Commit 523e594d authored by Ben Widawsky's avatar Ben Widawsky Committed by Dan Williams
Browse files

cxl/pci: Implement wait for media active 



CXL 2.0 8.1.3.8.2 states:

  Memory_Active: When set, indicates that the CXL Range 1 memory is
  fully initialized and available for software use. Must be set within
  Range 1. Memory_Active_Timeout of deassertion of reset to CXL device
  if CXL.mem HwInit Mode=1

Unfortunately, Memory_Active can take quite a long time depending on
media size (up to 256s per 2.0 spec). Provide a callback for the
eventual establishment of CXL.mem operations via the 'cxl_mem' driver
the 'struct cxl_memdev'. The implementation waits for 60s by default for
now and can be overridden by the mbox_ready_time module parameter.

Signed-off-by: default avatarBen Widawsky <ben.widawsky@intel.com>
[djbw: switch to sleeping wait]
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164298427373.3018233.9309741847039301834.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 560f7855

drivers/cxl/cxlmem.h

+2 −0
Original line number Diff line number Diff line
@@ -132,6 +132,7 @@ struct cxl_endpoint_dvsec_info { 
 * @component_reg_phys: register base of component registers

 * @info: Cached DVSEC information about the device.

 * @mbox_send: @dev specific transport for transmitting mailbox commands

 * @wait_media_ready: @dev specific method to await media ready

 *

 * See section 8.2.9.5.2 Capacity Configuration and Label Storage for

 * details on capacity parameters.
@@ -165,6 +166,7 @@ struct cxl_dev_state { 
	struct cxl_endpoint_dvsec_info info;



	int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd);

	int (*wait_media_ready)(struct cxl_dev_state *cxlds);

};



enum cxl_opcode {

drivers/cxl/pci.c

+48 −1
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ 
static unsigned short mbox_ready_timeout = 60;

module_param(mbox_ready_timeout, ushort, 0644);

MODULE_PARM_DESC(mbox_ready_timeout,

		 "seconds to wait for mailbox ready status");

		 "seconds to wait for mailbox ready / memory active status");



static int cxl_pci_mbox_wait_for_doorbell(struct cxl_dev_state *cxlds)

{
@@ -418,6 +418,51 @@ static int wait_for_valid(struct cxl_dev_state *cxlds) 
	return -ETIMEDOUT;

}



/*

 * Wait up to @mbox_ready_timeout for the device to report memory

 * active.

 */

static int wait_for_media_ready(struct cxl_dev_state *cxlds)

{

	struct pci_dev *pdev = to_pci_dev(cxlds->dev);

	int d = cxlds->cxl_dvsec;

	bool active = false;

	u64 md_status;

	int rc, i;



	rc = wait_for_valid(cxlds);

	if (rc)

		return rc;



	for (i = mbox_ready_timeout; i; i--) {

		u32 temp;

		int rc;



		rc = pci_read_config_dword(

			pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &temp);

		if (rc)

			return rc;



		active = FIELD_GET(CXL_DVSEC_MEM_ACTIVE, temp);

		if (active)

			break;

		msleep(1000);

	}



	if (!active) {

		dev_err(&pdev->dev,

			"timeout awaiting memory active after %d seconds\n",

			mbox_ready_timeout);

		return -ETIMEDOUT;

	}



	md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);

	if (!CXLMDEV_READY(md_status))

		return -EIO;



	return 0;

}



static int cxl_dvsec_ranges(struct cxl_dev_state *cxlds)

{

	struct cxl_endpoint_dvsec_info *info = &cxlds->info;
@@ -528,6 +573,8 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
		dev_warn(&pdev->dev,

			 "Device DVSEC not present, skip CXL.mem init\n");



	cxlds->wait_media_ready = wait_for_media_ready;



	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);

	if (rc)

		return rc;

tools/testing/cxl/test/mem.c

+8 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#include <linux/platform_device.h>

#include <linux/mod_devicetable.h>

#include <linux/module.h>

#include <linux/delay.h>

#include <linux/sizes.h>

#include <linux/bits.h>

#include <cxlmem.h>
@@ -236,6 +237,12 @@ static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd * 
	return rc;

}



static int cxl_mock_wait_media_ready(struct cxl_dev_state *cxlds)

{

	msleep(100);

	return 0;

}



static void label_area_release(void *lsa)

{

	vfree(lsa);
@@ -262,6 +269,7 @@ static int cxl_mock_mem_probe(struct platform_device *pdev) 
		return PTR_ERR(cxlds);



	cxlds->mbox_send = cxl_mock_mbox_send;

	cxlds->wait_media_ready = cxl_mock_wait_media_ready;

	cxlds->payload_size = SZ_4K;



	rc = cxl_enumerate_cmds(cxlds);