bus";
+ reg = <0x80 0x80>, <0xc00 0x20>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ clocks = <&syscon ASPEED_CLK_APB>;
+ resets = <&syscon ASPEED_RESET_I2C>;
+ clock-frequency = <100000>;
+ interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+ };
diff --git a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
index 5b9bd2feda3b..d4e4f412feba 100644
--- a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
@@ -4,7 +4,7 @@
$id: http://devicetree.org/schemas/i2c/aspeed,i2c.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
-title: ASPEED I2C on the AST24XX, AST25XX, and AST26XX SoCs
+title: ASPEED I2C on the AST24XX, AST25XX SoCs
maintainers:
- Rayn Chen <rayn_chen@aspeedtech.com>
@@ -17,7 +17,6 @@ properties:
enum:
- aspeed,ast2400-i2c-bus
- aspeed,ast2500-i2c-bus
- - aspeed,ast2600-i2c-bus
reg:
minItems: 1
--
2.34.1
^ permalink raw reply related
* [PATCH v29 0/4] Add ASPEED AST2600 I2C controller driver
From: Ryan Chen @ 2026-04-15 5:14 UTC (permalink / raw)
To: jk, andriy.shevchenko, Andi Shyti, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Joel Stanley, Andrew Jeffery,
Benjamin Herrenschmidt, Rayn Chen, Philipp Zabel
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-aspeed,
linux-kernel, openbmc, Ryan Chen
This series adds support for the AST2600 I2C controller “new register
set” implementation.
The AST2600 I2C controller introduces a revised register layout which
separates controller and target functionality into distinct register
blocks, and extends clock divider configuration and packet-based
transfer support compared to the legacy mixed register layout used on
earlier ASPEED SoCs.
The current driver implementation for the AST2600 I2C peripheral is
through the hardware's "compatibility mode", which exposes a register
set that matches the previous generation hardware (AST2500 and earlier).
Instead, add a driver that works in new-register-set mode, to allow the
new features, and will provide support for future hardware that will
not implement compatibility mode.
In order to support the new mode, we need a DT binding change to
reflect the reference to the global register set. Since the binding
still represents the same (AST2600 SoC) physical hardware, we continue
to use the existing compatible string of "aspeed,ast2600-i2c-bus".
However: since we're changing semantics for an existing binding, we
allow backwards compatibility by selecting on presence/absence of the
newly-added properties, and fall back to the old driver (ie., in
compatibility mode) when we detect a DT using the old binding spec.
Specifically:
- ast2600-i2c-bus nodes that provide the `aspeed,global-regs` property
(present in the new binding and absent in the legacy binding) will be
successfully probed by the new driver
- ast2600-i2c-bus nodes without `aspeed,global-regs` continue to use the
existing driver (in legacy register mode), ensuring that platforms
with the current DTBs remain functional
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v29:
- 2/4: remove aspeed,enable-dma properties.
- 3/4: update commit message remove transfer mode selection.
- 3/4: remove sysfs file.
- 3/4: remove define I2C_TARGET_MSG_BUF_SIZE and AST2600_I2C_DMA_SIZE.
- 3/4: remove buf_index in struct ast2600_i2c_bus.
- 3/4, 4/4: remove dma/byte mode, use buffer mode only.
- 4/4: fix race between unreg_target and IRQ handler.
- 4/4: move i2cs ier enable from ast2600_i2c_init to probe after master ier enable.
- Link to v28: https://lore.kernel.org/r/20260330-upstream_i2c-v28-0-17bdae39c5cb@aspeedtech.com
Changes in v28:
- 2/4: update commit message correspond with aspeed,enable-dma.
- 2/4: remove aspeed,transfer-mode and add aspeed,enable-dma property
and description.
- 2/4: Fix aspeed,enable-dma description to reflect hardware capability
rather than software behavior.
- 3/4: Separate xfer_mode_store into distinct parse and availability-check
steps by introducing ast2600_i2c_xfer_mode_check().
- 3/4: fix tx dma memcpy source point address.
- 3/4: Use a temporary variable for devm_platform_get_and_ioremap_resource()
to avoid storing an ERR_PTR in i2c_bus->buf_base; drop the redundant
NULL assignment in the error path since i2c_bus is kzalloc()ed.
- 3/4: Add ABI documentation file
Documentation/ABI/testing/sysfs-driver-ast2600-i2c.
- 4/4: fix typo condication -> condition.
- 4/4: fix compile error, when disable CONFIG_I2C_SLAVE.
- Link to v27: https://lore.kernel.org/r/20260324-upstream_i2c-v27-0-f19b511c8c28@aspeedtech.com
Changes in v27:
- 1/4 use aspeed,enable-dma instead aspeed,transfer-mode.
- 2/4 remove aspeed,transfer-mode selection instad aspeed,transfer-mode
- 2/4 add sysfs for xfer mode.
- Link to v26: https://lore.kernel.org/r/20260309-upstream_i2c-v26-0-5fedcff8ffe8@aspeedtech.com
Changes in v26:
- 1/4: binding reworks based on review feedback
- Link to v25: https://lore.kernel.org/r/20260225-upstream_i2c-v25-0-9f4bdd954f3f@aspeedtech.com
Changes in v25:
- Use b4 to send series.
- Rebase on v7.0-rc1.
- Clarify cover letter and commit logs based on review feedback.
- Remove the i2c-aspeed-core multiplexer infrastructure and
implement driver selection via conditional -ENODEV handling
in individual probe() functions.
- 3/4: incorporate review feedback and refactor new driver
- Link to v24: https://lore.kernel.org/r/20251118014034.820988-1-ryan_chen@aspeedtech.com
Changes in v24:
- aspeed,ast2600-i2c.yaml
- fix make dt_binding_check blank warning.
- Link to v23: https://lore.kernel.org/all/20251117025040.3622984-1-ryan_chen@aspeedtech.com/
Changes in v23:
- update typo patch (1/4) commit message.
- aspeed,ast2600-i2c.yaml
- update reg and description.
- i2c-ast2600.c controller
- replace ast2600_select_i2c_clock to ast2600_i2c_ac_timing_config.
- i2c-ast2600.c target
- I2C_TARGET_MSG_BUF_SIZE 256 to 4096
- remove blank line.
- refine Master comment description to controller
- Link to v22: https://lore.kernel.org/all/20251112085649.1903631-1-ryan_chen@aspeedtech.com/
Changes in v22:
- update patch (1/4) commit message add dts example reason.
- aspeed,ast2600-i2c.yaml @patch (1/4)
- rename ast2600-i2c.yaml to aspeed,ast2600-i2c.yaml.
- update reg, clock-frequency description.
- aspeed,ast2600-i2c.yaml @patch (2/4)
- aspeed,transfer-mode, aspeed,transfer-mode add for ast2600.
- i2c-aspeed-core.c,h @patch (3/4)
- add i2c-aspeed-core allow both old and new device trees using the
same compatible string "aspeed,ast2600-i2c-bus".
- Link to v21: https://lore.kernel.org/all/20251027061240.3427875-1-ryan_chen@aspeedtech.com/
Changes in v21:
- update patch (1/4) commit message
- i2c-ast2600.c
- move rst to local variable in ast2600_i2c_probe().
- Link to v20: https://lore.kernel.org/all/20251021013548.2375190-1-ryan_chen@aspeedtech.com/
Changes in v20:
- ast2600-i2c.yaml
- fix warning at make dt_binding_check.
- Link to v19: https://lore.kernel.org/all/20251020013200.1858325-1-ryan_chen@aspeedtech.com/
Changes in v19:
- Split AST2600 binding into its own YAML file
- Removed `aspeed,ast2600-i2c-bus` from `aspeed,i2c.yaml`
- Added `aspeed,global-regs` and `aspeed,transfer-mode` to AST2600 binding
- Link to v18: https://lore.kernel.org/all/20250820051832.3605405-1-ryan_chen@aspeedtech.com/
Changes in v18:
- refine patch (1/3) commit message (reason for commit not list.)
- i2c-ast2600.c
- remove redundant reset_control_deassert in driver probe.
- remove reset_control_assert(i2c_bus->rst) in driver remove.
- Link to v17: https://lore.kernel.org/all/20250814084156.1650432-1-ryan_chen@aspeedtech.com/
Changes in v17:
- move i2c new mode register and feature into driver commit message.
- aspeed,i2c.yaml
- remove multi-master properties.
- use aspeed,transfer-mode properties for aspeed,enable-byte/enable-dma.
-i2c-ast2600.c
- rename dma_safe_buf to controller_dma_safe_buf.
- fix ast2600_i2c_recover_bus return overflow warnings.
- add ast2600_i2c_target_packet_buff_irq unhandle case.
- add parameter "cmd" in ast2600_i2c_setup_dma_rx,
ast2600_i2c_setup_buff_rx, ast2600_i2c_setup_byte_rx
- use reset_control_deassert replace
devm_reset_control_get_shared_deasserted.
- useaspeed,transfer-mode properties for transfer mode setting.
- change compatible = "aspeed,ast2600-i2cv2" to "aspeed,ast2600-i2c-bus".
- Link to v16: https://lore.kernel.org/all/20250224055936.1804279-1-ryan_chen@aspeedtech.com/
Changes in v16:
- aspeed,i2c.yaml: add aspeed,enable-byte properties for force byte mode.
- i2c-ast2600.c
- change include asm/unaligned.h to linux/unaligned.h.
- add reset timeout councter when slave active timeout.
- modify issue i2c_recovery_bus before slave re-enable.
- add aspeed,enable-byte properties.
- Link to v15: https://lore.kernel.org/all/20241007035235.2254138-1-ryan_chen@aspeedtech.com/
Changes in v15:
- i2c-ast2600.c
- add include unaligned.h
- rename all master -> controller, slave -> target.
- keep multi-master to align property.
- remove no used element in ast2600_i2c_bus.
- Link to v14: https://lore.kernel.org/all/20241002070213.1165263-1-ryan_chen@aspeedtech.com/
Changes in v14:
- aspeed,i2c.yaml
- v13 change people reviewed-by tag, v14 fixed to original people tag,
modify to Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
- struct ast2600_i2c_bus layout optimal.
- ast2600_select_i2c_clock refine.
- ast2600_i2c_recover_bus overridden fix.
- dma_mapping_error() returned error code shadowed modify.
- buffer register in a 4-byte aligned simplified
- remove smbus alert
- Link to v13: https://lore.kernel.org/all/20240819092850.1590758-1-ryan_chen@aspeedtech.com/
Changes in v13:
- separate i2c master and slave driver to be two patchs.
- modify include header list, add bits.h include. remove of*.h
- modify (((x) >> 24) & GENMASK(5, 0)) to (((x) & GENMASK(29, 24)) >> 24)
- modify ast2600_select_i2c_clock function implement.
- modify ast2600_i2c_recover_bus function u32 claim to
u32 state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
- Link to v12: https://lore.kernel.org/all/20230714074522.23827-1-ryan_chen@aspeedtech.com/
Changes in v12:
- aspeed,i2c.yaml
- add Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
- i2c-ast2600.c
- update include by alphabetical order
- make just a one TAB and put the last two lines on the single one
- remove no used timing_table structre
- remove enum explicit assinment
- rewritten to avoid this and using loop in ast2600_select_i2c_clock
- use GENMASK for most 0xffff
- remove too many parentheses
- use str_read_write replace read write string
- remove redundant blank line after ast2600_i2c_bus_of_table
- fix wrong multi-line style of the comment
- use macro for i2c standard speeds
- remove useless noise dev_info
- Link to v11: https://lore.kernel.org/all/20230430041712.3247998-1-ryan_chen@aspeedtech.com/
Changes in v11:
- aspeed,i2c.yaml
- no change, the same with v10.
- i2c-ast2600.c
- modify alert_enable from int -> boolean.
- modify dbg string recovery -> recover.
- remove no need to init 0.
- remove new line after break.
- remove unneeded empty line.
- modify dma_alloc_coherent to dmam_alloc_coherent
- modify probe nomem return dev_err_probe
- modify i2c_add_adapter to devm_i2c_adapter
- modify checkpatch: Alignment should match open parenthesis
- modify checkpatch: braces {} should be used on all arms of this statement
- modify checkpatch: Unbalanced braces around else statement
- Link to v10: https://lore.kernel.org/all/20230415012848.1777768-1-ryan_chen@aspeedtech.com/
Changes in v10:
- aspeed,i2c.yaml
- move unevaluatedProperties after allOf.
- remove extra one blank line.
- i2c-ast2600.c
- no change, the same with v8.
- Link to v9: https://lore.kernel.org/all/20230405022825.333246-1-ryan_chen@aspeedtech.com/
Changes in v9:
- aspeed,i2c.yaml
- backoff to v7.
- no fix typo in maintainer's name and email. this would be another patch.
- no remove address-cells, size-cells, this would be another patch.
- use aspeed,enable-dma property instead of aspeed,xfer-mode selection.
- fix allOf and else false properties for aspeed,ast2600-i2cv2.
- i2c-ast2600.c
- no change, the same with v8
- Link to v8: https://lore.kernel.org/all/20230330073259.485606-1-ryan_chen@aspeedtech.com/
Changes in v8:
- aspeed,i2c.yaml
- modify commit message.
- Fix typo in maintainer's name and email.
- remove address-cells, size-cells.
- i2c-ast2600.c
- move "i2c timeout counter" comment description before property_read.
- remove redundant code "return ret" in probe end.
- Link to v7: https://lore.kernel.org/all/20230327092524.3916389-1-ryan_chen@aspeedtech.com/
Changes in v7:
- aspeed,i2c.yaml
- Update ASPEED I2C maintainers email.
- use aspeed,enable-dma property instead of aspeed,xfer-mode selection.
- fix allOf and else false properties for aspeed,ast2600-i2cv2.
- i2c-ast2600.c
- remove aspeed,xfer-mode instead of aspeed,enable-dma mode. buffer mode
is default.
- remove aspeed,timeout instead of i2c-scl-clk-low-timeout-us for
timeout setting.
- Link to v6: https://lore.kernel.org/all/20230226031321.3126756-1-ryan_chen@aspeedtech.com/
Changes in v6:
- remove aspeed,i2cv2.yaml, merge to aspeed,i2c.yaml -add support for
i2cv2 properites.
- i2c-ast2600.c
- fix ast2600_i2c_remove ordering.
- remove ast2600_i2c_probe goto labels, and add dev_err_probe -remove
redundant deb_dbg debug message.
- rename gr_regmap -> global_regs
- Link to v5: https://lore.kernel.org/all/20230220061745.1973981-1-ryan_chen@aspeedtech.com/
Changes in v5:
- remove ast2600-i2c-global.yaml, i2c-ast2600-global.c.
- i2c-ast2600.c
- remove legacy clock divide, all go for new clock divide.
- remove duplicated read isr.
- remove no used driver match
- fix probe return for each labels return.
- global use mfd driver, driver use phandle to regmap read/write.
- rename aspeed,i2c-ast2600.yaml to aspeed,i2cv2.yaml -remove bus-frequency.
- add required aspeed,gr
- add timeout, byte-mode, buff-mode properites.
- Link to v4: https://lore.kernel.org/all/20230201103359.1742140-1-ryan_chen@aspeedtech.com/
Changes in v4:
- fix i2c-ast2600.c driver buffer mode use single buffer conflit in
master slave mode both enable.
- fix kmemleak issue when use dma mode.
- fix typo aspeed,i2c-ast2600.yaml compatible is "aspeed,ast2600-i2c"
- fix typo aspeed,i2c-ast2600.ymal to aspeed,i2c-ast2600.yaml
- Link to v3: https://lore.kernel.org/all/20220516064900.30517-1-ryan_chen@aspeedtech.com/
Changes in v3:
- fix i2c global clock divide default value.
- remove i2c slave no used dev_dbg info.
- Link to v2: https://lore.kernel.org/all/20220413101735.27678-1-ryan_chen@aspeedtech.com/
Changes in v2:
- add i2c global ymal file commit.
