[PATCH v2 2/2] ARM: at91: pm: switch to the PIE infrastructure
From: Alexandre Belloni
Date: Tue Jun 28 2016 - 18:45:45 EST
Using the PIE infrastructure allows to write the whole suspend/resume
functions in C instead of assembly.
The only remaining assembly instruction is wfi for armv5
It makes the code shorter and clearer.
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
---
arch/arm/mach-at91/Kconfig | 1 +
arch/arm/mach-at91/Makefile | 2 +-
arch/arm/mach-at91/pm.c | 31 ++--
arch/arm/mach-at91/pm/.gitignore | 2 +
arch/arm/mach-at91/pm/Makefile | 3 +
arch/arm/mach-at91/pm/atmel_pm.c | 97 +++++++++++
arch/arm/mach-at91/pm_suspend.S | 338 ---------------------------------------
7 files changed, 114 insertions(+), 360 deletions(-)
create mode 100644 arch/arm/mach-at91/pm/.gitignore
create mode 100644 arch/arm/mach-at91/pm/Makefile
create mode 100644 arch/arm/mach-at91/pm/atmel_pm.c
delete mode 100644 arch/arm/mach-at91/pm_suspend.S
diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 08047afdf38e..ab430c04a699 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -5,6 +5,7 @@ menuconfig ARCH_AT91
select COMMON_CLK_AT91
select PINCTRL
select SOC_BUS
+ select PIE
if ARCH_AT91
config SOC_SAMA5D2
diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile
index c5bbf8bb8c0f..062336de4f66 100644
--- a/arch/arm/mach-at91/Makefile
+++ b/arch/arm/mach-at91/Makefile
@@ -10,7 +10,7 @@ obj-$(CONFIG_SOC_SAMA5) += sama5.o
# Power Management
obj-$(CONFIG_PM) += pm.o
-obj-$(CONFIG_PM) += pm_suspend.o
+obj-$(CONFIG_PM) += pm/
ifeq ($(CONFIG_CPU_V7),y)
AFLAGS_pm_suspend.o := -march=armv7-a
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index f06270198bf1..f2f2a97ee1de 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -21,6 +21,7 @@
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
+#include <linux/pie.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/clk/at91_pmc.h>
@@ -56,6 +57,8 @@ static struct {
void __iomem *at91_ramc_base[2];
+static struct pie_chunk *atmel_pm_pie;
+
static int at91_pm_valid_state(suspend_state_t state)
{
switch (state) {
@@ -133,10 +136,6 @@ EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
static void (*at91_suspend_sram_fn)(void __iomem *pmc, void __iomem *ramc0,
void __iomem *ramc1, int memctrl);
-extern void at91_pm_suspend_in_sram(void __iomem *pmc, void __iomem *ramc0,
- void __iomem *ramc1, int memctrl);
-extern u32 at91_pm_suspend_in_sram_sz;
-
static void at91_pm_suspend(suspend_state_t state)
{
unsigned int pm_data = at91_pm_data.memctrl;
@@ -370,11 +369,12 @@ void at91sam9_idle(void)
cpu_do_idle();
}
+extern void atmel_pm_suspend(void __iomem *pmc, void __iomem *ramc0,
+ void __iomem *ramc1, int memctrl);
+
static void __init at91_pm_sram_init(void)
{
struct gen_pool *sram_pool;
- phys_addr_t sram_pbase;
- unsigned long sram_base;
struct device_node *node;
struct platform_device *pdev = NULL;
