mmc: sdhci: Use "mmc" directly rather than "host->mmc"

Clean up the code to use the "mmc" directly instead of "host->mmc".
If the code sits in hot code path, this clean up also brings trvial
performance improvement. Take the sdhci_post_req() for example:

before the patch:
     ...
     8d0:	a9be7bfd 	stp	x29, x30, [sp, #-32]!
     8d4:	910003fd 	mov	x29, sp
     8d8:	f9000bf3 	str	x19, [sp, #16]
     8dc:	f9400833 	ldr	x19, [x1, #16]
     8e0:	b9404261 	ldr	w1, [x19, #64]
     8e4:	34000161 	cbz	w1, 910 <sdhci_post_req+0x50>
     8e8:	f9424400 	ldr	x0, [x0, #1160]
     8ec:	d2800004 	mov	x4, #0x0                   	// #0
     8f0:	b9401a61 	ldr	w1, [x19, #24]
     8f4:	b9403262 	ldr	w2, [x19, #48]
     8f8:	f9400000 	ldr	x0, [x0]
     8fc:	f278003f 	tst	x1, #0x100
     900:	f9401e61 	ldr	x1, [x19, #56]
     904:	1a9f17e3 	cset	w3, eq  // eq = none
     908:	11000463 	add	w3, w3, #0x1
     90c:	94000000 	bl	0 <dma_unmap_sg_attrs>
     ...

After the patch:
     ...
     8d0:	a9be7bfd 	stp	x29, x30, [sp, #-32]!
     8d4:	910003fd 	mov	x29, sp
     8d8:	f9000bf3 	str	x19, [sp, #16]
     8dc:	f9400833 	ldr	x19, [x1, #16]
     8e0:	b9404261 	ldr	w1, [x19, #64]
     8e4:	34000141 	cbz	w1, 90c <sdhci_post_req+0x4c>
     8e8:	b9401a61 	ldr	w1, [x19, #24]
     8ec:	d2800004 	mov	x4, #0x0                   	// #0
     8f0:	b9403262 	ldr	w2, [x19, #48]
     8f4:	f9400000 	ldr	x0, [x0]
     8f8:	f278003f 	tst	x1, #0x100
     8fc:	f9401e61 	ldr	x1, [x19, #56]
     900:	1a9f17e3 	cset	w3, eq  // eq = none
     904:	11000463 	add	w3, w3, #0x1
     908:	94000000 	bl	0 <dma_unmap_sg_attrs>
     ...

We saved one ldr instruction: "ldr     x0, [x0, #1160]"

Signed-off-by: Jisheng Zhang <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>

drivers/mmc/host/sdhci.c

@@ -907,7 +907,7 @@ static void sdhci_calc_sw_timeout(struct sdhci_host *host,
 
 	if (data) {
 		blksz = data->blksz;
-		freq = host->mmc->actual_clock ? : host->clock;
+		freq = mmc->actual_clock ? : host->clock;
 		transfer_time = (u64)blksz * NSEC_PER_SEC * (8 / bus_width);
 		do_div(transfer_time, freq);
 		/* multiply by '2' to account for any unknowns */
@@ -2269,14 +2269,14 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
 		if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK &&
 		    host->clock) {
-			host->timeout_clk = host->mmc->actual_clock ?
-						host->mmc->actual_clock / 1000 :
+			host->timeout_clk = mmc->actual_clock ?
+						mmc->actual_clock / 1000 :
 						host->clock / 1000;
-			host->mmc->max_busy_timeout =
+			mmc->max_busy_timeout =
 				host->ops->get_max_timeout_count ?
 				host->ops->get_max_timeout_count(host) :
 				1 << 27;
-			host->mmc->max_busy_timeout /= host->timeout_clk;
+			mmc->max_busy_timeout /= host->timeout_clk;
 		}
 	}
 
@@ -2399,7 +2399,7 @@ static int sdhci_get_cd(struct mmc_host *mmc)
 		return 0;
 