- rename file name from new to ast2600.
aspeed-i2c-new-global.c -> i2c-ast2600-global.c
aspeed-i2c-new-global.h -> i2c-ast2600-global.h
i2c-new-aspeed.c -> i2c-ast2600.c
- rename all driver function name to ast2600.
- Link to v1: https://lore.kernel.org/all/20220323004009.943298-1-ryan_chen@aspeedtech.com/
---
Ryan Chen (4):
dt-bindings: i2c: Split AST2600 binding into a new YAML
dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs properties
i2c: ast2600: Add controller driver for AST2600 new register set
i2c: ast2600: Add target mode support
.../bindings/i2c/aspeed,ast2600-i2c.yaml | 69 ++
.../devicetree/bindings/i2c/aspeed,i2c.yaml | 3 +-
drivers/i2c/busses/Makefile | 2 +-
drivers/i2c/busses/i2c-aspeed.c | 5 +
drivers/i2c/busses/i2c-ast2600.c | 1148 ++++++++++++++++++++
5 files changed, 1224 insertions(+), 3 deletions(-)
---
base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
change-id: 20260223-upstream_i2c-ebd07f89739c
Best regards,
--
Ryan Chen <ryan_chen@aspeedtech.com>
^ permalink raw reply
* Re: [PATCH v2 4/6] ASoC: renesas: fsi: refactor clock initialization
From: Kuninori Morimoto @ 2026-04-15 4:55 UTC (permalink / raw)
To: Bui Duc Phuc
Cc: broonie, lgirdwood, robh, krzk+dt, conor+dt, geert+renesas,
magnus.damm, perex, tiwai, linux-sound, linux-renesas-soc,
devicetree, linux-kernel
In-Reply-To: <CAABR9nERzKW=2vZTWNuTcjz4KuVyc+eaCKBNP6ZGb4UAYw3qUQ@mail.gmail.com>
Hi Bui
> > I have mentioned in previous mail to just move fsi_clk_init(), but why do
> > you need to move it ? It works without any issue without moving function,
> > I guess ?
>
> I moved fsi_clk_init() below the two functions fsi_clk_set_rate_cpg
> and fsi_clk_set_rate_external because, inside fsi_clk_init(),
> I assign these functions to clock->set_rate. Moving the function was
> necessary to avoid compilation errors.
Ah, OK.
So the patch 1) moves fsi_clk_init() and 2) update it.
It is including many features in 1 patch. Please separate it.
One note here is that /* clock function */ is for all fsi_clk_xxx(),
so don't move it.
> > And why you need to call fsi_clk_init() twice ?
> The FSI controller has two independent ports (Port A and Port B).
> Each port requires its own clock resource initialization and configuration.
Ah, yes indeed.
Thank you for your help !!
Best regards
---
Kuninori Morimoto
^ permalink raw reply
* Re: [PATCH v7 2/2] iio: dac: ad5706r: Add support for AD5706R DAC
From: Andy Shevchenko @ 2026-04-15 4:52 UTC (permalink / raw)
To: Torreno, Alexis Czezar
Cc: Jonathan Cameron, Lars-Peter Clausen, Hennerich, Michael,
David Lechner, Sa, Nuno, Andy Shevchenko, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, linux-iio@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
In-Reply-To: <PH0PR03MB6351E875581B45ED279785D0F1222@PH0PR03MB6351.namprd03.prod.outlook.com>
On Wed, Apr 15, 2026 at 01:10:09AM +0000, Torreno, Alexis Czezar wrote:
...
> > > + case IIO_CHAN_INFO_RAW:
> > > + if (!in_range(val, 0, AD5706R_DAC_MAX_CODE))
> >
> > I'm not seeing a strong reason to use in_range() here (hopefully I didn't
> > suggest it in an earlier review ;) It make sense when we have a val >= base &&
> > val < base + length. With base as 0 and MAX_CODE not 'obviously' from it's
> > name being the length (it only is becauset he base is 0) this seems odd.
> >
> > if (val < 0 || val >= AD5706R_DAC_MAX_CODE) Though see
> > above on MAX_CODE not being the maximum code...
>
> I think around v3 Andy suggested the use of in_range, as the function itself helps
> document what the line does. Is this a style preference?
I believe it was me, who suggested that, but we can open code it. Indeed, it's
just a style preference in this case.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply
* [PATCH 5/5] media: synopsys: Add support for i.MX95
From: Guoniu Zhou @ 2026-04-15 3:46 UTC (permalink / raw)
To: Michael Riesch, Mauro Carvalho Chehab, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Heiko Stuebner,
Laurent Pinchart, Frank Li
Cc: linux-media, linux-kernel, devicetree, imx, linux-arm-kernel,
linux-rockchip, Guoniu Zhou
In-Reply-To: <20260415-csi2_imx95-v1-0-7d63f3508719@oss.nxp.com>
Add support for the i.MX95 MIPI CSI-2 receiver. The i.MX95 variant is
nearly identical to i.MX93, with the main difference being the use of
IDI (Image Data Interface) instead of IPI (Image Pixel Interface).
However, the IDI interface is transparent to software, requiring only
a different register map definition while sharing the same PHY control
functions with i.MX93.
Signed-off-by: Guoniu Zhou <guoniu.zhou@oss.nxp.com>
---
drivers/media/platform/synopsys/dw-mipi-csi2rx.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
index 27e4c1027816..bbb41baf789e 100644
--- a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
+++ b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
@@ -154,6 +154,17 @@ static const u32 imx93_regs[DW_MIPI_CSI2RX_MAX] = {
[DW_MIPI_CSI2RX_IPI_SOFTRSTN] = DW_REG(0xa0),
};
+static const u32 imx95_regs[DW_MIPI_CSI2RX_MAX] = {
+ [DW_MIPI_CSI2RX_N_LANES] = DW_REG(0x4),
+ [DW_MIPI_CSI2RX_RESETN] = DW_REG(0x8),
+ [DW_MIPI_CSI2RX_PHY_SHUTDOWNZ] = DW_REG(0x40),
+ [DW_MIPI_CSI2RX_DPHY_RSTZ] = DW_REG(0x44),
+ [DW_MIPI_CSI2RX_PHY_STATE] = DW_REG(0x48),
+ [DW_MIPI_CSI2RX_PHY_STOPSTATE] = DW_REG(0x4c),
+ [DW_MIPI_CSI2RX_PHY_TST_CTRL0] = DW_REG(0x50),
+ [DW_MIPI_CSI2RX_PHY_TST_CTRL1] = DW_REG(0x54),
+};
+
static const struct v4l2_mbus_framefmt default_format = {
.width = 3840,
.height = 2160,
@@ -901,11 +912,22 @@ static const struct dw_mipi_csi2rx_drvdata imx93_drvdata = {
.wait_for_phy_stopstate = imx93_csi2rx_wait_for_phy_stopstate,
};
+static const struct dw_mipi_csi2rx_drvdata imx95_drvdata = {
+ .regs = imx95_regs,
+ .dphy_assert_reset = imx93_csi2rx_dphy_assert_reset,
+ .dphy_deassert_reset = imx93_csi2rx_dphy_deassert_reset,
+ .wait_for_phy_stopstate = imx93_csi2rx_wait_for_phy_stopstate,
+};
+
static const struct of_device_id dw_mipi_csi2rx_of_match[] = {
{
.compatible = "fsl,imx93-mipi-csi2",
.data = &imx93_drvdata,
},
+ {
+ .compatible = "fsl,imx95-mipi-csi2",
+ .data = &imx95_drvdata,
+ },
{
.compatible = "rockchip,rk3568-mipi-csi2",
.data = &rk3568_drvdata,
--
2.34.1
^ permalink raw reply related
* [PATCH 4/5] media: dt-bindings: add NXP i.MX95 compatible string
From: Guoniu Zhou @ 2026-04-15 3:46 UTC (permalink / raw)
To: Michael Riesch, Mauro Carvalho Chehab, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Heiko Stuebner,
Laurent Pinchart, Frank Li
Cc: linux-media, linux-kernel, devicetree, imx, linux-arm-kernel,
linux-rockchip, Guoniu Zhou
In-Reply-To: <20260415-csi2_imx95-v1-0-7d63f3508719@oss.nxp.com>
The i.MX95 CSI-2 controller is nearly identical to i.MX93, with the
only difference being the use of IDI (Image Data Interface) instead
of IPI (Image Pixel Interface). The binding constraints are otherwise
the same.
Signed-off-by: Guoniu Zhou <guoniu.zhou@oss.nxp.com>
---
.../devicetree/bindings/media/rockchip,rk3568-mipi-csi2.yaml | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/media/rockchip,rk3568-mipi-csi2.yaml b/Documentation/devicetree/bindings/media/rockchip,rk3568-mipi-csi2.yaml
index 4ac4a3b6f406..78371e039e55 100644
--- a/Documentation/devicetree/bindings/media/rockchip,rk3568-mipi-csi2.yaml
+++ b/Documentation/devicetree/bindings/media/rockchip,rk3568-mipi-csi2.yaml
@@ -18,6 +18,7 @@ properties:
compatible:
enum:
- fsl,imx93-mipi-csi2
+ - fsl,imx95-mipi-csi2
- rockchip,rk3568-mipi-csi2
reg:
@@ -124,7 +125,9 @@ allOf:
properties:
compatible:
contains:
- const: fsl,imx93-mipi-csi2
+ enum:
+ - fsl,imx93-mipi-csi2
+ - fsl,imx95-mipi-csi2
then:
properties:
interrupts:
--
2.34.1
^ permalink raw reply related
* [PATCH 3/5] media: synopsys: Add PHY stopstate wait for i.MX93
From: Guoniu Zhou @ 2026-04-15 3:46 UTC (permalink / raw)
To: Michael Riesch, Mauro Carvalho Chehab, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Heiko Stuebner,
Laurent Pinchart, Frank Li
Cc: linux-media, linux-kernel, devicetree, imx, linux-arm-kernel,
linux-rockchip, Guoniu Zhou
In-Reply-To: <20260415-csi2_imx95-v1-0-7d63f3508719@oss.nxp.com>
Implement waiting for D-PHY lanes to enter stop state on i.MX93. This
ensures proper PHY initialization by verifying that the clock lane and
all active data lanes have entered the stop state before proceeding with
further operations.
Signed-off-by: Guoniu Zhou <guoniu.zhou@oss.nxp.com>
---
drivers/media/platform/synopsys/dw-mipi-csi2rx.c | 38 ++++++++++++++++++++++++
1 file changed, 38 insertions(+)
diff --git a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
index 85a2a95bf080..27e4c1027816 100644
--- a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
+++ b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
@@ -11,6 +11,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
@@ -35,6 +36,8 @@
#define DW_REG_EXIST BIT(31)
#define DW_REG(x) (DW_REG_EXIST | (x))
+#define DPHY_STOPSTATE_CLK_LANE BIT(16)
+
#define DPHY_TEST_CTRL0_TEST_CLR BIT(0)
#define IPI_VCID_VC(x) FIELD_PREP(GENMASK(1, 0), (x))
@@ -65,6 +68,7 @@ enum dw_mipi_csi2rx_regs_index {
DW_MIPI_CSI2RX_PHY_TST_CTRL0,
DW_MIPI_CSI2RX_PHY_TST_CTRL1,
DW_MIPI_CSI2RX_PHY_SHUTDOWNZ,
+ DW_MIPI_CSI2RX_PHY_STOPSTATE,
DW_MIPI_CSI2RX_IPI_DATATYPE,
DW_MIPI_CSI2RX_IPI_MEM_FLUSH,
DW_MIPI_CSI2RX_IPI_MODE,
@@ -87,6 +91,7 @@ struct dw_mipi_csi2rx_drvdata {
void (*dphy_assert_reset)(struct dw_mipi_csi2rx_device *csi2);
void (*dphy_deassert_reset)(struct dw_mipi_csi2rx_device *csi2);
void (*ipi_enable)(struct dw_mipi_csi2rx_device *csi2);
+ int (*wait_for_phy_stopstate)(struct dw_mipi_csi2rx_device *csi2);
};
struct dw_mipi_csi2rx_format {
@@ -139,6 +144,7 @@ static const u32 imx93_regs[DW_MIPI_CSI2RX_MAX] = {
[DW_MIPI_CSI2RX_PHY_SHUTDOWNZ] = DW_REG(0x40),
[DW_MIPI_CSI2RX_DPHY_RSTZ] = DW_REG(0x44),
[DW_MIPI_CSI2RX_PHY_STATE] = DW_REG(0x48),
+ [DW_MIPI_CSI2RX_PHY_STOPSTATE] = DW_REG(0x4c),
[DW_MIPI_CSI2RX_PHY_TST_CTRL0] = DW_REG(0x50),
[DW_MIPI_CSI2RX_PHY_TST_CTRL1] = DW_REG(0x54),
[DW_MIPI_CSI2RX_IPI_MODE] = DW_REG(0x80),
@@ -410,6 +416,12 @@ static int dw_mipi_csi2rx_start(struct dw_mipi_csi2rx_device *csi2)
dw_mipi_csi2rx_write(csi2, DW_MIPI_CSI2RX_RESETN, 1);
+ if (csi2->drvdata->wait_for_phy_stopstate) {
+ ret = csi2->drvdata->wait_for_phy_stopstate(csi2);
+ if (ret)
+ return ret;
+ }
+
if (csi2->drvdata->ipi_enable)
csi2->drvdata->ipi_enable(csi2);
@@ -856,11 +868,37 @@ static void imx93_csi2rx_dphy_ipi_enable(struct dw_mipi_csi2rx_device *csi2)
dw_mipi_csi2rx_write(csi2, DW_MIPI_CSI2RX_IPI_MODE, val);
}
+static int imx93_csi2rx_wait_for_phy_stopstate(struct dw_mipi_csi2rx_device *csi2)
+{
+ struct device *dev = csi2->dev;
+ void __iomem *addr;
+ u32 stopstate_mask;
+ u32 val;
+ int ret;
+
+ if (!dw_mipi_csi2rx_has_reg(csi2, DW_MIPI_CSI2RX_PHY_STOPSTATE)) {
+ dev_err(dev, "phy_stopstate register not available\n");
+ return -ENXIO;
+ }
+
+ stopstate_mask = DPHY_STOPSTATE_CLK_LANE | GENMASK(csi2->lanes_num - 1, 0);
+ addr = dw_mipi_csi2rx_get_regaddr(csi2, DW_MIPI_CSI2RX_PHY_STOPSTATE);
+
+ ret = readl_poll_timeout(addr, val, (val & stopstate_mask) != stopstate_mask,
+ 1000, 2000000);
+ if (ret)
+ dev_err(dev, "lanes are not in stop state: %#x, expected %#x\n",
+ val, stopstate_mask);
+
+ return ret;
+}
+
static const struct dw_mipi_csi2rx_drvdata imx93_drvdata = {
.regs = imx93_regs,
.dphy_assert_reset = imx93_csi2rx_dphy_assert_reset,
.dphy_deassert_reset = imx93_csi2rx_dphy_deassert_reset,
.ipi_enable = imx93_csi2rx_dphy_ipi_enable,
+ .wait_for_phy_stopstate = imx93_csi2rx_wait_for_phy_stopstate,
};
static const struct of_device_id dw_mipi_csi2rx_of_match[] = {
--
2.34.1
^ permalink raw reply related
* [PATCH 2/5] media: synopsys: Add support for multiple streams
From: Guoniu Zhou @ 2026-04-15 3:46 UTC (permalink / raw)
To: Michael Riesch, Mauro Carvalho Chehab, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Heiko Stuebner,
Laurent Pinchart, Frank Li
Cc: linux-media, linux-kernel, devicetree, imx, linux-arm-kernel,
linux-rockchip, Guoniu Zhou
In-Reply-To: <20260415-csi2_imx95-v1-0-7d63f3508719@oss.nxp.com>
The current driver only supports single stream operation. Add support
for multiple concurrent streams by tracking enabled streams with a
bitmask and only initializing the hardware once for the first stream.
