msm8916-openwrt/target/linux/bcm27xx/patches-6.6/950-0983-drivers-mmc-preallocate-a-block-for-SD-extension-reg.patch
Álvaro Fernández Rojas 8c405cdccc bcm27xx: add 6.6 kernel patches
The patches were generated from the RPi repo with the following command:
git format-patch v6.6.34..rpi-6.1.y

Some patches needed rebasing and, as usual, the applied and reverted, wireless
drivers, Github workflows, READMEs and defconfigs patches were removed.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2024-06-18 18:52:49 +02:00

156 lines
4.1 KiB
Diff

From d8748eda96b47efea833e2a6ea478bb370654f1d Mon Sep 17 00:00:00 2001
From: Jonathan Bell <jonathan@raspberrypi.com>
Date: Wed, 20 Mar 2024 13:00:30 +0000
Subject: [PATCH 0983/1085] drivers: mmc: preallocate a block for SD extension
register accesses
The Performance Extension register is regularly accessed in a hot path
to do write cache flushes. Don't invoke kmalloc/kfree for every access,
preallocate a 512B buffer for this purpose.
Also remove an unused alloc in sd_enable_cache().
Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
---
drivers/mmc/core/bus.c | 2 ++
drivers/mmc/core/sd.c | 34 +++++++++++-----------------------
include/linux/mmc/card.h | 1 +
3 files changed, 14 insertions(+), 23 deletions(-)
--- a/drivers/mmc/core/bus.c
+++ b/drivers/mmc/core/bus.c
@@ -264,6 +264,8 @@ static void mmc_release_card(struct devi
sdio_free_common_cis(card);
+ kfree(card->ext_reg_buf);
+
kfree(card->info);
kfree(card);
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1025,9 +1025,8 @@ int sd_write_ext_reg(struct mmc_card *ca
struct scatterlist sg;
u8 *reg_buf;
- reg_buf = kzalloc(512, GFP_KERNEL);
- if (!reg_buf)
- return -ENOMEM;
+ reg_buf = card->ext_reg_buf;
+ memset(reg_buf, 0, 512);
mrq.cmd = &cmd;
mrq.data = &data;
@@ -1059,8 +1058,6 @@ int sd_write_ext_reg(struct mmc_card *ca
mmc_set_data_timeout(&data, card);
mmc_wait_for_req(host, &mrq);
- kfree(reg_buf);
-
/*
* Note that, the SD card is allowed to signal busy on DAT0 up to 1s
* after the CMD49. Although, let's leave this to be managed by the
@@ -1101,9 +1098,7 @@ static int sd_parse_ext_reg_power(struct
int err;
u8 *reg_buf;
- reg_buf = kzalloc(512, GFP_KERNEL);
- if (!reg_buf)
- return -ENOMEM;
+ reg_buf = card->ext_reg_buf;
/* Read the extension register for power management function. */
err = sd_read_ext_reg(card, fno, page, offset, 512, reg_buf);
@@ -1133,7 +1128,6 @@ static int sd_parse_ext_reg_power(struct
card->ext_power.offset = offset;
out:
- kfree(reg_buf);
return err;
}
@@ -1143,9 +1137,7 @@ static int sd_parse_ext_reg_perf(struct
int err;
u8 *reg_buf;
- reg_buf = kzalloc(512, GFP_KERNEL);
- if (!reg_buf)
- return -ENOMEM;
+ reg_buf = card->ext_reg_buf;
err = sd_read_ext_reg(card, fno, page, offset, 512, reg_buf);
if (err) {
@@ -1188,7 +1180,6 @@ static int sd_parse_ext_reg_perf(struct
card->ext_perf.offset = offset;
out:
- kfree(reg_buf);
return err;
}
@@ -1259,6 +1250,12 @@ static int sd_read_ext_regs(struct mmc_c
if (!gen_info_buf)
return -ENOMEM;
+ card->ext_reg_buf = kzalloc(512, GFP_KERNEL);
+ if (!card->ext_reg_buf) {
+ err = -ENOMEM;
+ goto out;
+ }
+
/*
* Read 512 bytes of general info, which is found at function number 0,
* at page 0 and with no offset.
@@ -1325,9 +1322,7 @@ static int sd_flush_cache(struct mmc_hos
if (!sd_cache_enabled(host))
return 0;
- reg_buf = kzalloc(512, GFP_KERNEL);
- if (!reg_buf)
- return -ENOMEM;
+ reg_buf = card->ext_reg_buf;
/*
* Set Flush Cache at bit 0 in the performance enhancement register at
@@ -1363,21 +1358,15 @@ static int sd_flush_cache(struct mmc_hos
if (reg_buf[0] & BIT(0))
err = -ETIMEDOUT;
out:
- kfree(reg_buf);
return err;
}
static int sd_enable_cache(struct mmc_card *card)
{
- u8 *reg_buf;
int err;
card->ext_perf.feature_enabled &= ~SD_EXT_PERF_CACHE;
- reg_buf = kzalloc(512, GFP_KERNEL);
- if (!reg_buf)
- return -ENOMEM;
-
/*
* Set Cache Enable at bit 0 in the performance enhancement register at
* 260 bytes offset.
@@ -1396,7 +1385,6 @@ static int sd_enable_cache(struct mmc_ca
card->ext_perf.feature_enabled |= SD_EXT_PERF_CACHE;
out:
- kfree(reg_buf);
return err;
}
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -320,6 +320,7 @@ struct mmc_card {
struct sd_switch_caps sw_caps; /* switch (CMD6) caps */
struct sd_ext_reg ext_power; /* SD extension reg for PM */
struct sd_ext_reg ext_perf; /* SD extension reg for PERF */
+ u8 *ext_reg_buf; /* 512 byte block for extension register R/W */
unsigned int sdio_funcs; /* number of SDIO functions */
atomic_t sdio_funcs_probed; /* number of probed SDIO funcs */