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authorClaudiu Beznea <claudiu.beznea@microchip.com>2021-09-30 18:42:19 +0300
committerNicolas Ferre <nicolas.ferre@microchip.com>2021-10-04 12:08:34 +0200
commitd8d667ee0236dec6d717f27eec690d1324e7f322 (patch)
treec3d088a77b2325dccc6de2de7a452282d891fd78
parente42cbbe5c9a2a8423db4b1c32ec2a443d4de6323 (diff)
ARM: at91: pm: preload base address of controllers in tlb
In suspend/resume procedure for AT91 architecture different controllers (PMC, SHDWC, RAM, RAM PHY, SFRBU) are accessed to do the proper settings for power saving. Commit f0bbf17958e8 ("ARM: at91: pm: add self-refresh support for sama7g5") introduced the access to RAMC PHY controller for SAMA7G5. The access to this controller is done after RAMC ports are closed, thus any TLB walk necessary for RAMC PHY virtual address will fail. In the development branch this was not encountered. However, on current kernel the issue is reproducible. To solve the issue the previous mechanism of pre-loading the TLB with the RAMC PHY virtual address has been used. However, only the addition of this new pre-load breaks the functionality for ARMv5 based devices (SAM9X60). This behavior has been encountered previously while debugging this code and using the same mechanism for pre-loading address for different controllers (e.g. pin controller, the assumption being that other requested translations are replaced from TLB). To solve this new issue the TLB flush + the extension of pre-loading the rest of controllers to TLB (e.g. PMC, RAMC) has been added. The rest of the controllers should have been pre-loaded previously, anyway. Fixes: f0bbf17958e8 ("ARM: at91: pm: add self-refresh support for sama7g5") Depends-on: e42cbbe5c9a2 ("ARM: at91: pm: group constants and addresses loading") Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> Link: https://lore.kernel.org/r/20210930154219.2214051-4-claudiu.beznea@microchip.com
-rw-r--r--arch/arm/mach-at91/pm_suspend.S25
1 files changed, 24 insertions, 1 deletions
diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
index 34f251fdb743..fdb4f63ecde4 100644
--- a/arch/arm/mach-at91/pm_suspend.S
+++ b/arch/arm/mach-at91/pm_suspend.S
@@ -1014,6 +1014,10 @@ ENTRY(at91_pm_suspend_in_sram)
mov tmp1, #0
mcr p15, 0, tmp1, c7, c10, 4
+ /* Flush tlb. */
+ mov r4, #0
+ mcr p15, 0, r4, c8, c7, 0
+
ldr tmp1, [r0, #PM_DATA_PMC_MCKR_OFFSET]
str tmp1, .mckr_offset
ldr tmp1, [r0, #PM_DATA_PMC_VERSION]
@@ -1023,23 +1027,42 @@ ENTRY(at91_pm_suspend_in_sram)
ldr tmp1, [r0, #PM_DATA_MODE]
str tmp1, .pm_mode
+ /*
+ * ldrne below are here to preload their address in the TLB as access
+ * to RAM may be limited while in self-refresh.
+ */
ldr tmp1, [r0, #PM_DATA_PMC]
str tmp1, .pmc_base
+ cmp tmp1, #0
+ ldrne tmp2, [tmp1, #0]
+
ldr tmp1, [r0, #PM_DATA_RAMC0]
str tmp1, .sramc_base
+ cmp tmp1, #0
+ ldrne tmp2, [tmp1, #0]
+
ldr tmp1, [r0, #PM_DATA_RAMC1]
str tmp1, .sramc1_base
+ cmp tmp1, #0
+ ldrne tmp2, [tmp1, #0]
+
+#ifndef CONFIG_SOC_SAM_V4_V5
+ /* ldrne below are here to preload their address in the TLB */
ldr tmp1, [r0, #PM_DATA_RAMC_PHY]
str tmp1, .sramc_phy_base
- /* Both ldrne below are here to preload their address in the TLB */
+ cmp tmp1, #0
+ ldrne tmp2, [tmp1, #0]
+
ldr tmp1, [r0, #PM_DATA_SHDWC]
str tmp1, .shdwc
cmp tmp1, #0
ldrne tmp2, [tmp1, #0]
+
ldr tmp1, [r0, #PM_DATA_SFRBU]
str tmp1, .sfrbu
cmp tmp1, #0
ldrne tmp2, [tmp1, #0x10]
+#endif
/* Active the self-refresh mode */
at91_sramc_self_refresh_ena