This enables use cases such as surround view systems where multiple
camera streams need to be processed simultaneously through the same
CSI-2 receiver interface.
Signed-off-by: Guoniu Zhou <guoniu.zhou@oss.nxp.com>
---
drivers/media/platform/synopsys/dw-mipi-csi2rx.c | 45 ++++++++++++++----------
1 file changed, 27 insertions(+), 18 deletions(-)
diff --git a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
index 46e2a4315ac2..85a2a95bf080 100644
--- a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
+++ b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
@@ -113,6 +113,7 @@ struct dw_mipi_csi2rx_device {
enum v4l2_mbus_type bus_type;
u32 lanes_num;
+ u64 enabled_streams;
const struct dw_mipi_csi2rx_drvdata *drvdata;
};
@@ -528,28 +529,31 @@ static int dw_mipi_csi2rx_enable_streams(struct v4l2_subdev *sd,
DW_MIPI_CSI2RX_PAD_SRC,
&streams_mask);
- ret = pm_runtime_resume_and_get(dev);
- if (ret)
- goto err;
+ if (!csi2->enabled_streams) {
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret)
+ return ret;
- ret = dw_mipi_csi2rx_start(csi2);
- if (ret) {
- dev_err(dev, "failed to enable CSI hardware\n");
- goto err_pm_runtime_put;
+ ret = dw_mipi_csi2rx_start(csi2);
+ if (ret) {
+ pm_runtime_put(dev);
+ dev_err(dev, "failed to enable CSI hardware\n");
+ return ret;
+ }
}
ret = v4l2_subdev_enable_streams(remote_sd, remote_pad->index, mask);
- if (ret)
- goto err_csi_stop;
+ if (ret) {
+ if (!csi2->enabled_streams) {
+ dw_mipi_csi2rx_stop(csi2);
+ pm_runtime_put(dev);
+ }
+ return ret;
+ }
- return 0;
+ csi2->enabled_streams |= streams_mask;
-err_csi_stop:
- dw_mipi_csi2rx_stop(csi2);
-err_pm_runtime_put:
- pm_runtime_put(dev);
-err:
- return ret;
+ return 0;
}
static int dw_mipi_csi2rx_disable_streams(struct v4l2_subdev *sd,
@@ -572,10 +576,15 @@ static int dw_mipi_csi2rx_disable_streams(struct v4l2_subdev *sd,
&streams_mask);
ret = v4l2_subdev_disable_streams(remote_sd, remote_pad->index, mask);
+ if (ret)
+ dev_err(dev, "failed to disable streams on remote subdev: %d\n", ret);
- dw_mipi_csi2rx_stop(csi2);
+ csi2->enabled_streams &= ~streams_mask;
- pm_runtime_put(dev);
+ if (!csi2->enabled_streams) {
+ dw_mipi_csi2rx_stop(csi2);
+ pm_runtime_put(dev);
+ }
return ret;
}
--
2.34.1
^ permalink raw reply related
* [PATCH 1/5] media: synopsys: Add support for RAW16 Bayer formats
From: Guoniu Zhou @ 2026-04-15 3:46 UTC (permalink / raw)
To: Michael Riesch, Mauro Carvalho Chehab, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Heiko Stuebner,
Laurent Pinchart, Frank Li
Cc: linux-media, linux-kernel, devicetree, imx, linux-arm-kernel,
linux-rockchip, Guoniu Zhou
In-Reply-To: <20260415-csi2_imx95-v1-0-7d63f3508719@oss.nxp.com>
This enables the driver to handle higher bit-depth raw image data
from image sensors that support 16-bit output.
Signed-off-by: Guoniu Zhou <guoniu.zhou@oss.nxp.com>
---
drivers/media/platform/synopsys/dw-mipi-csi2rx.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
index ce17f986279e..46e2a4315ac2 100644
--- a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
+++ b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
@@ -252,6 +252,26 @@ static const struct dw_mipi_csi2rx_format formats[] = {
.depth = 12,
.csi_dt = MIPI_CSI2_DT_RAW12,
},
+ {
+ .code = MEDIA_BUS_FMT_SBGGR16_1X16,
+ .depth = 16,
+ .csi_dt = MIPI_CSI2_DT_RAW16,
+ },
+ {
+ .code = MEDIA_BUS_FMT_SGBRG16_1X16,
+ .depth = 16,
+ .csi_dt = MIPI_CSI2_DT_RAW16,
+ },
+ {
+ .code = MEDIA_BUS_FMT_SGRBG16_1X16,
+ .depth = 16,
+ .csi_dt = MIPI_CSI2_DT_RAW16,
+ },
+ {
+ .code = MEDIA_BUS_FMT_SRGGB16_1X16,
+ .depth = 16,
+ .csi_dt = MIPI_CSI2_DT_RAW16,
+ },
};
static inline struct dw_mipi_csi2rx_device *to_csi2(struct v4l2_subdev *sd)
--
2.34.1
^ permalink raw reply related
* [PATCH 0/5] media: synopsys: enhancements and i.MX95 support
From: Guoniu Zhou @ 2026-04-15 3:46 UTC (permalink / raw)
To: Michael Riesch, Mauro Carvalho Chehab, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Heiko Stuebner,
Laurent Pinchart, Frank Li
Cc: linux-media, linux-kernel, devicetree, imx, linux-arm-kernel,
linux-rockchip, Guoniu Zhou
This series enhances the Synopsys DesignWare MIPI CSI-2 receiver driver
with multiple stream support and adds i.MX95 platform support.
The i.MX95 variant is similar to i.MX93 but uses IDI instead of IPI. Since
IDI is software transparent, only a different register map is needed.
Tested on i.MX93 and i.MX95 platforms.
Signed-off-by: Guoniu Zhou <guoniu.zhou@oss.nxp.com>
---
Guoniu Zhou (5):
media: synopsys: Add support for RAW16 Bayer formats
media: synopsys: Add support for multiple streams
media: synopsys: Add PHY stopstate wait for i.MX93
media: dt-bindings: add NXP i.MX95 compatible string
media: synopsys: Add support for i.MX95
.../bindings/media/rockchip,rk3568-mipi-csi2.yaml | 5 +-
drivers/media/platform/synopsys/dw-mipi-csi2rx.c | 125 ++++++++++++++++++---
2 files changed, 111 insertions(+), 19 deletions(-)
---
base-commit: 4fbeef21f5387234111b5d52924e77757626faa5
change-id: 20260414-csi2_imx95-65ad0e7f630a
Best regards,
--
Guoniu Zhou <guoniu.zhou@oss.nxp.com>
^ permalink raw reply
* [PATCH RFC v3 11/11] ACPI: RISC-V: Add support for RISC-V Quality of Service Controller (RQSC)
From: Drew Fustini @ 2026-04-15 1:54 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Call acpi_parse_rqsc() from acpi_arch_init() to discover CBQRI
controllers when an RQSC table is present. The RQSC table is optional;
AE_NOT_FOUND is silenced since many systems will not have QoS
controllers. Other ACPI failures are reported as errors.
Link: https://github.com/riscv-non-isa/riscv-cbqri/releases/tag/v1.0
Link: https://github.com/riscv-non-isa/riscv-rqsc/blob/main/src/
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
drivers/acpi/riscv/init.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/acpi/riscv/init.c b/drivers/acpi/riscv/init.c
index 7c00f7995e86..8a74dff42dce 100644
--- a/drivers/acpi/riscv/init.c
+++ b/drivers/acpi/riscv/init.c
@@ -4,12 +4,35 @@
* Author: Sunil V L <sunilvl@ventanamicro.com>
*/
+#define pr_fmt(fmt) "ACPI: RQSC: " fmt
+
#include <linux/acpi.h>
#include "init.h"
void __init acpi_arch_init(void)
{
+ struct acpi_table_header *rqsc;
+ acpi_status status;
+ int rc;
+
riscv_acpi_init_gsi_mapping();
+
if (IS_ENABLED(CONFIG_ACPI_RIMT))
riscv_acpi_rimt_init();
+
+ if (IS_ENABLED(CONFIG_RISCV_ISA_SSQOSID) && !acpi_disabled) {
+ status = acpi_get_table(ACPI_SIG_RQSC, 0, &rqsc);
+ if (status == AE_NOT_FOUND) {
+ /* RQSC is optional; silence on systems without it */
+ } else if (ACPI_FAILURE(status)) {
+ pr_err("failed to get ACPI RQSC table: %s\n",
+ acpi_format_exception(status));
+ } else {
+ rc = acpi_parse_rqsc(rqsc);
+ if (rc < 0)
+ pr_err("failed to parse ACPI RQSC table: %d\n",
+ rc);
+ acpi_put_table(rqsc);
+ }
+ }
}
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 10/11] ACPI: RISC-V: Parse RISC-V Quality of Service Controller (RQSC) table
From: Drew Fustini @ 2026-04-15 1:54 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Add parser for the ACPI RQSC table which describes the capacity and
bandwidth QoS controllers in a system. For each table entry, allocate a
cbqri_controller struct and populate it with the controller type, MMIO
base address, RCID/MCID counts, and resource identifiers (cache ID for
capacity controllers, proximity domain for bandwidth controllers).
Cache controller cpumasks are resolved via
acpi_pptt_get_cpumask_from_cache_id(). Bandwidth controller cpumasks
are derived from the proximity domain's NUMA node. Controllers with
invalid addresses or failed cpumask lookups are skipped with a warning.
The populated controller list is consumed by qos_resctrl_setup() in
arch/riscv/kernel/qos/ to probe the hardware and register resctrl
domains.
Link: https://github.com/riscv-non-isa/riscv-cbqri/releases/tag/v1.0
Link: https://github.com/riscv-non-isa/riscv-rqsc/blob/main/src/
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
MAINTAINERS | 1 +
arch/riscv/include/asm/acpi.h | 10 ++++
drivers/acpi/riscv/Makefile | 1 +
drivers/acpi/riscv/rqsc.c | 136 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 148 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index af9698a16439..d5ec7d29bf11 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22786,6 +22786,7 @@ S: Supported
F: arch/riscv/include/asm/qos.h
F: arch/riscv/include/asm/resctrl.h
F: arch/riscv/kernel/qos/
+F: drivers/acpi/riscv/rqsc.c
F: include/linux/riscv_qos.h
RISC-V RPMI AND MPXY DRIVERS
diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h
index 6e13695120bc..62296a2a519b 100644
--- a/arch/riscv/include/asm/acpi.h
+++ b/arch/riscv/include/asm/acpi.h
@@ -71,6 +71,16 @@ int acpi_get_riscv_isa(struct acpi_table_header *table,
void acpi_get_cbo_block_size(struct acpi_table_header *table, u32 *cbom_size,
u32 *cboz_size, u32 *cbop_size);
+
+#ifdef CONFIG_RISCV_ISA_SSQOSID
+int __init acpi_parse_rqsc(struct acpi_table_header *table);
+#else
+static inline int acpi_parse_rqsc(struct acpi_table_header *table)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_RISCV_ISA_SSQOSID */
+
#else
static inline void acpi_init_rintc_map(void) { }
static inline struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu)
diff --git a/drivers/acpi/riscv/Makefile b/drivers/acpi/riscv/Makefile
index 1284a076fa88..d7ae8729987a 100644
--- a/drivers/acpi/riscv/Makefile
+++ b/drivers/acpi/riscv/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-y += rhct.o init.o irq.o
+obj-$(CONFIG_RISCV_ISA_SSQOSID) += rqsc.o
obj-$(CONFIG_ACPI_PROCESSOR_IDLE) += cpuidle.o
obj-$(CONFIG_ACPI_CPPC_LIB) += cppc.o
obj-$(CONFIG_ACPI_RIMT) += rimt.o
diff --git a/drivers/acpi/riscv/rqsc.c b/drivers/acpi/riscv/rqsc.c
new file mode 100644
index 000000000000..f647051be0bf
--- /dev/null
+++ b/drivers/acpi/riscv/rqsc.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 Tenstorrent
+ * Author: Drew Fustini <fustini@kernel.org>
+ */
+
+#define pr_fmt(fmt) "ACPI: RQSC: " fmt
+
+#include <linux/acpi.h>
+#include <linux/bits.h>
+#include <linux/riscv_qos.h>
+
+#define CBQRI_CTRL_SIZE 0x1000
+
+int __init acpi_parse_rqsc(struct acpi_table_header *table)
+{
+ struct acpi_table_rqsc *rqsc;
+ struct acpi_table_rqsc_fields *end;
+ struct acpi_table_rqsc_fields *node;
+ int err;
+ int num_controllers = 0;
+
+ rqsc = (struct acpi_table_rqsc *)table;
+
+ end = ACPI_ADD_PTR(struct acpi_table_rqsc_fields, rqsc, rqsc->header.length);
+
+ for (node = ACPI_ADD_PTR(struct acpi_table_rqsc_fields, rqsc,
+ sizeof(struct acpi_table_rqsc));
+ node < end;
+ node = ACPI_ADD_PTR(struct acpi_table_rqsc_fields, node, node->length)
+ ) {
+ struct cbqri_controller *ctrl;
+
+ if (node->length < sizeof(*node)) {
+ pr_err("malformed RQSC entry: length %u < %zu, aborting\n",
+ node->length, sizeof(*node));
+ err = -EINVAL;
+ goto err_free_controllers;
+ }
+
+ ctrl = kzalloc_obj(*ctrl, GFP_KERNEL);
+ if (!ctrl) {
+ err = -ENOMEM;
+ goto err_free_controllers;
+ }
+
+ ctrl->type = node->type;
+ /* reg[1] is the MMIO base address per the RQSC table layout */
+ ctrl->addr = node->reg[1];
+ ctrl->size = CBQRI_CTRL_SIZE;
+ ctrl->rcid_count = node->rcid;
+ ctrl->mcid_count = node->mcid;
+
+ if (!ctrl->addr) {
+ pr_warn("skipping controller with invalid addr=0x0\n");
+ kfree(ctrl);
+ continue;
+ }
+
+ if (node->nres == 0) {
+ pr_warn("controller at %pa has no resource descriptors, skipping\n",
+ &ctrl->addr);
+ kfree(ctrl);
+ continue;
+ }
+
+ if (node->length < sizeof(*node) + sizeof(node->res[0])) {
+ pr_warn("controller at %pa: node too short for resource descriptor, skipping\n",
+ &ctrl->addr);
+ kfree(ctrl);
+ continue;
+ }
+
+ if (node->nres > 1)
+ pr_warn("controller at %pa has %u resource descriptors, using first\n",
+ &ctrl->addr, node->nres);
+
+ pr_debug("Found controller with type %u addr %pa size %pa rcid %u mcid %u\n",
+ ctrl->type, &ctrl->addr, &ctrl->size,
+ ctrl->rcid_count, ctrl->mcid_count);
+ if (ctrl->type == CBQRI_CONTROLLER_TYPE_CAPACITY) {
+ ctrl->cache.cache_id = (u32)node->res[0].id1;
+ ctrl->cache.cache_level =
+ find_acpi_cache_level_from_id(ctrl->cache.cache_id);
+
+ if (acpi_pptt_get_cache_size_from_id(ctrl->cache.cache_id,
+ &ctrl->cache.cache_size)) {
+ pr_warn("failed to determine size for cache id 0x%x\n",
+ ctrl->cache.cache_id);
+ ctrl->cache.cache_size = 0;
+ }
+
+ pr_debug("Cache controller has ID 0x%x level %u size %u\n",
+ ctrl->cache.cache_id, ctrl->cache.cache_level,
+ ctrl->cache.cache_size);
+
+ /*
+ * For CBQRI, any cpu (technically a hart in RISC-V terms)
+ * can access the memory-mapped registers of any CBQRI
+ * controller in the system.