@@ -397,23 +397,12 @@ static void __init at91_pm_sram_init(void)
return;
}
- sram_base = gen_pool_alloc(sram_pool, at91_pm_suspend_in_sram_sz);
- if (!sram_base) {
- pr_warn("%s: unable to alloc sram!\n", __func__);
+ atmel_pm_pie = pie_load_sections(sram_pool, atmel_pm,
+ arch_arm_mach_at91_pm);
+ if (IS_ERR(atmel_pm_pie))
return;
- }
-
- sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
- at91_suspend_sram_fn = __arm_ioremap_exec(sram_pbase,
- at91_pm_suspend_in_sram_sz, false);
- if (!at91_suspend_sram_fn) {
- pr_warn("SRAM: Could not map\n");
- return;
- }
- /* Copy the pm suspend handler to SRAM */
- at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
- &at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
+ at91_suspend_sram_fn = fn_to_pie(atmel_pm_pie, atmel_pm_suspend);
}
static const struct of_device_id atmel_pmc_ids[] __initconst = {
diff --git a/arch/arm/mach-at91/pm/.gitignore b/arch/arm/mach-at91/pm/.gitignore
new file mode 100644
index 000000000000..1cb8879eb0bf
--- /dev/null
+++ b/arch/arm/mach-at91/pm/.gitignore
@@ -0,0 +1,2 @@
+*.lds*
+*.syms
diff --git a/arch/arm/mach-at91/pm/Makefile b/arch/arm/mach-at91/pm/Makefile
new file mode 100644
index 000000000000..c12d54862c10
--- /dev/null
+++ b/arch/arm/mach-at91/pm/Makefile
@@ -0,0 +1,3 @@
+PIE_NAME := atmel_pm
+
+include arch/arm/pie/Makefile.pie
diff --git a/arch/arm/mach-at91/pm/atmel_pm.c b/arch/arm/mach-at91/pm/atmel_pm.c
new file mode 100644
index 000000000000..7f391addd2da
--- /dev/null
+++ b/arch/arm/mach-at91/pm/atmel_pm.c
@@ -0,0 +1,97 @@
+#include <linux/io.h>
+#include <linux/clk/at91_pmc.h>
+#include <linux/mfd/syscon/atmel-mc.h>
+#include <linux/pie.h>
+#include "../pm.h"
+
+#define SRAMC_SELF_FRESH_ACTIVE 0x01
+#define SRAMC_SELF_FRESH_EXIT 0x00
+
+static void at91_sramc_self_refresh(unsigned int is_active,
+ unsigned int memtype,
+ void __iomem *sdramc_base,
+ void __iomem *sdramc_base1)
+{
+ static unsigned int lpr, mdr, lpr1, mdr1;
+
+ switch (memtype) {
+ case AT91_MEMCTRL_MC:
+ /*
+ * at91rm9200 Memory controller
+ */
+ if (is_active)
+ __raw_writel(1, sdramc_base + AT91_MC_SDRAMC_SRR);
+ break;
+
+ case AT91_MEMCTRL_DDRSDR:
+ if (is_active) {
+ mdr = __raw_readl(sdramc_base + AT91_DDRSDRC_MDR);
+ lpr = __raw_readl(sdramc_base + AT91_DDRSDRC_LPR);
+
+ if ((mdr & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR)
+ __raw_writel((mdr & ~AT91_DDRSDRC_MD) |
+ AT91_DDRSDRC_MD_DDR2, sdramc_base +
+ AT91_DDRSDRC_MDR);
+ __raw_writel((lpr & ~AT91_DDRSDRC_LPCB) |
+ AT91_DDRSDRC_LPCB_SELF_REFRESH, sdramc_base
+ + AT91_DDRSDRC_LPR);
+
+ if (sdramc_base1) {
+ mdr1 = __raw_readl(sdramc_base1 + AT91_DDRSDRC_MDR);
+ lpr1 = __raw_readl(sdramc_base1 + AT91_DDRSDRC_LPR);
+ if ((mdr1 & AT91_DDRSDRC_MD) == AT91_DDRSDRC_MD_LOW_POWER_DDR)
+ __raw_writel((mdr1 & ~AT91_DDRSDRC_MD) |
+ AT91_DDRSDRC_MD_DDR2,
+ sdramc_base1 +