 	/* If nonremovable, assume that the card is always present. */
-	if (!mmc_card_is_removable(host->mmc))
+	if (!mmc_card_is_removable(mmc))
 		return 1;
 
 	/*
@@ -2489,14 +2489,14 @@ void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
 	unsigned long flags;
 
 	if (enable)
-		pm_runtime_get_noresume(host->mmc->parent);
+		pm_runtime_get_noresume(mmc->parent);
 
 	spin_lock_irqsave(&host->lock, flags);
 	sdhci_enable_sdio_irq_nolock(host, enable);
 	spin_unlock_irqrestore(&host->lock, flags);
 
 	if (!enable)
-		pm_runtime_put_noidle(host->mmc->parent);
+		pm_runtime_put_noidle(mmc->parent);
 }
 EXPORT_SYMBOL_GPL(sdhci_enable_sdio_irq);
 
@@ -2837,7 +2837,7 @@ int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		goto out;
 	}
 
-	host->mmc->retune_period = tuning_count;
+	mmc->retune_period = tuning_count;
 
 	if (host->tuning_delay < 0)
 		host->tuning_delay = opcode == MMC_SEND_TUNING_BLOCK;
@@ -2886,11 +2886,10 @@ static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable)
 static void sdhci_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
 				int err)
 {
-	struct sdhci_host *host = mmc_priv(mmc);
 	struct mmc_data *data = mrq->data;
 
 	if (data->host_cookie != COOKIE_UNMAPPED)
-		dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
 			     mmc_get_dma_dir(data));
 
 	data->host_cookie = COOKIE_UNMAPPED;
@@ -2941,9 +2940,9 @@ static void sdhci_card_event(struct mmc_host *mmc)
 	/* Check sdhci_has_requests() first in case we are runtime suspended */
 	if (sdhci_has_requests(host) && !present) {
 		pr_err("%s: Card removed during transfer!\n",
-			mmc_hostname(host->mmc));
+			mmc_hostname(mmc));
 		pr_err("%s: Resetting controller.\n",
-			mmc_hostname(host->mmc));
+			mmc_hostname(mmc));
 
 		sdhci_do_reset(host, SDHCI_RESET_CMD);
 		sdhci_do_reset(host, SDHCI_RESET_DATA);
@@ -3677,23 +3676,23 @@ int sdhci_resume_host(struct sdhci_host *host)
 			host->ops->enable_dma(host);
 	}
 
-	if ((host->mmc->pm_flags & MMC_PM_KEEP_POWER) &&
+	if ((mmc->pm_flags & MMC_PM_KEEP_POWER) &&
 	    (host->quirks2 & SDHCI_QUIRK2_HOST_OFF_CARD_ON)) {
 		/* Card keeps power but host controller does not */
 		sdhci_init(host, 0);
 		host->pwr = 0;
 		host->clock = 0;
 		mmc->ops->set_ios(mmc, &mmc->ios);
 	} else {
-		sdhci_init(host, (host->mmc->pm_flags & MMC_PM_KEEP_POWER));
+		sdhci_init(host, (mmc->pm_flags & MMC_PM_KEEP_POWER));
 	}
 
 	if (host->irq_wake_enabled) {
 		sdhci_disable_irq_wakeups(host);
 	} else {
 		ret = request_threaded_irq(host->irq, sdhci_irq,
 					   sdhci_thread_irq, IRQF_SHARED,
-					   mmc_hostname(host->mmc), host);
+					   mmc_hostname(mmc), host);
 		if (ret)
 			return ret;
 	}
@@ -4380,7 +4379,7 @@ int sdhci_setup_host(struct sdhci_host *host)
 
 	if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) &&
 	    mmc_card_is_removable(mmc) &&
-	    mmc_gpio_get_cd(host->mmc) < 0)
+	    mmc_gpio_get_cd(mmc) < 0)
 		mmc->caps |= MMC_CAP_NEEDS_POLL;
 
 	if (!IS_ERR(mmc->supply.vqmmc)) {