+ */
+ err = acpi_pptt_get_cpumask_from_cache_id(ctrl->cache.cache_id,
+ &ctrl->cache.cpu_mask);
+ if (err) {
+ pr_warn("Failed to get cpumask for cache id 0x%x (%d), skipping\n",
+ ctrl->cache.cache_id, err);
+ kfree(ctrl);
+ continue;
+ }
+
+ } else if (ctrl->type == CBQRI_CONTROLLER_TYPE_BANDWIDTH) {
+ ctrl->mem.prox_dom = (u32)node->res[0].id1;
+ cpumask_copy(&ctrl->mem.cpu_mask,
+ cpumask_of_node(pxm_to_node(ctrl->mem.prox_dom)));
+ pr_debug("Memory controller with proximity domain %u\n",
+ ctrl->mem.prox_dom);
+ }
+
+ /* List shared with RISC-V QoS resctrl implementation */
+ list_add_tail(&ctrl->list, &cbqri_controllers);
+ num_controllers++;
+ }
+
+ pr_info("found %d CBQRI controllers\n", num_controllers);
+ return 0;
+
+err_free_controllers:
+ while (!list_empty(&cbqri_controllers)) {
+ struct cbqri_controller *ctrl;
+
+ ctrl = list_first_entry(&cbqri_controllers, struct cbqri_controller, list);
+ list_del(&ctrl->list);
+ kfree(ctrl);
+ }
+ return err;
+}
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 09/11] DO NOT MERGE: include: acpi: actbl2: Add structs for RQSC table
From: Drew Fustini @ 2026-04-15 1:54 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Add structs for the RQSC table which describes the properties of the
RISC-V QoS controllers (CBQRI) in the system. The table also describes
the topological arrangement of the QoS controllers and resources in the
system. The topology is expressed in terms of the location of the
resources within the system and the relation between the QoS Controller
and the resource it manages.
Note: This is a placeholder for RFC review purposes. The actbl2.h
change must go through upstream ACPICA first and will be replaced by
the auto-generated ACPICA commit once the RQSC spec is ratified.
Link: https://github.com/riscv-non-isa/riscv-cbqri/releases/tag/v1.0
Link: https://github.com/riscv-non-isa/riscv-rqsc/blob/main/src/chapter2.adoc
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
include/acpi/actbl2.h | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
index 5c0b55e7b3e4..d6f272e848fa 100644
--- a/include/acpi/actbl2.h
+++ b/include/acpi/actbl2.h
@@ -55,6 +55,7 @@
#define ACPI_SIG_RGRT "RGRT" /* Regulatory Graphics Resource Table */
#define ACPI_SIG_RHCT "RHCT" /* RISC-V Hart Capabilities Table */
#define ACPI_SIG_RIMT "RIMT" /* RISC-V IO Mapping Table */
+#define ACPI_SIG_RQSC "RQSC" /* RISC-V Quality of Service Controller */
#define ACPI_SIG_SBST "SBST" /* Smart Battery Specification Table */
#define ACPI_SIG_SDEI "SDEI" /* Software Delegated Exception Interface Table */
#define ACPI_SIG_SDEV "SDEV" /* Secure Devices table */
@@ -3351,6 +3352,41 @@ enum acpi_rgrt_image_type {
ACPI_RGRT_TYPE_RESERVED = 2 /* 2 and greater are reserved */
};
+/*******************************************************************************
+ *
+ * RQSC - RISC-V Quality of Service Controller
+ * Version 1
+ *
+ ******************************************************************************/
+
+struct acpi_table_rqsc_fields_res {
+ u8 type;
+ u8 resv;
+ u16 length;
+ u16 flags;
+ u8 resv2;
+ u8 id_type;
+ u64 id1;
+ u32 id2;
+};
+
+struct acpi_table_rqsc_fields {
+ u8 type;
+ u8 resv;
+ u16 length;
+ u32 reg[3];
+ u16 rcid;
+ u16 mcid;
+ u16 flags;
+ u16 nres;
+ struct acpi_table_rqsc_fields_res res[];
+};
+
+struct acpi_table_rqsc {
+ struct acpi_table_header header; /* Common ACPI table header */
+ u32 num;
+};
+
/*******************************************************************************
*
* RHCT - RISC-V Hart Capabilities Table
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 08/11] ACPI: PPTT: Add acpi_pptt_get_cache_size_from_id helper
From: Drew Fustini @ 2026-04-15 1:54 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Add helper to look up a cache's size from its cache ID in the PPTT
table. This is needed by the RISC-V RQSC parser to determine the cache
size for CBQRI capacity controllers.
The implementation follows the pattern established by
find_acpi_cache_level_from_id() and acpi_pptt_get_cpumask_from_cache_id():
uses acpi_get_pptt(), upgrade_pptt_cache(), checks all three cache types,
and uses the do/while empty-detection loop.
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
drivers/acpi/pptt.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/acpi.h | 8 +++++++
2 files changed, 71 insertions(+)
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index de5f8c018333..36e375551b43 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c
@@ -1063,3 +1063,66 @@ int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, cpumask_t *cpus)
return 0;
}
+
+/**
+ * acpi_pptt_get_cache_size_from_id() - Get the size of the specified cache
+ * @cache_id: The id field of the cache
+ * @size: Where to store the cache size in bytes
+ *
+ * Determine the size of the cache identified by cache_id. This allows the
+ * property to be found even if the CPUs are offline.
+ *
+ * The PPTT table must be rev 3 or later.
+ *
+ * Return: -ENOENT if the PPTT doesn't exist, the revision isn't supported or
+ * the cache cannot be found. Otherwise returns 0 and sets *size.
+ */
+int acpi_pptt_get_cache_size_from_id(u32 cache_id, u32 *size)
+{
+ int cpu;
+ struct acpi_table_header *table;
+
+ table = acpi_get_pptt();
+ if (!table)
+ return -ENOENT;
+
+ if (table->revision < 3)
+ return -ENOENT;
+
+ for_each_possible_cpu(cpu) {
+ bool empty;
+ int level = 1;
+ u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ struct acpi_pptt_processor *cpu_node;
+
+ cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
+ if (!cpu_node)
+ continue;
+
+ do {
+ int cache_type[] = {CACHE_TYPE_INST, CACHE_TYPE_DATA, CACHE_TYPE_UNIFIED};
+
+ empty = true;
+ for (int i = 0; i < ARRAY_SIZE(cache_type); i++) {
+ struct acpi_pptt_cache *cache;
+ struct acpi_pptt_cache_v1_full *cache_v1;
+
+ cache = acpi_find_cache_node(table, acpi_cpu_id, cache_type[i],
+ level, &cpu_node);
+ if (!cache)
+ continue;
+
+ empty = false;
+
+ cache_v1 = upgrade_pptt_cache(cache);
+ if (cache_v1 && cache_v1->cache_id == cache_id) {
+ *size = cache->size;
+ return 0;
+ }
+ }
+ level++;
+ } while (!empty);
+ }
+
+ return -ENOENT;
+}
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 4d2f0bed7a06..0596ec18f522 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1547,6 +1547,7 @@ int find_acpi_cpu_topology_package(unsigned int cpu);
int find_acpi_cpu_topology_hetero_id(unsigned int cpu);
void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus);
int find_acpi_cache_level_from_id(u32 cache_id);
+int acpi_pptt_get_cache_size_from_id(u32 cache_id, u32 *size);
int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, cpumask_t *cpus);
#else
static inline int acpi_pptt_cpu_is_thread(unsigned int cpu)
@@ -1571,10 +1572,17 @@ static inline int find_acpi_cpu_topology_hetero_id(unsigned int cpu)
}
static inline void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id,
cpumask_t *cpus) { }
+
static inline int find_acpi_cache_level_from_id(u32 cache_id)
{
return -ENOENT;
}
+
+static inline int acpi_pptt_get_cache_size_from_id(u32 cache_id, u32 *size)
+{
+ return -ENOENT;
+}
+
static inline int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id,
cpumask_t *cpus)
{
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 07/11] RISC-V: QoS: enable resctrl support for Ssqosid
From: Drew Fustini @ 2026-04-15 1:54 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Wire up the RISC-V QoS resctrl implementation:
Add a late_initcall that checks for the Ssqosid extension and, if
present, calls qos_resctrl_setup() to probe CBQRI controllers and
initialize the resctrl filesystem, then registers CPU hotplug callbacks.
Make CONFIG_RISCV_ISA_SSQOSID select ARCH_HAS_CPU_RESCTRL and
RESCTRL_FS, and depends on MISC_FILESYSTEMS.
Add qos_resctrl.o to the build when CONFIG_RISCV_ISA_SSQOSID is set.
Co-developed-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
arch/riscv/Kconfig | 3 +++
arch/riscv/kernel/qos/Makefile | 2 +-
arch/riscv/kernel/qos/qos.c | 32 ++++++++++++++++++++++++++++++++
3 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 92d2265a0c61..b2fef15b3d4f 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -597,7 +597,10 @@ config RISCV_ISA_SVNAPOT
config RISCV_ISA_SSQOSID
bool "Ssqosid extension support for supervisor mode Quality of Service ID"
+ depends on MISC_FILESYSTEMS
default n
+ select ARCH_HAS_CPU_RESCTRL
+ select RESCTRL_FS
help
Adds support for the Ssqosid ISA extension (Supervisor-mode
Quality of Service ID).
diff --git a/arch/riscv/kernel/qos/Makefile b/arch/riscv/kernel/qos/Makefile
index 9f996263a86d..9ed0c13a854d 100644
--- a/arch/riscv/kernel/qos/Makefile
+++ b/arch/riscv/kernel/qos/Makefile
@@ -1,2 +1,2 @@
# SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_RISCV_ISA_SSQOSID) += qos.o
+obj-$(CONFIG_RISCV_ISA_SSQOSID) += qos.o qos_resctrl.o
diff --git a/arch/riscv/kernel/qos/qos.c b/arch/riscv/kernel/qos/qos.c
index a3c2b910e2e0..560607abf10a 100644
--- a/arch/riscv/kernel/qos/qos.c
+++ b/arch/riscv/kernel/qos/qos.c
@@ -1,8 +1,40 @@
// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/riscv_qos.h>
+
+#include <asm/csr.h>
#include <asm/qos.h>
+#include "internal.h"
+
/* cached value of srmcfg csr for each cpu */
DEFINE_PER_CPU(u32, cpu_srmcfg);
/* default srmcfg value for each cpu, set via resctrl cpu assignment */
DEFINE_PER_CPU(u32, cpu_srmcfg_default);
+
+static int __init qos_arch_late_init(void)
+{
+ int err;
+
+ if (!riscv_isa_extension_available(NULL, SSQOSID))
+ return -ENODEV;
+
+ err = qos_resctrl_setup();
+ if (err)
+ return err;
+
+ err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "qos:online",
+ qos_resctrl_online_cpu,
+ qos_resctrl_offline_cpu);
+ if (err < 0) {
+ resctrl_exit();
+ return err;
+ }
+
+ return 0;
+}
+late_initcall(qos_arch_late_init);
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 06/11] RISC-V: QoS: add resctrl setup and domain management
From: Drew Fustini @ 2026-04-15 1:54 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Add the setup and domain management layer: domain allocation
(qos_new_domain), controller value initialization
(qos_init_domain_ctrlval), resource struct initialization for cache and
bandwidth resources, domain registration with the resctrl filesystem
(qos_resctrl_add_controller_domain), and the top-level setup function
(qos_resctrl_setup) that probes all controllers and calls resctrl_init().
Also add qos_resctrl_online_cpu() and qos_resctrl_offline_cpu() for CPU
hotplug integration.
Co-developed-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
arch/riscv/kernel/qos/qos_resctrl.c | 295 +++++++++++++++++++++++++++++++++++-
1 file changed, 294 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/qos/qos_resctrl.c b/arch/riscv/kernel/qos/qos_resctrl.c
index a4a120f89840..8d7e3b0abb75 100644
--- a/arch/riscv/kernel/qos/qos_resctrl.c
+++ b/arch/riscv/kernel/qos/qos_resctrl.c
@@ -675,7 +675,23 @@ void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_l3_mon_domai
void resctrl_arch_reset_all_ctrls(struct rdt_resource *r)
{
- /* not implemented for the RISC-V resctrl implementation */
+ struct cbqri_resctrl_res *hw_res;
+ struct rdt_ctrl_domain *d;
+ enum resctrl_conf_type t;
+ u32 default_ctrl;
+ int i;
+
+ lockdep_assert_cpus_held();
+
+ hw_res = container_of(r, struct cbqri_resctrl_res, resctrl_res);
+ default_ctrl = resctrl_get_default_ctrl(r);
+
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ for (i = 0; i < hw_res->max_rcid; i++) {
+ for (t = 0; t < CDP_NUM_TYPES; t++)
+ resctrl_arch_update_one(r, d, i, t, default_ctrl);
+ }
+ }
}
void resctrl_arch_pre_mount(void)
@@ -797,3 +813,280 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
spin_unlock(&ctrl->lock);
return val;
}
+
+static struct rdt_ctrl_domain *qos_new_domain(struct cbqri_controller *ctrl)
+{
+ struct cbqri_resctrl_dom *hw_dom;
+ struct rdt_ctrl_domain *domain;
+
+ hw_dom = kzalloc_obj(*hw_dom, GFP_KERNEL);
+ if (!hw_dom)
+ return NULL;
+
+ /* associate this cbqri_controller with the domain */
+ hw_dom->hw_ctrl = ctrl;
+
+ /* the rdt_domain struct from inside the cbqri_resctrl_dom struct */
+ domain = &hw_dom->resctrl_ctrl_dom;
+
+ INIT_LIST_HEAD(&domain->hdr.list);
+
+ return domain;
+}
+
+static int qos_init_domain_ctrlval(struct rdt_resource *r, struct rdt_ctrl_domain *d)
+{
+ struct cbqri_resctrl_res *hw_res;
+ int err = 0;
+ int i;
+
+ hw_res = container_of(r, struct cbqri_resctrl_res, resctrl_res);
+
+ for (i = 0; i < hw_res->max_rcid; i++) {
+ err = resctrl_arch_update_one(r, d, i, 0, resctrl_get_default_ctrl(r));
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+static int qos_init_cache_resource(struct cbqri_controller *ctrl,
+ struct cbqri_resctrl_res *cbqri_res,
+ enum resctrl_res_level rid, char *name,
+ enum resctrl_scope scope)
+{
+ struct rdt_resource *res = &cbqri_res->resctrl_res;
+
+ /* Already initialized by a previous controller at this cache level */
+ if (res->name) {
+ if (cbqri_res->max_rcid != ctrl->rcid_count ||
+ res->cache.cbm_len != ctrl->cc.ncblks) {
+ pr_err("%s controllers have mismatched capabilities\n",
+ name);
+ return -EINVAL;
+ }
+ return 0;
+ }
+
+ cbqri_res->max_rcid = ctrl->rcid_count;
+ cbqri_res->max_mcid = ctrl->mcid_count;
+ res->rid = rid;
+ res->name = name;
+ res->alloc_capable = ctrl->alloc_capable;
+ res->schema_fmt = RESCTRL_SCHEMA_BITMAP;
+ res->ctrl_scope = scope;
+ res->cache.cbm_len = ctrl->cc.ncblks;
+ res->cache.shareable_bits = resctrl_get_default_ctrl(res);
+ res->cache.min_cbm_bits = 1;
+ return 0;
+}
+
+static int qos_init_membw_resource(struct cbqri_controller *ctrl,
+ struct cbqri_resctrl_res *cbqri_res)
+{
+ struct rdt_resource *res = &cbqri_res->resctrl_res;
+
+ if (res->name) {
+ if (cbqri_res->max_rcid != ctrl->rcid_count ||
+ res->membw.max_bw != DIV_ROUND_UP(ctrl->bc.mrbwb * 100,
+ ctrl->bc.nbwblks)) {
+ pr_err("MB controllers have mismatched capabilities\n");
+ return -EINVAL;
+ }
+ return 0;
+ }
+
+ cbqri_res->max_rcid = ctrl->rcid_count;
+ cbqri_res->max_mcid = ctrl->mcid_count;
+ res->rid = RDT_RESOURCE_MBA;
+ res->name = "MB";
+ res->alloc_capable = ctrl->alloc_capable;
+ res->schema_fmt = RESCTRL_SCHEMA_RANGE;
+ /*
+ * resctrl requires a cache scope for MBA domains. Use L3 as a
+ * proxy until the framework supports non-cache scopes for
+ * bandwidth resources.