+ AT91_DDRSDRC_MDR);
+ __raw_writel((lpr1 & ~AT91_DDRSDRC_LPCB) |
+ AT91_DDRSDRC_LPCB_SELF_REFRESH,
+ sdramc_base1 + AT91_DDRSDRC_LPR);
+ }
+ } else {
+ __raw_writel(mdr, sdramc_base + AT91_DDRSDRC_MDR);
+ __raw_writel(lpr, sdramc_base + AT91_DDRSDRC_LPR);
+ if (sdramc_base1) {
+ __raw_writel(mdr, sdramc_base1 + AT91_DDRSDRC_MDR);
+ __raw_writel(lpr, sdramc_base1 + AT91_DDRSDRC_LPR);
+ }
+ }
+ break;
+
+ case AT91_MEMCTRL_SDRAMC:
+ if (is_active) {
+ lpr = __raw_readl(sdramc_base + AT91_SDRAMC_LPR);
+
+ __raw_writel((lpr & ~AT91_SDRAMC_LPCB) |
+ AT91_SDRAMC_LPCB_SELF_REFRESH, sdramc_base
+ + AT91_SDRAMC_LPR);
+ } else {
+ __raw_writel(lpr, sdramc_base + AT91_SDRAMC_LPR);
+ }
+ break;
+ }
+}
+
+void atmel_pm_suspend(void __iomem *pmc, void __iomem *ramc0,
+ void __iomem *ramc1, int memctrl)
+{
+ int memtype, pm_mode;
+
+ memtype = memctrl & AT91_PM_MEMTYPE_MASK;
+ pm_mode = (memctrl >> AT91_PM_MODE_OFFSET) & AT91_PM_MODE_MASK;
+
+ dsb();
+
+ at91_sramc_self_refresh(1, memtype, ramc0, ramc1);
+
+#if defined(CONFIG_CPU_V7)
+ dsb();
+ wfi();
+#else
+ asm volatile ("mcr p15, 0, %0, c7, c0, 4" \
+ : : "r" (0) : "memory");
+#endif
+
+ at91_sramc_self_refresh(0, memtype, ramc0, ramc1);
+}
+EXPORT_PIE_SYMBOL(atmel_pm_suspend);
diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
deleted file mode 100644
index a25defda3d22..000000000000
--- a/arch/arm/mach-at91/pm_suspend.S
+++ /dev/null
@@ -1,338 +0,0 @@
-/*
- * arch/arm/mach-at91/pm_slow_clock.S
- *
- * Copyright (C) 2006 Savin Zlobec
- *
- * AT91SAM9 support:
- * Copyright (C) 2007 Anti Sullin <anti.sullin@xxxxxxxxxxxxxx
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- */
-#include <linux/linkage.h>
-#include <linux/clk/at91_pmc.h>
-#include "pm.h"
-
-#define SRAMC_SELF_FRESH_ACTIVE 0x01
-#define SRAMC_SELF_FRESH_EXIT 0x00
-
-pmc .req r0
-tmp1 .req r4
-tmp2 .req r5
-
-/*
- * Wait until master clock is ready (after switching master clock source)
- */
- .macro wait_mckrdy
-1: ldr tmp1, [pmc, #AT91_PMC_SR]
- tst tmp1, #AT91_PMC_MCKRDY
- beq 1b
- .endm
-
-/*
- * Wait until master oscillator has stabilized.
- */
- .macro wait_moscrdy
-1: ldr tmp1, [pmc, #AT91_PMC_SR]
- tst tmp1, #AT91_PMC_MOSCS
- beq 1b
- .endm
-
-/*
- * Wait until PLLA has locked.
- */
- .macro wait_pllalock
-1: ldr tmp1, [pmc, #AT91_PMC_SR]
- tst tmp1, #AT91_PMC_LOCKA
- beq 1b
- .endm
-
-/*
- * Put the processor to enter the idle state
- */
- .macro at91_cpu_idle
-
-#if defined(CONFIG_CPU_V7)
- mov tmp1, #AT91_PMC_PCK
- str tmp1, [pmc, #AT91_PMC_SCDR]
-
- dsb
-
- wfi @ Wait For Interrupt
-#else
- mcr p15, 0, tmp1, c7, c0, 4
-#endif
-
- .endm
-
- .text
-
- .arm
-
-/*
- * void at91_pm_suspend_in_sram(void __iomem *pmc, void __iomem *sdramc,
- * void __iomem *ramc1, int memctrl)
- * @input param:
- * @r0: base address of AT91_PMC
- * @r1: base address of SDRAM Controller (SDRAM, DDRSDR, or AT91_SYS)
