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Commit ee84a2e4 authored by Sujeev Dias's avatar Sujeev Dias Committed by Gerrit - the friendly Code Review server
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mhi: core: add support for collecting device ram dump during panic 



For debugging purpose, we'd like to collect device ram dump
context when kernel panic happens. This patch adds support
for such requirement.

CRs-Fixed: 2221004
Change-Id: Ie0e829bd53f777da8d7d94e3261f2f7668e7a844
Signed-off-by: default avatarSujeev Dias <sdias@codeaurora.org>
parent 42123387

drivers/bus/mhi/core/mhi_boot.c

+95 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
 */



#include <linux/debugfs.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/dma-direction.h>

#include <linux/dma-mapping.h>
@@ -42,6 +43,97 @@ static void mhi_rddm_prepare(struct mhi_controller *mhi_cntrl, 
	}

}



/* collect rddm during kernel panic */

static int __mhi_download_rddm_in_panic(struct mhi_controller *mhi_cntrl)

{

	int ret;

	struct mhi_buf *mhi_buf;

	u32 sequence_id;

	u32 rx_status;

	enum MHI_EE ee;

	struct image_info *rddm_image = mhi_cntrl->rddm_image;

	const u32 delayus = 100;

	u32 retry = (mhi_cntrl->timeout_ms * 1000) / delayus;

	void __iomem *base = mhi_cntrl->bhi;



	MHI_LOG("Entered with pm_state:%s dev_state:%s ee:%s\n",

		to_mhi_pm_state_str(mhi_cntrl->pm_state),

		TO_MHI_STATE_STR(mhi_cntrl->dev_state),

		TO_MHI_EXEC_STR(mhi_cntrl->ee));



	/*

	 * This should only be executing during a kernel panic, we expect all

	 * other cores to shutdown while we're collecting rddm buffer. After

	 * returning from this function, we expect device to reset.

	 *

	 * Normaly, we would read/write pm_state only after grabbing

	 * pm_lock, since we're in a panic, skipping it.

	 */



	if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state))

		return -EIO;



	/*

	 * There is no gurantee this state change would take effect since

	 * we're setting it w/o grabbing pmlock, it's best effort

	 */

	mhi_cntrl->pm_state = MHI_PM_LD_ERR_FATAL_DETECT;

	/* update should take the effect immediately */

	smp_wmb();



	/* setup the RX vector table */

	mhi_rddm_prepare(mhi_cntrl, rddm_image);

	mhi_buf = &rddm_image->mhi_buf[rddm_image->entries - 1];



	MHI_LOG("Starting BHIe programming for RDDM\n");



	mhi_write_reg(mhi_cntrl, base, BHIE_RXVECADDR_HIGH_OFFS,

		      upper_32_bits(mhi_buf->dma_addr));



	mhi_write_reg(mhi_cntrl, base, BHIE_RXVECADDR_LOW_OFFS,

		      lower_32_bits(mhi_buf->dma_addr));



	mhi_write_reg(mhi_cntrl, base, BHIE_RXVECSIZE_OFFS, mhi_buf->len);

	sequence_id = prandom_u32() & BHIE_RXVECSTATUS_SEQNUM_BMSK;



	if (unlikely(!sequence_id))

		sequence_id = 1;





	mhi_write_reg_field(mhi_cntrl, base, BHIE_RXVECDB_OFFS,

			    BHIE_RXVECDB_SEQNUM_BMSK, BHIE_RXVECDB_SEQNUM_SHFT,

			    sequence_id);



	MHI_LOG("Trigger device into RDDM mode\n");

	mhi_set_mhi_state(mhi_cntrl, MHI_STATE_SYS_ERR);



	MHI_LOG("Waiting for image download completion\n");

	while (retry--) {

		ret = mhi_read_reg_field(mhi_cntrl, base, BHIE_RXVECSTATUS_OFFS,

					 BHIE_RXVECSTATUS_STATUS_BMSK,

					 BHIE_RXVECSTATUS_STATUS_SHFT,

					 &rx_status);

		if (ret)

			return -EIO;



		if (rx_status == BHIE_RXVECSTATUS_STATUS_XFER_COMPL) {

			MHI_LOG("RDDM successfully collected\n");

			return 0;

		}



		udelay(delayus);

	}



	ee = mhi_get_exec_env(mhi_cntrl);

	ret = mhi_read_reg(mhi_cntrl, base, BHIE_RXVECSTATUS_OFFS, &rx_status);



	MHI_ERR("Did not complete RDDM transfer\n");

	MHI_ERR("Current EE:%s\n", TO_MHI_EXEC_STR(ee));

	MHI_ERR("RXVEC_STATUS:0x%x, ret:%d\n", rx_status, ret);



	return -EIO;

}



/* download ramdump image from device */

int mhi_download_rddm_img(struct mhi_controller *mhi_cntrl, bool in_panic)

{
@@ -56,6 +148,9 @@ int mhi_download_rddm_img(struct mhi_controller *mhi_cntrl, bool in_panic) 
	if (!rddm_image)

		return -ENOMEM;



	if (in_panic)

		return __mhi_download_rddm_in_panic(mhi_cntrl);



	MHI_LOG("Waiting for device to enter RDDM state from EE:%s\n",

		TO_MHI_EXEC_STR(mhi_cntrl->ee));

drivers/bus/mhi/core/mhi_internal.h

+1 −0
Original line number Diff line number Diff line
@@ -654,6 +654,7 @@ void mhi_write_db(struct mhi_controller *mhi_cntrl, void __iomem *db_addr, 
void mhi_ring_cmd_db(struct mhi_controller *mhi_cntrl, struct mhi_cmd *mhi_cmd);

void mhi_ring_chan_db(struct mhi_controller *mhi_cntrl,

		      struct mhi_chan *mhi_chan);

void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl, enum MHI_STATE state);



/* memory allocation methods */

static inline void *mhi_alloc_coherent(struct mhi_controller *mhi_cntrl,

drivers/bus/mhi/core/mhi_pm.c

+1 −2
Original line number Diff line number Diff line
@@ -161,8 +161,7 @@ enum MHI_PM_STATE __must_check mhi_tryset_pm_state( 
	return mhi_cntrl->pm_state;

}



static void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl,

			      enum MHI_STATE state)

void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl, enum MHI_STATE state)

{

	if (state == MHI_STATE_RESET) {

		mhi_write_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,