+ */
+ res->ctrl_scope = RESCTRL_L3_CACHE;
+ res->membw.delay_linear = true;
+ res->membw.arch_needs_linear = true;
+ res->membw.throttle_mode = THREAD_THROTTLE_UNDEFINED;
+ res->membw.min_bw = 1;
+ res->membw.max_bw = DIV_ROUND_UP(ctrl->bc.mrbwb * 100, ctrl->bc.nbwblks);
+ res->membw.bw_gran = 1;
+ return 0;
+}
+
+static int qos_resctrl_add_controller_domain(struct cbqri_controller *ctrl)
+{
+ struct rdt_ctrl_domain *domain;
+ struct cbqri_resctrl_res *cbqri_res = NULL;
+ struct rdt_resource *res = NULL;
+ struct list_head *pos = NULL;
+ int err;
+
+ domain = qos_new_domain(ctrl);
+ if (!domain)
+ return -ENOSPC;
+
+ switch (ctrl->type) {
+ case CBQRI_CONTROLLER_TYPE_CAPACITY:
+ cpumask_copy(&domain->hdr.cpu_mask, &ctrl->cache.cpu_mask);
+ domain->hdr.id = ctrl->cache.cache_id;
+
+ if (ctrl->cache.cache_level == 2) {
+ cbqri_res = &cbqri_resctrl_resources[RDT_RESOURCE_L2];
+ err = qos_init_cache_resource(ctrl, cbqri_res,
+ RDT_RESOURCE_L2, "L2",
+ RESCTRL_L2_CACHE);
+ } else if (ctrl->cache.cache_level == 3) {
+ cbqri_res = &cbqri_resctrl_resources[RDT_RESOURCE_L3];
+ err = qos_init_cache_resource(ctrl, cbqri_res,
+ RDT_RESOURCE_L3, "L3",
+ RESCTRL_L3_CACHE);
+ } else {
+ pr_err("unknown cache level %d\n", ctrl->cache.cache_level);
+ err = -ENODEV;
+ }
+ if (err)
+ goto err_free_domain;
+ res = &cbqri_res->resctrl_res;
+ break;
+
+ case CBQRI_CONTROLLER_TYPE_BANDWIDTH:
+ cpumask_copy(&domain->hdr.cpu_mask, &ctrl->mem.cpu_mask);
+ domain->hdr.id = ctrl->mem.prox_dom;
+ if (ctrl->alloc_capable) {
+ cbqri_res = &cbqri_resctrl_resources[RDT_RESOURCE_MBA];
+ err = qos_init_membw_resource(ctrl, cbqri_res);
+ if (err)
+ goto err_free_domain;
+ res = &cbqri_res->resctrl_res;
+ }
+ break;
+
+ default:
+ pr_err("unknown controller type %d\n", ctrl->type);
+ err = -ENODEV;
+ goto err_free_domain;
+ }
+
+ if (!res)
+ goto out;
+
+ err = qos_init_domain_ctrlval(res, domain);
+ if (err)
+ goto err_free_domain;
+
+ if (resctrl_find_domain(&res->ctrl_domains, domain->hdr.id, &pos)) {
+ pr_err("duplicate domain id %d for resource %s\n",
+ domain->hdr.id, res->name);
+ err = -EEXIST;
+ goto err_free_domain;
+ }
+ if (pos)
+ list_add_tail(&domain->hdr.list, pos);
+ else
+ list_add_tail(&domain->hdr.list, &res->ctrl_domains);
+
+ err = resctrl_online_ctrl_domain(res, domain);
+ if (err) {
+ pr_err("failed to online domain %d\n", domain->hdr.id);
+ list_del(&domain->hdr.list);
+ goto err_free_domain;
+ }
+
+out:
+ return 0;
+
+err_free_domain:
+ kfree(container_of(domain, struct cbqri_resctrl_dom, resctrl_ctrl_dom));
+ return err;
+}
+
+int qos_resctrl_setup(void)
+{
+ struct rdt_ctrl_domain *domain, *domain_temp;
+ struct cbqri_controller *ctrl;
+ struct cbqri_resctrl_res *res;
+ int err = 0;
+ int i = 0;
+
+ max_rmid = U32_MAX;
+
+ for (i = 0; i < RDT_NUM_RESOURCES; i++) {
+ res = &cbqri_resctrl_resources[i];
+ INIT_LIST_HEAD(&res->resctrl_res.ctrl_domains);
+ INIT_LIST_HEAD(&res->resctrl_res.mon_domains);
+ res->resctrl_res.rid = i;
+ }
+
+ list_for_each_entry(ctrl, &cbqri_controllers, list) {
+ err = cbqri_probe_controller(ctrl);
+ if (err) {
+ pr_err("%s(): failed (%d)\n", __func__, err);
+ goto err_free_controllers_list;
+ }
+
+ err = qos_resctrl_add_controller_domain(ctrl);
+ if (err) {
+ pr_err("%s(): failed to add controller domain (%d)\n", __func__, err);
+ goto err_free_controllers_list;
+ }
+
+ /*
+ * CDP (code data prioritization) on x86 is similar to
+ * the AT (access type) field in CBQRI. CDP only supports
+ * caches so this must be a CBQRI capacity controller.
+ */
+ if (ctrl->type == CBQRI_CONTROLLER_TYPE_CAPACITY &&
+ ctrl->cc.supports_alloc_at_code) {
+ if (ctrl->cache.cache_level == 2)
+ exposed_cdp_l2_capable = true;
+ else
+ exposed_cdp_l3_capable = true;
+ }
+ }
+ pr_debug("alloc=%d cdp_l2=%d cdp_l3=%d\n",
+ exposed_alloc_capable,
+ exposed_cdp_l2_capable, exposed_cdp_l3_capable);
+
+ err = resctrl_init();
+ if (err)
+ goto err_free_controllers_list;
+
+ return 0;
+
+err_free_controllers_list:
+ for (i = 0; i < RDT_NUM_RESOURCES; i++) {
+ res = &cbqri_resctrl_resources[i];
+ list_for_each_entry_safe(domain, domain_temp, &res->resctrl_res.ctrl_domains,
+ hdr.list) {
+ resctrl_offline_ctrl_domain(&res->resctrl_res, domain);
+ list_del(&domain->hdr.list);
+ kfree(container_of(domain, struct cbqri_resctrl_dom, resctrl_ctrl_dom));
+ }
+ }
+
+ list_for_each_entry(ctrl, &cbqri_controllers, list) {
+ if (!ctrl->base)
+ break;
+ iounmap(ctrl->base);
+ ctrl->base = NULL;
+ release_mem_region(ctrl->addr, ctrl->size);
+ }
+
+ return err;
+}
+
+int qos_resctrl_online_cpu(unsigned int cpu)
+{
+ resctrl_online_cpu(cpu);
+ return 0;
+}
+
+int qos_resctrl_offline_cpu(unsigned int cpu)
+{
+ resctrl_offline_cpu(cpu);
+ return 0;
+}
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 05/11] RISC-V: QoS: add resctrl arch callbacks for CBQRI controllers
From: Drew Fustini @ 2026-04-15 1:53 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Implement the resctrl architecture callbacks required by the resctrl
filesystem and expose them via arch/riscv/include/asm/resctrl.h.
These include capability reporting, CDP enable/disable, CLOSID/RMID
encoding, scheduler integration (sched_in, set_closid_rmid,
sync_cpu_closid_rmid), domain config read/write (update_one,
update_domains, get_config), and stub implementations for monitoring
operations not yet supported on RISC-V.
The function prototypes and inline stubs are declared in
include/linux/riscv_qos.h alongside the implementations in
arch/riscv/kernel/qos/qos_resctrl.c.
Co-developed-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
MAINTAINERS | 1 +
arch/riscv/include/asm/resctrl.h | 7 +
arch/riscv/kernel/qos/qos_resctrl.c | 367 ++++++++++++++++++++++++++++++++++++
include/linux/riscv_qos.h | 33 ++++
4 files changed, 408 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 6a66d7047c51..af9698a16439 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22784,6 +22784,7 @@ R: yunhui cui <cuiyunhui@bytedance.com>
L: linux-riscv@lists.infradead.org
S: Supported
F: arch/riscv/include/asm/qos.h
+F: arch/riscv/include/asm/resctrl.h
F: arch/riscv/kernel/qos/
F: include/linux/riscv_qos.h
diff --git a/arch/riscv/include/asm/resctrl.h b/arch/riscv/include/asm/resctrl.h
new file mode 100644
index 000000000000..48ad45cbe25c
--- /dev/null
+++ b/arch/riscv/include/asm/resctrl.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASM_RISCV_RESCTRL_H
+#define _ASM_RISCV_RESCTRL_H
+
+#include <linux/riscv_qos.h>
+
+#endif /* _ASM_RISCV_RESCTRL_H */
diff --git a/arch/riscv/kernel/qos/qos_resctrl.c b/arch/riscv/kernel/qos/qos_resctrl.c
index 6d294f2f2504..a4a120f89840 100644
--- a/arch/riscv/kernel/qos/qos_resctrl.c
+++ b/arch/riscv/kernel/qos/qos_resctrl.c
@@ -2,6 +2,7 @@
#define pr_fmt(fmt) "qos: resctrl: " fmt
+#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/io-64-nonatomic-lo-hi.h>
@@ -430,3 +431,369 @@ static int cbqri_probe_controller(struct cbqri_controller *ctrl)
release_mem_region(ctrl->addr, ctrl->size);
return err;
}
+
+bool resctrl_arch_alloc_capable(void)
+{
+ return exposed_alloc_capable;
+}
+
+bool resctrl_arch_mon_capable(void)
+{
+ /* Monitoring not yet implemented */
+ return false;
+}
+
+bool resctrl_arch_get_cdp_enabled(enum resctrl_res_level rid)
+{
+ switch (rid) {
+ case RDT_RESOURCE_L2:
+ return is_cdp_l2_enabled;
+
+ case RDT_RESOURCE_L3:
+ return is_cdp_l3_enabled;
+
+ default:
+ return false;
+ }
+}
+
+int resctrl_arch_set_cdp_enabled(enum resctrl_res_level rid, bool enable)
+{
+ switch (rid) {
+ case RDT_RESOURCE_L2:
+ if (!exposed_cdp_l2_capable)
+ return -ENODEV;
+ is_cdp_l2_enabled = enable;
+ break;
+
+ case RDT_RESOURCE_L3:
+ if (!exposed_cdp_l3_capable)
+ return -ENODEV;
+ is_cdp_l3_enabled = enable;
+ break;
+
+ default:
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+struct rdt_resource *resctrl_arch_get_resource(enum resctrl_res_level l)
+{
+ if (l >= RDT_NUM_RESOURCES)
+ return NULL;
+
+ return &cbqri_resctrl_resources[l].resctrl_res;
+}
+
+bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt)
+{
+ return false;
+}
+
+void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r,
+ enum resctrl_event_id evtid)
+{
+ /* RISC-V can always read an rmid, nothing needs allocating */
+ return NULL;
+}
+
+void resctrl_arch_mon_ctx_free(struct rdt_resource *r,
+ enum resctrl_event_id evtid, void *arch_mon_ctx)
+{
+ /* No arch-private monitoring context to free */
+}
+
+void resctrl_arch_config_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
+ enum resctrl_event_id evtid, u32 rmid, u32 closid,
+ u32 cntr_id, bool assign)
+{
+ /* MBM counter assignment not supported */
+}
+
+int resctrl_arch_cntr_read(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
+ u32 unused, u32 rmid, int cntr_id,
+ enum resctrl_event_id eventid, u64 *val)
+{
+ /* MBM counter assignment not supported */
+ return -EOPNOTSUPP;
+}
+
+bool resctrl_arch_mbm_cntr_assign_enabled(struct rdt_resource *r)
+{
+ /* MBM counter assignment not supported */
+ return false;
+}
+
+int resctrl_arch_mbm_cntr_assign_set(struct rdt_resource *r, bool enable)
+{
+ /* MBM counter assignment not supported */
+ return 0;
+}
+
+void resctrl_arch_reset_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
+ u32 unused, u32 rmid, int cntr_id,
+ enum resctrl_event_id eventid)
+{
+ /* MBM counter assignment not supported */
+}
+
+bool resctrl_arch_get_io_alloc_enabled(struct rdt_resource *r)
+{
+ /* CBQRI does not have I/O-specific allocation */
+ return false;
+}
+
+int resctrl_arch_io_alloc_enable(struct rdt_resource *r, bool enable)
+{
+ /* CBQRI does not have I/O-specific allocation */
+ return 0;
+}
+
+/*
+ * Note about terminology between x86 (Intel RDT/AMD QoS) and RISC-V:
+ * CLOSID on x86 is RCID on RISC-V
+ * RMID on x86 is MCID on RISC-V
+ */
+u32 resctrl_arch_get_num_closid(struct rdt_resource *res)
+{
+ struct cbqri_resctrl_res *hw_res;
+
+ hw_res = container_of(res, struct cbqri_resctrl_res, resctrl_res);
+
+ return hw_res->max_rcid;
+}
+
+u32 resctrl_arch_system_num_rmid_idx(void)
+{
+ return max_rmid;
+}
+
+u32 resctrl_arch_rmid_idx_encode(u32 closid, u32 rmid)
+{
+ return rmid;
+}
+
+void resctrl_arch_rmid_idx_decode(u32 idx, u32 *closid, u32 *rmid)
+{
+ *closid = RISCV_RESCTRL_EMPTY_CLOSID;
+ *rmid = idx;
+}
+
+void resctrl_arch_set_cpu_default_closid_rmid(int cpu, u32 closid, u32 rmid)
+{
+ u32 srmcfg;
+
+ WARN_ON_ONCE((closid & SRMCFG_RCID_MASK) != closid);
+ WARN_ON_ONCE((rmid & SRMCFG_MCID_MASK) != rmid);
+
+ srmcfg = rmid << SRMCFG_MCID_SHIFT;
+ srmcfg |= closid;
+ WRITE_ONCE(per_cpu(cpu_srmcfg_default, cpu), srmcfg);
+}
+
+void resctrl_arch_sched_in(struct task_struct *tsk)
+{
+ __switch_to_srmcfg(tsk);
+}
+
+void resctrl_arch_set_closid_rmid(struct task_struct *tsk, u32 closid, u32 rmid)
+{
+ u32 srmcfg;
+
+ WARN_ON_ONCE((closid & SRMCFG_RCID_MASK) != closid);
+ WARN_ON_ONCE((rmid & SRMCFG_MCID_MASK) != rmid);
+
+ srmcfg = rmid << SRMCFG_MCID_SHIFT;
+ srmcfg |= closid;
+ WRITE_ONCE(tsk->thread.srmcfg, srmcfg);
+}
+
+void resctrl_arch_sync_cpu_closid_rmid(void *info)
+{
+ struct resctrl_cpu_defaults *r = info;
+
+ lockdep_assert_preemption_disabled();
+
+ if (r) {
+ resctrl_arch_set_cpu_default_closid_rmid(smp_processor_id(),
+ r->closid, r->rmid);
+ }
+
+ resctrl_arch_sched_in(current);
+}
+
+bool resctrl_arch_match_closid(struct task_struct *tsk, u32 closid)
+{
+ return (READ_ONCE(tsk->thread.srmcfg) & SRMCFG_RCID_MASK) == closid;
+}
+
+bool resctrl_arch_match_rmid(struct task_struct *tsk, u32 closid, u32 rmid)
+{
+ u32 tsk_rmid;
+
+ tsk_rmid = READ_ONCE(tsk->thread.srmcfg);
+ tsk_rmid >>= SRMCFG_MCID_SHIFT;
+ tsk_rmid &= SRMCFG_MCID_MASK;
+
+ return tsk_rmid == rmid;
+}
+
+int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain_hdr *hdr,
+ u32 closid, u32 rmid, enum resctrl_event_id eventid,
+ void *arch_priv, u64 *val, void *arch_mon_ctx)
+{
+ /*
+ * Cache occupancy and bandwidth monitoring are not yet implemented
+ * for RISC-V CBQRI. This will be added in a future series once the
+ * resctrl framework supports monitoring domains at non-L3 scopes.