- * @r2: base address of second SDRAM Controller or 0 if not present
- * @r3: pm information
- */
-/* at91_pm_suspend_in_sram must be 8-byte aligned per the requirements of fncpy() */
- .align 3
-ENTRY(at91_pm_suspend_in_sram)
- /* Save registers on stack */
- stmfd sp!, {r4 - r12, lr}
-
- /* Drain write buffer */
- mov tmp1, #0
- mcr p15, 0, tmp1, c7, c10, 4
-
- str r0, .pmc_base
- str r1, .sramc_base
- str r2, .sramc1_base
-
- and r0, r3, #AT91_PM_MEMTYPE_MASK
- str r0, .memtype
-
- lsr r0, r3, #AT91_PM_MODE_OFFSET
- and r0, r0, #AT91_PM_MODE_MASK
- str r0, .pm_mode
-
- /* Active the self-refresh mode */
- mov r0, #SRAMC_SELF_FRESH_ACTIVE
- bl at91_sramc_self_refresh
-
- ldr r0, .pm_mode
- tst r0, #AT91_PM_SLOW_CLOCK
- beq skip_disable_main_clock
-
- ldr pmc, .pmc_base
-
- /* Save Master clock setting */
- ldr tmp1, [pmc, #AT91_PMC_MCKR]
- str tmp1, .saved_mckr
-
- /*
- * Set the Master clock source to slow clock
- */
- bic tmp1, tmp1, #AT91_PMC_CSS
- str tmp1, [pmc, #AT91_PMC_MCKR]
-
- wait_mckrdy
-
- /* Save PLLA setting and disable it */
- ldr tmp1, [pmc, #AT91_CKGR_PLLAR]
- str tmp1, .saved_pllar
-
- mov tmp1, #AT91_PMC_PLLCOUNT
- orr tmp1, tmp1, #(1 << 29) /* bit 29 always set */
- str tmp1, [pmc, #AT91_CKGR_PLLAR]
-
- /* Turn off the main oscillator */
- ldr tmp1, [pmc, #AT91_CKGR_MOR]
- bic tmp1, tmp1, #AT91_PMC_MOSCEN
- orr tmp1, tmp1, #AT91_PMC_KEY
- str tmp1, [pmc, #AT91_CKGR_MOR]
-
-skip_disable_main_clock:
- ldr pmc, .pmc_base
-
- /* Wait for interrupt */
- at91_cpu_idle
-
- ldr r0, .pm_mode
- tst r0, #AT91_PM_SLOW_CLOCK
- beq skip_enable_main_clock
-
- ldr pmc, .pmc_base
-
- /* Turn on the main oscillator */
- ldr tmp1, [pmc, #AT91_CKGR_MOR]
- orr tmp1, tmp1, #AT91_PMC_MOSCEN
- orr tmp1, tmp1, #AT91_PMC_KEY
- str tmp1, [pmc, #AT91_CKGR_MOR]
-
- wait_moscrdy
-
- /* Restore PLLA setting */
- ldr tmp1, .saved_pllar
- str tmp1, [pmc, #AT91_CKGR_PLLAR]
-
- tst tmp1, #(AT91_PMC_MUL & 0xff0000)
- bne 3f
- tst tmp1, #(AT91_PMC_MUL & ~0xff0000)
- beq 4f
-3:
- wait_pllalock
-4:
-
- /*
- * Restore master clock setting
- */
- ldr tmp1, .saved_mckr
- str tmp1, [pmc, #AT91_PMC_MCKR]
-
- wait_mckrdy
-
-skip_enable_main_clock:
- /* Exit the self-refresh mode */
- mov r0, #SRAMC_SELF_FRESH_EXIT
- bl at91_sramc_self_refresh
-
- /* Restore registers, and return */
- ldmfd sp!, {r4 - r12, pc}
-ENDPROC(at91_pm_suspend_in_sram)
-
-/*
- * void at91_sramc_self_refresh(unsigned int is_active)
- *
- * @input param:
- * @r0: 1 - active self-refresh mode
- * 0 - exit self-refresh mode
- * register usage:
- * @r1: memory type
- * @r2: base address of the sram controller
- */
-
-ENTRY(at91_sramc_self_refresh)
- ldr r1, .memtype
- ldr r2, .sramc_base
-
- cmp r1, #AT91_MEMCTRL_MC
- bne ddrc_sf
-
- /*
- * at91rm9200 Memory controller
- */
-
- /*
- * For exiting the self-refresh mode, do nothing,
- * automatically exit the self-refresh mode.