+ */
+ return -EOPNOTSUPP;
+}
+
+void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
+ u32 closid, u32 rmid, enum resctrl_event_id eventid)
+{
+ /* Monitoring not yet supported; nothing to reset */
+}
+
+void resctrl_arch_mon_event_config_read(void *info)
+{
+ /* Monitoring not yet supported; no event config */
+}
+
+void resctrl_arch_mon_event_config_write(void *info)
+{
+ /* Monitoring not yet supported; no event config */
+}
+
+void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_l3_mon_domain *d)
+{
+ /* Monitoring not yet supported; nothing to reset */
+}
+
+void resctrl_arch_reset_all_ctrls(struct rdt_resource *r)
+{
+ /* not implemented for the RISC-V resctrl implementation */
+}
+
+void resctrl_arch_pre_mount(void)
+{
+ /* All controllers discovered at boot via late_initcall; nothing to do */
+}
+
+int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain *d,
+ u32 closid, enum resctrl_conf_type t, u32 cfg_val)
+{
+ struct cbqri_controller *ctrl;
+ struct cbqri_resctrl_dom *dom;
+ struct cbqri_config cfg;
+ int err = 0;
+
+ dom = container_of(d, struct cbqri_resctrl_dom, resctrl_ctrl_dom);
+ ctrl = dom->hw_ctrl;
+
+ if (!r->alloc_capable)
+ return -EINVAL;
+
+ switch (r->rid) {
+ case RDT_RESOURCE_L2:
+ case RDT_RESOURCE_L3:
+ cfg.cbm = cfg_val;
+ err = cbqri_apply_cache_config(dom, closid, t, &cfg);
+ break;
+ case RDT_RESOURCE_MBA:
+ /* convert from percentage to bandwidth blocks */
+ cfg.rbwb = cfg_val * ctrl->bc.nbwblks / 100;
+ cfg.rbwb = min_t(u64, cfg.rbwb, ctrl->bc.mrbwb);
+ err = cbqri_apply_bw_config(dom, closid, t, &cfg);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return err;
+}
+
+int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
+{
+ struct resctrl_staged_config *cfg;
+ enum resctrl_conf_type t;
+ struct rdt_ctrl_domain *d;
+ int err = 0;
+
+ /* Walking r->ctrl_domains, ensure it can't race with cpuhp */
+ lockdep_assert_cpus_held();
+
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ for (t = 0; t < CDP_NUM_TYPES; t++) {
+ cfg = &d->staged_config[t];
+ if (!cfg->have_new_ctrl)
+ continue;
+ err = resctrl_arch_update_one(r, d, closid, t, cfg->new_ctrl);
+ if (err) {
+ pr_err("%s(): update failed (err=%d)\n", __func__, err);
+ return err;
+ }
+ }
+ }
+ return err;
+}
+
+u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
+ u32 closid, enum resctrl_conf_type type)
+{
+ struct cbqri_resctrl_dom *hw_dom;
+ struct cbqri_controller *ctrl;
+ u32 val;
+ u32 rbwb;
+ int err;
+
+ hw_dom = container_of(d, struct cbqri_resctrl_dom, resctrl_ctrl_dom);
+
+ ctrl = hw_dom->hw_ctrl;
+
+ val = resctrl_get_default_ctrl(r);
+
+ if (!r->alloc_capable)
+ return val;
+
+ spin_lock(&ctrl->lock);
+
+ switch (r->rid) {
+ case RDT_RESOURCE_L2:
+ case RDT_RESOURCE_L3:
+ /* Clear cc_block_mask before read limit operation */
+ cbqri_set_cbm(ctrl, 0);
+
+ /* Capacity read limit operation for RCID (closid) */
+ err = cbqri_cc_alloc_op(ctrl, CBQRI_CC_ALLOC_CTL_OP_READ_LIMIT, closid, type);
+ if (err < 0) {
+ pr_err("%s(): operation failed: err = %d\n", __func__, err);
+ break;
+ }
+
+ /* Read capacity block mask for RCID (closid) */
+ val = ioread64(ctrl->base + CBQRI_CC_BLOCK_MASK_OFF);
+ break;
+
+ case RDT_RESOURCE_MBA:
+ /* Bandwidth read limit operation for RCID (closid) */
+ err = cbqri_bc_alloc_op(ctrl, CBQRI_BC_ALLOC_CTL_OP_READ_LIMIT, closid);
+ if (err < 0) {
+ pr_err("%s(): operation failed: err = %d\n", __func__, err);
+ break;
+ }
+
+ rbwb = cbqri_get_rbwb(ctrl);
+ val = DIV_ROUND_UP(rbwb * 100, ctrl->bc.nbwblks);
+ break;
+
+ default:
+ break;
+ }
+
+ spin_unlock(&ctrl->lock);
+ return val;
+}
diff --git a/include/linux/riscv_qos.h b/include/linux/riscv_qos.h
index 0f3daae2e84f..1712fb12f6bc 100644
--- a/include/linux/riscv_qos.h
+++ b/include/linux/riscv_qos.h
@@ -3,6 +3,7 @@
#ifndef __LINUX_RISCV_QOS_H
#define __LINUX_RISCV_QOS_H
+#include <linux/resctrl_types.h>
#include <linux/spinlock.h>
#include <linux/types.h>
@@ -73,4 +74,36 @@ struct cbqri_controller {
extern struct list_head cbqri_controllers;
+bool resctrl_arch_alloc_capable(void);
+bool resctrl_arch_mon_capable(void);
+
+struct rdt_resource;
+/*
+ * Note about terminology between x86 (Intel RDT/AMD QoS) and RISC-V:
+ * CLOSID on x86 is RCID on RISC-V
+ * RMID on x86 is MCID on RISC-V
+ * CDP on x86 is AT (access type) on RISC-V
+ */
+u32 resctrl_arch_rmid_idx_encode(u32 closid, u32 rmid);
+void resctrl_arch_rmid_idx_decode(u32 idx, u32 *closid, u32 *rmid);
+void resctrl_arch_set_cpu_default_closid_rmid(int cpu, u32 closid, u32 rmid);
+void resctrl_arch_sched_in(struct task_struct *tsk);
+void resctrl_arch_set_closid_rmid(struct task_struct *tsk, u32 closid, u32 rmid);
+bool resctrl_arch_match_closid(struct task_struct *tsk, u32 closid);
+bool resctrl_arch_match_rmid(struct task_struct *tsk, u32 closid, u32 rmid);
+void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, enum resctrl_event_id evtid);
+void resctrl_arch_mon_ctx_free(struct rdt_resource *r, enum resctrl_event_id evtid,
+ void *arch_mon_ctx);
+
+static inline unsigned int resctrl_arch_round_mon_val(unsigned int val)
+{
+ return val;
+}
+
+/* Not needed for RISC-V */
+static inline void resctrl_arch_enable_mon(void) { }
+static inline void resctrl_arch_disable_mon(void) { }
+static inline void resctrl_arch_enable_alloc(void) { }
+static inline void resctrl_arch_disable_alloc(void) { }
+
#endif /* __LINUX_RISCV_QOS_H */
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 04/11] RISC-V: QoS: add CBQRI hardware interface
From: Drew Fustini @ 2026-04-15 1:53 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Add the CBQRI controller hardware interface layer.
Define data structures representing CBQRI controller properties
(cbqri_controller) and hardware capabilities for capacity and bandwidth
controllers (riscv_cbqri_capacity_caps, riscv_cbqri_bandwidth_caps) in
include/linux/riscv_qos.h.
Define MMIO register offsets, field masks, and internal wrapper structs
(cbqri_resctrl_res, cbqri_resctrl_dom, cbqri_config) in internal.h.
Implement MMIO helpers for capacity block mask and bandwidth reservation,
alloc control operations for capacity and bandwidth controllers, and
probe functions to discover controller capabilities. A per-controller
spinlock serializes multi-step MMIO sequences.
Co-developed-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Adrien Ricciardi <aricciardi@baylibre.com>
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
MAINTAINERS | 1 +
arch/riscv/kernel/qos/internal.h | 81 +++++++
arch/riscv/kernel/qos/qos_resctrl.c | 432 ++++++++++++++++++++++++++++++++++++
include/linux/riscv_qos.h | 76 +++++++
4 files changed, 590 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index b17f885411ba..6a66d7047c51 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22785,6 +22785,7 @@ L: linux-riscv@lists.infradead.org
S: Supported
F: arch/riscv/include/asm/qos.h
F: arch/riscv/kernel/qos/
+F: include/linux/riscv_qos.h
RISC-V RPMI AND MPXY DRIVERS
M: Rahul Pathak <rahul@summations.net>
diff --git a/arch/riscv/kernel/qos/internal.h b/arch/riscv/kernel/qos/internal.h
new file mode 100644
index 000000000000..edbcbd9471b1
--- /dev/null
+++ b/arch/riscv/kernel/qos/internal.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASM_RISCV_QOS_INTERNAL_H
+#define _ASM_RISCV_QOS_INTERNAL_H
+
+#include <linux/bitfield.h>
+#include <linux/resctrl.h>
+#include <linux/riscv_qos.h>
+
+#define RISCV_RESCTRL_EMPTY_CLOSID ((u32)~0)
+
+#define CBQRI_CC_CAPABILITIES_OFF 0
+#define CBQRI_CC_MON_CTL_OFF 8
+#define CBQRI_CC_MON_CTL_VAL_OFF 16
+#define CBQRI_CC_ALLOC_CTL_OFF 24
+#define CBQRI_CC_BLOCK_MASK_OFF 32
+
+#define CBQRI_BC_CAPABILITIES_OFF 0
+#define CBQRI_BC_MON_CTL_OFF 8
+#define CBQRI_BC_MON_CTR_VAL_OFF 16
+#define CBQRI_BC_ALLOC_CTL_OFF 24
+#define CBQRI_BC_BW_ALLOC_OFF 32
+
+#define CBQRI_CC_CAPABILITIES_VER_MINOR_MASK GENMASK(3, 0)
+#define CBQRI_CC_CAPABILITIES_VER_MAJOR_MASK GENMASK(7, 4)
+
+#define CBQRI_CC_CAPABILITIES_NCBLKS_MASK GENMASK(23, 8)
+#define CBQRI_CC_CAPABILITIES_FRCID_MASK GENMASK(24, 24)
+
+#define CBQRI_BC_CAPABILITIES_VER_MINOR_MASK GENMASK(3, 0)
+#define CBQRI_BC_CAPABILITIES_VER_MAJOR_MASK GENMASK(7, 4)
+
+#define CBQRI_BC_CAPABILITIES_NBWBLKS_MASK GENMASK(23, 8)
+#define CBQRI_BC_CAPABILITIES_MRBWB_MASK GENMASK_ULL(47, 32)
+
+#define CBQRI_CONTROL_REGISTERS_OP_MASK GENMASK(4, 0)
+#define CBQRI_CONTROL_REGISTERS_AT_MASK GENMASK(7, 5)
+#define CBQRI_CONTROL_REGISTERS_AT_DATA 0
+#define CBQRI_CONTROL_REGISTERS_AT_CODE 1
+#define CBQRI_CONTROL_REGISTERS_RCID_MASK GENMASK(19, 8)
+#define CBQRI_CONTROL_REGISTERS_STATUS_MASK GENMASK_ULL(38, 32)
+#define CBQRI_CONTROL_REGISTERS_BUSY_MASK GENMASK_ULL(39, 39)
+#define CBQRI_CONTROL_REGISTERS_RBWB_MASK GENMASK(15, 0)
+
+#define CBQRI_CC_MON_CTL_OP_CONFIG_EVENT 1
+#define CBQRI_CC_MON_CTL_OP_READ_COUNTER 2
+#define CBQRI_CC_MON_CTL_STATUS_SUCCESS 1
+
+#define CBQRI_CC_ALLOC_CTL_OP_CONFIG_LIMIT 1
+#define CBQRI_CC_ALLOC_CTL_OP_READ_LIMIT 2
+#define CBQRI_CC_ALLOC_CTL_OP_FLUSH_RCID 3
+#define CBQRI_CC_ALLOC_CTL_STATUS_SUCCESS 1
+
+#define CBQRI_BC_MON_CTL_OP_CONFIG_EVENT 1
+#define CBQRI_BC_MON_CTL_OP_READ_COUNTER 2
+#define CBQRI_BC_MON_CTL_STATUS_SUCCESS 1
+
+#define CBQRI_BC_ALLOC_CTL_OP_CONFIG_LIMIT 1
+#define CBQRI_BC_ALLOC_CTL_OP_READ_LIMIT 2
+#define CBQRI_BC_ALLOC_CTL_STATUS_SUCCESS 1
+
+int qos_resctrl_setup(void);
+int qos_resctrl_online_cpu(unsigned int cpu);
+int qos_resctrl_offline_cpu(unsigned int cpu);
+
+struct cbqri_resctrl_res {
+ struct rdt_resource resctrl_res;
+ u32 max_rcid;
+ u32 max_mcid;
+};
+
+struct cbqri_resctrl_dom {
+ struct rdt_ctrl_domain resctrl_ctrl_dom;
+ struct cbqri_controller *hw_ctrl;
+};
+
+struct cbqri_config {
+ u64 cbm; /* capacity block mask */
+ u64 rbwb; /* reserved bandwidth blocks */
+};
+
+#endif /* _ASM_RISCV_QOS_INTERNAL_H */
diff --git a/arch/riscv/kernel/qos/qos_resctrl.c b/arch/riscv/kernel/qos/qos_resctrl.c
new file mode 100644
index 000000000000..6d294f2f2504
--- /dev/null
+++ b/arch/riscv/kernel/qos/qos_resctrl.c
@@ -0,0 +1,432 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#define pr_fmt(fmt) "qos: resctrl: " fmt
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/iopoll.h>
+#include <linux/ioport.h>
+#include <linux/resctrl.h>
+#include <linux/riscv_qos.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <asm/csr.h>
+#include <asm/qos.h>
+#include "internal.h"
+
+static struct cbqri_resctrl_res cbqri_resctrl_resources[RDT_NUM_RESOURCES];
+
+static bool exposed_alloc_capable;
+/* CDP (code data prioritization) on x86 is AT (access type) on RISC-V */
+static bool exposed_cdp_l2_capable;
+static bool exposed_cdp_l3_capable;
+static bool is_cdp_l2_enabled;
+static bool is_cdp_l3_enabled;
+
+/* used by resctrl_arch_system_num_rmid_idx() */
+static u32 max_rmid;
+
+LIST_HEAD(cbqri_controllers);
+
+static int cbqri_wait_busy_flag(struct cbqri_controller *ctrl, int reg_offset,
+ u64 *regp);
+
+/* Set capacity block mask (cc_block_mask) */
+static void cbqri_set_cbm(struct cbqri_controller *ctrl, u64 cbm)
+{
+ iowrite64(cbm, ctrl->base + CBQRI_CC_BLOCK_MASK_OFF);
+}
+
+/* Set the Rbwb (reserved bandwidth blocks) field in bc_bw_alloc */
+static void cbqri_set_rbwb(struct cbqri_controller *ctrl, u64 rbwb)
+{
+ u64 reg;
+
+ reg = ioread64(ctrl->base + CBQRI_BC_BW_ALLOC_OFF);
+ reg &= ~CBQRI_CONTROL_REGISTERS_RBWB_MASK;
+ reg |= FIELD_PREP(CBQRI_CONTROL_REGISTERS_RBWB_MASK, rbwb);
+ iowrite64(reg, ctrl->base + CBQRI_BC_BW_ALLOC_OFF);
+}
+
+/* Get the Rbwb (reserved bandwidth blocks) field in bc_bw_alloc */
+static u64 cbqri_get_rbwb(struct cbqri_controller *ctrl)
+{
+ u64 reg;
+
+ reg = ioread64(ctrl->base + CBQRI_BC_BW_ALLOC_OFF);
+ return FIELD_GET(CBQRI_CONTROL_REGISTERS_RBWB_MASK, reg);
+}
+
+static int cbqri_wait_busy_flag(struct cbqri_controller *ctrl, int reg_offset,
+ u64 *regp)
+{
+ u64 reg;
+ int ret;
+
+ ret = readq_poll_timeout_atomic(ctrl->base + reg_offset, reg,
+ !FIELD_GET(CBQRI_CONTROL_REGISTERS_BUSY_MASK, reg),
+ 0, 1000);
+ if (!ret && regp)
+ *regp = reg;
+
+ return ret;
+}
+
+/* Perform capacity allocation control operation on capacity controller */
+static int cbqri_cc_alloc_op(struct cbqri_controller *ctrl, int operation, int rcid,
+ enum resctrl_conf_type type)
+{
+ int reg_offset = CBQRI_CC_ALLOC_CTL_OFF;
+ int status;
+ u64 reg;
+
+ reg = ioread64(ctrl->base + reg_offset);
+ reg &= ~CBQRI_CONTROL_REGISTERS_OP_MASK;
+ reg |= FIELD_PREP(CBQRI_CONTROL_REGISTERS_OP_MASK, operation);
+ reg &= ~CBQRI_CONTROL_REGISTERS_RCID_MASK;
+ reg |= FIELD_PREP(CBQRI_CONTROL_REGISTERS_RCID_MASK, rcid);
+
+ /* CBQRI capacity AT is only supported on L2 and L3 caches for now */
+ if (ctrl->type == CBQRI_CONTROLLER_TYPE_CAPACITY &&
+ ((ctrl->cache.cache_level == 2 && is_cdp_l2_enabled) ||
+ (ctrl->cache.cache_level == 3 && is_cdp_l3_enabled))) {
+ reg &= ~CBQRI_CONTROL_REGISTERS_AT_MASK;
+ switch (type) {
+ case CDP_CODE:
+ reg |= FIELD_PREP(CBQRI_CONTROL_REGISTERS_AT_MASK,
+ CBQRI_CONTROL_REGISTERS_AT_CODE);
+ break;
+ case CDP_DATA:
+ default:
+ reg |= FIELD_PREP(CBQRI_CONTROL_REGISTERS_AT_MASK,
+ CBQRI_CONTROL_REGISTERS_AT_DATA);
+ break;
+ }
+ }
+
+ iowrite64(reg, ctrl->base + reg_offset);
+
+ if (cbqri_wait_busy_flag(ctrl, reg_offset, ®) < 0) {
+ pr_err("%s(): BUSY timeout when executing the operation\n", __func__);
+ return -EIO;
+ }
+
+ status = FIELD_GET(CBQRI_CONTROL_REGISTERS_STATUS_MASK, reg);
+ if (status != CBQRI_CC_ALLOC_CTL_STATUS_SUCCESS) {
+ pr_err("%s(): operation %d failed: status=%d\n", __func__, operation, status);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/*
+ * Write a capacity block mask and verify the hardware accepted it by
+ * reading back the value after a CONFIG_LIMIT + READ_LIMIT sequence.
+ */
+static int cbqri_apply_cache_config(struct cbqri_resctrl_dom *hw_dom, u32 closid,
+ enum resctrl_conf_type type, struct cbqri_config *cfg)
+{
+ struct cbqri_controller *ctrl = hw_dom->hw_ctrl;
+ int err = 0;
+ u64 reg;
+
+ spin_lock(&ctrl->lock);
+
+ /* Set capacity block mask (cc_block_mask) */
+ cbqri_set_cbm(ctrl, cfg->cbm);
+
+ /* Capacity config limit operation */
+ err = cbqri_cc_alloc_op(ctrl, CBQRI_CC_ALLOC_CTL_OP_CONFIG_LIMIT, closid, type);
+ if (err < 0) {
+ pr_err("%s(): operation failed: err = %d\n", __func__, err);
+ goto out;
+ }
+
+ /* Clear cc_block_mask before read limit to verify op works */
+ cbqri_set_cbm(ctrl, 0);
+
+ /* Perform a capacity read limit operation to verify blockmask */
+ err = cbqri_cc_alloc_op(ctrl, CBQRI_CC_ALLOC_CTL_OP_READ_LIMIT, closid, type);
+ if (err < 0) {
+ pr_err("%s(): operation failed: err = %d\n", __func__, err);
+ goto out;
+ }
+
+ /* Read capacity blockmask to verify it matches the requested config */
+ reg = ioread64(ctrl->base + CBQRI_CC_BLOCK_MASK_OFF);
+ if (reg != cfg->cbm) {
+ pr_err("%s(): failed to verify allocation (reg:%llx != cbm:%llx)\n",
+ __func__, reg, cfg->cbm);
+ err = -EIO;
+ }
+
+out:
+ spin_unlock(&ctrl->lock);
+ return err;
+}
+
+/* Perform bandwidth allocation control operation on bandwidth controller */
+static int cbqri_bc_alloc_op(struct cbqri_controller *ctrl, int operation, int rcid)
+{
+ int reg_offset = CBQRI_BC_ALLOC_CTL_OFF;
+ int status;
+ u64 reg;
+
+ reg = ioread64(ctrl->base + reg_offset);
+ reg &= ~CBQRI_CONTROL_REGISTERS_OP_MASK;
+ reg |= FIELD_PREP(CBQRI_CONTROL_REGISTERS_OP_MASK, operation);
+ reg &= ~CBQRI_CONTROL_REGISTERS_RCID_MASK;
+ reg |= FIELD_PREP(CBQRI_CONTROL_REGISTERS_RCID_MASK, rcid);
+ iowrite64(reg, ctrl->base + reg_offset);
+
+ if (cbqri_wait_busy_flag(ctrl, reg_offset, ®) < 0) {
+ pr_err("%s(): BUSY timeout when executing the operation\n", __func__);
+ return -EIO;
+ }
+
+ status = FIELD_GET(CBQRI_CONTROL_REGISTERS_STATUS_MASK, reg);
+ if (status != CBQRI_BC_ALLOC_CTL_STATUS_SUCCESS) {
+ pr_err("%s(): operation %d failed with status = %d\n",
+ __func__, operation, status);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/*
+ * Write a bandwidth reservation and verify the hardware accepted it by
+ * reading back the value after a CONFIG_LIMIT + READ_LIMIT sequence.
+ */
+static int cbqri_apply_bw_config(struct cbqri_resctrl_dom *hw_dom, u32 closid,
+ enum resctrl_conf_type type, struct cbqri_config *cfg)
+{
+ struct cbqri_controller *ctrl = hw_dom->hw_ctrl;
+ int ret = 0;
+ u64 reg;
+
+ spin_lock(&ctrl->lock);
+
+ /* Set reserved bandwidth blocks */
+ cbqri_set_rbwb(ctrl, cfg->rbwb);
+
+ /* Bandwidth config limit operation */
+ ret = cbqri_bc_alloc_op(ctrl, CBQRI_BC_ALLOC_CTL_OP_CONFIG_LIMIT, closid);
+ if (ret < 0) {
+ pr_err("%s(): operation failed: ret = %d\n", __func__, ret);
+ goto out;
+ }
+
+ /* Clear rbwb before read limit to verify op works */
+ cbqri_set_rbwb(ctrl, 0);
+
+ /* Bandwidth allocation read limit operation to verify */
+ ret = cbqri_bc_alloc_op(ctrl, CBQRI_BC_ALLOC_CTL_OP_READ_LIMIT, closid);
+ if (ret < 0)
+ goto out;
+
+ /* Read bandwidth allocation to verify it matches the requested config */
+ reg = cbqri_get_rbwb(ctrl);
+ if (reg != cfg->rbwb) {
+ pr_err("%s(): failed to verify allocation (reg:%llx != rbwb:%llu)\n",
+ __func__, reg, cfg->rbwb);
+ ret = -EIO;
+ }
+
+out:
+ spin_unlock(&ctrl->lock);
+ return ret;
+}
+
+static int cbqri_probe_feature(struct cbqri_controller *ctrl, int reg_offset,
+ int operation, int *status, bool *access_type_supported)
+{
+ u64 reg, saved_reg;
+ int at;
+
+ /* Keep the initial register value to preserve the WPRI fields */
+ reg = ioread64(ctrl->base + reg_offset);
+ saved_reg = reg;
+
+ /* Execute the requested operation to find if the register is implemented */
+ reg &= ~CBQRI_CONTROL_REGISTERS_OP_MASK;
+ reg |= FIELD_PREP(CBQRI_CONTROL_REGISTERS_OP_MASK, operation);
+ iowrite64(reg, ctrl->base + reg_offset);
+ if (cbqri_wait_busy_flag(ctrl, reg_offset, ®) < 0) {
+ pr_err("%s(): BUSY timeout when executing the operation\n", __func__);
+ return -EIO;
+ }
+
+ /* Get the operation status */
+ *status = FIELD_GET(CBQRI_CONTROL_REGISTERS_STATUS_MASK, reg);
+
+ /*
+ * Check for the AT support if the register is implemented
+ * (if not, the status value will remain 0)
+ */
+ if (*status != 0) {
+ /* Set the AT field to a valid value */
+ reg = saved_reg;
+ reg &= ~CBQRI_CONTROL_REGISTERS_AT_MASK;
+ reg |= FIELD_PREP(CBQRI_CONTROL_REGISTERS_AT_MASK,
+ CBQRI_CONTROL_REGISTERS_AT_CODE);
+ iowrite64(reg, ctrl->base + reg_offset);
+ if (cbqri_wait_busy_flag(ctrl, reg_offset, ®) < 0) {
+ pr_err("%s(): BUSY timeout when setting AT field\n", __func__);
+ return -EIO;
+ }
+
+ /*
+ * If the AT field value has been reset to zero,
+ * then the AT support is not present
+ */
+ at = FIELD_GET(CBQRI_CONTROL_REGISTERS_AT_MASK, reg);
+ if (at == CBQRI_CONTROL_REGISTERS_AT_CODE)
+ *access_type_supported = true;
+ else
+ *access_type_supported = false;
+ }
+
+ /* Restore the original register value */
+ iowrite64(saved_reg, ctrl->base + reg_offset);
+ if (cbqri_wait_busy_flag(ctrl, reg_offset, NULL) < 0) {
+ pr_err("%s(): BUSY timeout when restoring the original register value\n", __func__);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int cbqri_probe_cc(struct cbqri_controller *ctrl)
+{
+ int err, status;
+ u64 reg;
+
+ reg = ioread64(ctrl->base + CBQRI_CC_CAPABILITIES_OFF);
+ if (reg == 0)
+ return -ENODEV;
+
+ ctrl->ver_minor = FIELD_GET(CBQRI_CC_CAPABILITIES_VER_MINOR_MASK, reg);
+ ctrl->ver_major = FIELD_GET(CBQRI_CC_CAPABILITIES_VER_MAJOR_MASK, reg);
+ ctrl->cc.supports_alloc_op_flush_rcid =
+ FIELD_GET(CBQRI_CC_CAPABILITIES_FRCID_MASK, reg);
+ ctrl->cc.ncblks = FIELD_GET(CBQRI_CC_CAPABILITIES_NCBLKS_MASK, reg);
+
+ pr_debug("version=%d.%d ncblks=%d cache_level=%d\n",
+ ctrl->ver_major, ctrl->ver_minor,
+ ctrl->cc.ncblks, ctrl->cache.cache_level);
+
+ /* Probe allocation features (monitoring not yet implemented) */
+ err = cbqri_probe_feature(ctrl, CBQRI_CC_ALLOC_CTL_OFF,
+ CBQRI_CC_ALLOC_CTL_OP_READ_LIMIT,
+ &status, &ctrl->cc.supports_alloc_at_code);
+ if (err)
+ return err;
+
+ if (status == CBQRI_CC_ALLOC_CTL_STATUS_SUCCESS) {
+ ctrl->alloc_capable = true;
+ exposed_alloc_capable = true;
+ }
+
+ return 0;
+}
+
+static int cbqri_probe_bc(struct cbqri_controller *ctrl)
+{
+ int err, status;
+ u64 reg;
+
+ reg = ioread64(ctrl->base + CBQRI_BC_CAPABILITIES_OFF);
+ if (reg == 0)
+ return -ENODEV;
+
+ ctrl->ver_minor = FIELD_GET(CBQRI_BC_CAPABILITIES_VER_MINOR_MASK, reg);
+ ctrl->ver_major = FIELD_GET(CBQRI_BC_CAPABILITIES_VER_MAJOR_MASK, reg);
+ ctrl->bc.nbwblks = FIELD_GET(CBQRI_BC_CAPABILITIES_NBWBLKS_MASK, reg);
+ ctrl->bc.mrbwb = FIELD_GET(CBQRI_BC_CAPABILITIES_MRBWB_MASK, reg);
+
+ if (!ctrl->bc.nbwblks) {
+ pr_err("bandwidth controller has nbwblks=0\n");
+ return -EINVAL;
+ }
+
+ pr_debug("version=%d.%d nbwblks=%d mrbwb=%d\n",
+ ctrl->ver_major, ctrl->ver_minor,
+ ctrl->bc.nbwblks, ctrl->bc.mrbwb);
+
+ /* Probe allocation features (monitoring not yet implemented) */
+ err = cbqri_probe_feature(ctrl, CBQRI_BC_ALLOC_CTL_OFF,
+ CBQRI_BC_ALLOC_CTL_OP_READ_LIMIT,
+ &status, &ctrl->bc.supports_alloc_at_code);
+ if (err)
+ return err;
+
+ if (status == CBQRI_BC_ALLOC_CTL_STATUS_SUCCESS) {
+ ctrl->alloc_capable = true;
+ exposed_alloc_capable = true;
+ }
+
+ return 0;
+}
+
+static int cbqri_probe_controller(struct cbqri_controller *ctrl)
+{
+ int err;
+
+ pr_debug("controller info: type=%d addr=%pa size=%pa max-rcid=%u max-mcid=%u\n",
+ ctrl->type, &ctrl->addr, &ctrl->size,
+ ctrl->rcid_count, ctrl->mcid_count);
+
+ if (!ctrl->addr) {
+ pr_warn("%s(): controller has invalid addr=0x0, skipping\n", __func__);
+ return -EINVAL;
+ }
+
+ if (!request_mem_region(ctrl->addr, ctrl->size, "cbqri_controller")) {
+ pr_err("%s(): request_mem_region failed for %pa\n",
+ __func__, &ctrl->addr);
+ return -EBUSY;
+ }
+
+ ctrl->base = ioremap(ctrl->addr, ctrl->size);
+ if (!ctrl->base) {
+ pr_err("%s(): ioremap failed for %pa\n", __func__, &ctrl->addr);
+ err = -ENOMEM;
+ goto err_release;
+ }
+
+ spin_lock_init(&ctrl->lock);
+
+ switch (ctrl->type) {
+ case CBQRI_CONTROLLER_TYPE_CAPACITY:
+ err = cbqri_probe_cc(ctrl);
+ break;
+ case CBQRI_CONTROLLER_TYPE_BANDWIDTH:
+ err = cbqri_probe_bc(ctrl);
+ break;
+ default:
+ pr_err("unknown controller type %d\n", ctrl->type);
+ err = -ENODEV;
+ break;
+ }
+
+ if (err)
+ goto err_iounmap;
+
+ /*
+ * max_rmid is used by resctrl_arch_system_num_rmid_idx()
+ * Find the smallest mcid_count amongst all controllers.