- */
- tst r0, #SRAMC_SELF_FRESH_ACTIVE
- beq exit_sramc_sf
-
- /* Active SDRAM self-refresh mode */
- mov r3, #1
- str r3, [r2, #AT91_MC_SDRAMC_SRR]
- b exit_sramc_sf
-
-ddrc_sf:
- cmp r1, #AT91_MEMCTRL_DDRSDR
- bne sdramc_sf
-
- /*
- * DDR Memory controller
- */
- tst r0, #SRAMC_SELF_FRESH_ACTIVE
- beq ddrc_exit_sf
-
- /* LPDDR1 --> force DDR2 mode during self-refresh */
- ldr r3, [r2, #AT91_DDRSDRC_MDR]
- str r3, .saved_sam9_mdr
- bic r3, r3, #~AT91_DDRSDRC_MD
- cmp r3, #AT91_DDRSDRC_MD_LOW_POWER_DDR
- ldreq r3, [r2, #AT91_DDRSDRC_MDR]
- biceq r3, r3, #AT91_DDRSDRC_MD
- orreq r3, r3, #AT91_DDRSDRC_MD_DDR2
- streq r3, [r2, #AT91_DDRSDRC_MDR]
-
- /* Active DDRC self-refresh mode */
- ldr r3, [r2, #AT91_DDRSDRC_LPR]
- str r3, .saved_sam9_lpr
- bic r3, r3, #AT91_DDRSDRC_LPCB
- orr r3, r3, #AT91_DDRSDRC_LPCB_SELF_REFRESH
- str r3, [r2, #AT91_DDRSDRC_LPR]
-
- /* If using the 2nd ddr controller */
- ldr r2, .sramc1_base
- cmp r2, #0
- beq no_2nd_ddrc
-
- ldr r3, [r2, #AT91_DDRSDRC_MDR]
- str r3, .saved_sam9_mdr1
- bic r3, r3, #~AT91_DDRSDRC_MD
- cmp r3, #AT91_DDRSDRC_MD_LOW_POWER_DDR
- ldreq r3, [r2, #AT91_DDRSDRC_MDR]
- biceq r3, r3, #AT91_DDRSDRC_MD
- orreq r3, r3, #AT91_DDRSDRC_MD_DDR2
- streq r3, [r2, #AT91_DDRSDRC_MDR]
-
- /* Active DDRC self-refresh mode */
- ldr r3, [r2, #AT91_DDRSDRC_LPR]
- str r3, .saved_sam9_lpr1
- bic r3, r3, #AT91_DDRSDRC_LPCB
- orr r3, r3, #AT91_DDRSDRC_LPCB_SELF_REFRESH
- str r3, [r2, #AT91_DDRSDRC_LPR]
-
-no_2nd_ddrc:
- b exit_sramc_sf
-
-ddrc_exit_sf:
- /* Restore MDR in case of LPDDR1 */
- ldr r3, .saved_sam9_mdr
- str r3, [r2, #AT91_DDRSDRC_MDR]
- /* Restore LPR on AT91 with DDRAM */
- ldr r3, .saved_sam9_lpr
- str r3, [r2, #AT91_DDRSDRC_LPR]
-
- /* If using the 2nd ddr controller */
- ldr r2, .sramc1_base
- cmp r2, #0
- ldrne r3, .saved_sam9_mdr1
- strne r3, [r2, #AT91_DDRSDRC_MDR]
- ldrne r3, .saved_sam9_lpr1
- strne r3, [r2, #AT91_DDRSDRC_LPR]
-
- b exit_sramc_sf
-
- /*
- * SDRAMC Memory controller
- */
-sdramc_sf:
- tst r0, #SRAMC_SELF_FRESH_ACTIVE
- beq sdramc_exit_sf
-
- /* Active SDRAMC self-refresh mode */
- ldr r3, [r2, #AT91_SDRAMC_LPR]
- str r3, .saved_sam9_lpr
- bic r3, r3, #AT91_SDRAMC_LPCB
- orr r3, r3, #AT91_SDRAMC_LPCB_SELF_REFRESH
- str r3, [r2, #AT91_SDRAMC_LPR]
-
-sdramc_exit_sf:
- ldr r3, .saved_sam9_lpr
- str r3, [r2, #AT91_SDRAMC_LPR]
-
-exit_sramc_sf:
- mov pc, lr
-ENDPROC(at91_sramc_self_refresh)
-
-.pmc_base:
- .word 0
-.sramc_base:
- .word 0
-.sramc1_base:
- .word 0
-.memtype:
- .word 0
-.pm_mode:
- .word 0
-.saved_mckr:
- .word 0
-.saved_pllar:
- .word 0
-.saved_sam9_lpr:
- .word 0
-.saved_sam9_lpr1:
- .word 0
-.saved_sam9_mdr:
- .word 0
-.saved_sam9_mdr1:
- .word 0
-
-ENTRY(at91_pm_suspend_in_sram_sz)
- .word .-at91_pm_suspend_in_sram
--
2.8.1