+ */
+ max_rmid = min(max_rmid, ctrl->mcid_count);
+
+ return 0;
+
+err_iounmap:
+ iounmap(ctrl->base);
+ ctrl->base = NULL;
+err_release:
+ release_mem_region(ctrl->addr, ctrl->size);
+ return err;
+}
diff --git a/include/linux/riscv_qos.h b/include/linux/riscv_qos.h
new file mode 100644
index 000000000000..0f3daae2e84f
--- /dev/null
+++ b/include/linux/riscv_qos.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __LINUX_RISCV_QOS_H
+#define __LINUX_RISCV_QOS_H
+
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/qos.h>
+
+enum cbqri_controller_type {
+ CBQRI_CONTROLLER_TYPE_CAPACITY,
+ CBQRI_CONTROLLER_TYPE_BANDWIDTH,
+ CBQRI_CONTROLLER_TYPE_UNKNOWN
+};
+
+/* Capacity Controller hardware capabilities */
+struct riscv_cbqri_capacity_caps {
+ u16 ncblks; /* number of capacity blocks */
+
+ bool supports_alloc_at_code;
+ bool supports_alloc_op_flush_rcid;
+};
+
+/* Bandwidth Controller hardware capabilities */
+struct riscv_cbqri_bandwidth_caps {
+ u16 nbwblks; /* number of bandwidth blocks */
+ u16 mrbwb; /* max reserved bw blocks */
+
+ bool supports_alloc_at_code;
+};
+
+struct cbqri_controller {
+ void __iomem *base;
+ /*
+ * Protects multi-step MMIO register sequences on this controller.
+ * CBQRI operations (e.g. CONFIG_LIMIT, READ_LIMIT) require writing
+ * an operation register, waiting for the busy flag to clear, then
+ * reading back the result. These sequences must be atomic per
+ * controller to prevent interleaving.
+ */
+ spinlock_t lock;
+
+ int ver_major;
+ int ver_minor;
+
+ struct riscv_cbqri_bandwidth_caps bc;
+ struct riscv_cbqri_capacity_caps cc;
+
+ bool alloc_capable;
+
+ phys_addr_t addr;
+ phys_addr_t size;
+ enum cbqri_controller_type type;
+ u32 rcid_count;
+ u32 mcid_count;
+ struct list_head list;
+
+ struct cache_controller {
+ u32 cache_level;
+ u32 cache_size; /* in bytes */
+ struct cpumask cpu_mask;
+ /* Unique Cache ID from the PPTT table's Cache Type Structure */
+ u32 cache_id;
+ } cache;
+
+ struct mem_controller {
+ /* Proximity Domain from SRAT table Memory Affinity Controller */
+ u32 prox_dom;
+ struct cpumask cpu_mask;
+ } mem;
+};
+
+extern struct list_head cbqri_controllers;
+
+#endif /* __LINUX_RISCV_QOS_H */
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 03/11] RISC-V: Add support for srmcfg CSR from Ssqosid extension
From: Drew Fustini @ 2026-04-15 1:53 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Add support for the srmcfg CSR defined in the Ssqosid ISA extension.
The CSR contains two fields:
- Resource Control ID (RCID) for resource allocation
- Monitoring Counter ID (MCID) for tracking resource usage
Requests from a hart to shared resources are tagged with these IDs,
allowing resource usage to be associated with the running task.
Add a srmcfg field to thread_struct with the same format as the CSR so
the scheduler can set the RCID and MCID for each task on context switch.
A per-cpu cpu_srmcfg variable mirrors the CSR state to avoid redundant
writes, as L1D-hot memory access is faster than a CSR read and avoids
traps under virtualization.
Add a per-cpu cpu_srmcfg_default variable to store the default srmcfg
for each CPU, as set by resctrl CPU group assignment. On context switch,
if the next task belongs to the default resource group (srmcfg == 0),
the CPU's default value is used instead. This implements resctrl
resource allocation rule 2: default-group tasks on a CPU assigned to a
specific group receive that group's allocations.
Link: https://github.com/riscv/riscv-ssqosid/releases/tag/v1.0
Co-developed-by: Kornel Dulęba <mindal@semihalf.com>
Signed-off-by: Kornel Dulęba <mindal@semihalf.com>
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
MAINTAINERS | 8 ++++++
arch/riscv/Kconfig | 17 +++++++++++++
arch/riscv/include/asm/csr.h | 6 +++++
arch/riscv/include/asm/processor.h | 3 +++
arch/riscv/include/asm/qos.h | 52 ++++++++++++++++++++++++++++++++++++++
arch/riscv/include/asm/switch_to.h | 3 +++
arch/riscv/kernel/Makefile | 2 ++
arch/riscv/kernel/qos/Makefile | 2 ++
arch/riscv/kernel/qos/qos.c | 8 ++++++
9 files changed, 101 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index c3fe46d7c4bc..b17f885411ba 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22778,6 +22778,14 @@ F: drivers/perf/riscv_pmu.c
F: drivers/perf/riscv_pmu_legacy.c
F: drivers/perf/riscv_pmu_sbi.c
+RISC-V QOS RESCTRL SUPPORT
+M: Drew Fustini <fustini@kernel.org>
+R: yunhui cui <cuiyunhui@bytedance.com>
+L: linux-riscv@lists.infradead.org
+S: Supported
+F: arch/riscv/include/asm/qos.h
+F: arch/riscv/kernel/qos/
+
RISC-V RPMI AND MPXY DRIVERS
M: Rahul Pathak <rahul@summations.net>
M: Anup Patel <anup@brainfault.org>
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 90c531e6abf5..92d2265a0c61 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -595,6 +595,23 @@ config RISCV_ISA_SVNAPOT
If you don't know what to do here, say Y.
+config RISCV_ISA_SSQOSID
+ bool "Ssqosid extension support for supervisor mode Quality of Service ID"
+ default n
+ help
+ Adds support for the Ssqosid ISA extension (Supervisor-mode
+ Quality of Service ID).
+
+ Ssqosid defines the srmcfg CSR which allows the system to tag the
+ running process with an RCID (Resource Control ID) and MCID
+ (Monitoring Counter ID). The RCID is used to determine resource
+ allocation. The MCID is used to track resource usage in event
+ counters.
+
+ For example, a cache controller may use the RCID to apply a
+ cache partitioning scheme and use the MCID to track how much
+ cache a process, or a group of processes, is using.
+
config RISCV_ISA_SVPBMT
bool "Svpbmt extension support for supervisor mode page-based memory types"
depends on 64BIT && MMU
diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 31b8988f4488..dc13835bd661 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -84,6 +84,11 @@
#define SATP_ASID_MASK _AC(0xFFFF, UL)
#endif
+/* SRMCFG fields */
+#define SRMCFG_RCID_MASK _AC(0x00000FFF, UL)
+#define SRMCFG_MCID_MASK _AC(0x00000FFF, UL)
+#define SRMCFG_MCID_SHIFT 16
+
/* Exception cause high bit - is an interrupt if set */
#define CAUSE_IRQ_FLAG (_AC(1, UL) << (__riscv_xlen - 1))
@@ -328,6 +333,7 @@
#define CSR_STVAL 0x143
#define CSR_SIP 0x144
#define CSR_SATP 0x180
+#define CSR_SRMCFG 0x181
#define CSR_STIMECMP 0x14D
#define CSR_STIMECMPH 0x15D
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 4c3dd94d0f63..feaee2502593 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -123,6 +123,9 @@ struct thread_struct {
/* A forced icache flush is not needed if migrating to the previous cpu. */
unsigned int prev_cpu;
#endif
+#ifdef CONFIG_RISCV_ISA_SSQOSID
+ u32 srmcfg;
+#endif
};
/* Whitelist the fstate from the task_struct for hardened usercopy */
diff --git a/arch/riscv/include/asm/qos.h b/arch/riscv/include/asm/qos.h
new file mode 100644
index 000000000000..aa96bb5a153c
--- /dev/null
+++ b/arch/riscv/include/asm/qos.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_RISCV_QOS_H
+#define _ASM_RISCV_QOS_H
+
+#ifdef CONFIG_RISCV_ISA_SSQOSID
+
+#include <linux/sched.h>
+
+#include <asm/csr.h>
+#include <asm/hwcap.h>
+
+/* cached value of srmcfg csr for each cpu */
+DECLARE_PER_CPU(u32, cpu_srmcfg);
+
+/* default srmcfg value for each cpu, set via resctrl cpu assignment */
+DECLARE_PER_CPU(u32, cpu_srmcfg_default);
+
+static inline void __switch_to_srmcfg(struct task_struct *next)
+{
+ u32 thread_srmcfg;
+
+ thread_srmcfg = READ_ONCE(next->thread.srmcfg);
+
+ /*
+ * Tasks in the default resource group have closid=0 and rmid=0,
+ * so thread.srmcfg is 0. For these tasks, use this CPU's default
+ * srmcfg instead. This implements resctrl rule 2: a default-group
+ * task running on a CPU assigned to a specific group uses that
+ * group's allocations.
+ */
+ if (thread_srmcfg == 0)
+ thread_srmcfg = __this_cpu_read(cpu_srmcfg_default);
+
+ if (thread_srmcfg != __this_cpu_read(cpu_srmcfg)) {
+ __this_cpu_write(cpu_srmcfg, thread_srmcfg);
+ csr_write(CSR_SRMCFG, thread_srmcfg);
+ }
+}
+
+static __always_inline bool has_srmcfg(void)
+{
+ return riscv_has_extension_unlikely(RISCV_ISA_EXT_SSQOSID);
+}
+
+#else /* ! CONFIG_RISCV_ISA_SSQOSID */
+
+struct task_struct;
+static __always_inline bool has_srmcfg(void) { return false; }
+static inline void __switch_to_srmcfg(struct task_struct *next) { }
+
+#endif /* CONFIG_RISCV_ISA_SSQOSID */
+#endif /* _ASM_RISCV_QOS_H */
diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
index 0e71eb82f920..1c7ea53ec012 100644
--- a/arch/riscv/include/asm/switch_to.h
+++ b/arch/riscv/include/asm/switch_to.h
@@ -14,6 +14,7 @@
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/csr.h>
+#include <asm/qos.h>
#ifdef CONFIG_FPU
extern void __fstate_save(struct task_struct *save_to);
@@ -119,6 +120,8 @@ do { \
__switch_to_fpu(__prev, __next); \
if (has_vector() || has_xtheadvector()) \
__switch_to_vector(__prev, __next); \
+ if (has_srmcfg()) \
+ __switch_to_srmcfg(__next); \
if (switch_to_should_flush_icache(__next)) \
local_flush_icache_all(); \
__switch_to_envcfg(__next); \
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index cabb99cadfb6..82157aae6401 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -128,3 +128,5 @@ obj-$(CONFIG_ACPI_NUMA) += acpi_numa.o
obj-$(CONFIG_GENERIC_CPU_VULNERABILITIES) += bugs.o
obj-$(CONFIG_RISCV_USER_CFI) += usercfi.o
+
+obj-$(CONFIG_RISCV_ISA_SSQOSID) += qos/
diff --git a/arch/riscv/kernel/qos/Makefile b/arch/riscv/kernel/qos/Makefile
new file mode 100644
index 000000000000..9f996263a86d
--- /dev/null
+++ b/arch/riscv/kernel/qos/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_RISCV_ISA_SSQOSID) += qos.o
diff --git a/arch/riscv/kernel/qos/qos.c b/arch/riscv/kernel/qos/qos.c
new file mode 100644
index 000000000000..a3c2b910e2e0
--- /dev/null
+++ b/arch/riscv/kernel/qos/qos.c
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <asm/qos.h>
+
+/* cached value of srmcfg csr for each cpu */
+DEFINE_PER_CPU(u32, cpu_srmcfg);
+
+/* default srmcfg value for each cpu, set via resctrl cpu assignment */
+DEFINE_PER_CPU(u32, cpu_srmcfg_default);
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 02/11] RISC-V: Detect the Ssqosid extension
From: Drew Fustini @ 2026-04-15 1:53 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Ssqosid is the RISC-V Quality-of-Service (QoS) Identifiers specification
which defines the Supervisor Resource Management Configuration (srmcfg)
register.
Link: https://github.com/riscv/riscv-ssqosid/releases/tag/v1.0
Co-developed-by: Kornel Dulęba <mindal@semihalf.com>
Signed-off-by: Kornel Dulęba <mindal@semihalf.com>
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
arch/riscv/include/asm/hwcap.h | 1 +
arch/riscv/kernel/cpufeature.c | 1 +
2 files changed, 2 insertions(+)
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 7ef8e5f55c8d..b83dae5cebb9 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -112,6 +112,7 @@
#define RISCV_ISA_EXT_ZCLSD 103
#define RISCV_ISA_EXT_ZICFILP 104
#define RISCV_ISA_EXT_ZICFISS 105
+#define RISCV_ISA_EXT_SSQOSID 106
#define RISCV_ISA_EXT_XLINUXENVCFG 127
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 1734f9a4c2fd..c0717a861a3c 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -582,6 +582,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
__RISCV_ISA_EXT_SUPERSET(ssnpm, RISCV_ISA_EXT_SSNPM, riscv_xlinuxenvcfg_exts),
+ __RISCV_ISA_EXT_DATA(ssqosid, RISCV_ISA_EXT_SSQOSID),
__RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
__RISCV_ISA_EXT_DATA(svade, RISCV_ISA_EXT_SVADE),
__RISCV_ISA_EXT_DATA_VALIDATE(svadu, RISCV_ISA_EXT_SVADU, riscv_ext_svadu_validate),
--
2.43.0
^ permalink raw reply related
* [PATCH RFC v3 01/11] dt-bindings: riscv: Add Ssqosid extension description
From: Drew Fustini @ 2026-04-15 1:53 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Alexandre Ghiti,
Radim Krčmář, Samuel Holland, Adrien Ricciardi,
Nicolas Pitre, Kornel Dulęba, Atish Patra, Atish Kumar Patra,
Vasudevan Srinivasan, Ved Shanbhogue, Conor Dooley, yunhui cui,
Chen Pei, Liu Zhiwei, Weiwei Li, guo.wenjia23, Gong Shuai,
Gong Shuai, liu.qingtao2, Reinette Chatre, Tony Luck, Babu Moger,
Peter Newman, Fenghua Yu, James Morse, Ben Horgan, Dave Martin,
Rob Herring, Conor Dooley, Krzysztof Kozlowski, Rafael J. Wysocki,
Len Brown, Robert Moore, Sunil V L, Drew Fustini
Cc: linux-kernel, linux-riscv, x86, linux-acpi, acpica-devel,
devicetree, Paul Walmsley
In-Reply-To: <20260414-ssqosid-cbqri-rqsc-v7-0-v3-0-b3b2e7e9847a@kernel.org>
Document the ratified Supervisor-mode Quality of Service ID (Ssqosid)
extension v1.0.
Link: https://github.com/riscv/riscv-ssqosid/releases/tag/v1.0
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Drew Fustini <fustini@kernel.org>
---
Documentation/devicetree/bindings/riscv/extensions.yaml | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index c6ec9290fe07..1f3853a68760 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -232,6 +232,12 @@ properties:
ratified at commit d70011dde6c2 ("Update to ratified state")
of riscv-j-extension.
+ - const: ssqosid
+ description: |
+ The Ssqosid extension for Quality of Service ID is ratified
+ as v1.0 in commit 5059e0ca641c ("Merge pull request #7 from
+ ved-rivos/Ratified") of riscv-ssqosid.
+
- const: ssstateen
description: |
The standard Ssstateen extension for supervisor-mode view of the
--
2.43.0
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